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Sample records for surrounding host tissue

  1. The dorsal skinfold chamber: window into the dynamic interaction of biomaterials with their surrounding host tissue

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    MW Laschke

    2011-09-01

    Full Text Available The implantation of biomaterials into the human body has become an indispensable part of almost all fields of modern medicine. Accordingly, there is an increasing need for appropriate approaches, which can be used to evaluate the suitability of different biomaterials for distinct clinical indications. The dorsal skinfold chamber is a sophisticated experimental model, which has been proven to be extremely valuable for the systematic in vivo analysis of the dynamic interaction of small biomaterial implants with the surrounding host tissue in rats, hamsters and mice. By means of intravital fluorescence microscopy, this chronic model allows for repeated analyses of various cellular, molecular and microvascular mechanisms, which are involved in the early inflammatory and angiogenic host tissue response to biomaterials during the initial 2-3 weeks after implantation. Therefore, the dorsal skinfold chamber has been broadly used during the last two decades to assess the in vivo performance of prosthetic vascular grafts, metallic implants, surgical meshes, bone substitutes, scaffolds for tissue engineering, as well as for locally or systemically applied drug delivery systems. These studies have contributed to identify basic material properties determining the biocompatibility of the implants and vascular ingrowth into their surface or internal structures. Thus, the dorsal skinfold chamber model does not only provide deep insights into the complex interactions of biomaterials with the surrounding soft tissues of the host but also represents an important tool for the future development of novel biomaterials aiming at an optimisation of their biofunctionality in clinical practice.

  2. Tissue reaction surrounding miniscrews for orthodontic anchorage: An animal experiment

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    Stephanie Shih-Hsuan Chen

    2012-03-01

    Results and conclusions: (1 Tissue surrounding roots damaged by a miniscrew showed a significant inflammatory response. (2 Root resorption was occasionally observed after 3 weeks following insertion of a miniscrew even if the miniscrew was not in direct contact with the root. (3 Root repair was noted with a cementoblast lining along the resorption surface at as early as 3 weeks after miniscrew insertion. Alveolar bone filled in the lesion when the root damage was large so that the contour of the alveolar bone followed that of the damaged root, with the width of the periodontal ligament space being maintained. (4 Stable miniscrews were mainly those which did not contact adjacent roots, and for which the surrounding tissue showed only a small inflammatory response with some extent of direct bone contact around the miniscrew. On the contrary, most of the failed miniscrews were those which had direct contact with adjacent roots, and which exhibited severe tissue inflammation and were covered by thick layers of soft tissue. Failure was detected 3 weeks after insertion. Surprisingly, the epithelial lining surrounding the miniscrews might not have spontaneously resolved 6 weeks after screw removal. Persistent infection in the sinus tract was noted, and this would require attention.

  3. VEGF in hepatocellular carcinoma and surrounding cirrhotic liver tissues

    Institute of Scientific and Technical Information of China (English)

    Muriel Mathonnet; Bernard Descottes; Denis Valleix; Francois Labrousse; Yves Denizot

    2006-01-01

    @@ TO THE EDITOR We read with a great interest the recent work of Deli and colleagues.[1] in the World Journal of Gastroenterology reporting vascular endothelial growth factor (VEGF) expression in hepatocellular carcinoma (HCC) and cirrhotic liver tissues.

  4. Ethical issues surrounding the transplantation of human fetal tissues.

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    Hurd, R E

    1992-12-01

    Organ transplants have been one of the greatest advances in medicine. However, organs from living relatives or cadavers are in short supply, and many people die awaiting a donor organ. Increasing the donor pool by using organs from aborted fetuses has been proposed to increase the supply. In addition, there are benefits of using fetal tissue including its particular usefulness in children, the fact that it is not readily rejected, and its potential for growth. Guidelines for fetal research were issued in 1975, but a research moratorium was imposed in 1988 to allow study of ethical and legal issues. While the federal government delays in lifting the ban, several states have written laws governing experimentation with fetuses. Ethical arguments against using fetal tissue for organ transplant include a concern that this would create a branch of biomedicine which depends on the continuation of induced abortions. This could lead to neglect of research for other therapies. The timing and type of abortion should continue to benefit the mother, rather than the organ recipient. Ethicists debate whether or not use of aborted tissue implies complicity in the abortion process beyond that which exists for all members of a society which permits abortion. They also wonder whether knowing that some good could come of an abortion would influence a woman's decision to have one. Proposals to keep the use of fetal tissue ethical include banning the commercial use of sale of tissues, forbidding designation of the tissue recipient (to prevent harvesting fetal tissue for a relative), separating abortion counseling and management from harvesting of the tissue, and obtaining informed consent (perhaps from a proxy surrogate rather than from the mother) for the use of fetal tissue. When the medical and ethical communities have reached some consensus on these issues, crafted safeguards, and precluded conflicts of interest, then restrictions on government funding should be lifted. Whereas it

  5. Impact of surrounding tissue on conductance measurement of coronary and peripheral lumen area.

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    Won Choi, Hyo; Jansen, Benjamin; Zhang, Zhen-Du; Kassab, Ghassan S

    2012-11-07

    Parallel conductance (electric current flow through surrounding tissue) is an important determinant of accurate measurements of arterial lumen diameter, using the conductance method. The present study is focused on the role of non-uniform geometrical/electrical configurations of surrounding tissue, which are a primary source of electric current leakage. Computational models were constructed to simulate the conductance catheter measurement with two different excitation electrodes spacings (i.e. 12 and 20 mm for coronary and peripheral sizing, respectively) for different vessel-tissue configurations: (i) blood vessel fully embedded in muscle tissue, (ii) blood vessel superficially embedded in muscle tissue, and (iii) blood vessel superficially embedded in muscle tissue with fat covering half of the arterial vessel (anterior portion). The simulations suggest that the parallel conductance and accuracy of measurement is dependent on the inhomogeneous/anisotropic configuration of surrounding tissue, including the asymmetric dimension and anisotropy in electrical conductivity of surrounding tissue. Specifically, the measurement was shown to be accurate as long as the vessel was superficial, regardless of the considerable total surrounding tissue dimension for coronary or peripheral arteries. Moreover, it was shown that the unfavourable impact of parallel conductance on the accuracy of conductance catheter measurement is decreased by the combination of a lower transverse electrical conductivity of surrounding muscle tissue, a smaller electrode spacing and a larger lumen diameter. The present findings confirm that the conductance catheter technique provides an accurate platform for sizing of clinically relevant (i.e. superficial and diseased) arteries.

  6. The surrounding tissue modifies the placental stem villous vascular responses

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn; Forman, Axel; Aalkjær, Christian;

    2014-01-01

    Background: The placenta is the base for the exchange of nutrients, oxygen and waste products for the fetus. The placental vessels hold a crucial role in regulation of blood flow, and compromised function may lead to complications like growth retardation and preeclampsia where no specific treatment...... is available. In-depth understanding of the mechanisms involved in control of placental vascular tone are needed to develop new tissue targets for therapeutic intervention. Method: From fresh born placentas segments of stem villous arteries were carefully dissected. The artery branches were divided...

  7. Alveolar rhabdomyosarcoma involving the mandibular ramus and its surrounding tissues

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    Yoon, Suk Ja; Kang, Byung Cheol [Chonnam National University College of Medicine, Gwangju (Korea, Republic of)

    2004-06-15

    Rhabdomyosarcoma, when it occurs in the head and neck, is primarily found in children. Alveolar rhabdomyosarcoma is rarely seen in the oral lesion, comparing to the embryonal and the pleomorphic variants. This is a report of a case of alveolar rhabdomyosarcoma in the mandible in a ten-year old girl who complained of a non-painful swelling on the right cheek. The right lower 1st molar was mobile. Her radiographs revealed an extensive radiolucency with somewhat irregular border on the right mandibular ramus. The right mandibular 1st and 2nd molars lost their lamina dura and were floating. CT images revealed smooth-outlined soft tissue mass occupying the pterygomandibular space, the infratemporal space, and the masseteric muscle with thinning and perforation of the right mandibular angle and ramus. Histopathological and immunohistochemical findings established the final diagnosis of alveolar rhabdomyosarcoma.

  8. Mechanical Behavior of the Near-field Host Rock Surrounding Excavations

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    Kelkar, Sharad M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Robinson, Bruce Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-09

    This report is being prepared under the FY14 activity FT-14LA0818069, Mechanical and Hydrological Behavior of the Near-Field Host Rock Surrounding Excavations, and fulfills the Los Alamos National Laboratory deliverable M4FT-14LA08180610, which in PICS:NE is titled “Draft report, Test Plan for Mechanical and Hydrological Behavior of the Near-field Host Rock Surrounding Excavations.” Since the report is an intermediate deliverable intended as input to the eventual test plan for this test, rather than being an actual test plan, the activity title is used as the title of this document to avoid confusion as to the contents in the report. This report summarizes efforts to simulate mechanical processes occurring within a hypothetical high-level waste (HLW) repository in bedded salt. The report summarizes work completed since the last project deliverable, “Coupled model for heat and water transport in a high level waste repository in salt “, a Level 2 milestone submitted to DOE in September 2013 (Stauffer et al., 2013).

  9. HIV behavioural surveillance among refugees and surrounding host communities in Uganda, 2006.

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    Harrison, Kathleen McDavid; Claass, Johanna; Spiegel, Paul B; Bamuturaki, Judith; Patterson, Njogu; Muyonga, Michael; Tatwebwa, Lillian

    2009-03-01

    We used a standardised behavioural surveillance survey (BSS), modified to be directly relevant to populations in conflict and post-conflict settings as well as to their surrounding host populations, to survey the populations of a refugee settlement in south-western Uganda and its surrounding area. Two-stage probability sampling was used to conduct 800 interviews in each population. The BSS questionnaire adapted for displaced populations was administered to adults aged 15-59 years. It collected information on HIV knowledge, attitudes and practices; issues before, during and after displacement; level of interaction and sexual exploitation among the refugees and host communities (i.e., nationals). Population parameters were compared and 95% confidence intervals were calculated for core HIV indicators. The demographic characteristics were similar (except for educational achievement), and HIV awareness was very high (>95%) in both populations. The refugees reported more-accepting attitudes towards persons with HIV than did nationals (19% versus 13%; p refugees than nationals reported ever having had transactional sex (10% versus 6%; p refugees and nationals reported experiencing forced sex, which mostly occurred post-displacement and after the arrival of refugees, respectively. Nationals reported more frequent travel to refugee settlements than reported by refugees to national villages (22% versus 11%; p refugees may be at elevated risk for HIV infection, due to forced sex, transactional sex and other vulnerabilities, warrants further examination through qualitative research. The findings indicate a need for additional, focused HIV-prevention programmes, such as youth education, for both refugees and Ugandan nationals.

  10. Differences in HIV-related behaviors at Lugufu refugee camp and surrounding host villages, Tanzania

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    Mbaruku Godfrey

    2008-10-01

    Full Text Available Abstract Background An HIV behavioral surveillance survey was undertaken in November 2005 at Lugufu refugee camp and surrounding host villages, located near western Tanzania's border with the Democratic Republic of Congo (DRC. Methods The sample size was 1,743 persons based on cluster survey methodology. All members of selected households between 15–49 years old were eligible respondents. Questions included HIV-related behaviors, population displacement, mobility, networking and forced sex. Data was analyzed using Stata to measure differences in proportions (chi-square and differences in means (t-test between gender, age groups, and settlement location for variables of interest. Results Study results reflect the complexity of factors that may promote or inhibit HIV transmission in conflict-affected and displaced populations. Within this setting, factors that may increase the risk of HIV infections among refugees compared to the population in surrounding villages include young age of sexual initiation among males (15.9 years vs. 19.8 years, p = .000, high-risk sex partners in the 15–24 year age group (40% vs. 21%, χ2 33.83, p = .000, limited access to income (16% vs. 51% χ2 222.94, p = .000, and the vulnerability of refugee women, especially widowed, divorced and never-married women, to transactional sex (married vs. never married, divorced, widowed: for 15–24 age group, 4% and 18% respectively, χ2 8.07, p = .004; for 25–49 age group, 4% and 23% respectively, χ2 21.46, p = .000. A majority of both refugee and host village respondents who experienced forced sex in the past 12 months identified their partner as perpetrator (64% camp and 87% in villages. Although restrictions on movements in and out of the camp exist, there was regular interaction between communities. Condom use was found to be below 50%, and expanded population networks may also increase opportunities for HIV transmission. Availability of refugee health services may be

  11. TELOMERASE ACTIVITY IN HUMAN GASTRIC AND COLORECTAL CANCER AND SURROUNDING TISSUES

    Institute of Scientific and Technical Information of China (English)

    CHEN Wen; ZHANG Qiao; WAN De-sen; CUN Ling-yun; WU Cheng-qiu; PAN Zhi-zhong

    1999-01-01

    Objective: To study the telomerase activities in human gastric and colorectal tumors. Methods: The telomerase activity was assayed by the telomeric repeat amplification protocol (TRAP) technique. Forty human tumor samples including 9 colonic, 20 rectal and 11gastric carcinomas and their surrounding tissues were used for the detection. Results: Thirty-six out of 40human tumor samples exhibited telomerase activity regardless of the stages or the differentiation of the tumors. However, only 1 out of 39 tumor surrounding tissues showed telomerase activity. Conclusion: Telomerase may be a good diagnosis biomarker for tumor detection.

  12. The Tissue Implant Response Surrounding Subcutaneous TCP, HA, And ALCAP Bioceramics.

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    Butler, K R; Benghuzzi, Hamed; Tucci, Michelle; Puckett, A D

    2015-01-01

    The objective of this investigation was to quantify and further elucidate the tissue-implant response in the fibrous tissue surrounding tricalcium phosphate (TCP), hydroxyapatite (HA), and aluminum calcium phosphate (ALCAP) implants when implanted subcutaneously. Sixteen animals in four experimental groups (n = 4/group) were implanted with one implant each: Group I (control, TCP), Group II (HA), and Group III (ALCAP). At 90 days post-implantation, the fibrous tissue surrounding the implants was harvested. Sections of stained fibrous tissue were evaluated for the presence of macrophages, fibrocytes, neutrophils, vascularity and thickness for all three groups using semi-automated quantitative methods. The analysis indicated Group III demonstrated a significantly higher number of neutrophils but fewer macrophages and blood vessels per high power field and had a substantially thinner fibrous tissue capsule thickness compared to Groups I and II (alpha=0.05). Group II elicited a greater response of fibroblasts compared to Groups I and III suggesting HA may provide a slightly higher degree of stability to the implant. In total, these findings suggest both TCP and HA behave similarly in vivo when compared to ALCAP and may be better choices for subcutaneous soft-tissue application compared to ALCAP.

  13. Optical detection of carotenoid antioxidants in human bone and surrounding tissue.

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    Ermakov, Igor V; Ermakova, Maia R; Rosenberg, Thomas D; Gellermann, Werner

    2013-11-01

    Carotenoids are known to play an important role in health and disease state of living human tissue based on their antioxidant and optical filtering functions. In this study, we show that carotenoids exist in human bone and surrounding fatty tissue both in significant and individually variable concentrations. Measurements of biopsied tissue samples with molecule-specific Raman spectroscopy and high-performance liquid chromatography reveal that all carotenoids that are known to exist in human skin are also present in human bone. This includes all carotenes, lycopene, β-cryptoxanthin, lutein, and zeaxanthin. We propose quantitative reflection imaging as a noncontact optical method suitable for the measurement of composite carotenoid levels in bone and surrounding tissue exposed during open surgeries such as total knee arthroplasty, and as a proof of concept, demonstrate carotenoid measurements in biopsied bone samples. This will allow one to establish potential correlations between internal tissue carotenoid levels and levels in skin and to potentially use already existing optical skin carotenoid tests as surrogate marker for bone carotenoid status.

  14. Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system*

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    Zan, Peng; Yang, Bang-hua; Shao, Yong; Yan, Guo-zheng; Liu, Hua

    2010-01-01

    This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10–107 Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system. PMID:21121071

  15. Dynamic myosin activation promotes collective morphology and migration by locally balancing oppositional forces from surrounding tissue.

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    Aranjuez, George; Burtscher, Ashley; Sawant, Ketki; Majumder, Pralay; McDonald, Jocelyn A

    2016-06-15

    Migrating cells need to overcome physical constraints from the local microenvironment to navigate their way through tissues. Cells that move collectively have the additional challenge of negotiating complex environments in vivo while maintaining cohesion of the group as a whole. The mechanisms by which collectives maintain a migratory morphology while resisting physical constraints from the surrounding tissue are poorly understood. Drosophila border cells represent a genetic model of collective migration within a cell-dense tissue. Border cells move as a cohesive group of 6-10 cells, traversing a network of large germ line-derived nurse cells within the ovary. Here we show that the border cell cluster is compact and round throughout their entire migration, a shape that is maintained despite the mechanical pressure imposed by the surrounding nurse cells. Nonmuscle myosin II (Myo-II) activity at the cluster periphery becomes elevated in response to increased constriction by nurse cells. Furthermore, the distinctive border cell collective morphology requires highly dynamic and localized enrichment of Myo-II. Thus, activated Myo-II promotes cortical tension at the outer edge of the migrating border cell cluster to resist compressive forces from nurse cells. We propose that dynamic actomyosin tension at the periphery of collectives facilitates their movement through restrictive tissues.

  16. Surface position, not signaling from surrounding maternal tissues, specifies aleurone epidermal cell fate in maize.

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    Gruis, Darren Fred; Guo, Hena; Selinger, David; Tian, Qing; Olsen, Odd-Arne

    2006-07-01

    Maize (Zea mays) endosperm consists of an epidermal-like surface layer of aleurone cells, an underlying body of starchy endosperm cells, and a basal layer of transfer cells. To determine whether surrounding maternal tissues perform a role in specifying endosperm cell fates, a maize endosperm organ culture technique was established whereby the developing endosperm is completely removed from surrounding maternal tissues. Using cell type-specific fluorescence markers, we show that aleurone cell fate specification occurs exclusively in response to surface position and does not require specific, continued maternal signal input. The starchy endosperm and aleurone cell fates are freely interchangeable throughout the lifespan of the endosperm, with internalized aleurone cells converting to starchy endosperm cells and with starchy endosperm cells that become positioned at the surface converting to aleurone cells. In contrast to aleurone and starchy endosperm cells, transfer cells fail to develop in in vitro-grown endosperm, supporting earlier indications that maternal tissue interaction is required to fully differentiate this cell type. Several parameters confirm that the maize endosperm organ cultures described herein retain the main developmental features of in planta endosperm, including fidelity of aleurone mutant phenotypes, temporal and spatial control of cell type-specific fluorescent markers, specificity of cell type transcripts, and control of mitotic cell divisions.

  17. CD163/Hemoglobin Oxygenase-1 Pathway Regulates Inflammation in Hematoma Surrounding Tissues after Intracerebral Hemorrhage.

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    Liu, BaoHua; Hu, BeiLei; Shao, ShengMin; Wu, Wei; Fan, LiuBo; Bai, GuangHui; Shang, Ping; Wang, XiaoTong

    2015-12-01

    The aim of the present study was to investigate changes in the expression of CD163 and hemoglobin oxygenase-1 (HO-1) in brain tissue surrounding hematomas after intracerebral hemorrhage (ICH), and correlations with other factors. Brain tissues in the close surrounding of ICH hematomas (n = 27, ICH group) were collected at 6 hours or less, 6-24 hours, 24-72 hours, and more than 72 hours after bleeding onset, and more distant tissues (n = 12, control group) were histologically analyzed with hematoxylin and eosin staining and transmission electron microscopy. Interleukin (IL)-1, IL-10, and tumor necrosis factor-alpha, as well as the expression of CD163 and HO-1, were assessed using immunochemistry, Western blotting, and reverse transcription-polymerase chain reaction. Apoptosis rates were determined with terminal deoxynucleotidyl transferase dUTP nick end labeling assays. The expressions of the inflammatory cytokines IL-1 and tumor necrosis factor-alpha were increased at 6-24 hours (P CD163 and HO-1 expressions gradually increased from 6 to 24 hours to peaks at more than 72 hours after ICH onset (P CD163 and HO-1 expressions reached peaks and inflammatory cytokine expressions dropped. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  18. Impact of mechanical stretch on the cell behaviors of bone and surrounding tissues

    Directory of Open Access Journals (Sweden)

    Hye-Sun Yu

    2016-02-01

    Full Text Available Mechanical loading is recognized to play an important role in regulating the behaviors of cells in bone and surrounding tissues in vivo. Many in vitro studies have been conducted to determine the effects of mechanical loading on individual cell types of the tissues. In this review, we focus specifically on the use of the Flexercell system as a tool for studying cellular responses to mechanical stretch. We assess the literature describing the impact of mechanical stretch on different cell types from bone, muscle, tendon, ligament, and cartilage, describing individual cell phenotype responses. In addition, we review evidence regarding the mechanotransduction pathways that are activated to potentiate these phenotype responses in different cell populations.

  19. The importance of surrounding tissues and window settings for contouring of moving targets

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    Borm, Kai Joachim [Technische Universitaet Muenchen, Medical School, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Oechsner, Markus; Berndt, Johannes; Combs, Stephanie Elisabeth; Molls, Michael; Duma, Marciana Nona [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany)

    2015-09-15

    The aim of the study was to assess the importance of surrounding tissues for the delineation of moving targets in tissue-specific phantoms and to find optimal settings for lung, soft tissue, and liver tumors. Tumor movement was simulated by a water-filled table tennis ball (target volume, TV). Three phantoms were created: corkboards to simulate lung tissue (lung phantom, LunPh), animal fat as fatty soft tissue (fatty tissue phantom, FatPh), and water enhanced with contrast medium as the liver tissue (liver phantom, LivPh). Slow planning three-dimensional compute tomography images (3D-CTs) were acquired with and without phantom movements. One-dimensional tumor movement (1D), three-dimensional tumor movement (3D), as well as a real patient's tumor trajectories were simulated. The TV was contoured using two lung window settings, two soft-tissue window settings, and one liver window setting. The volumes were compared to mathematical calculated values. TVs were underestimated in all phantoms due to movement. The use of soft-tissue windows in the LivPh led to a significantunderestimation of the TV (70.8 % of calculated TV). When common window settings [LunPh + 200 HU/-1,000 HU (upper window/lower window threshold); FatPh: + 240 HU/-120 HU; LivPh: + 175 HU/+ 50 HU] were used, the contoured TVs were: LivPh, 84.0 %; LunPh, 93.2 %, and FatPh, 92.8 %. The lower window threshold had a significant impact on the size of the delineated TV, whereas changes of the upper threshold led only to small differences. The decisive factor for window settings is the lower window threshold (for adequate TV delineation in the lung and fatty-soft tissue it should be lower than density values of surrounding tissue). The use of a liver window should be considered. (orig.) [German] Das Ziel dieser Arbeit war es, den Einfluss des umgebenden Gewebes auf die Konturierung bewegter Objekte zu untersuchen. Um die optimalen CT-Fensterungen fuer Lungen-, Weichteil- und Lebertumoren zu bestimmen

  20. Mandibular advancement decreases pressures in the tissues surrounding the upper airway in rabbits.

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    Kairaitis, Kristina; Stavrinou, Rosie; Parikh, Radha; Wheatley, John R; Amis, Terence C

    2006-01-01

    The pharyngeal airway can be considered as an airway luminal shape formed by surrounding tissues, contained within a bony enclosure formed by the mandible, skull base, and cervical vertebrae. Mandibular advancement (MA), a therapy for obstructive sleep apnea, is thought to increase the size of this bony enclosure and to decrease the pressure in the upper airway extraluminal tissue space (ETP). We examined the effect of MA on upper airway airflow resistance (Rua) and ETP in a rabbit model. We studied 11 male, supine, anesthetized, spontaneously breathing New Zealand White rabbits in which ETP was measured via pressure transducer-tipped catheters inserted into the tissues surrounding the lateral (ETPlat) and anterior (ETPant) pharyngeal wall. Airflow, measured via surgically inserted pneumotachograph in series with the trachea, and tracheal pressure were recorded while graded MA at 75 degrees and 100 degrees to the horizontal was performed using an external traction device. Data were analyzed using a linear mixed-effects statistical model. We found that MA at 100 degrees increased mouth opening from 4.7 +/- 0.4 to 6.6 +/- 0.4 (SE) mm (n = 7; P < 0.004), whereas mouth opening did not change from baseline (4.0 +/- 0.2 mm) with MA at 75 degrees . MA at both 75 degrees and 100 degrees decreased mean ETPlat and ETPant by approximately 0.1 cmH2O/mm MA (n = 7-11; all P < 0.0005). However, the fall in Rua (measured at 20 ml/s) with MA was greater for MA at 75 degrees (approximately 0.03 mmH2O.ml(-1).s.mm(-1)) than at 100 degrees (approximately 0.01 mmH2O.ml(-1).s.mm(-1); P < 0.02). From these findings, we conclude that MA decreases ETP and is more effective in reducing Rua without mouth opening.

  1. Distribution of natural killer cells and T-lymphocyte subsets in peripheral blood, gallbladder cancer and surrounding tissue

    Institute of Scientific and Technical Information of China (English)

    Gang Liu; Hong Ren; Xue-Jun Sun; Jing-Sen Shi

    2007-01-01

    BACKGROUND:The patient with malignant tumor always show immunologic function drawback and ingravescent with tumor development, especially in the aspect of cell-mediated immunity. This study was undertaken to deifne the relationship between the immune function of local cells and cancer development by investigating the distribution of natural killer (NK) cells and T-lymphocyte subsets in peripheral blood, the cancer tissue and the tissue surrounding gallbladder carcinoma. METHODS:The numbers of CD4+and CD8+T-lymphocytes and NK cells were measured by lfow cytometry in samples taken from gallbladder cancer tissue, the surrounding tissues and peripheral blood of 38 patients, and compared with the numbers in the peripheral blood and gallbladder tissue of 30 patients with cholecystitis as controls. RESULTS:The numbers of CD4+and CD8+T-cells and NK cells in gallbladder cancer tissues were signiifcantly higher than those in the surrounding tissue and gallbladder with gallstone. However, the ratio of CD4+/CD8+was lower in the cancer tissue than that in the surrounding tissue and tissue from gallbladders with gallstones. The distribution of CD4+ and CD8+ T-cells and NK cells in mucous membrane of cholecystitis gallbladder and that in the tissue surrounding gallbladder cancer were signiifcantly different. CONCLUSIONS:Disproportionate and imbalanced distri-bution of NK cells and subsets of T-lymphocytes occurs in the mucous membrane proper of gallbladder cancer and surrounding tissue. Although gallbladder cancer tissue has higher expressions of CD4+, CD8+and NK cells, the immune function is low or in an inhibited state. In gallbladder cancer immunization therapy, local cellular immunological function should be enhanced and the protective barrier improved.

  2. Characterisation by PIXE RBS of metallic contamination of tissues surrounding a metallic prosthesis on a knee

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    Guibert, G.; Irigaray, J. L.; Moretto, Ph.; Sauvage, T.; Kemeny, J. L.; Cazenave, A.; Jallot, E.

    2006-09-01

    Implants used as biomaterials have to fulfill conditions of functionality, compatibility and sometimes bioactivity. There are four main families of biomaterials: metals and metal alloys, polymers, bioceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. This debris may develop toxicity, inflammation and prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters influencing the tissue responses. In this paper, we characterised metallic contamination produced by knee prosthesis, composed with TiAl 6V 4 or Co-Cr-Mo alloys, into surrounding capsular tissue by depth migration, in vivo behaviour, content, size and nature of debris by PIXE (Particle Induced X-ray Emission) method associated with RBS (Rutherford Backscattering Spectroscopy). Debris distribution in the whole articulation is very heterogeneous. Debris migrates several thousand micrometers in tissues, with a characteristic decrease. Solid metallic particles of about micrometer size are found in the most polluted samples, in both alloys TiAl 6V 4 and Cr-Co-Mo. In the mean volume analysed by PIXE, the concentration mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TiAl 6V 4 debris and show the chemical evolution of Cr-Co-Mo debris. Development of a protocol to prepare thin targets permits us to correlate PIXE and histological analysis in the same zone. The fibrous tissue (collagen fibres, fibroblasts) and macrophage cells are observed with optical microscope in polluted areas. This protocol could locate other pathologies in ppm contamination range, thanks to the great sensitivity of the PIXE method.

  3. A critical evaluation of bifidobacterial adhesion to the host tissue

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    Christina Westermann

    2016-08-01

    Full Text Available Bifidobacteria are common inhabitants of the human gastrointestinal tract that, despite a long history of research, have not shown any pathogenic potential whatsoever. By contrast, some bifidobacteria are associated with a number of health-related benefits for the host. The reported beneficial effects of bifidobacteria include competitive exclusion of pathogens, alleviation of symptoms of irritable bowel syndrome and inflammatory bowel disease, and modulation of intestinal and systemic immune responses. Based on these effects, bifidobacteria are widely used as probiotics by pharmaceutical and dairy industries. In order to exert a beneficial effect bifidobacteria have to, at least transiently, colonize the host in a sufficient population size. Besides other criteria such as resistance to manufacturing processes and intestinal transit, potential probiotic bacteria are tested for adhesion to the host structures including intestinal epithelial cells (IECs, mucus and extracellular matrix (ECM components. In the present review article, we summarize the current knowledge on bifidobacterial structures that mediate adhesion to host tissue and compare these to similar structures of pathogenic bacteria. This reveals that most of the adhesive structures and mechanisms involved in adhesion of bifidobacteria to host tissue are similar or even identical to those employed by pathogens to cause disease. It is thus reasonable to assume that these structures and mechanisms are equally important for commensal or probiotic bacteria and play a similar role in the beneficial effects exerted by bifidobacteria.

  4. In vivo corrosion behaviour of magnesium alloy in association with surrounding tissue response in rats.

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    Miura, Chieko; Shimizu, Yoshinaka; Imai, Yoshimichi; Mukai, Toshiji; Yamamoto, Akiko; Sano, Yuya; Ikeo, Naoko; Isozaki, Shuji; Takahashi, Toru; Oikawa, Miho; Kumamoto, Hiroyuki; Tachi, Masahiro

    2016-03-07

    Biodegradable magnesium (Mg) alloys are the most promising candidates for osteosynthesis devices. However, their in vivo corrosion behaviour has not been fully elucidated. The aim of this study was to clarify the influence of the physiological environment surrounding Mg alloys on their corrosion behaviour. A Mg-1.0Al alloy with a fine-grained structure was formed into plates using titanium (Ti) as a control. These plates were implanted into the subperiosteum in the head, subcutaneous tissue of the back, and in the muscle of the femur of rats for 1, 2 and 4 weeks. The volumes of the remaining Mg alloy and of the insoluble salt deposition and gas cavities around the Mg alloy were determined by microtomography, and the volume losses were calculated. Then, the tissue response around the plates in each implantation site was examined histopathologically, and its relation to the respective volume loss was analyzed. These analyses determined that the Mg alloy was corroded fastest in the head, at an intermediate level in the back, and slowest in the femur. The insoluble salt deposition at the Mg alloy surface had no influence on the volume loss. Gas cavities formed around the Mg alloy at all implantation sites and decreased after 4 weeks. Histopathological examination revealed that the Mg alloy exhibited good biocompatibility, as was seen with Ti. In addition, vascularized fibrous capsules formed around the plates and became mature with time. Notably, the volume loss in the different anatomical locations correlated with capsule thickness. Together, our results suggest that, to facilitate the successful clinical application of Mg alloys, it will be necessary to further comprehend their interactions with specific in vivo environments.

  5. Evaluation of alginate as a substitute for root-surrounding tissues in electronic root canal measurements.

    Science.gov (United States)

    Lipski, Mariusz; Trąbska-Świstelnicka, Marlena; Woźniak, Krzysztof; Dembowska, Elżbieta; Droździk, Agnieszka

    2013-12-01

    Alginate as a substitute for root-surrounding tissue was investigated. The electronic working lengths of root canals under clinical conditions were compared with an in vitro simulation of the same teeth extracted and embedded in alginate. The working lengths in 26 teeth were determined on two occasions using an electronic apex locator, before extraction and after extraction with the same teeth embedded in an alginate mass. The apical 4 mm of the root canals were exposed following the measurements, and the distances between the apical constrictions and the tips of files repositioned in the canals were measured and recorded. The mean distance between the file tip and the constriction was +0.33 mm (±0.38) in vivo and +0.32 mm (±0.30) in vitro. The Wilcoxon signed-rank test indicated that these means were not significantly different. The apical constriction was assessed to be within the limits of 0.5 mm in 80.7% of in vivo cases and in 76.9% of extracted teeth. Statistical analysis demonstrated that there was no significant difference between the results recorded in vivo and in vitro regarding apical constriction localisation. Based on the results of this study, the alginate mass is a useful tool in evaluating the performance of electronic apex locators.

  6. The importance of tissue environment surrounding the tumor on the development of cancer cachexia.

    Science.gov (United States)

    Chiba, Fumihiro; Soda, Kuniyasu; Yamada, Shigeki; Tokutake, Yuka; Chohnan, Shigeru; Konishi, Fumio; Rikiyama, Toshiki

    2014-01-01

    The relationship between host factors and cancer cachexia was investigated. A single cell clone (clone 5 tumor) established from colon 26 adenocarcinoma by limiting dilution cell cloning methods was employed to eliminate the inoculation site-dependent differences in the composition of cell clones. Clone 5 tumor did not provoke manifestations of cancer cachexia when inoculated in subcutaneous tissue. However, when inoculated in the gastrocnemius muscle, the peritoneal cavity or the thoracic cavity of CD2F1 male mice, typical manifestations of cancer cachexia were observed in all groups of mice with intergroup variations. The blood levels of various cytokines, chemokines and hormones were increased but with wide intergroup variations. Analyses by stepwise multiple regression models revealed that serum interleukin-10 was the most significant factor associated with manifestations of cancer cachexia, suggesting the possible involvement of mechanisms similar to cancer patients suffering cancer cachexia. White blood cells, especially neutrophils, seemed to have some roles on the induction of cancer cachexia, because massive infiltrations and an increase in peripheral blood were observed in cachectic mice bearing clone 5 tumors. The amount of malonyl-CoA in liver correlated with manifestations of cancer cachexia, however the mRNA levels of spermidine/spermine N-1 acetyl transferase (SSAT) (of which overexpression has been shown to provoke manifestations similar to cancer cachexia) were not necessarily associated with cancer cachexia. These data suggest that the induction of cancer cachexia depends on the environment in which the tumor grows and that the infiltration of host immune cells into the tumor and the resultant increase in inflammation result in the production of cachectic factors, such as cytokines, leading to SSAT activation. Further, multiple factors likely mediate the mechanisms of cancer cachexia. Finally, this animal model was suitable for the investigation

  7. Pathogenesis, tissue distribution and host response to Rhabdochlamydia porcellionis infection in rough woodlouse Porcellio scaber.

    Science.gov (United States)

    Kostanjšek, Rok; Pirc Marolt, Tinkara

    2015-02-01

    Rhabdochlamydia porcellionis is a known intracellular pathogen in digestive glands of the terrestrial isopod crustacean Porcellio scaber. To describe the pathogenesis, tissue distribution and host response to R. porcellionis, we conducted microscopic observations and localization of infection in tissues by Fluorescent In Situ Hybridization (FISH). Digestive glands were confirmed as the primary site of infection. From there, R. porcellionis disseminates either through the apical membrane of infected cells into the lumen of digestive glands and further throughout the digestive tract or into the surrounding hemocoel by rupture of the basal membrane and lamina of infected digestive gland cells. Once in the hemocoel, R. porcellionis infects hindgut cells, hemocytes and hemopoetic tissues while the ventral nerve cord and gonads seem to be devoid of infection despite the presence of rhabdochlamydia on the surface of these organs. The host response to R. porcellionis includes aggregation of hemocytes around the infected cells and formation of multilayered melanized nodules exhibiting endogenous fluorescence. The structure of nodules is asymmetric when hemocytes are deposited on the basal side of infected gut and digestive glands cells, or symmetric, when nodules entrapping clusters of rhabdochlamydiae are deposited on other organs in the hemocoel. The study also revealed a high prevalence of infection in P. scaber populations (up to 27%) and confirmed its detrimental effect on the host. Although agility, behavior and molting cycle of infected animals appear unaffected, in the later stages R. porcellionis infection manifests as severe damage to the digestive system and decreased feeding, which eventually lead to the death of the host organism.

  8. Carcinoma cells misuse the host tissue damage response to invade the brain

    Science.gov (United States)

    Chuang, Han-Ning; van Rossum, Denise; Sieger, Dirk; Siam, Laila; Klemm, Florian; Bleckmann, Annalen; Bayerlová, Michaela; Farhat, Katja; Scheffel, Jörg; Schulz, Matthias; Dehghani, Faramarz; Stadelmann, Christine; Hanisch, Uwe-Karsten; Binder, Claudia; Pukrop, Tobias

    2013-01-01

    The metastatic colonization of the brain by carcinoma cells is still barely understood, in particular when considering interactions with the host tissue. The colonization comes with a substantial destruction of the surrounding host tissue. This leads to activation of damage responses by resident innate immune cells to protect, repair, and organize the wound healing, but may distract from tumoricidal actions. We recently demonstrated that microglia, innate immune cells of the CNS, assist carcinoma cell invasion. Here we report that this is a fatal side effect of a physiological damage response of the brain tissue. In a brain slice coculture model, contact with both benign and malignant epithelial cells induced a response by microglia and astrocytes comparable to that seen at the interface of human cerebral metastases. While the glial damage response intended to protect the brain from intrusion of benign epithelial cells by inducing apoptosis, it proved ineffective against various malignant cell types. They did not undergo apoptosis and actually exploited the local tissue reaction to invade instead. Gene expression and functional analyses revealed that the C-X-C chemokine receptor type 4 (CXCR4) and WNT signaling were involved in this process. Furthermore, CXCR4-regulated microglia were recruited to sites of brain injury in a zebrafish model and CXCR4 was expressed in human stroke patients, suggesting a conserved role in damage responses to various types of brain injuries. Together, our findings point to a detrimental misuse of the glial damage response program by carcinoma cells resistant to glia-induced apoptosis. PMID:23832647

  9. Nodular osteochondrogenic activity in soft tissue surrounding osteoma in neurogenic para osteo-arthropathy: morphological and immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Denys P

    2004-11-01

    Full Text Available Abstract Background Neurogenic Para-Osteo-Arthropathy (NPOA occurs as a consequence of central nervous system injuries or some systemic conditions. They are characterized by bone formation around the main joints. Methods In order to define some biological features of NPOAs, histological and immunohistological studies of the soft tissue surrounding osteoma and Ultrasound examination (US of NPOA before the appearance of abnormal ossification on plain radiographs were performed. Results We have observed a great number of ossifying areas scattered in soft tissues. US examination have also shown scattered ossifying areas at the early stage of ossification. A high osteogenic activity was detected in these tissues and all the stages of the endochondral process were observed. Mesenchymal cells undergo chondrocytic differentiation to further terminal maturation with hypertrophy, which sustains mineralization followed by endochondral ossification process. Conclusion We suggest that periosteoma soft tissue reflect early stage of osteoma formation and could be a model to study the mechanism of osteoma formation and we propose a mechanism of the NPOA formation in which sympathetic dystony and altered mechanical loading induce changes which could be responsible for the cascade of cellular events leading to cartilage and bone formation.

  10. Initial Symbiont Contact Orchestrates Host Organ-wide Transcriptional Changes that Prime Tissue Colonization

    Science.gov (United States)

    Kremer, Natacha; Philipp, Eva E.R.; Carpentier, Marie-Christine; Brennan, Caitlin A.; Kraemer, Lars; Altura, Melissa A.; Augustin, René; Häsler, Robert; Heath-Heckman, Elizabeth A. C.; Peyer, Suzanne M.; Schwartzman, Julia; Rader, Bethany; Ruby, Edward G.; Rosenstiel, Philip; McFall-Ngai, Margaret J.

    2013-01-01

    SUMMARY Upon transit to colonization sites, bacteria often experience critical priming that prepares them for subsequent, specific interactions with the host; however, the underlying mechanisms are poorly described. During initiation of the symbiosis between the bacterium Vibrio fischeri and its squid host, which can be observed directly and in real time, ~5 V. fischeri cells aggregate along the mucociliary membranes of a superficial epithelium prior to entering host tissues. Here we show that these few early host-associated symbionts specifically induce robust changes in host gene expression that are critical to subsequent colonization steps. This exquisitely sensitive response to its specific symbiotic partner includes the upregulation of a host endochitinase, whose activity hydrolyzes polymeric chitin in the mucus into chitobiose, thereby priming the symbiont and also producing a chemoattractant gradient that promotes V. fischeri migration into host tissues. Thus, the host responds transcriptionally upon initial symbiont contact, which facilitates subsequent colonization. PMID:23954157

  11. Lipidomic differentiation between human kidney tumors and surrounding normal tissues using HILIC-HPLC/ESI-MS and multivariate data analysis.

    Science.gov (United States)

    Cífková, Eva; Holčapek, Michal; Lísa, Miroslav; Vrána, David; Melichar, Bohuslav; Študent, Vladimír

    2015-09-01

    The characterization of differences among polar lipid classes in tumors and surrounding normal tissues of 20 kidney cancer patients is performed by hydrophilic interaction liquid chromatography (HILIC) coupled to electrospray ionization mass spectrometry (ESI-MS). The detailed analysis of identified lipid classes using relative abundances of characteristic ions in negative- and positive-ion modes is used for the determination of more than 120 individual lipid species containing attached fatty acyls of different chain length and double bond number. Lipid species are described using relative abundances, providing a better visualization of lipidomic differences between tumor and normal tissues. The multivariate data analysis methods using unsupervised principal component analysis (PCA) and supervised orthogonal partial least square (OPLS) are used for the characterization of statistically significant differences in identified lipid species. Ten most significant up- and down-regulated lipids in OPLS score plots are also displayed by box plots. A notable increase of relative abundances of lipids containing four and more double bonds is detected in tumor compared to normal tissues. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. A Three-Dimensional Finite Element Study on the Biomechanical Simulation of Various Structured Dental Implants and Their Surrounding Bone Tissues

    OpenAIRE

    Zhang, Gong; Yuan, Hai; Chen, Xianshuai; Wang, Weijun; Chen, Jianyu; Liang, Jimin; Zhang, Peng

    2016-01-01

    Background/Purpose. This three-dimensional finite element study observed the stress distribution characteristics of 12 types of dental implants and their surrounding bone tissues with various structured abutments, implant threads, and healing methods under different amounts of concentrated loading. Materials and Methods. A three-dimensional geometrical model of a dental implant and its surrounding bone tissue was created; the model simulated a screw applied with a preload of 200 N or a torque...

  13. Photodynamic Inactivation of Root Canal Bacteria by Light Activation through Human Dental Hard and Simulated Surrounding Tissue

    Science.gov (United States)

    Cieplik, Fabian; Pummer, Andreas; Leibl, Christoph; Regensburger, Johannes; Schmalz, Gottfried; Buchalla, Wolfgang; Hiller, Karl-Anton; Maisch, Tim

    2016-01-01

    Introduction: Photodynamic inactivation of bacteria (PIB) may be a supportive antimicrobial approach for use in endodontics, but sufficient activation of photosensitizers (PS) in root canals is a critical point. Therefore, aim of this study was to evaluate the ability of PS absorbing blue (TMPyP) or red light (Methylene Blue; MB) for light activation through human dental hard and simulated surrounding tissue to inactivate root canal bacteria. Methods: A tooth model was fabricated with a human premolar and two molars in an acrylic resin bloc simulating the optical properties of a porcine jaw. The distal root canal of the first molar was enlarged to insert a glass tube (external diameter 2 mm) containing PS and stationary-phase Enterococcus faecalis. Both PS (10 μM) were irradiated for 120 s with BlueV (20 mW/cm2; λem = 400–460 nm) or PDT 1200L (37.8 mW/cm2; λem = 570–680 nm; both: Waldmann Medizintechnik), respectively. Irradiation parameters ensured identical numbers of photons absorbed by each PS. Three setups were chosen: irradiating the glass pipette only (G), the glass pipette inside the single tooth without (GT) and with (GTM) simulated surrounding tissues. Colony forming units (CFU) were evaluated. Transmission measurements of the buccal halves of hemisected mandibular first molars were performed by means of a photospectrometer. Results: PIB with both PS led to reduction by ≥ 5 log10 of E. faecalis CFU for each setup. From transmission measurements, a threshold wavelength λth for allowing an amount of light transmission for sufficient activation of PS was determined to be 430 nm. Conclusion: This study can be seen as proof of principle that light activation of given intra-canal PS from outside a tooth may be possible at wavelengths ≥ 430 nm, facilitating clinical application of PIB in endodontics. PMID:27379059

  14. Characterisation by PIXE-RBS of metallic contamination of tissues surrounding a metallic prosthesis on a knee

    Energy Technology Data Exchange (ETDEWEB)

    Guibert, G. [Laboratoire de Physique Corpusculaire de Clermont-Ferrand, IN2P3/CNRS UMR 6533, Universite Blaise Pascal, 63177 Aubiere Cedex (France)]. E-mail: geoffroy.guibert@he-arc.ch; Irigaray, J.L. [Laboratoire de Physique Corpusculaire de Clermont-Ferrand, IN2P3/CNRS UMR 6533, Universite Blaise Pascal, 63177 Aubiere Cedex (France); Moretto, Ph. [Centre d' Etudes Nucleaires de Bordeaux-Gradignan, IN2P3/CNRS UMR 5797, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Sauvage, T. [Centre d' Etudes et de Recherches par Irradiation, CNRS Orleans France, 3A rue de la ferollerie, 45071 Orleans Cedex 2 (France); Kemeny, J.L. [CHU, Service d' Anatomie et de Cytologie Pathologiques, Universite d' Auvergne, 63100 Clermont-Ferrand (France); Cazenave, A. [Institut Calot, 62608 Berck sur Mer Cedex (France); Jallot, E. [Laboratoire de Physique Corpusculaire de Clermont-Ferrand, IN2P3/CNRS UMR 6533, Universite Blaise Pascal, 63177 Aubiere Cedex (France)

    2006-09-15

    Implants used as biomaterials have to fulfill conditions of functionality, compatibility and sometimes bioactivity. There are four main families of biomaterials: metals and metal alloys, polymers, bioceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. This debris may develop toxicity, inflammation and prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters influencing the tissue responses. In this paper, we characterised metallic contamination produced by knee prosthesis, composed with TiAl{sub 6}V{sub 4} or Co-Cr-Mo alloys, into surrounding capsular tissue by depth migration, in vivo behaviour, content, size and nature of debris by PIXE (Particle Induced X-ray Emission) method associated with RBS (Rutherford Backscattering Spectroscopy). Debris distribution in the whole articulation is very heterogeneous. Debris migrates several thousand micrometers in tissues, with a characteristic decrease. Solid metallic particles of about micrometer size are found in the most polluted samples, in both alloys TiAl{sub 6}V{sub 4} and Cr-Co-Mo. In the mean volume analysed by PIXE, the concentration mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TiAl{sub 6}V{sub 4} debris and show the chemical evolution of Cr-Co-Mo debris. Development of a protocol to prepare thin targets permits us to correlate PIXE and histological analysis in the same zone. The fibrous tissue (collagen fibres, fibroblasts) and macrophage cells are observed with optical microscope in polluted areas. This protocol could locate other pathologies in ppm contamination range, thanks to the great sensitivity of the PIXE method.

  15. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python

    Directory of Open Access Journals (Sweden)

    Nicolas eRey-Villamizar

    2014-04-01

    Full Text Available In this article, we describe use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis task, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral brain tissue images surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels, 6,000$times$10,000$times$500 voxels with 16 bits/voxel, implying image sizes exceeding 250GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analytics for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment consisting. Our Python script enables efficient data storage and movement between compute and storage servers, logging all processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

  16. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python.

    Science.gov (United States)

    Rey-Villamizar, Nicolas; Somasundar, Vinay; Megjhani, Murad; Xu, Yan; Lu, Yanbin; Padmanabhan, Raghav; Trett, Kristen; Shain, William; Roysam, Badri

    2014-01-01

    In this article, we describe the use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes, including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis tasks, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral images of brain tissue surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels. Each channel consists of 6000 × 10,000 × 500 voxels with 16 bits/voxel, implying image sizes exceeding 250 GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analysis for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN) capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment. Our Python script enables efficient data storage and movement between computers and storage servers, logs all the processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

  17. Host tissues as microhabitats for Wolbachia and quantitative insights into the bacterial community in terrestrial isopods.

    Science.gov (United States)

    Dittmer, J; Beltran-Bech, S; Lesobre, J; Raimond, M; Johnson, M; Bouchon, D

    2014-05-01

    Animal-bacterial symbioses are highly dynamic in terms of multipartite interactions, both between the host and its symbionts as well as between the different bacteria constituting the symbiotic community. These interactions will be reflected by the titres of the individual bacterial taxa, for example via host regulation of bacterial loads or competition for resources between symbionts. Moreover, different host tissues represent heterogeneous microhabitats for bacteria, meaning that host-associated bacteria might establish tissue-specific bacterial communities. Wolbachia are widespread endosymbiotic bacteria, infecting a large number of arthropods and filarial nematodes. However, relatively little is known regarding direct interactions between Wolbachia and other bacteria. This study represents the first quantitative investigation of tissue-specific Wolbachia-microbiota interactions in the terrestrial isopod Armadillidium vulgare. To this end, we obtained a more complete picture of the Wolbachia distribution patterns across all major host tissues, integrating all three feminizing Wolbachia strains (wVulM, wVulC, wVulP) identified to date in this host. Interestingly, the different Wolbachia strains exhibited strain-specific tissue distribution patterns, with wVulM reaching lower titres in most tissues. These patterns were consistent across different host genetic backgrounds and might reflect different co-evolutionary histories between the Wolbachia strains and A. vulgare. Moreover, Wolbachia-infected females carried higher total bacterial loads in several, but not all, tissues, irrespective of the Wolbachia strain. Taken together, this quantitative approach indicates that Wolbachia is part of a potentially more diverse bacterial community, as exemplified by the presence of highly abundant bacterial taxa in the midgut caeca of several A. vulgare populations.

  18. Novel Bioceramic Urethral Bulking Agents Elicit Improved Host Tissue Responses in a Rat Model

    DEFF Research Database (Denmark)

    Mann-Gow, Travis K; King, Benjamin J; El-Ghannam, Ahmed;

    2016-01-01

    Objectives. To test the physical properties and host response to the bioceramic particles, silica-calcium phosphate (SCPC10) and Cristobalite, in a rat animal model and compare their biocompatibility to the current clinically utilized urethral bulking materials. Material and Methods. The novel...... agents using a rat animal model and hard tissue histology techniques compared two newly developed bioactive ceramic particles to three of the currently used bulking agents. The local host tissue response and bulking effects of bioceramic particles were superior while also possessing a comparable safety...

  19. In situ regeneration of skeletal muscle tissue through host cell recruitment.

    Science.gov (United States)

    Ju, Young Min; Atala, Anthony; Yoo, James J; Lee, Sang Jin

    2014-10-01

    Standard reconstructive procedures for restoring normal function after skeletal muscle defects involve the use of existing host tissues such as muscular flaps. In many instances, this approach is not feasible and delays the rehabilitation process and restoration of tissue function. Currently, cell-based tissue engineering strategies have been used for reconstruction; however, donor tissue biopsy and ex vivo cell manipulation are required prior to implantation. The present study aimed to overcome these limitations by demonstrating mobilization of muscle cells into a target-specific site for in situ muscle regeneration. First, we investigated whether host muscle cells could be mobilized into an implanted scaffold. Poly(l-lactic acid) (PLLA) scaffolds were implanted in the tibialis anterior (TA) muscle of rats, and the retrieved scaffolds were characterized by examining host cell infiltration in the scaffolds. The host cell infiltrates, including Pax7+ cells, gradually increased with time. Second, we demonstrated that host muscle cells could be enriched by a myogenic factor released from the scaffolds. Gelatin-based scaffolds containing a myogenic factor were implanted in the TA muscle of rats, and the Pax7+ cell infiltration and newly formed muscle fibers were examined. By the second week after implantation, the Pax7+ cell infiltrates and muscle formation were significantly accelerated within the scaffolds containing insulin-like growth factor 1 (IGF-1). Our data suggest an ability of host stem cells to be recruited into the scaffolds with the capability of differentiating to muscle cells. In addition, the myogenic factor effectively promoted host cell recruitment, which resulted in accelerating muscle regeneration in situ.

  20. Tissue and host tropism of influenza viruses:Importance of quantitative analysis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    It is generally accepted that human influenza viruses preferentially bind to cell-surface glycoproteins/ glycolipids containing sialic acids in α2,6-linkage; while avian and equine influenza viruses preferentially bind to those containing sialic acids in α2,3-linkage. Even though this generalized view is accurate for H3 subtype isolates, it may not be accurate and absolute for all subtypes of influenza A viruses and, therefore, needs to be reevaluated carefully and realistically. Some of the studies published in major scientific journals on the subject of tissue tropism of influenza viruses are inconsistent and caused confusion in the scientific community. One of the reasons for the inconsistency is that most studies were quantitative descriptions of sialic acid receptor distributions based on lectin or influenza virus immunohistochemistry results with limited numbers of stained cells. In addition, recent studies indicate that α2,3- and α2,6-linked sialic acids are not the sole receptors determining tissue and host tropism of influenza viruses. In fact, determinants for tissue and host tropism of human, avian and animal influenza viruses are more complex than what has been generally accepted. Other factors, such as glycan topology, concentration of invading viruses, local density of receptors, lipid raft microdomains, coreceptors or sialic acid-independent receptors, may also be important. To more efficiently control the global spread of pandemic influenza such as the current circulating influenza A H1N1, it is crucial to clarify the determinants for tissue and host tropism of influenza viruses through quantitative analysis of experimental results. In this review, I will comment on some conflicting issues related to tissue and host tropism of influenza viruses, discuss the importance of quantitative analysis of lectin and influenza virus immunohistochemistry results and point out directions for future studies in this area, which should lead to a better

  1. Host genetics and environmental factors regulate ecological succession of the mouse colon tissue-associated microbiota.

    Directory of Open Access Journals (Sweden)

    Philip Smith

    Full Text Available BACKGROUND: The integration of host genetics, environmental triggers and the microbiota is a recognised factor in the pathogenesis of barrier function diseases such as IBD. In order to determine how these factors interact to regulate the host immune response and ecological succession of the colon tissue-associated microbiota, we investigated the temporal interaction between the microbiota and the host following disruption of the colonic epithelial barrier. METHODOLOGY/PRINCIPAL FINDINGS: Oral administration of DSS was applied as a mechanistic model of environmental damage of the colon and the resulting inflammation characterized for various parameters over time in WT and Nod2 KO mice. RESULTS: In WT mice, DSS damage exposed the host to the commensal flora and led to a migration of the tissue-associated bacteria from the epithelium to mucosal and submucosal layers correlating with changes in proinflammatory cytokine profiles and a progressive transition from acute to chronic inflammation of the colon. Tissue-associated bacteria levels peaked at day 21 post-DSS and declined thereafter, correlating with recruitment of innate immune cells and development of the adaptive immune response. Histological parameters, immune cell infiltration and cytokine biomarkers of inflammation were indistinguishable between Nod2 and WT littermates following DSS, however, Nod2 KO mice demonstrated significantly higher tissue-associated bacterial levels in the colon. DSS damage and Nod2 genotype independently regulated the community structure of the colon microbiota. CONCLUSIONS/SIGNIFICANCE: The results of these experiments demonstrate the integration of environmental and genetic factors in the ecological succession of the commensal flora in mammalian tissue. The association of Nod2 genotype (and other host polymorphisms and environmental factors likely combine to influence the ecological succession of the tissue-associated microflora accounting in part for their

  2. Neutrophil elastase causes tissue damage that decreases host tolerance to lung infection with burkholderia species.

    Directory of Open Access Journals (Sweden)

    Manoranjan Sahoo

    2014-08-01

    Full Text Available Two distinct defense strategies can protect the host from infection: resistance is the ability to destroy the infectious agent, and tolerance is the ability to withstand infection by minimizing the negative impact it has on the host's health without directly affecting pathogen burden. Burkholderia pseudomallei is a Gram-negative bacterium that infects macrophages and causes melioidosis. We have recently shown that inflammasome-triggered pyroptosis and IL-18 are equally important for resistance to B. pseudomallei, whereas IL-1β is deleterious. Here we show that the detrimental role of IL-1β during infection with B. pseudomallei (and closely related B. thailandensis is due to excessive recruitment of neutrophils to the lung and consequent tissue damage. Mice deficient in the potentially damaging enzyme neutrophil elastase were less susceptible than the wild type C57BL/6J mice to infection, although the bacterial burdens in organs and the extent of inflammation were comparable between C57BL/6J and elastase-deficient mice. In contrast, lung tissue damage and vascular leakage were drastically reduced in elastase-deficient mice compared to controls. Bradykinin levels were higher in C57BL/6 than in elastase-deficient mice; administration of a bradykinin antagonist protected mice from infection, suggesting that increased vascular permeability mediated by bradykinin is one of the mechanisms through which elastase decreases host tolerance to melioidosis. Collectively, these results demonstrate that absence of neutrophil elastase increases host tolerance, rather than resistance, to infection by minimizing host tissue damage.

  3. In situ tissue engineering of functional small-diameter blood vessels by host circulating cells only

    NARCIS (Netherlands)

    Talacua, Hanna; Smits, Anthal I P M; Muylaert, Dimitri E P; Van Rijswijk, Jan Willem; Vink, Aryan; Verhaar, Marianne C.; Driessen-Mol, Anita; Van Herwerden, Lex A.; Bouten, Carlijn V C; Kluin, Jolanda; Baaijens, Frank P T

    2015-01-01

    Inflammation is a natural phase of the wound healing response, which can be harnessed for the in situ tissue engineering of small-diameter blood vessels using instructive, bioresorbable synthetic grafts. This process is dependent on colonization of the graft by host circulating cells and subsequent

  4. In situ tissue engineering of functional small-diameter blood vessels by host circulating cells only

    NARCIS (Netherlands)

    Talacua, Hanna; Smits, Anthal I P M; Muylaert, Dimitri E P; Van Rijswijk, Jan Willem; Vink, Aryan; Verhaar, Marianne C.; Driessen-Mol, Anita; Van Herwerden, Lex A.; Bouten, Carlijn V C; Kluin, Jolanda; Baaijens, Frank P T

    2015-01-01

    Inflammation is a natural phase of the wound healing response, which can be harnessed for the in situ tissue engineering of small-diameter blood vessels using instructive, bioresorbable synthetic grafts. This process is dependent on colonization of the graft by host circulating cells and subsequent

  5. Novel Bioceramic Urethral Bulking Agents Elicit Improved Host Tissue Responses in a Rat Model

    Science.gov (United States)

    Mann-Gow, Travis K.; King, Benjamin J.; El-Ghannam, Ahmed; Knabe-Ducheyne, Christine; Kida, Masatoshi; Dall, Ole M.; Krhut, Jan

    2016-01-01

    Objectives. To test the physical properties and host response to the bioceramic particles, silica-calcium phosphate (SCPC10) and Cristobalite, in a rat animal model and compare their biocompatibility to the current clinically utilized urethral bulking materials. Material and Methods. The novel bulking materials, SCPC10 and Cristobalite, were suspended in hyaluronic acid sodium salt and injected into the mid urethra of a rat. Additional animals were injected with bulking materials currently in clinical use. Physiological response was assessed using voiding trials, and host tissue response was evaluated using hard tissue histology and immunohistochemical analysis. Distant organs were evaluated for the presence of particles or their components. Results. Histological analysis of the urethral tissue five months after injection showed that both SCPC10 and Cristobalite induced a more robust fibroblastic and histiocytic reaction, promoting integration and encapsulation of the particle aggregates, leading to a larger bulking effect. Concentrations of Ca, Na, Si, and P ions in the experimental groups were comparable to control animals. Conclusions. This side-by-side examination of urethral bulking agents using a rat animal model and hard tissue histology techniques compared two newly developed bioactive ceramic particles to three of the currently used bulking agents. The local host tissue response and bulking effects of bioceramic particles were superior while also possessing a comparable safety profile. PMID:27688751

  6. Novel Bioceramic Urethral Bulking Agents Elicit Improved Host Tissue Responses in a Rat Model

    Directory of Open Access Journals (Sweden)

    Travis K. Mann-Gow

    2016-01-01

    Full Text Available Objectives. To test the physical properties and host response to the bioceramic particles, silica-calcium phosphate (SCPC10 and Cristobalite, in a rat animal model and compare their biocompatibility to the current clinically utilized urethral bulking materials. Material and Methods. The novel bulking materials, SCPC10 and Cristobalite, were suspended in hyaluronic acid sodium salt and injected into the mid urethra of a rat. Additional animals were injected with bulking materials currently in clinical use. Physiological response was assessed using voiding trials, and host tissue response was evaluated using hard tissue histology and immunohistochemical analysis. Distant organs were evaluated for the presence of particles or their components. Results. Histological analysis of the urethral tissue five months after injection showed that both SCPC10 and Cristobalite induced a more robust fibroblastic and histiocytic reaction, promoting integration and encapsulation of the particle aggregates, leading to a larger bulking effect. Concentrations of Ca, Na, Si, and P ions in the experimental groups were comparable to control animals. Conclusions. This side-by-side examination of urethral bulking agents using a rat animal model and hard tissue histology techniques compared two newly developed bioactive ceramic particles to three of the currently used bulking agents. The local host tissue response and bulking effects of bioceramic particles were superior while also possessing a comparable safety profile.

  7. Tissue-specific patterning of host innate immune responses by Staphylococcus aureus α-toxin.

    Science.gov (United States)

    Becker, Russell E N; Berube, Bryan J; Sampedro, Georgia R; DeDent, Andrea C; Bubeck Wardenburg, Juliane

    2014-01-01

    Immunomodulatory cytotoxins are prominent virulence factors produced by Staphylococcus aureus, a leading cause of bacterial sepsis, skin infection, and pneumonia. S. aureus α-toxin is a pore-forming toxin that utilizes a widely expressed receptor, ADAM10, to injure the host epithelium, endothelium, and immune cells. As each host tissue is characterized by a unique composition of resident cells and recruited immune cells, the outcome of α-toxin-mediated injury may depend on the infected tissue environment. Utilizing myeloid lineage-specific Adam10 knockout mice, we show that α-toxin exerts tissue-specific effects on innate immunity to staphylococcal infection. Loss of ADAM10 expression exacerbates skin infection, yet affords protection against lethal pneumonia. These diverse outcomes are not related to altered immune cell recruitment, but rather correlate with a defect in toxin-induced IL-1β production. Extension of these studies through analysis of ADAM10 double-knockout mice affecting both the myeloid lineage and either the skin or lung epithelium highlight the prominence of toxin-induced injury to the epithelium in governing the outcome of infection. Together, these studies provide evidence of tissue specificity of pore-forming cytotoxin action in the modulation of host immunity, and illustrate that the outcome of infection is a collective manifestation of all effects of the toxin within the tissue microenvironment.

  8. The chemical form of metallic debris in tissues surrounding metal-on-metal hips with unexplained failure.

    Science.gov (United States)

    Hart, Alister J; Quinn, Paul D; Sampson, Barry; Sandison, Ann; Atkinson, Kirk D; Skinner, John A; Powell, Jonathan J; Mosselmans, J Fred W

    2010-11-01

    Implant-derived material from metal-on-metal (MOM) hip arthroplasties may be responsible for an unexplained tissue inflammatory response. The chemical form of the metal species in the tissues is predominantly chromium (Cr), but the currently used techniques have not been able to determine whether this is Cr(III) phosphate or Cr(III) oxide. The analytical challenge must overcome the fact that the metal in the tissues is at a relatively low concentration and tissue preparation or the microscopy beam used can affect the results. Microfocus X-ray spectroscopy using a synchrotron beam is useful in addressing both these issues. Using this technique we compared tissue from failed MOM hips with: (1) tissue from metal-on-polyethylene (MOP) hips; (2) chemical standards; (3) metal discs cut from MOM hips. The most abundant implant-related species in all MOM hip tissues contained Cr. Comparison with standards revealed the chemical form was Cr(III) phosphate, which did not vary with manufacturer type (four types analysed) or level of blood metal ions. Cobalt (Co) and molybdenum (Mo) were occasionally present in areas of high Cr. Co was normally found in a metallic state in the tissue, while Mo was found in an oxidized state. The variety of metallic species may have arisen from corrosion, wear or a combination of both. No evidence of Cr(VI) was seen in the tissues examined.

  9. Extensive HIV-1 intra-host recombination is common in tissues with abnormal histopathology.

    Directory of Open Access Journals (Sweden)

    Susanna L Lamers

    Full Text Available There is evidence that immune-activated macrophages infected with the Human Immunodeficiency Virus (HIV are associated with tissue damage and serve as a long-lived viral reservoir during therapy. In this study, we analyzed 780 HIV genetic sequences generated from 53 tissues displaying normal and abnormal histopathology. We found up to 50% of the sequences from abnormal lymphoid and macrophage rich non-lymphoid tissues were intra-host viral recombinants. The presence of extensive recombination, especially in non-lymphoid tissues, implies that HIV-1 infected macrophages may significantly contribute to the generation of elusive viral genotypes in vivo. Because recombination has been implicated in immune evasion, the acquisition of drug-resistance mutations, and alterations of viral co-receptor usage, any attempt towards the successful eradication of HIV-1 requires therapeutic approaches targeting tissue macrophages.

  10. Safety Study of Photodynamic Therapy Using Talaporfin Sodium in the Pancreas and Surrounding Tissues in the Syrian Golden Hamster

    Directory of Open Access Journals (Sweden)

    Johannes Wittmann

    2014-01-01

    Full Text Available Aim. To assess the safety of photodynamic therapy (PDT using talaporfin sodium on the pancreas and surrounding organs in normal hamsters. Methods. Fluorescence microscopy documented talaporfin levels in liver, duodenum, and pancreas up to 24 hours after photosensitisation. Lesion size in liver 3 days after PDT (50 J, 5 mg/kg, variable drug-light interval (DLI was documented to optimise the DLI. Using optimum DLI, pancreas and surrounding organs were treated with laser fibre touching the surface and animals were killed at 3 or 21 days. Results. Peak fluorescence was seen in duodenum and pancreas at 15 mins (second lower peak at 2 hours. Liver fluorescence was consistently high (peak 1 hour until after 4 hours. Optimum DLI was seen at 15 minutes. The pancreas was relatively resistant to direct PDT injury (small lesions at high doses but surrounding stomach, duodenum, and liver were more susceptible with evidence of adhesions and full thickness damage (localised peritonitis and duodenal perforation at highest doses. Conclusion. The safety profile is similar to PDT with longer acting photosensitisers. The pancreas appears safe to treat, but care is required to avoid high light doses to the intestinal tract, particularly the duodenum.

  11. A Three-Dimensional Finite Element Study on the Biomechanical Simulation of Various Structured Dental Implants and Their Surrounding Bone Tissues.

    Science.gov (United States)

    Zhang, Gong; Yuan, Hai; Chen, Xianshuai; Wang, Weijun; Chen, Jianyu; Liang, Jimin; Zhang, Peng

    2016-01-01

    Background/Purpose. This three-dimensional finite element study observed the stress distribution characteristics of 12 types of dental implants and their surrounding bone tissues with various structured abutments, implant threads, and healing methods under different amounts of concentrated loading. Materials and Methods. A three-dimensional geometrical model of a dental implant and its surrounding bone tissue was created; the model simulated a screw applied with a preload of 200 N or a torque of 0.2 N·m and a prosthetic crown applied with a vertical or an inclined force of 100 N. The Von Mises stress was evaluated on the 12 types of dental implants and their surrounding bone tissues. Results. Under the same loading force, the stress influence on the implant threads was not significant; however, the stress influence on the cancellous bone was obvious. The stress applied to the abutment, cortical bone, and cancellous bone by the inclined force applied to the crown was larger than the stress applied by the vertical force to the crown, and the abutment stress of the nonsubmerged healing implant system was higher than that of the submerged healing implant system. Conclusion. A dental implant system characterised by a straight abutment, rectangle tooth, and nonsubmerged healing may provide minimum value for the implant-bone interface.

  12. A Three-Dimensional Finite Element Study on the Biomechanical Simulation of Various Structured Dental Implants and Their Surrounding Bone Tissues

    Directory of Open Access Journals (Sweden)

    Gong Zhang

    2016-01-01

    Full Text Available Background/Purpose. This three-dimensional finite element study observed the stress distribution characteristics of 12 types of dental implants and their surrounding bone tissues with various structured abutments, implant threads, and healing methods under different amounts of concentrated loading. Materials and Methods. A three-dimensional geometrical model of a dental implant and its surrounding bone tissue was created; the model simulated a screw applied with a preload of 200 N or a torque of 0.2 N·m and a prosthetic crown applied with a vertical or an inclined force of 100 N. The Von Mises stress was evaluated on the 12 types of dental implants and their surrounding bone tissues. Results. Under the same loading force, the stress influence on the implant threads was not significant; however, the stress influence on the cancellous bone was obvious. The stress applied to the abutment, cortical bone, and cancellous bone by the inclined force applied to the crown was larger than the stress applied by the vertical force to the crown, and the abutment stress of the nonsubmerged healing implant system was higher than that of the submerged healing implant system. Conclusion. A dental implant system characterised by a straight abutment, rectangle tooth, and nonsubmerged healing may provide minimum value for the implant-bone interface.

  13. Host tissue destruction by Entamoeba histolytica: molecules mediating adhesion, cytolysis, and proteolysis

    Directory of Open Access Journals (Sweden)

    Rolf D. Horstmann

    1992-01-01

    Full Text Available Entamoeba histolytica, the protozoan parasite causing human amoebisis, has recently been found to comprise two genetically distinct forms, potentially pathogenic and constitutively nonpathogenic ones. Host tissue destruction by pathogenic forms is belived to result from cell functions mediaed by a lectin-type adherence receptor, a pore-forming peptide involved in host cell lysis, and abundant expression of cysteine proteinase(s. Isolation and molecular cloning of these amoeba products have provided the tools for structural analyses and manipulations of cell functions including comparisons between pathogenic and nonpathogenic forms.

  14. Two New Complete Genome Sequences Offer Insight into Host and Tissue Specificity of Plant Pathogenic Xanthomonas spp.▿†

    Science.gov (United States)

    Bogdanove, Adam J.; Koebnik, Ralf; Lu, Hong; Furutani, Ayako; Angiuoli, Samuel V.; Patil, Prabhu B.; Van Sluys, Marie-Anne; Ryan, Robert P.; Meyer, Damien F.; Han, Sang-Wook; Aparna, Gudlur; Rajaram, Misha; Delcher, Arthur L.; Phillippy, Adam M.; Puiu, Daniela; Schatz, Michael C.; Shumway, Martin; Sommer, Daniel D.; Trapnell, Cole; Benahmed, Faiza; Dimitrov, George; Madupu, Ramana; Radune, Diana; Sullivan, Steven; Jha, Gopaljee; Ishihara, Hiromichi; Lee, Sang-Won; Pandey, Alok; Sharma, Vikas; Sriariyanun, Malinee; Szurek, Boris; Vera-Cruz, Casiana M.; Dorman, Karin S.; Ronald, Pamela C.; Verdier, Valérie; Dow, J. Maxwell; Sonti, Ramesh V.; Tsuge, Seiji; Brendel, Volker P.; Rabinowicz, Pablo D.; Leach, Jan E.; White, Frank F.; Salzberg, Steven L.

    2011-01-01

    Xanthomonas is a large genus of bacteria that collectively cause disease on more than 300 plant species. The broad host range of the genus contrasts with stringent host and tissue specificity for individual species and pathovars. Whole-genome sequences of Xanthomonas campestris pv. raphani strain 756C and X. oryzae pv. oryzicola strain BLS256, pathogens that infect the mesophyll tissue of the leading models for plant biology, Arabidopsis thaliana and rice, respectively, were determined and provided insight into the genetic determinants of host and tissue specificity. Comparisons were made with genomes of closely related strains that infect the vascular tissue of the same hosts and across a larger collection of complete Xanthomonas genomes. The results suggest a model in which complex sets of adaptations at the level of gene content account for host specificity and subtler adaptations at the level of amino acid or noncoding regulatory nucleotide sequence determine tissue specificity. PMID:21784931

  15. Two new complete genome sequences offer insight into host and tissue specificity of plant pathogenic Xanthomonas spp.

    Science.gov (United States)

    Bogdanove, Adam J; Koebnik, Ralf; Lu, Hong; Furutani, Ayako; Angiuoli, Samuel V; Patil, Prabhu B; Van Sluys, Marie-Anne; Ryan, Robert P; Meyer, Damien F; Han, Sang-Wook; Aparna, Gudlur; Rajaram, Misha; Delcher, Arthur L; Phillippy, Adam M; Puiu, Daniela; Schatz, Michael C; Shumway, Martin; Sommer, Daniel D; Trapnell, Cole; Benahmed, Faiza; Dimitrov, George; Madupu, Ramana; Radune, Diana; Sullivan, Steven; Jha, Gopaljee; Ishihara, Hiromichi; Lee, Sang-Won; Pandey, Alok; Sharma, Vikas; Sriariyanun, Malinee; Szurek, Boris; Vera-Cruz, Casiana M; Dorman, Karin S; Ronald, Pamela C; Verdier, Valérie; Dow, J Maxwell; Sonti, Ramesh V; Tsuge, Seiji; Brendel, Volker P; Rabinowicz, Pablo D; Leach, Jan E; White, Frank F; Salzberg, Steven L

    2011-10-01

    Xanthomonas is a large genus of bacteria that collectively cause disease on more than 300 plant species. The broad host range of the genus contrasts with stringent host and tissue specificity for individual species and pathovars. Whole-genome sequences of Xanthomonas campestris pv. raphani strain 756C and X. oryzae pv. oryzicola strain BLS256, pathogens that infect the mesophyll tissue of the leading models for plant biology, Arabidopsis thaliana and rice, respectively, were determined and provided insight into the genetic determinants of host and tissue specificity. Comparisons were made with genomes of closely related strains that infect the vascular tissue of the same hosts and across a larger collection of complete Xanthomonas genomes. The results suggest a model in which complex sets of adaptations at the level of gene content account for host specificity and subtler adaptations at the level of amino acid or noncoding regulatory nucleotide sequence determine tissue specificity.

  16. Myeloperoxidase targets oxidative host attacks to Salmonella and prevents collateral tissue damage.

    Science.gov (United States)

    Schürmann, Nura; Forrer, Pascal; Casse, Olivier; Li, Jiagui; Felmy, Boas; Burgener, Anne-Valérie; Ehrenfeuchter, Nikolaus; Hardt, Wolf-Dietrich; Recher, Mike; Hess, Christoph; Tschan-Plessl, Astrid; Khanna, Nina; Bumann, Dirk

    2017-01-23

    Host control of infections crucially depends on the capability to kill pathogens with reactive oxygen species (ROS). However, these toxic molecules can also readily damage host components and cause severe immunopathology. Here, we show that neutrophils use their most abundant granule protein, myeloperoxidase, to target ROS specifically to pathogens while minimizing collateral tissue damage. A computational model predicted that myeloperoxidase efficiently scavenges diffusible H2O2 at the surface of phagosomal Salmonella and converts it into highly reactive HOCl (bleach), which rapidly damages biomolecules within a radius of less than 0.1 μm. Myeloperoxidase-deficient neutrophils were predicted to accumulate large quantities of H2O2 that still effectively kill Salmonella, but most H2O2 would leak from the phagosome. Salmonella stimulation of neutrophils from normal and myeloperoxidase-deficient human donors experimentally confirmed an inverse relationship between myeloperoxidase activity and extracellular H2O2 release. Myeloperoxidase-deficient mice infected with Salmonella had elevated hydrogen peroxide tissue levels and exacerbated oxidative damage of host lipids and DNA, despite almost normal Salmonella control. These data show that myeloperoxidase has a major function in mitigating collateral tissue damage during antimicrobial oxidative bursts, by converting diffusible long-lived H2O2 into highly reactive, microbicidal and locally confined HOCl at pathogen surfaces.

  17. Dendroctonus armandi (Curculionidae: Scolytinae) cytochrome P450s display tissue specificity and responses to host terpenoids.

    Science.gov (United States)

    Dai, Lulu; Ma, Mingyuan; Gao, Guanqun; Chen, Hui

    2016-11-01

    Bark beetles oxidize the defensive allelochemicals of their host trees both to detoxify them and convert them into components of their pheromone systems which were catalyzed by cytochrome P450 enzymes (CYPs) and occur in different tissues of the insect. We study P450 genes in the Chinese white pine beetle (Dendroctonus armandi), and some bio-information analysis was done for the full-length deduced amino acid sequences. The tissue specificity of these P450 genes was determined in three tissues (antenna, gut and reproductive organs). Differential expression of the P450 genes was observed between sexes, and within these significant differences exposed to stimuli (α-pinene (1:1 racemic mix), (S)-(-)-α-pinene, (S)-(-)-β-pinene, (+)-3-carene, (±)-limonene and turpentine oil) at 24h. Increased expression of P450 genes suggested that they play a role in the detoxification of monoterpenes released by the host trees. The different transcript accumulation patterns of these bark beetle P450 genes provided insight into ecological interactions of D. armandi with its host pine.

  18. Molecular identification of foreign inclusions in inflammatory tissue surrounding metal implants by Fourier transform laser microprobe mass spectrometry.

    Science.gov (United States)

    De Nollin, S; Poels, K; Van Vaeck, L; De Clerck, N; Bakker, A; Duwel, V; Vandevelde, D; Van Marck, E

    1997-01-01

    Fourier transform laser microprobe mass spectrometry (FT LMMS) is a novel technique for micro-analysis of solids with a lateral resolution in the 5 microns range. One of the major advantages of the technique is the capability to perform characterisation of the molecular composition of both organic and inorganic compounds. The information is directly deduced from the signals without the aid of reference spectra. FT LMMS was applied to the characterisation of black tissue fragments in a biopsy from a patient, in which a constrained condylar nodular knee system was implanted ten years ago. The tissue contained numerous foreign giant cells with a black non-birefringent pigment in their cytoplasm. FT LMMS analysis allowed us to detect directly by means of molecular signals, that the debris consisted primarily of titanium oxide and not metallic titanium, while the implant itself only contained titanium.

  19. Phenotypic changes of p53, HER2, and FAS system in multiple normal tissues surrounding breast cancer.

    Science.gov (United States)

    Mottolese, Marcella; Nádasi, Edit A; Botti, Claudio; Cianciulli, Anna M; Merola, Roberta; Buglioni, Simonetta; Benevolo, Maria; Giannarelli, Diana; Marandino, Ferdinando; Donnorso, Raffaele Perrone; Venturo, Irene; Natali, Pier Giorgio

    2005-07-01

    To determine whether phenotypic field changes occur in tissues adjacent to carcinoma, we assayed, by immunohistochemistry, the expression of HER-2, p53, Fas, and FasL in 72 breast cancers (BC) and multiple autologous peritumoral tissues (PTTs) sampled up to 5 cm distance and in 44 benign breast tumors (BBTs). About 5% and 3% of the PTTs and 4.5% and 6.8% of BBTs showed alterations in HER2 and p53 expression, respectively. Of interest, gene amplification was observed in 50% of HER2 positive PTTs, but not in any HER2 positive BBTs. Fas, highly expressed in BBTs and downregulated in BC, maintained its expression in PTTs, whereas FasL, usually negative in BBTs, was upregulated in BC as well as in the PTTs closest (1 cm) to the invasive lesion. Our data suggest that FasL could be a potential novel biomarker of transformation, which may identify, along with HER2 and p53, precursor lesions in a genetically altered breast tissue.

  20. Anthelmintic efficacy against tissue-arrested larvae of Ancylostoma caninum in murine hosts.

    Science.gov (United States)

    Arasu, P

    1998-12-01

    Third-stage larvae of the major human and canine Ancylostoma hookworm species have the capacity to undergo developmental arrest in the somatic tissues of an infected host. Arrested larvae reactivate at opportune periods such as pregnancy, which results in the transmammary transmission of infection to the nursing neonates. Using murine paratenic hosts to focus specifically on tissue-arrested stages of Ancylostoma caninum, the present study found that neither recommended nor elevated doses of commonly used anthelmintics were effective in eliminating latent infections at the accepted standard of greater than 90% reduction in parasite burden. Of the drugs tested, i.e., pyrantel, fenbendazole, ivermectin, and milbemycin, ivermectin was the most effective and engendered an 80% reduction in the burden of tissue-arrested A. caninum larvae but only if administered repeatedly or at elevated doses. Studies in 2 inbred mouse strains, BALB/c (H-2b) and C57BL/6 (H-2d), that typically display divergent immune responses to various infections showed no significant differences in the efficacies of the drugs tested. The results of this study indicate that there is still a need for effective strategies of eradicating latent infections with tissue-arrested hookworm larvae.

  1. Use of a Rabbit Soft Tissue Chamber Model to Investigate Campylobacter jejuni - Host Interactions

    Directory of Open Access Journals (Sweden)

    Annika eFlint

    2010-11-01

    Full Text Available Despite the prevalence of C. jejuni as an important food borne pathogen, the microbial factors governing its infection process are poorly characterized. In this study, we developed a novel rabbit soft tissue chamber model to investigate C. jejuni interactions with its host. The in vivo transcriptome profile of C. jejuni was monitored as a function of time post-infection by competitive microarray hybridization with cDNA obtained from C. jejuni grown in vitro. Genome-wide expression analysis identified 449 genes expressed at significantly different levels in vivo. Genes implicated to play important roles in early colonization of C. jejuni within the tissue chamber include up-regulation of genes involved in ribosomal protein synthesis and modification, heat shock response, and primary adaptation to the host environment (DccSR regulon. Genes encoding proteins involved in the TCA cycle and flagella related components were found to be significantly down regulated during early colonization. Oxidative stress defense and stringent response genes were found to be maximally induced during the acute infectious phase. Overall, these findings reveal possible mechanisms involved in adaptation of Campylobacter to the host.

  2. Host origin and tissue microhabitat shaping the microbiota of the terrestrial isopod Armadillidium vulgare.

    Science.gov (United States)

    Dittmer, Jessica; Lesobre, Jérôme; Moumen, Bouziane; Bouchon, Didier

    2016-05-01

    We present the first in-depth investigation of the host-associated microbiota of the terrestrial isopod crustacean Armadillidium vulgare. This species is an important decomposer of organic matter in terrestrial ecosystems and a major model organism for arthropod-Wolbachia symbioses due to its well-characterized association with feminizing Wolbachia 16S rRNA gene pyrotags were used to characterize its bacterial microbiota at multiple levels: (i) in individuals from laboratory lineages and field populations and (ii) in various host tissues. This integrative approach allowed us to reveal an unexpectedly high bacterial diversity, placing this species in the same league as termites in terms of symbiotic diversity. Interestingly, both animal groups belong to the same ecological guild in terrestrial ecosystems. While Wolbachia represented the predominant taxon in infected individuals, it was not the only major player. Together, the most abundant taxa represented a large scope of symbiotic interactions, including bacterial pathogens, a reproductive parasite (Wolbachia) and potential nutritional symbionts. Furthermore, we demonstrate that individuals from different populations harboured distinct bacterial communities, indicating a strong link between the host-associated microbiota and environmental bacteria, possibly due to terrestrial isopod nutritional ecology. Overall, this work highlights the need for more studies of host-microbiota interactions and bacterial diversity in non-insect arthropods.

  3. Large-scale proteomics differentiates cholesteatoma from surrounding tissues and identifies novel proteins related to the pathogenesis.

    Directory of Open Access Journals (Sweden)

    Anders Britze

    Full Text Available Cholesteatoma is the growth of keratinizing squamous epithelium in the middle ear. It is associated with severe complications and has a poorly understood etiopathogenesis. Here, we present the results from extensive bioinformatics analyses of the first large-scale proteomic investigation of cholesteatoma. The purpose of this study was to take an unbiased approach to identifying alterations in protein expression and in biological processes, in order to explain the characteristic phenotype of this skin-derived tumor. Five different human tissue types (cholesteatoma, neck of cholesteatoma, tympanic membrane, external auditory canal skin, and middle ear mucosa were analyzed. More than 2,400 unique proteins were identified using nanoLC-MS/MS based proteomics (data deposited to the ProteomeXchange, and 295 proteins were found to be differentially regulated in cholesteatoma. Validation analyses were performed by SRM mass spectrometry. Proteins found to be up- or down-regulated in cholesteatoma were analyzed using Ingenuity Pathway Analysis and clustered into functional groups, for which activation state and associations to disease processes were predicted. Cholesteatoma contained high levels of pro-inflammatory S100 proteins, such as S100A7A and S100A7. Several proteases, such as ELANE, were up-regulated, whereas extracellular matrix proteins, such as COL18A1 and NID2, were under-represented. This may lead to alterations in integrity and differentiation of the tissue (as suggested by the up-regulation of KRT4 in the cholesteatoma. The presented data on the differential protein composition in cholesteatoma corroborate previous studies, highlight novel protein functionalities involved in the pathogenesis, and identify new areas for targeted research that hold therapeutic potential for the disease.

  4. Differences between perivascular adipose tissue surrounding the heart and the internal mammary artery: possible role for the leptin-inflammation-fibrosis-hypoxia axis.

    Science.gov (United States)

    Drosos, Ioannis; Chalikias, Georgios; Pavlaki, Maria; Kareli, Dimitra; Epitropou, Grigorios; Bougioukas, Georgios; Mikroulis, Dimitrios; Konstantinou, Fotios; Giatromanolaki, Alexandra; Ritis, Konstantinos; Münzel, Thomas; Tziakas, Dimitrios; Konstantinides, Stavros; Schäfer, Katrin

    2016-11-01

    The factors mediating the paracrine effects of perivascular adipose tissue (PVAT) in atherosclerosis are largely unknown. The adipokine leptin has been implicated in the increased cardiovascular risk in obesity and may locally promote neointima formation independently of circulating leptin levels. In patients with established coronary artery disease, we examined the expression of leptin as well as of its possible inducers in 'cardiac' PVAT surrounding the aortic root and coronary arteries (C-PVAT), and compared it to the PVAT surrounding the internal mammary artery (IMA-PVAT), a vessel resistant to atherosclerosis. Tissue specimens collected from male patients undergoing coronary artery bypass surgery were processed for real-time PCR, ELISA, in situ hybridization, and immunohistochemistry analysis. Leptin protein expression was elevated in C-PVAT compared to IMA-PVAT, independent of serum leptin levels. Compared to IMA-PVAT, C-PVAT exhibited more pronounced angiogenesis and inflammation, as indicated by significantly higher numbers of PECAM1-positive vessels and CD68-positive macrophages, and was characterized by a greater extent of fibrosis and hypoxia. Increased expression of hypoxia-inducible factor-1α and Fos-like antigen (FOSL)2, factors known to enhance leptin gene transcription, was observed in C-PVAT. As a proof of concept, exposure of human adipocytes to chemical hypoxia resulted in significantly increased FOSL2 and leptin mRNA levels. A higher degree of local tissue hypoxia and up-regulation of leptin expression in the perivascular adipose tissue, along with increased vascularization, inflammation, and fibrosis, may contribute to the increased atherosclerotic plaque burden in the coronary arteries compared to the IMA.

  5. Histophilus somni biofilm formation in cardiopulmonary tissue of the bovine host following respiratory challenge

    DEFF Research Database (Denmark)

    Sandal, Indra; Shao, Jian Q.; Annadata, Satish

    2009-01-01

    diseases in bovines, and readily forms biofilms in vitro. In the present study the capability of H. somni to form biofilms in cardiopulmonary tissue following experimental respiratory infection in the bovine host was examined by light microscopy, transmission electron microscopy, immunoelectron microscopy...... cultured with H. somni from heart and lung samples. Transposon mutagenesis of H. somni strain 2336 resulted in the generation of mutants that expressed more or less biofilm. than the parent strain. Six mutants deficient in biofilm formation had an insertion in the gene encoding for a homolog of filamentous...... haemagglutinin (FHA), predicted to be involved in attachment. Thus, this investigation demonstrated that H. somni is capable of forming a biofilm in its natural host, that such a biofilm may be capable of harboring other bovine respiratory disease pathogens, and that the genes responsible for biofilm formation...

  6. Innervation and functional characteristics of connective tissues, especially elastic fibers, in human fetal thoracic intervertebral articular capsule and its surroundings.

    Science.gov (United States)

    Shiraishi, Yosuke; Kobayashi, Miya; Yasui, Masaya; Ozaki, Noriyuki; Sugiura, Yasuo

    2003-05-01

    The articular capsules between the thoracic vertebrae, which have physiologically different functions from those of other levels of the vertebrae, have yet to be subjected to neuro-anatomical and fine structural analysis. In the present study, we analyzed serial frozen sections of decalcified thoracic vertebrae in human fetuses, and identified the articular capsule tissue with its unique distribution of elastic fibers. The fine structure of the elastic fibers was studied by transmission electron microscopy. In the early-stage fetus, the fibrous membrane forming the lateral intervertebral articular capsule contained abundant thin elastic fibers consisting of microfibrils. In the late-stage fetus, the lateral capsule of fibrous membrane was occupied by thick elastic fibers. A medial articular capsule, namely the ligamenta flava, contained numerous thick elastic fibers in both early and late-stage fetuses. The distributional differences in nerve fibers between early and late-stage fetuses were determined by immunostaining, using antibodies raised against protein gene product 9.5 (PGP 9.5; ubiquitin carboxyl-terminal hydrolase). Innervation by PGP 9.5 immunoreactive fibers was limited to the areas of the articular capsules near the blood vessels, which may indicate their functional relation with blood flow. No PGP 9.5 immunoreactive fibers were found in the ligamenta flava of the late-stage fetus. Innervation might be directly involved in the development of the intervertebral articular capsules in normal human fetuses.

  7. Is forced migration a barrier to treatment success? Similar HIV treatment outcomes among refugees and a surrounding host community in Kuala Lumpur, Malaysia.

    Science.gov (United States)

    Mendelsohn, Joshua B; Schilperoord, Marian; Spiegel, Paul; Balasundaram, Susheela; Radhakrishnan, Anuradha; Lee, Christopher K C; Larke, Natasha; Grant, Alison D; Sondorp, Egbert; Ross, David A

    2014-02-01

    In response to an absence of studies among refugees and host communities accessing highly active antiretroviral therapy (HAART) in urban settings, our objective was to compare adherence and virological outcomes among clients attending a public clinic in Kuala Lumpur, Malaysia. A cross-sectional survey was conducted among adult clients (≥18 years). Data sources included a structured questionnaire that measured self-reported adherence, a pharmacy-based measure of HAART prescription refills over the previous 24 months, and HIV viral loads. The primary outcome was unsuppressed viral load (≥40 copies/mL). Among a sample of 153 refugees and 148 host community clients, refugees were younger (median age 35 [interquartile range, IQR 31, 39] vs 40 years [IQR 35, 48], p refugee and host clients were refugees vs 16 % of host clients, p = 0.54). Refugee status was not independently associated with the outcome (adjusted odds ratio, aOR = 1.28, 95 % CI 0.52, 3.14). Overall, the proportions of refugee and host community clients with unsuppressed viral loads and sub-optimal adherence were similar, supporting the idea that refugees in protracted asylum situations are able to sustain good treatment outcomes and should explicitly be included in the HIV strategic plans of host countries with a view to expanding access in accordance with national guidelines for HAART.

  8. Fungal endophytes of aquatic macrophytes: diverse host-generalists characterized by tissue preferences and geographic structure.

    Science.gov (United States)

    Sandberg, Dustin C; Battista, Lorna J; Arnold, A Elizabeth

    2014-05-01

    Most studies of endophytic symbionts have focused on terrestrial plants, neglecting the ecologically and economically important plants present in aquatic ecosystems. We evaluated the diversity, composition, host and tissue affiliations, and geographic structure of fungal endophytes associated with common aquatic plants in lentic waters in northern Arizona, USA. Endophytes were isolated in culture from roots and photosynthetic tissues during two growing seasons. A total of 226 isolates representing 60 putative species was recovered from 9,600 plant tissue segments. Although isolation frequency was low, endophytes were phylogenetically diverse and species-rich. Comparisons among the most thoroughly sampled species and reservoirs revealed that isolation frequency and diversity did not differ significantly between collection periods, among species, among reservoirs, or as a function of depth. However, community structure differed significantly among reservoirs and tissue types. Phylogenetic analyses of a focal genus (Penicillium) corroborated estimates of species boundaries and informed community analyses, highlighting clade- and genotype-level affiliations of aquatic endophytes with both sediment- and waterborne fungi, and endophytes of proximate terrestrial plants. Together these analyses provide a first quantitative examination of endophytic associations in roots and foliage of aquatic plants and can be used to optimize survey strategies for efficiently capturing fungal biodiversity at local and regional scales.

  9. Bevacizumab Inhibits Breast Cancer-Induced Osteolysis, Surrounding Soft Tissue Metastasis, and Angiogenesis in Rats as Visualized by VCT and MRI

    Directory of Open Access Journals (Sweden)

    Tobias Bäuerle

    2008-05-01

    Full Text Available The aim of this study was to evaluate the effect of an antiangiogenic treatment with the vascular endothelial growth factor antibody bevacizumab in an experimental model of breast cancer bone metastasis and to monitor osteolysis, soft tissue tumor, and angiogenesis in bone metastasis noninvasively by volumetric computed tomography (VCT and magnetic resonance imaging (MRI. After inoculation of MDA-MB-231 human breast cancer cells into nude rats, bone metastasis was monitored with contrast-enhanced VCT and MRI from day 30 to day 70 after tumor cell inoculation, respectively. Thereby, animals of the treatment group (10 mg/kg bevacizumab IV weekly, n = 15 were compared with sham-treated animals (n = 17. Treatment with bevacizumab resulted in a significant difference versus control in osteolytic as well as soft tissue lesion sizes (days 50 to 70 and 40 to 70 after tumor cell inoculation, respectively; P < .05. This observation was paralleled with significantly reduced vascularization in the treatment group as shown by reduced increase in relative signal intensity in dynamic contrast-enhanced MRI from days 40 to 70 (P < .05. Contrast-enhanced VCT and histology confirmed decreased angiogenesis as well as new bone formation after application of bevacizumab. In conclusion, bevacizumab significantly inhibited osteolysis, surrounding soft tissue tumor growth, and angiogenesis in an experimental model of breast cancer bone metastasis as visualized by VCT and MRI.

  10. The enzyme profiles in the connective tissue attaching pin bones to the surrounding tissue is specific in farmed salmon (Salmo salar) and cod (Gadus morhua L.).

    Science.gov (United States)

    Vuong, Tram T; Rønning, Sissel B; Kolset, Svein O; Pedersen, Mona E

    2017-02-01

    Post mortem storage is a necessary process for removal of pin bones without destruction of fillets, thereby avoiding volume and economic loss. However, the enzymes involved in loosening pin bones during storage have not been studied to a great extent. In this study, the activities and localization of MMPs in the connective tissue (CT) of pin bones dissected from fillet of salmon and cod were investigated. Interestingly, the enzyme activity profile in these two species was different during post mortem storage of fish fillets. Adding MMP inhibitor (GM6001) and serine protease inhibitor (Pefabloc) revealed different effects in the two species, suggesting different regulations in salmon and cod. In situ zymography with the same inhibitors verified MMP and serine protease activity in CT close to pin bone at early post mortem (6 h) in salmon. However, MMP inhibition was not evident in cod in this area at that time point. Immunohistochemistry further revealed MMP9 and MMP13 were located more to the outer rim of CT, facing the pin bone and adipose tissue, while MMP7 was more randomly distributed within CT in salmon. In contrast, all these three MMPs were randomly distributed in CT in cod. In summary, our study reveals different MMP enzyme profiles in salmon and cod in the pin bone area, influenced by serine proteases, and suggests that MMPs and serine proteases must be taken in consideration when studying the conditions for early pin bone removal.

  11. Circulating Trypanosoma cruzi populations differ from those found in the tissues of the same host during acute experimental infection.

    Science.gov (United States)

    Lo Presti, M Silvina; Esteves, Blanca H; Moya, Diego; Bazán, P Carolina; Strauss, Mariana; Báez, Alejandra L; Pizzi, Rogelio; Quispe Ricalde, M Antonieta; Valladares, Basilio; Rivarola, H Walter; Paglini-Oliva, Patricia A

    2014-05-01

    We evaluated the presence and distribution of two Trypanosoma cruzi natural isolates in blood, heart, skeletal muscle, liver, and spleen tissues in the acute phase of the experimental infection (35 days postinfection) in order to determine if the populations present in blood were different to those found in the tissues of the same host. Thirty mice were infected with 50 forms of each isolate or with a combination of them. Presence and molecular characterization of the parasites in the host tissues were determined by specific PCR. Cardiac and skeletal muscle alterations were analyzed by histological studies. T. cruzi variability in the host tissues was analyzed through RFLP studies. Both isolates used consisted of a mixture of two T. cruzi lineages. Specific PCRs were positive for most of the samples from the 3 groups analyzed. Cardiac and skeletal muscle sections from the groups infected with one isolate presented mild to moderate inflammatory infiltrates; the group infected with both isolates showed severe inflammatory infiltrates and the presence of amastigote nests in both tissues. Different parasite populations were found in circulation and in the tissues from the same host. These results are important for patients with high probability of mixed infections in endemic areas and contribute to the knowledge of parasite/host interactions.

  12. Clinical implications of oral candidiasis: host tissue damage and disseminated bacterial disease.

    Science.gov (United States)

    Kong, Eric F; Kucharíková, Sona; Van Dijck, Patrick; Peters, Brian M; Shirtliff, Mark E; Jabra-Rizk, Mary Ann

    2015-02-01

    The clinical significance of polymicrobial interactions, particularly those between commensal species with high pathogenic potential, remains largely understudied. Although the dimorphic fungal species Candida albicans and the bacterium Staphylococcus aureus are common cocolonizers of humans, they are considered leading opportunistic pathogens. Oral candidiasis specifically, characterized by hyphal invasion of oral mucosal tissue, is the most common opportunistic infection in HIV(+) and immunocompromised individuals. In this study, building on our previous findings, a mouse model was developed to investigate whether the onset of oral candidiasis predisposes the host to secondary staphylococcal infection. The findings demonstrated that in mice with oral candidiasis, subsequent exposure to S. aureus resulted in systemic bacterial infection with high morbidity and mortality. Histopathology and scanning electron microscopy of tongue tissue from moribund animals revealed massive C. albicans hyphal invasion coupled with S. aureus deep tissue infiltration. The crucial role of hyphae in the process was demonstrated using a non-hypha-producing and a noninvasive hypha-producing mutant strains of C. albicans. Further, in contrast to previous findings, S. aureus dissemination was aided but not contingent upon the presence of the Als3p hypha-specific adhesion. Importantly, impeding development of mucosal C. albicans infection by administering antifungal fluconazole therapy protected the animals from systemic bacterial disease. The combined findings from this study demonstrate that oral candidiasis may constitute a risk factor for disseminated bacterial disease warranting awareness in terms of therapeutic management of immunocompromised individuals.

  13. Analysis of specific absorption rate and internal electric field in human biological tissues surrounding an air-core coil-type transcutaneous energy transmission transformer.

    Science.gov (United States)

    Shiba, Kenji; Zulkifli, Nur Elina Binti; Ishioka, Yuji

    2017-06-01

    In this study, we analyzed the internal electric field E and specific absorption rate (SAR) of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. Using an electromagnetic simulator, we created a model of human biological tissues consisting of a dry skin, wet skin, fat, muscle, and cortical bone. A primary coil was placed on the surface of the skin, and a secondary coil was located subcutaneously inside the body. The E and SAR values for the model representing a 34-year-old male subject were analyzed using electrical frequencies of 0.3-1.5 MHz. The transmitting power was 15 W, and the load resistance was 38.4 Ω. The results showed that the E values were below the International Commission on Non-ionizing Radiation Protection (ICNIRP) limit for the general public exposure between the frequencies of 0.9 and 1.5 MHz, and SAR values were well below the limit prescribed by the ICNIRP for the general public exposure between the frequencies of 0.3 and 1.2 MHz.

  14. Isolates of citrus exocortis viroid recovered by host and tissue selection.

    Science.gov (United States)

    Semancik, J S; Szychowski, J A; Rakowski, A G; Symons, R H

    1993-11-01

    Isolates of citrus exocortis viroid (CEV) from a single sweet orange citrus source have been selected by sequential passage through the alternative hosts citron, Gynura aurantiaca, a hybrid tomato Lycopersicon esculentum x L. peruvianum, and from disorganized callus culture of the hybrid tomato. The distinctions in symptom expression, titre and electrophoretic mobility among the CEV isolates, operationally termed CEVc (citron), CEVg (Gynura), CEVt (tomato) and CEVcls (callus) are supported by characteristically different nucleotide sequences. The nucleotide sequence of full-length cDNA clones of CEVc purified from citron shows exchanges not reported for any previously described CEV variant. An unusual number of exchanges have been localized in the terminal domains of all the isolates analysed here. A common pattern of nucleotide exchanges, described as a 'tomato signature', can be detected in all of the isolates derived from hybrid tomato tissues.

  15. Evaluation of models for estimating changes in fracture permeability due to thermo-mechanical stresses in host rock surrounding a potential repository

    Energy Technology Data Exchange (ETDEWEB)

    Berge, P A; Blair, S C; Shaffer, R J; Wang, H F

    1997-02-18

    We provide in this report a methodology to estimate bounds on the changes in fracture permeability due to thermal-mechanical processes associated with excavation of drifts and emplacement of waste. This report is the first milestone associated with Task A of the LLNL initiative to evaluate available methods for estimating chamges in fracture permeability surrounding drifts in the Exploratory Studies Facility (ESF) and the potential repository at Yucca Mountain in response to (1) construction-induced stress changes and (2) subsequent thermal pulse effects due to waste emplacement. These results are needed for modeling changes in repository-level moisture movement and seepage.

  16. Is Forced Migration a Barrier to Treatment Success? Similar HIV Treatment Outcomes Among Refugees and a Surrounding Host Community in Kuala Lumpur, Malaysia

    OpenAIRE

    Mendelsohn, JB; Schilperoord, M; Spiegel, P.; Balasundaram, S; Radhakrishnan, A; Lee, CK; Larke, N; Grant, AD; Sondorp, E; Ross, DA

    2013-01-01

    In response to an absence of studies among refugees and host communities accessing highly active antiretroviral therapy (HAART) in urban settings, our objective was to compare adherence and virological outcomes among clients attending a public clinic in Kuala Lumpur, Malaysia. A cross-sectional survey was conducted among adult clients (≥18 years). Data sources included a structured questionnaire that measured self-reported adherence, a pharmacy-based measure of HAART prescription refills over...

  17. Genome degradation in Brucella ovis corresponds with narrowing of its host range and tissue tropism.

    Directory of Open Access Journals (Sweden)

    Renee M Tsolis

    Full Text Available Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis.

  18. Effects of Coralliophila violacea on tissue loss in the scleractinian corals Porites spp. depend on host response

    Science.gov (United States)

    Raymundo, L.; Work, Thierry M.; Miller, R.L.; Lozada-Misa, P.L.

    2016-01-01

    We investigated interactions between the corallivorous gastropod Coralliophila violacea and its preferred hosts Porites spp. Our objectives were to experimentally determine whether tissue loss could progress in Porites during or after Coralliophila predation on corals with and without tissue loss and to histologically document snail predation. In 64% of feeding scars, tissue regenerated within 3 wk, leaving no trace of predation. However, in roughly 28% of scars, lesions progressed to subacute tissue loss resembling white syndrome. In feeding experiments, scars from snails previously fed diseased tissue developed progressive tissue loss twice as frequently as scars from snails previously fed healthy tissue. Scars from previously healthy-fed snails were 3 times as likely to heal as those from previously diseased-fed snails. Histology revealed marked differences in host responses to snails; P. cylindrica manifested a robust inflammatory response with fewer secondary colonizing organisms such as algae, sponges, and helminths, whereas P. rus showed no evident inflammation and more secondary colonization. We conclude that lesion progression associated with Coralliophila may be associated with secondary colonization of coral tissues damaged by predator-induced trauma and necrosis. Importantly, variation at the cellular level should be considered when explaining interspecific differences in host responses in corals impacted by phenomena such as predation.

  19. Endogenous tissue factor pathway inhibitor has a limited effect on host defence in murine pneumococcal pneumonia.

    Science.gov (United States)

    van den Boogaard, Florry E; van 't Veer, Cornelis; Roelofs, Joris J T H; Meijers, Joost C M; Schultz, Marcus J; Broze, George J; van der Poll, Tom

    2015-07-01

    Streptococcus (S.) pneumoniae is the most common causative pathogen in community-acquired pneumonia. Coagulation and inflammation interact in the host response to infection. Tissue factor pathway inhibitor (TFPI) is a natural anticoagulant protein that inhibits tissue factor (TF), the main activator of inflammation-induced coagulation. It was the objective of this study to investigate the effect of endogenous TFPI levels on coagulation, inflammation and bacterial growth during S. pneumoniae pneumonia in mice. The effect of low endogenous TFPI levels was studied by administration of a neutralising anti-TFPI antibody to wild-type mice, and by using genetically modified mice expressing low levels of TFPI, due to a genetic deletion of the first Kunitz domain of TFPI (TFPIK1(-/-)) rescued with a human TFPI transgene. Pneumonia was induced by intranasal inoculation with S. pneumoniae and samples were obtained at 6, 24 and 48 hours after infection. Anti-TFPI reduced TFPI activity by ~50 %. Homozygous lowTFPI mice and heterozygous controls had ~10 % and ~50 % of normal TFPI activity, respectively. TFPI levels did not influence bacterial growth or dissemination. Whereas lung pathology was unaffected in all groups, mice with ~10 % (but not with ~50 %) of TFPI levels displayed elevated lung cytokine and chemokine concentrations 24 hours after infection. None of the groups with low TFPI levels showed an altered procoagulant response in lungs or plasma during pneumonia. These data argue against an important role for endogenous TFPI in the antibacterial, inflammatory and procoagulant response during pneumococcal pneumonia.

  20. The Respiratory Pathogen Moraxella catarrhalis Targets Collagen for Maximal Adherence to Host Tissues

    Directory of Open Access Journals (Sweden)

    Birendra Singh

    2016-03-01

    Full Text Available Moraxella catarrhalis is a human respiratory pathogen that causes acute otitis media in children and is associated with exacerbations in patients suffering from chronic obstructive pulmonary disease (COPD. The first step in M. catarrhalis colonization is adherence to the mucosa, epithelial cells, and extracellular matrix (ECM. The objective of this study was to evaluate the role of M. catarrhalis interactions with collagens from various angles. Clinical isolates (n = 43 were tested for collagen binding, followed by a detailed analysis of protein-protein interactions using recombinantly expressed proteins. M. catarrhalis-dependent interactions with collagen produced by human lung fibroblasts and tracheal tissues were studied by utilizing confocal immunohistochemistry and high-resolution scanning electron microscopy. A mouse smoke-induced chronic obstructive pulmonary disease (COPD model was used to estimate the adherence of M. catarrhalis in vivo. We found that all M. catarrhalis clinical isolates tested adhered to fibrillar collagen types I, II, and III and network-forming collagens IV and VI. The trimeric autotransporter adhesins ubiquitous surface protein A2 (UspA2 and UspA2H were identified as major collagen-binding receptors. M. catarrhalis wild type adhered to human tracheal tissue and collagen-producing lung fibroblasts, whereas UspA2 and UspA2H deletion mutants did not. Moreover, in the COPD mouse model, bacteria devoid of UspA2 and UspA2H had a reduced level of adherence to the respiratory tract compared to the adherence of wild-type bacteria. Our data therefore suggest that the M. catarrhalis UspA2 and UspA2H-dependent interaction with collagens is highly critical for adherence in the host and, furthermore, may play an important role in the establishment of disease.

  1. The Respiratory Pathogen Moraxella catarrhalis Targets Collagen for Maximal Adherence to Host Tissues

    Science.gov (United States)

    Singh, Birendra; Alvarado-Kristensson, Maria; Johansson, Martin; Hallgren, Oskar; Westergren-Thorsson, Gunilla; Mörgelin, Matthias

    2016-01-01

    ABSTRACT Moraxella catarrhalis is a human respiratory pathogen that causes acute otitis media in children and is associated with exacerbations in patients suffering from chronic obstructive pulmonary disease (COPD). The first step in M. catarrhalis colonization is adherence to the mucosa, epithelial cells, and extracellular matrix (ECM). The objective of this study was to evaluate the role of M. catarrhalis interactions with collagens from various angles. Clinical isolates (n = 43) were tested for collagen binding, followed by a detailed analysis of protein-protein interactions using recombinantly expressed proteins. M. catarrhalis-dependent interactions with collagen produced by human lung fibroblasts and tracheal tissues were studied by utilizing confocal immunohistochemistry and high-resolution scanning electron microscopy. A mouse smoke-induced chronic obstructive pulmonary disease (COPD) model was used to estimate the adherence of M. catarrhalis in vivo. We found that all M. catarrhalis clinical isolates tested adhered to fibrillar collagen types I, II, and III and network-forming collagens IV and VI. The trimeric autotransporter adhesins ubiquitous surface protein A2 (UspA2) and UspA2H were identified as major collagen-binding receptors. M. catarrhalis wild type adhered to human tracheal tissue and collagen-producing lung fibroblasts, whereas UspA2 and UspA2H deletion mutants did not. Moreover, in the COPD mouse model, bacteria devoid of UspA2 and UspA2H had a reduced level of adherence to the respiratory tract compared to the adherence of wild-type bacteria. Our data therefore suggest that the M. catarrhalis UspA2 and UspA2H-dependent interaction with collagens is highly critical for adherence in the host and, furthermore, may play an important role in the establishment of disease. PMID:27006460

  2. Ecosystem engineering and manipulation of host plant tissues by the insect borer Oncideres albomarginata chamela.

    Science.gov (United States)

    Calderón-Cortés, Nancy; Uribe-Mú, Claudia A; Martínez-Méndez, A Karen; Escalera-Vázquez, Luis H; Cristobal-Pérez, E Jacob; García-Oliva, Felipe; Quesada, Mauricio

    2016-01-01

    Ecosystem engineering by insect herbivores occurs as the result of structural modification of plants manipulated by insects. However, only few studies have evaluated the effect of these modifications on the plant responses induced by stem-borers that act as ecosystem engineers. In this study, we evaluated the responses induced by the herbivory of the twig-girdler beetle Oncideres albomarginata chamela (Cerambycidae: Lamiinae) on its host plant Spondias purpurea (Anacardiaceae), and its relationship with the ecosystem engineering process carried out by this stem-borer. Our results demonstrated that O. albomarginata chamela branch removal induced the development of lateral branches increasing the resources needed for the development of future insect generations, of its own offspring and of many other insect species. Detached branches represent habitats with high content of nitrogen and phosphorous, which eventually can be incorporated into the ecosystem, increasing nutrient cycling efficiency. Consequently, branch removal and the subsequent plant tissue regeneration induced by O. albomarginata chamela represent key mechanisms underlying the ecosystem engineering process carried out by this stem-borer, which enhances arthropod diversity in the ecosystem.

  3. The contribution of tumor and host tissue factor expression to oncogene-driven gliomagenesis.

    Science.gov (United States)

    Magnus, Nathalie; Meehan, Brian; Garnier, Delphine; Hashemi, Maryam; Montermini, Laura; Lee, Tae Hoon; Milsom, Chloe; Pawlinski, Rafal; Ohlfest, John; Anderson, Mark; Mackman, Nigel; Rak, Janusz

    2014-11-14

    Glioblastoma multiforme (GBM) is an aggressive form of glial brain tumors, associated with angiogenesis, thrombosis, and upregulation of tissue factor (TF), the key cellular trigger of coagulation and signaling. Since TF is upregulated by oncogenic mutations occurring in different subsets of human brain tumors we investigated whether TF contributes to tumourigenesis driven by oncogenic activation of EGFR (EGFRvIII) and RAS pathways in the brain. Here we show that TF expression correlates with poor prognosis in glioma, but not in GBM. In situ, the TF protein expression is heterogeneously expressed in adult and pediatric gliomas. GBM cells harboring EGFRvIII (U373vIII) grow aggressively as xenografts in SCID mice and their progression is delayed by administration of monoclonal antibodies blocking coagulant (CNTO 859) and signaling (10H10) effects of TF in vivo. Mice in which TF gene is disrupted in the neuroectodermal lineage exhibit delayed progression of spontaneous brain tumors driven by oncogenic N-ras and SV40 large T antigen (SV40LT) expressed under the control of sleeping beauty transposase. Reduced host TF levels in low-TF/SCID hypomorphic mice mitigated growth of glioma subcutaneously but not in the brain. Thus, we suggest that tumor-associated TF may serve as therapeutic target in the context of oncogene-driven disease progression in a subset of glioma.

  4. Genomic Modifiers of Natural Killer Cells, Immune Responsiveness and Lymphoid Tissue Remodeling Together Increase Host Resistance to Viral Infection.

    Science.gov (United States)

    Gillespie, Alyssa Lundgren; Teoh, Jeffrey; Lee, Heather; Prince, Jessica; Stadnisky, Michael D; Anderson, Monique; Nash, William; Rival, Claudia; Wei, Hairong; Gamache, Awndre; Farber, Charles R; Tung, Kenneth; Brown, Michael G

    2016-02-01

    The MHC class I D(k) molecule supplies vital host resistance during murine cytomegalovirus (MCMV) infection. Natural killer (NK) cells expressing the Ly49G2 inhibitory receptor, which specifically binds D(k), are required to control viral spread. The extent of D(k)-dependent host resistance, however, differs significantly amongst related strains of mice, C57L and MA/My. As a result, we predicted that relatively small-effect modifier genetic loci might together shape immune cell features, NK cell reactivity, and the host immune response to MCMV. A robust D(k)-dependent genetic effect, however, has so far hindered attempts to identify additional host resistance factors. Thus, we applied genomic mapping strategies and multicolor flow cytometric analysis of immune cells in naive and virus-infected hosts to identify genetic modifiers of the host immune response to MCMV. We discovered and validated many quantitative trait loci (QTL); these were mapped to at least 19 positions on 16 chromosomes. Intriguingly, one newly discovered non-MHC locus (Cmv5) controlled splenic NK cell accrual, secondary lymphoid organ structure, and lymphoid follicle development during MCMV infection. We infer that Cmv5 aids host resistance to MCMV infection by expanding NK cells needed to preserve and protect essential tissue structural elements, to enhance lymphoid remodeling and to increase viral clearance in spleen.

  5. Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus)

    Science.gov (United States)

    McGrew, Ashley K.; O'Hara, Todd M.; Stricker, Craig A.; Castellini, Margaret; Beckmen, Kimberlee B.; Salman, Mo D.; Ballweber, Lora R.

    2015-01-01

    Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to beToxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from < 1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ13C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host.

  6. Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus).

    Science.gov (United States)

    McGrew, Ashley K; O'Hara, Todd M; Stricker, Craig A; Castellini, J Margaret; Beckmen, Kimberlee B; Salman, Mo D; Ballweber, Lora R

    2015-12-01

    Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to be Toxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from <1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ13C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Tissue dual RNA-seq allows fast discovery of infection-specific functions and riboregulators shaping host-pathogen transcriptomes.

    Science.gov (United States)

    Nuss, Aaron M; Beckstette, Michael; Pimenova, Maria; Schmühl, Carina; Opitz, Wiebke; Pisano, Fabio; Heroven, Ann Kathrin; Dersch, Petra

    2017-01-31

    Pathogenic bacteria need to rapidly adjust their virulence and fitness program to prevent eradication by the host. So far, underlying adaptation processes that drive pathogenesis have mostly been studied in vitro, neglecting the true complexity of host-induced stimuli acting on the invading pathogen. In this study, we developed an unbiased experimental approach that allows simultaneous monitoring of genome-wide infection-linked transcriptional alterations of the host and colonizing extracellular pathogens. Using this tool for Yersinia pseudotuberculosis-infected lymphatic tissues, we revealed numerous alterations of host transcripts associated with inflammatory and acute-phase responses, coagulative activities, and transition metal ion sequestration, highlighting that the immune response is dominated by infiltrating neutrophils and elicits a mixed TH17/TH1 response. In consequence, the pathogen's response is mainly directed to prevent phagocytic attacks. Yersinia up-regulates the gene and expression dose of the antiphagocytic type III secretion system (T3SS) and induces functions counteracting neutrophil-induced ion deprivation, radical stress, and nutritional restraints. Several conserved bacterial riboregulators were identified that impacted this response. The strongest influence on virulence was found for the loss of the carbon storage regulator (Csr) system, which is shown to be essential for the up-regulation of the T3SS on host cell contact. In summary, our established approach provides a powerful tool for the discovery of infection-specific stimuli, induced host and pathogen responses, and underlying regulatory processes.

  8. The dosimetric impact of daily setup error on target volumes and surrounding normal tissue in the treatment of prostate cancer with intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Algan, Ozer, E-mail: oalgan@ouhsc.edu [Department of Radiation Oncology, Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Jamgade, Ambarish; Ali, Imad; Christie, Alana; Thompson, J. Spencer; Thompson, David; Ahmad, Salahuddin; Herman, Terence [Department of Radiation Oncology, Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2012-01-01

    parameter for the surrounding normal tissue except for the dose received by the penile bulb and the right hip. Our dosimetric evaluation suggests significant underdosing with inaccurate target localization and emphasizes the importance of accurate patient setup and target localization. Further studies are needed to evaluate the impact of intrafraction organ motion, rotation, and deformation on doses delivered to target volumes.

  9. 阴茎及其毗邻组织三维虚拟模型的建立%3-Dimensional model reconstruction of penis and surrounding tissue

    Institute of Scientific and Technical Information of China (English)

    王睿恒; 曹川; 梅文铭; 王文献; 谭立文; 李世荣

    2012-01-01

    目的 探讨基于磁共振图像建立阴茎及其毗邻结构三维虚拟模型的可行性,为个性化阴茎整复手术仿真系统的开发提供建模方法.方法 采用适宜的参数获得磁共振图像,在Amira软件中运用面绘制方法对正常成人阴茎及其毗邻组织进行三维重建和立体显示.结果 3.0 mm层厚的快速自旋回波T2加权磁共振图像,可清晰显示阴茎及周围解剖结构且轮廓分明,以此建立的模型可清晰显示阴茎海绵体、阴茎悬韧带等结构的形态和相互位置关系,可见阴茎悬韧带呈纵行附着于耻骨联合与阴茎海绵体背侧之间,阴茎海绵体脚附着于耻骨下支.结论 基于磁共振图像建立阴茎及其毗邻组织三维模型是一种可行的方法,建立的模型可用于开发个性化阴茎整复手术仿真系统.%Objective To evaluate the feasibility of 3-Dimensional(3-D) model reconstruction of penis and surrounding structures based on magnetic resonance images,which may provide the model building method for modeling surgery of individual penoplasty.Methods Magnetic resonance (MR)images of penis with different imaging parameters were evaluated.With the surface rendering construction,the 3D virtual model was established by Amira software.Results The anatomical details imaging is better in T2-weighted fast spin-echo images with 3.0 mm slice thickness.The established model based on the MR images can show the soft-tissue,suspensory ligament of the penis.The suspensory ligament stretches between the pubic symphysis and the corpora cavernosa.The penile roots attach to inferior ramus of pubis.Conclusions MR imaging provides enough anatomical information for modeling.It can be used for the development of model surgery system of individual penoplasty.

  10. The dosimetric impact of daily setup error on target volumes and surrounding normal tissue in the treatment of prostate cancer with intensity-modulated radiation therapy.

    Science.gov (United States)

    Algan, Ozer; Jamgade, Ambarish; Ali, Imad; Christie, Alana; Thompson, J Spencer; Thompson, David; Ahmad, Salahuddin; Herman, Terence

    2012-01-01

    The purpose of this study was to evaluate the impact of daily setup error and interfraction organ motion on the overall dosimetric radiation treatment plans. Twelve patients undergoing definitive intensity-modulated radiation therapy (IMRT) treatments for prostate cancer were evaluated in this institutional review board-approved study. Each patient had fiducial markers placed into the prostate gland before treatment planning computed tomography scan. IMRT plans were generated using the Eclipse treatment planning system. Each patient was treated to a dose of 8100 cGy given in 45 fractions. In this study, we retrospectively created a plan for each treatment day that had a shift available. To calculate the dose, the patient would have received under this plan, we mathematically "negated" the shift by moving the isocenter in the exact opposite direction of the shift. The individualized daily plans were combined to generate an overall plan sum. The dose distributions from these plans were compared with the treatment plans that were used to treat the patients. Three-hundred ninety daily shifts were negated and their corresponding plans evaluated. The mean isocenter shift based on the location of the fiducial markers was 3.3 ± 6.5 mm to the right, 1.6 ± 5.1 mm posteriorly, and 1.0 ± 5.0 mm along the caudal direction. The mean D95 doses for the prostate gland when setup error was corrected and uncorrected were 8228 and 7844 cGy (p 1200 cGy and for the PTV8100 could approach almost 2000 cGy when comparing corrected against uncorrected plans. There was no statistically significant difference in the D35 parameter for the surrounding normal tissue except for the dose received by the penile bulb and the right hip. Our dosimetric evaluation suggests significant underdosing with inaccurate target localization and emphasizes the importance of accurate patient setup and target localization. Further studies are needed to evaluate the impact of intrafraction organ motion, rotation

  11. Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus)

    Energy Technology Data Exchange (ETDEWEB)

    McGrew, Ashley K. [Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619 (United States); O' Hara, Todd M. [Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619 (United States); Wildlife Toxicology Laboratory, Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Stricker, Craig A. [U. S. Geological Survey, Fort Collins Science Center, Denver, CO 80225 (United States); Margaret Castellini, J. [Wildlife Toxicology Laboratory, Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Beckmen, Kimberlee B. [Alaska Department of Fish & Game, Fairbanks, AK (United States); Salman, Mo D. [Animal Population Health Institute, Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523-1644 (United States); Ballweber, Lora R. [Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619 (United States)

    2015-12-01

    Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to be Toxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from < 1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ{sup 13}C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host. - Highlights: • [THg] and stable isotopes together provide insight on host-parasite-Hg interactions. • A

  12. Detection of spirorchiid trematodes in gastropod tissues by polymerase chain reaction: preliminary identification of an intermediate host of Learedius learedi.

    Science.gov (United States)

    Stacy, Brian A; Frankovich, Thomas; Greiner, Ellis; Alleman, A Rick; Herbst, Lawrence H; Klein, Paul; Bolten, Alan; McIntosh, Antoinette; Jacobson, Elliott R

    2010-08-01

    Marine spirorchiid trematodes are associated with morbidity and mortality in sea turtles worldwide. The intermediate hosts remain unknown, and discovery efforts are hindered by the large number and great diversity of potential hosts within sea turtle habitats, as well the potential for low prevalence and overdispersion. A high-throughput DNA extraction and polymerase chain reaction-based method was developed to detect the internal transcribed spacer 2 (ITS2) region of the ribosomal gene of 2 spirorchiid genera, Learedius and Hapalotrema , within pooled samples of gastropod tissues. A model system consisting of freshwater snail ( Pomacea bridgesii ) tissues and DNA extracts spiked with adult Learedius learedi and known quantities of spirorchiid DNA was used to develop and test the technique. Threshold of detection was found to be equivalent to an early prepatent infection within 1.5 g of gastropod tissue. This technique was used to screen approximately 25 species of marine gastropods at a captive facility where green turtles ( Chelonia mydas ) become infected by L. learedi . The parasite was detected in a sample of knobby keyhole limpet ( Fissurella nodosa ), thus providing the first evidence of an intermediate host for a marine spirorchiid trematode. This technique has many potential applications in trematode life cycle discovery studies.

  13. Evaluation of adhesion formation and host tissue response to intra-abdominal polytetrafluoroethylene mesh and composite prosthetic mesh.

    Science.gov (United States)

    Matthews, Brent D; Mostafa, Gamal; Carbonell, Alfredo M; Joels, Charles S; Kercher, Kent W; Austin, Catherine; Norton, H James; Heniford, B Todd

    2005-02-01

    The purpose of this study was to measure the extent of adhesion formation to ePTFE mesh (DualMesh, W.L. Gore & Associates, Inc, Flagstaff, AZ) and two composite prosthetic materials, ePTFE and polypropylene (Bard Composix, C.R. Bard, Inc, Murray Hill, NJ) and hyaluronic acid/carboxymethylcellulose and polypropylene (Sepramesh, Genzyme Corp, Cambridge, MA) after their intra-abdominal placement on an intact peritoneum, simulating laparoscopic ventral hernia repair, and to evaluate host tissue response to the prosthetic biomaterials. Through a midline laparotomy, a 2 x 2 cm piece of mesh (n = 60) was sewn to an intact peritoneum on each side of a midline incision in 30 New Zealand white rabbits. Mesh adhesions were scored using a modified Diamond scale (0 = 0%, 1 = 1-25%, 2 = 26-50%, 3 >50%) at 1, 3, 9, and 16 weeks by serial microlaparoscopy (2 mm). All laparoscopic evaluations were videotaped for blinded scoring by three surgeons. Host tissue response was graded (1-4) for inflammation, tissue ingrowth, and mesothelialization. The predominant cell type (polymorphonuclear leukocytes versus foreign body giant cell) was recorded. Statistical differences (P value DualMesh) intra-abdominal against an intact peritoneum results in significantly fewer adhesions than the composite prosthetic meshes during a 4-month follow-up. The host tissue response is equivalent for the three prosthetic biomaterials. The long-term consequences of increased adhesion formation to the composite meshes and the ultimate biocompatibility of the nonabsorbable and absorbable barriers on the polypropylene mesh are to be determined.

  14. Abiotic Versus Biotic Pathogens: Replicative Growth in Host Tissues Key to Discriminating Between Biotoxic Injury and Active Pathogenesis

    Science.gov (United States)

    Schuerger, Andrew C.; Ming, Douglas W.; Golden, D. C.

    2012-01-01

    Life can be defined as a self-sustaining chemical system capable of undergoing Darwinian evolution; a self-bounded, self-replicating, and self-perpetuating entity [1]. This definition should hold for terrestrial as well as extraterrestrial life-forms. Although, it is reasonable to expect that a Mars life-form would be more adaptable to Mars-like conditions than to Earth-like environments, it remains possible that negative ecological or host interactions might occur if Mars microbiota were to be inadvertently released into the terrestrial environment. A biogenic infectious agent can be defined as a self-sustaining chemical system capable of undergoing Darwinian evolution and derives its sustenance from a living cell or from the by-products of cell death. Disease can be de-fined as the detrimental alteration of one or more ordered metabolic processes in a living host caused by the continued irritation of a primary causal factor or factors; disease is a dynamic process [2]. In contrast, an injury is due to an instantaneous event; injury is not a dynamic process [2]. A causal agent of disease is defined as a pathogen, and can be either abiotic or biotic in nature. Diseases incited by biotic pathogens are the exceptions, not the norms, in terrestrial host-microbe interactions. Disease induction in a plant host can be conceptually characterized using the Disease Triangle (Fig. 1) in which disease occurs only when all host, pathogen, and environ-mental factors that contribute to the development of disease are within conducive ranges for a necessary minimum period of time. For example, plant infection and disease caused by the wheat leaf rust fungus, Puccinia recondita, occur only if virulent spores adhere to genetically susceptible host tissues for at least 4-6 hours under favorable conditions of temperature and moisture [3]. As long as one or more conditions required for disease initiation are not available, disease symptoms will not develop.

  15. In Planta Processing and Glycosylation of a Nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-Like Effector and Its Interaction with a Host CLAVATA2-Like Receptor to Promote Parasitism1[OPEN

    Science.gov (United States)

    Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S.; Mitchum, Melissa G.

    2015-01-01

    Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. PMID:25416475

  16. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    NARCIS (Netherlands)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars O.; Nielsen, Charlotte S.; Stahl, Wilhelm; Rühl, Ralph; Keijer, Jaap; Borel, Patrick

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e

  17. Blood flow responses to mild-intensity exercise in ectopic vs. orthotopic prostate tumors; dependence upon host tissue hemodynamics and vascular reactivity.

    Science.gov (United States)

    Garcia, Emmanuel; Becker, Veronika G C; McCullough, Danielle J; Stabley, John N; Gittemeier, Elizabeth M; Opoku-Acheampong, Alexander B; Sieman, Dietmar W; Behnke, Bradley J

    2016-07-01

    Given the critical role of tumor O2 delivery in patient prognosis and the rise in preclinical exercise oncology studies, we investigated tumor and host tissue blood flow at rest and during exercise as well as vascular reactivity using a rat prostate cancer model grown in two transplantation sites. In male COP/CrCrl rats, blood flow (via radiolabeled microspheres) to prostate tumors [R3327-MatLyLu cells injected in the left flank (ectopic) or ventral prostate (orthotopic)] and host tissue was measured at rest and during a bout of mild-intensity exercise. α-Adrenergic vasoconstriction to norepinephrine (NE: 10(-9) to 10(-4) M) was determined in arterioles perforating the tumors and host tissue. To determine host tissue exercise hyperemia in healthy tissue, a sham-operated group was included. Blood flow was lower at rest and during exercise in ectopic tumors and host tissue (subcutaneous adipose) vs. the orthotopic tumor and host tissue (prostate). During exercise, blood flow to the ectopic tumor significantly decreased by 25 ± 5% (SE), whereas flow to the orthotopic tumor increased by 181 ± 30%. Maximal vasoconstriction to NE was not different between arterioles from either tumor location. However, there was a significantly higher peak vasoconstriction to NE in subcutaneous adipose arterioles (92 ± 7%) vs. prostate arterioles (55 ± 7%). Establishment of the tumor did not alter host tissue blood flow from either location at rest or during exercise. These data demonstrate that blood flow in tumors is dependent on host tissue hemodynamics and that the location of the tumor may critically affect how exercise impacts the tumor microenvironment and treatment outcomes.

  18. Depletion of host CCR7(+) dendritic cells prevented donor T cell tissue tropism in anti-CD3-conditioned recipients.

    Science.gov (United States)

    He, Wei; Racine, Jeremy J; Johnston, Heather F; Li, Xiaofan; Li, Nainong; Cassady, Kaniel; Liu, Can; Deng, Ruishu; Martin, Paul; Forman, Stephen; Zeng, Defu

    2014-07-01

    We reported previously that anti-CD3 mAb treatment before hematopoietic cell transplantation (HCT) prevented graft-versus-host disease (GVHD) and preserved graft-versus-leukemia (GVL) effects in mice. These effects were associated with downregulated donor T cell expression of tissue-specific homing and chemokine receptors, marked reduction of donor T cell migration into GVHD target tissues, and deletion of CD103(+) dendritic cells (DCs) in mesenteric lymph nodes (MLN). MLN CD103(+) DCs and peripheral lymph node (PLN) DCs include CCR7(+) and CCR7(-) subsets, but the role of these DC subsets in regulating donor T cell expression of homing and chemokine receptors remain unclear. Here, we show that recipient CCR7(+), but not CCR7(-), DCs in MLN induced donor T cell expression of gut-specific homing and chemokine receptors in a retinoid acid-dependent manner. CCR7 regulated activated DC migration from tissue to draining lymph node, but it was not required for the ability of DCs to induce donor T cell expression of tissue-specific homing and chemokine receptors. Finally, anti-CD3 treatment depleted CCR7(+) but not CCR7(-) DCs by inducing sequential expansion and apoptosis of CCR7(+) DCs in MLN and PLN. Apoptosis of CCR7(+) DCs was associated with DC upregulation of Fas expression and natural killer cell but not T, B, or dendritic cell upregulation of FasL expression in the lymph nodes. These results suggest that depletion of CCR7(+) host-type DCs, with subsequent inhibition of donor T cell migration into GVHD target tissues, can be an effective approach in prevention of acute GVHD and preservation of GVL effects.

  19. Relaxivity of blood pool contrast agent depends on the host tissue as suggested by semianalytical simulations

    DEFF Research Database (Denmark)

    Jensen, Birgitte Fuglsang; Østergaard, Leif; Kiselev, Valerij G

    Concentration of MRI contrast agents (CA) is commonly determined indirectly using their relaxation effect. In quantitative perfusion studies, the change in the relaxation following a bolus passage is converted into concentrations assuming identical relaxivities for tissue and blood. Simulations...... can be applied to quantitation of perfusion, functional MRI and vessel size imaging...

  20. Comparative genomic and phenomic analysis of Clostridium difficile and Clostridium sordellii, two related pathogens with differing host tissue preference.

    Science.gov (United States)

    Scaria, Joy; Suzuki, Haruo; Ptak, Christopher P; Chen, Jenn-Wei; Zhu, Yongzhang; Guo, Xiao-Kui; Chang, Yung-Fu

    2015-06-10

    Clostridium difficile and C. sordellii are two anaerobic, spore forming, gram positive pathogens with a broad host range and the ability to cause lethal infections. Despite strong similarities between the two Clostridial strains, differences in their host tissue preference place C. difficile infections in the gastrointestinal tract and C. sordellii infections in soft tissues. In this study, to improve our understanding of C. sordellii and C. difficile virulence and pathogenesis, we have performed a comparative genomic and phenomic analysis of the two. The global phenomes of C. difficile and C. sordellii were compared using Biolog Phenotype microarrays. When compared to C. difficile, C. sordellii was found to better utilize more complex sources of carbon and nitrogen, including peptides. Phenotype microarray comparison also revealed that C. sordellii was better able to grow in acidic pH conditions. Using next generation sequencing technology, we determined the draft genome of C. sordellii strain 8483 and performed comparative genome analysis with C. difficile and other Clostridial genomes. Comparative genome analysis revealed the presence of several enzymes, including the urease gene cluster, specific to the C. sordellii genome that confer the ability of expanded peptide utilization and survival in acidic pH. The identified phenotypes of C. sordellii might be important in causing wound and vaginal infections respectively. Proteins involved in the metabolic differences between C. sordellii and C. difficile should be targets for further studies aimed at understanding C. difficile and C. sordellii infection site specificity and pathogenesis.

  1. The parasitic nematodes Hysterothylacium sp. type MB larvae as bioindicators of lead and cadmium: a comparative study of parasite and host tissues.

    Science.gov (United States)

    Khaleghzadeh-Ahangar, H; Malek, M; McKenzie, K

    2011-09-01

    Cadmium and lead concentrations were compared in tissues of cutlassfish, Trichiurus lepturus L., its intestinal nematode Hysterothylacium sp. type MB larvae, and in water from the same location in the Sea of Oman. Metal accumulation in hosts, parasites and sea water was measured by ICP-OES. Hysterothylacium larvae from the intestinal lumen and visceral cavity showed much higher metal concentrations than in host tissues or sea water. Statistical analyses revealed no significant differences in metal accumulation between infected and uninfected hosts. Cadmium concentration in the host muscle was lower than in intestine, liver and gonad tissues. The mean concentrations of lead and cadmium in nematodes were 289·03 and 81·5 times higher than in host intestine, 188·4 and 225 times higher than in host muscle, 108·6 and 65·3 times higher than in host gonads, 70·5 and 19·5 times higher than in host liver and 3351 and 148 times higher than in sea water. The results show the value of this and possibly related nematodes as bioindicators of heavy metals and their potential use in environmental studies.

  2. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    DEFF Research Database (Denmark)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars Ove

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e.......g. smoking), gender and age, as well as genetic variations including single nucleotide polymorphisms that govern carotenoid metabolism. These are expected to explain interindividual differences that contribute to carotenoid uptake, distribution, metabolism and excretion, and therefore possibly also...... their association with disease risk. For instance, digestion enzymes fostering micellization (PNLIP, CES), expression of uptake/efflux transporters (SRARB1, CD36, NPC1L1), cleavage enzymes (BCO1/2), intracellular transporters (FABP2), secretion into chylomicrons (APOB, MTTP), carotenoid metabolism in the blood...

  3. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    DEFF Research Database (Denmark)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars Ove

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e.......g. smoking), gender and age, as well as genetic variations including single nucleotide polymorphisms that govern carotenoid metabolism. These are expected to explain interindividual differences that contribute to carotenoid uptake, distribution, metabolism and excretion, and therefore possibly also...... their association with disease risk. For instance, digestion enzymes fostering micellization (PNLIP, CES), expression of uptake/efflux transporters (SRARB1, CD36, NPC1L1), cleavage enzymes (BCO1/2), intracellular transporters (FABP2), secretion into chylomicrons (APOB, MTTP), carotenoid metabolism in the blood...

  4. Dosimetric Evaluation of Three Partial Breast Irradiation Devices and the Dosimetric Effect of Tissue Thickness Surrounding a Multi-Lumen Partial Breast Applicator

    Science.gov (United States)

    Detwiler, Jordyn Ashle

    Many High Dose Rate treatment planning systems that are in use fail to correct for heterogeneities. If the treatment planning system does not correct for heterogeneities, it would assume that the patient is receiving full scatter when in reality, the patient will possibly be underdosed. A 1cm diameter planning target volume for a lumpectomy cavity could extend beyond the skin or chest wall for the patient and could be a great problem when it comes to treatment with the MammoSiteRTM single lumen breast applicator. A previous Monte Carlo study tested 3 MammoSiteRTM balloon sizes at various depths beyond the planning target volume to see how much tissue would be needed to achieve full scatter. The results showed that on average, if there was no tissue beyond the prescription line of 1cm there would be a 10% dose reduction for the breast -- skin interface. The purpose of this study is to use the Strut Adjusted Volume Implant (SAVI) multi-lumen breast applicator to re-create the measurements done with the MammoSiteRTM balloon and expand these measurements to include tissue thicknesses less than the PTV. Previous simulations with the MammoSiteRTM were done using Monte Carlo, with tissue thicknesses beyond the planning target volume of 0 -- 10cm. This study will re-create these measurements using Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) and also take measurements below the prescription line of 1cm due to the ability of the SAVI applicator to adjust dose to the skin.

  5. Can Breast Tumors Affect the Oxidative Status of the Surrounding Environment? A Comparative Analysis among Cancerous Breast, Mammary Adjacent Tissue, and Plasma.

    Science.gov (United States)

    Panis, C; Victorino, V J; Herrera, A C S A; Cecchini, A L; Simão, A N C; Tomita, L Y; Cecchini, R

    2015-01-01

    In this paper, we investigated the oxidative profile of breast tumors in comparison with their normal adjacent breast tissue. Our study indicates that breast tumors present enhanced oxidative/nitrosative stress, with concomitant augmented antioxidant capacity when compared to the adjacent normal breast. These data indicate that breast cancers may be responsible for the induction of a prooxidant environment in the mammary gland, in association with enhanced TNF-α and nitric oxide.

  6. Host Tissue Interaction, Fate, and Risks of Degradable and Nondegradable Gel Fillers

    DEFF Research Database (Denmark)

    Christensen, Lise

    2009-01-01

    -bindings to the polymer in order to obtain a more dense molecular structure, which will prolong degradation and filling effect of the gel. Other gel fillers contain particles of organic (poly-lactic acid) or inorganic (calcium hydroxylapatite) material, which have been used in human tissue for other purposes (degradable...... instead steroids or large doses of NSAIDs) the bacteria form a biofilm, which gives rise to a low-grade chronic infection that is resistant to antibiotics. Complications following particulated gels and silicone oil are not known, but bacteria in a biofilm and/or endotoxins released...

  7. Tissue-specific and SRSF1-dependent splicing of fibronectin, a matrix protein that controls host cell invasion

    Science.gov (United States)

    Lopez-Mejia, Isabel Cristina; De Toledo, Marion; Della Seta, Flavio; Fafet, Patrick; Rebouissou, Cosette; Deleuze, Virginie; Blanchard, Jean Marie; Jorgensen, Christian; Tazi, Jamal; Vignais, Marie-Luce

    2013-01-01

    Cell invasion targets specific tissues in physiological placental implantation and pathological metastasis, which raises questions about how this process is controlled. We compare dermis and endometrium capacities to support trophoblast invasion, using matching sets of human primary fibroblasts in a coculture assay with human placental explants. Substituting endometrium, the natural trophoblast target, with dermis dramatically reduces trophoblast interstitial invasion. Our data reveal that endometrium expresses a higher rate of the fibronectin (FN) extra type III domain A+ (EDA+) splicing isoform, which displays stronger matrix incorporation capacity. We demonstrate that the high FN content of the endometrium matrix, and not specifically the EDA domain, supports trophoblast invasion by showing that forced incorporation of plasma FN (EDA–) promotes efficient trophoblast invasion. We further show that the serine/arginine-rich protein serine/arginine-rich splicing factor 1 (SRSF1) is more highly expressed in endometrium and, using RNA interference, that it is involved in the higher EDA exon inclusion rate in endometrium. Our data therefore show a mechanism by which tissues can be distinguished, for their capacity to support invasion, by their different rates of EDA inclusion, linked to their SRSF1 protein levels. In the broader context of cancer pathology, the results suggest that SRSF1 might play a central role not only in the tumor cells, but also in the surrounding stroma. PMID:23966470

  8. Involvement of host stroma cells and tissue fibrosis in pancreatic tumor development in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Itai Spector

    Full Text Available INTRODUCTION: Stroma cells and extracellular matrix (ECM components provide the pivotal microenvironment for tumor development. The study aimed to evaluate the importance of the pancreatic stroma for tumor development. METHODS: Pancreatic tumor cells were implanted subcutaneously into green fluorescent protein transgenic mice, and stroma cells invading the tumors were identified through immunohistochemistry. Inhibition of tumor invasion by stroma cells was achieved with halofuginone, an inhibitor of TGFβ/Smad3 signaling, alone or in combination with chemotherapy. The origin of tumor ECM was evaluated with species-specific collagen I antibodies and in situ hybridization of collagen α1(I gene. Pancreatic fibrosis was induced by cerulean injection and tumors by spleen injection of pancreatic tumor cells. RESULTS: Inhibition of stroma cell infiltration and reduction of tumor ECM levels by halofuginone inhibited development of tumors derived from mouse and human pancreatic cancer cells. Halofuginone reduced the number only of stroma myofibroblasts expressing both contractile and collagen biosynthesis markers. Both stroma myofibroblasts and tumor cells generated ECM that contributes to tumor growth. Combination of treatments that inhibit stroma cell infiltration, cause apoptosis of myofibroblasts and inhibit Smad3 phosphorylation, with chemotherapy that increases tumor-cell apoptosis without affecting Smad3 phosphorylation was more efficacious than either treatment alone. More tumors developed in fibrotic than in normal pancreas, and prevention of tissue fibrosis greatly reduced tumor development. CONCLUSIONS: The utmost importance of tissue fibrosis and of stroma cells for tumor development presents potential new therapy targets, suggesting combination therapy against stroma and neoplastic cells as a treatment of choice.

  9. Manipulation of host plant cells and tissues by gall-inducing insects and adaptive strategies used by different feeding guilds.

    Science.gov (United States)

    Oliveira, D C; Isaias, R M S; Fernandes, G W; Ferreira, B G; Carneiro, R G S; Fuzaro, L

    2016-01-01

    Biologists who study insect-induced plant galls are faced with the overwhelming diversity of plant forms and insect species. A challenge is to find common themes amidst this diversity. We discuss common themes that have emerged from our cytological and histochemical studies of diverse neotropical insect-induced galls. Gall initiation begins with recognition of reactive plant tissues by gall inducers, with subsequent feeding and/or oviposition triggering a cascade of events. Besides, to induce the gall structure insects have to synchronize their life cycle with plant host phenology. We predict that reactive oxygen species (ROS) play a role in gall induction, development and histochemical gradient formation. Controlled levels of ROS mediate the accumulation of (poly)phenols, and phytohormones (such as auxin) at gall sites, which contributes to the new cell developmental pathways and biochemical alterations that lead to gall formation. The classical idea of an insect-induced gall is a chamber lined with a nutritive tissue that is occupied by an insect that directly harvests nutrients from nutritive cells via its mouthparts, which function mechanically and/or as a delivery system for salivary secretions. By studying diverse gall-inducing insects we have discovered that insects with needle-like sucking mouthparts may also induce a nutritive tissue, whose nutrients are indirectly harvested as the gall-inducing insects feeds on adjacent vascular tissues. Activity of carbohydrate-related enzymes across diverse galls corroborates this hypothesis. Our research points to the importance of cytological and histochemical studies for elucidating mechanisms of induced susceptibility and induced resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Marking 100 years since Rudolf Höber’s discovery of the insulating envelope surrounding cells and of the beta-dispersion exhibited by tissue

    Directory of Open Access Journals (Sweden)

    Ronald Pethig

    2012-11-01

    Full Text Available Between 1910 and 1913 Rudolf Höber presented proof that the interiors of red blood cells and muscle cells contain conducting electrolytes, and that each conducting core is contained within an insulating membrane.  He did this by demonstrating, in a series of remarkable electrical experiments, that the conductivity of compacted cell samples at low frequencies (~150 Hz was about ten-times less than the value obtained at ~5 MHz.  On perforation of the membrane, the low-frequency conductivity increased to a value approaching that exhibited at MHz frequencies. Apart from representing a major milestone in the development of cell biology and electrophysiology, Höber’s work was the first description of what we now call the dielectric b-dispersion exhibited by cell suspensions and fresh tissue.

  11. 利用残根行种植牙周围组织重建的牙龈美学效果分析%Dental implants gums surrounding tissue reconstruction of the aeshetic effect analysis

    Institute of Scientific and Technical Information of China (English)

    孙勇; 邹廷前; 罗铁柱; 丁少华

    2014-01-01

    目的:总结美学区域种植牙周围组织重建的临床效果。方法:通过残根引导牙龈再生,即刻种植+引导骨再生(guided bone regeneration GBR),临时冠修复获得种植牙牙龈美学效果。结果:所有种植体都发生了骨结合,龈乳头在邻间隙充盈效果满意。结论:种植牙周围组织重建使种植牙更容易获得良好的牙龈美学效果。%Objective:To summarize the clinical effect of dental implant surrounding tissue reconstruction. Method:through the residual root guide the gingival regeneration, immediate implant placement plus guided bone regeneration, temporary crown to obtain dental implant gingival aesthetic effectiveness. Result:all implants remained osseointegrated, gingival papilla in the adjacent gap filling effect is satisfactory. Conclusion:Dental implant surrounding tissue reconstruc-tion make it easier to obtain good effect of gingival aesthetics.

  12. Usefulness of Color Coding Resected Samples from a Pancreaticoduodenectomy with Tissue Marking Dyes for a Detailed Examination of Surgical Margin Surrounding the Uncinate Process of the Pancreas.

    Science.gov (United States)

    Mizutani, Satoshi; Suzuki, Hideyuki; Aimoto, Takayuki; Yamagishi, Seiji; Mishima, Keisuke; Watanabe, Masanori; Kitayama, Yasuhiko; Motoda, Norio; Isshiki, Saiko; Uchida, Eiji

    2017-01-01

    Characteristics of a cancer-positive margin around a resected uncinate process of the pancreas (MUP) due to a pancreticoduodenectomy are difficult to understand by standardized evaluation because of its complex anatomy. The purposes of this study were to subclassify the MUP with tissue marking dyes of different colors and to identify the characteristics of sites that showed positivity for cancer cells in patients with pancreatic head carcinoma who underwent circumferential superior mesenteric arterial nerve plexus-preserving pancreaticoduodenectomy. Results of this evaluation were used to review operation procedures and perioperative methods. We divided the MUP into 4 sections and stained each section with a different color. These sections were the pancreatic head nerve plexus margin (Area A), portal vein groove margin (Area B), superior mesenteric artery margin (Area C), and left of the superior mesenteric artery margin (Area D). The subjects evaluated were 45 patients who had carcinoma of the pancreatic head and were treated with circumferential superior mesenteric arterial nerve plexus-preserving pancreaticoduodenectomy. Of the 45 patients, nine cases (90%) of incomplete resection showed cancer-positivity in the MUP. Among the 4 sections of the MUP, the most cases of positive results [MUP (+) ] were found in Area B, with Area A (+), 0 case; Area B (+), 6 cases; Area C (+), 2 cases; and Area D (+), 3 cases (total, 11 sites in 9 patients). Relapse occurred in 7 of the 9 patients with MUP (+). Local recurrence was observed as initial relapse in all 3 patients with Area D (+). In contrast, the most common site of recurrence other than that in patients with Area D (+) was the liver. By subclassifying the MUP with tissue marking dyes of different colors, we could confirm regional characteristics of MUP (+). As a result, circumferential superior mesenteric arterial nerve plexus-preserving pancreticoduodenectomy was able to be performed in R0 operations in selected

  13. Computational deconvolution of gene expression by individual host cellular subsets from microarray analyses of complex, parasite-infected whole tissues.

    Science.gov (United States)

    Banskota, Nirad; Odegaard, Justin I; Rinaldi, Gabriel; Hsieh, Michael H

    2016-06-01

    Analyses of whole organs from parasite-infected animals can reveal the entirety of the host tissue transcriptome, but conventional approaches make it difficult to dissect out the contributions of individual cellular subsets to observed gene expression. Computational deconvolution of gene expression data may be one solution to this problem. We tested this potential solution by deconvoluting whole bladder gene expression microarray data derived from a model of experimental urogenital schistosomiasis. A supervised technique was used to group B-cell and T-cell related genes based on their cell types, with a semi-supervised technique to calculate the proportions of urothelial cells. We demonstrate that the deconvolution technique was able to group genes into their correct cell types with good accuracy. A clustering-based methodology was also used to improve prediction. However, incorrectly predicted genes could not be discriminated using this methodology. The incorrect predictions were primarily IgH- and IgK-related genes. To our knowledge, this is the first application of computational deconvolution to complex, parasite-infected whole tissues. Other computational techniques such as neural networks may need to be used to improve prediction. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  14. Sonographic evaluation of surrounding soft tissue lesions complicated with femur fracture%髋部股骨骨折合并周围软组织损伤的超声诊断

    Institute of Scientific and Technical Information of China (English)

    陈静; 农恒荣; 袁勇卫; 杜二珠; 王豫平

    2011-01-01

    目的 探讨超声检查髋部股骨骨折合并周围软组织损伤的多种声像图表现类型及其临床意义.方法 对154例X线检查证实髋部股骨骨折患者的X线图像及超声图像进行对比观察,重点观察骨折及其周围软组织损伤、髋关节囊积液及血肿等的影像显示(X线和超声),包括超声检查治疗前后的比较.结果 在X线检查证实髋部股骨骨折154例患者中,143例超声提示骨折的部位与X线片一致,11例超声不能明确提示X线片所示的骨折部位;超声检出髋部股骨骨折时合并周围软组织损伤148例(96.1%,148/154);总结其声像图表现有以下几种类型:(1)髋关节腔积液(12例).(2)髋关节腔内血块(35例).(3)骨折碎片嵌入肌肉(24例).(4)肌肉血肿(46例).(5)肌肉转子囊内积血(31例).X线通常难以提示髋部骨折合并软组织损伤的具体病变细节,154例中仅有9例臀大肌转子囊内积血合并肌肉内血肿时提示软组织肿胀.结论 超声能够充分显示髋部股骨骨折合并肌肉、韧带、关节囊等软组织损伤,其检测率远高于X线检查,其声像图存在多种类型,从而为临床治疗骨折后关节及肌肉损伤提供重要诊断信息;但超声存在着显示骨折损伤全貌的局限性.%Objective The surrounding soft tissue lesions complicated with femur fracture are extremely common. The detection rate of ultrasound and sonographic features were evaluated in this study. Methods A total of 154 cases with the femur fracture of hip confirmed by X-ray, were compared with those by ultrasonography, especially for the surrounding soft tissue lesions with femur fracture near the hip. Results In the 154 femur fracture cases confirmed by X-ray, the ultrasound finding in 143 cases were in accordance with those by X-ray, the 11 cases of femur fracture could not be found by ultrasound. There are 148 cases with soft tissue lesions surrounding the femur fracture near the hip had been diagnosed by

  15. Tissue loss (white syndrome) in the coral Montipora capitata is a dynamic disease with multiple host responses and potential causes

    Science.gov (United States)

    Work, Thierry M.; Russell, Robin; Aeby, Greta S.

    2012-01-01

    Tissue loss diseases or white syndromes (WS) are some of the most important coral diseases because they result in significant colony mortality and morbidity, threatening dominant Acroporidae in the Caribbean and Pacific. The causes of WS remain elusive in part because few have examined affected corals at the cellular level. We studied the cellular changes associated with WS over time in a dominant Hawaiian coral, Montipora capitata, and showed that: (i) WS has rapidly progressing (acute) phases mainly associated with ciliates or slowly progressing (chronic) phases mainly associated with helminths or chimeric parasites; (ii) these phases interchanged and waxed and waned; (iii) WS could be a systemic disease associated with chimeric parasitism or a localized disease associated with helminths or ciliates; (iv) corals responded to ciliates mainly with necrosis and to helminths or chimeric parasites with wound repair; (v) mixed infections were uncommon; and (vi) other than cyanobacteria, prokaryotes associated with cell death were not seen. Recognizing potential agents associated with disease at the cellular level and the host response to those agents offers a logical deductive rationale to further explore the role of such agents in the pathogenesis of WS in M. capitata and helps explain manifestation of gross lesions. This approach has broad applicability to the study of the pathogenesis of coral diseases in the field and under experimental settings.

  16. Simultaneous host and parasite expression profiling identifies tissue-specific transcriptional programs associated with susceptibility or resistance to experimental cerebral malaria

    Directory of Open Access Journals (Sweden)

    Liles W Conrad

    2006-11-01

    Full Text Available Abstract Background The development and outcome of cerebral malaria (CM reflects a complex interplay between parasite-expressed virulence factors and host response to infection. The murine CM model, Plasmodium berghei ANKA (PbA, which simulates many of the features of human CM, provides an excellent system to study this host/parasite interface. We designed "combination" microarrays that concurrently detect genome-wide transcripts of both PbA and mouse, and examined parasite and host transcriptional programs during infection of CM-susceptible (C57BL/6 and CM-resistant (BALB/c mice. Results Analysis of expression data from brain, lung, liver, and spleen of PbA infected mice showed that both host and parasite gene expression can be examined using a single microarray, and parasite transcripts can be detected within whole organs at a time when peripheral blood parasitemia is low. Parasites display a unique transcriptional signature in each tissue, and lung appears to be a large reservoir for metabolically active parasites. In comparisons of susceptible versus resistant animals, both host and parasite display distinct, organ-specific transcriptional profiles. Differentially expressed mouse genes were related to humoral immune response, complement activation, or cell-cell interactions. PbA displayed differential expression of genes related to biosynthetic activities. Conclusion These data show that host and parasite gene expression profiles can be simultaneously analysed using a single "combination" microarray, and that both the mouse and malaria parasite display distinct tissue- and strain-specific responses during infection. This technology facilitates the dissection of host-pathogen interactions in experimental cerebral malaria and could be extended to other disease models.

  17. Practices Surrounding Event Photos

    NARCIS (Netherlands)

    Vyas, Dhaval; Nijholt, Antinus; van der Veer, Gerrit C.; Kotzé, P.; Marsden, G.; Lindgaard, G.; Wesson, J.; Winckler, M.

    Sharing photos through mobile devices has a great potential for creating shared experiences of social events between co-located as well as remote participants. In order to design novel event sharing tools, we need to develop indepth understanding of current practices surrounding these so called

  18. An Emerging Approach for Parallel Quantification of Intracellular Protozoan Parasites and Host Cell Characterization Using TissueFAXS Cytometry.

    Science.gov (United States)

    Schmid, Maximilian; Dufner, Bianca; Dürk, Julius; Bedal, Konstanze; Stricker, Kristina; Prokoph, Lukas Ali; Koch, Christoph; Wege, Anja K; Zirpel, Henner; van Zandbergen, Ger; Ecker, Rupert; Boghiu, Bogdan; Ritter, Uwe

    2015-01-01

    Characterization of host-pathogen interactions is a fundamental approach in microbiological and immunological oriented disciplines. It is commonly accepted that host cells start to change their phenotype after engulfing pathogens. Techniques such as real time PCR or ELISA were used to characterize the genes encoding proteins that are associated either with pathogen elimination or immune escape mechanisms. Most of such studies were performed in vitro using primary host cells or cell lines. Consequently, the data generated with such approaches reflect the global RNA expression or protein amount recovered from all cells in culture. This is justified when all host cells harbor an equal amount of pathogens under experimental conditions. However, the uptake of pathogens by phagocytic cells is not synchronized. Consequently, there are host cells incorporating different amounts of pathogens that might result in distinct pathogen-induced protein biosynthesis. Therefore, we established a technique able to detect and quantify the number of pathogens in the corresponding host cells using immunofluorescence-based high throughput analysis. Paired with multicolor staining of molecules of interest it is now possible to analyze the infection profile of host cell populations and the corresponding phenotype of the host cells as a result of parasite load.

  19. Comparative Analyses of Tomato yellow leaf curl virus C4 Protein-Interacting Host Proteins in Healthy and Infected Tomato Tissues

    Directory of Open Access Journals (Sweden)

    Namgyu Kim

    2016-10-01

    Full Text Available Tomato yellow leaf curl virus (TYLCV, a member of the genus Begomovirus, is one of the most important viruses of cultivated tomatoes worldwide, mainly causing yellowing and curling of leaves with stunting in plants. TYLCV causes severe problems in sub-tropical and tropical countries, as well as in Korea. However, the mechanism of TYLCV infection remains unclear, although the function of each viral component has been identified. TYLCV C4 codes for a small protein involved in various cellular functions, including symptom determination, gene silencing, viral movement, and induction of the plant defense response. In this study, through yeast-two hybrid screenings, we identified TYLCV C4-interacting host proteins from both healthy and symptom-exhibiting tomato tissues, to determine the role of TYLCV C4 proteins in the infection processes. Comparative analyses of 28 proteins from healthy tissues and 36 from infected tissues showing interactions with TYLCV C4 indicated that TYLCV C4 mainly interacts with host proteins involved in translation, ubiquitination, and plant defense, and most interacting proteins differed between the two tissues but belong to similar molecular functional categories. Four proteins—two ribosomal proteins, S-adenosyl-L-homocysteine hydrolase, and 14-3-3 family protein—were detected in both tissues. Furthermore, the identified proteins in symptom-exhibiting tissues showed greater involvement in plant defenses. Some are key regulators, such as receptor-like kinases and pathogenesis-related proteins, of plant defenses. Thus, TYLCV C4 may contribute to the suppression of host defense during TYLCV infection and be involved in ubiquitination for viral infection.

  20. Indole-3-acetic acid (IAA) biosynthesis in the smut fungus Ustilago maydis and its relevance for increased IAA levels in infected tissue and host tumour formation.

    Science.gov (United States)

    Reineke, Gavin; Heinze, Bernadette; Schirawski, Jan; Buettner, Hermann; Kahmann, Regine; Basse, Christoph W

    2008-05-01

    Infection of maize (Zea mays) plants with the smut fungus Ustilago maydis is characterized by excessive host tumour formation. U. maydis is able to produce indole-3-acetic acid (IAA) efficiently from tryptophan. To assess a possible connection to the induction of host tumours, we investigated the pathways leading to fungal IAA biosynthesis. Besides the previously identified iad1 gene, we identified a second indole-3-acetaldehyde dehydrogenase gene, iad2. Deltaiad1Deltaiad2 mutants were blocked in the conversion of both indole-3-acetaldehyde and tryptamine to IAA, although the reduction in IAA formation from tryptophan was not significantly different from Deltaiad1 mutants. To assess an influence of indole-3-pyruvic acid on IAA formation, we deleted the aromatic amino acid aminotransferase genes tam1 and tam2 in Deltaiad1Deltaiad2 mutants. This revealed a further reduction in IAA levels by five- and tenfold in mutant strains harbouring theDeltatam1 andDeltatam1Deltatam2 deletions, respectively. This illustrates that indole-3-pyruvic acid serves as an efficient precursor for IAA formation in U. maydis. Interestingly, the rise in host IAA levels upon U. maydis infection was significantly reduced in tissue infected with Deltaiad1Deltaiad2Deltatam1 orDeltaiad1Deltaiad2Deltatam1Deltatam2 mutants, whereas induction of tumours was not compromised. Together, these results indicate that fungal IAA production critically contributes to IAA levels in infected tissue, but this is apparently not important for triggering host tumour formation.

  1. A Comprehensive MicroRNA Expression Profile of Liver and Lung Metastases of Colorectal Cancer with Their Corresponding Host Tissue and Its Prognostic Impact on Survival

    Science.gov (United States)

    Pecqueux, Mathieu; Liebetrau, Isabell; Werft, Wiebke; Dienemann, Hendrik; Muley, Thomas; Pfannschmidt, Joachim; Müssle, Benjamin; Rahbari, Nuh; Schölch, Sebastian; Büchler, Markus W.; Weitz, Jürgen; Reissfelder, Christoph; Kahlert, Christoph

    2016-01-01

    MicroRNAs are small non-coding RNAs with a length of 18–25 nucleotides. They can regulate tumor invasion and metastasis by changing the expression and translation of their target mRNAs. Their expression is substantially altered in colorectal cancer cells as well as in the adjacent tumor-associated stroma. Both of these compartments have a mutual influence on tumor progression. In the development of metastases, cancer cells initially interact with the host tissue. Therefore, compartment-specific expression signatures of these three locations—tumor, associated stroma, and host tissue—can provide new insights into the complex tumor biology of colorectal cancer. Frozen tissue samples of colorectal liver (n = 25) and lung metastases (n = 24) were laser microdissected to separate tumor cells and the adjacent tumor-associated stroma cells. Additionally, normal lung and liver tissue was collected from the same patients. We performed a microarray analysis in four randomly selected liver metastases and four randomly selected lung metastases, analyzing a total of 939 human miRNAs. miRNAs with a significant change >2-fold between the tumor, tumor stroma, and host tissue were analyzed in all samples using RT-qPCR (11 miRNAs) and correlated with the clinical data. We found a differential expression of several miRNAs between the tumor, the tumor-associated stroma, and the host tissue compartment. When comparing liver and lung metastases, miR-194 showed a 1.5-fold; miR-125, miR-127, and miR-192 showed a 2.5-fold; miR-19 and miR-215 a 3-fold; miR-145, miR-199-3, and miR-429 a 5-fold; miR-21 a 7-fold; and, finally, miR-199-5 a 12.5-fold downregulation in liver metastases compared to lung metastases. Furthermore miR-19, miR-125, miR-127, miR-192, miR-194, miR-199-5, and miR-215 showed a significant upregulation in the normal liver tissue compared to the normal lung tissue. Univariate analysis identified an association of poor survival with the expression of miR-125 (p = 0

  2. Host-bacterial interplay in periodontal disease

    Directory of Open Access Journals (Sweden)

    Rudrakshi Chickanna

    2015-01-01

    Full Text Available A literature search was performed using MEDLINE (PubMed and other electronic basis from 1991 to 2014. Search included books and journals based on the systematic and critical reviews, in vitro and in vivo clinical studies on molecular basis of host microbial interactions. Clearly, an understanding of the host susceptibility factor in addition to microbial factors by elucidating the molecular basis offers opportunity for therapeutic manipulation of advancing periodontal destruction. One of the hallmarks of pathogenesis is the ability of pathogenic organisms to invade surrounding tissues and to evade the host defence. This paper focuses the general overview of molecular mechanisms involved in the microbiota and host response to bacterial inimical behavior in periodontics.

  3. Coral host cells acidify symbiotic algal microenvironment to promote photosynthesis.

    Science.gov (United States)

    Barott, Katie L; Venn, Alexander A; Perez, Sidney O; Tambutté, Sylvie; Tresguerres, Martin

    2015-01-13

    Symbiotic dinoflagellate algae residing inside coral tissues supply the host with the majority of their energy requirements through the translocation of photosynthetically fixed carbon. The algae, in turn, rely on the host for the supply of inorganic carbon. Carbon must be concentrated as CO2 in order for photosynthesis to proceed, and here we show that the coral host plays an active role in this process. The host-derived symbiosome membrane surrounding the algae abundantly expresses vacuolar H(+)-ATPase (VHA), which acidifies the symbiosome space down to pH ∼ 4. Inhibition of VHA results in a significant decrease in average H(+) activity in the symbiosome of up to 75% and a significant reduction in O2 production rate, a measure of photosynthetic activity. These results suggest that host VHA is part of a previously unidentified carbon concentrating mechanism for algal photosynthesis and provide mechanistic evidence that coral host cells can actively modulate the physiology of their symbionts.

  4. Acellular dermal matrix and negative pressure wound therapy: a tissue-engineered alternative to free tissue transfer in the compromised host.

    Science.gov (United States)

    Menn, Zachary K; Lee, Edward; Klebuc, Michael J

    2012-02-01

    Free tissue transfer has revolutionized lower extremity reconstruction; however, its use in elderly patients with multiple medical problems can be associated with elevated rate s of perioperative morbidity and mortality. This study evaluates the use of acellular dermal matrix (ADM) in conjunction with negative pressure wound therapy (NPWT) and delayed skin graft application as an alternative to free tissue transfer in this compromised population. Bilayer, ADM (Integra, Plainsboro, NJ) was used in conjunction with NPWT (Wound V.A.C, Kinetic Concepts Inc., San Antonio, TX) to achieve vascularized coverage of complex lower extremity wounds with denuded tendon and bone in elderly, medically compromised patients. Following incorporation, the matrix was covered with split-thickness skin graft. Four patients (age range, 50 to 76 years) with multiple medical comorbidities were treated with the above protocol. The average time to complete vascularization of the matrix was 29 days. Definitive closure with split-thickness skin graft was achieved in three patients and one wound healed by secondary intention. No medical or surgical complications were encountered and stable soft tissue coverage was achieved in all patients. This early experience suggests that dermal substitute and NPWT with delayed skin graft application can provide a reasonable tissue-engineered alternative to free tissue transfer in the medically compromised individual.

  5. sek-1 is important in tissue-specific regulation of innate immunity during the Xoo infection in the model host Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Y Bai

    2014-08-01

    Full Text Available Xanthomonas oryzae pv. Oryzae (Xoo are plant pathogenic bacteria that can cause serious blight of rice. We have demonstrated that Xoo can infect the model organism C. elegans and p38 MAPK pathway plays specific roles in defense against the pathogen in our previous paper. Based on that p38 MAPK pathway can be activated in a range of tissues, it is intriguing to compare the tissue-specific activities of this pathway in host innate immunity. Here, transgenic worms that sek-1 expressed specifically in neurons system, ciliated sensory neurons, and intestine respectively are used to determine the nematode survival and transcriptional levels of immune-related genes. We report that SEK-1 and TOL-1 are not involved in C. elegans avoidance behavior, and ingestion of nematodes is related to the aversion and also the characteristics of bacteria. In addition, tol-1 and sek-1 participate the immune response to the infection by Xoo; sek-1 also exhibits tissue-specific activities in host innate immunity. Our findings suggest that overlapping immune effect may exist between the tol-1 and sek-1.

  6. Homing in on Acute Graft vs. Host Disease: Tissue-Specific T Regulatory and Th17 Cells

    OpenAIRE

    Engelhardt, Brian G.; Crowe, James E.

    2010-01-01

    Acute graft vs. host disease (aGVHD) is a major limitation of hematopoietic stem cell transplantation (HSCT), and it causes significant morbidity and mortality for this patient population. This immune-mediated injury occurs unpredictably and is caused by donor-derived T cells reacting to recipient alloantigens. Although donor Th1 cells play a critical role in aGVHD generation, numerous arms of both the innate and the adaptive immune systems along with determinants of lymphocyte trafficking ar...

  7. Effect of anodized oxidation on the surrounding tissue of orthodontic microscrew implants%正畸微种植体表面阳极氧化处理对周围骨组织的影响

    Institute of Scientific and Technical Information of China (English)

    陈岩; 赵文婷; 咏梅; 牛一山

    2012-01-01

    Objective To evaluate the effect of anodized oxidation of Ti-alloy microscrew implants on the osseointegration.Methods Twenty-four Ti-alloy microscrew implants were inserted in the femurs in two rabbits for six weeks.Half of the implants were pretreated in anodized solution as experimental group and others not treated as controls.Undecalcified and decalcified sections of the implants and surrounding tissue were examined with light microscope and the osseointegration rate was calculated.Results Osseointegration was seen in all samples in both groups and no fibrous tissue was seen between bone and implant.The osseointegration rate was slightly higher in the experimental group than in the controls.Conclusions Anodized oxidation could improve the osseointegration rate of Ti-alloy microscrew implants.%目的 通过组织形态学及组织形态测量学评价正畸微螺旋种植体表面阳极氧化处理对周围骨组织愈合情况的影响.方法 24枚钛合金正畸用微螺旋种植体种植于两只新西兰大白兔的后腿,在闭合环境下生长6周.12枚微种植体经过表面阳极氧化处理作为研究组;另外12枚表面没有经过任何处理作为对照组.兔处死后,部分微种植体及周围骨组织进行组织学苏木精-伊红染色(hematoxylin-eosin staining,HE)处理,每组有4枚微种植体及周围骨组织块采用维拉努埃瓦(Villanueva)染色.光学显微镜评价种植体的组织学变化并计算种植体的骨结合率.结果 两组种植体均与周围骨组织有一定的结合,其间无结缔组织可见.螺旋区骨纤维走向紊乱,表面阳极氧化组微种植体周围有较多的骨组织可见.阳极氧化组微种植体的骨结合率略高于对照组.结论 阳极氧化处理可能促进钛合金微种植体与周围骨组织的结合.

  8. Understanding the Molecular Mechanisms of Rifaximin in the Treatment of Gastrointestinal Disorders--A Focus on the Modulation of Host Tissue Function.

    Science.gov (United States)

    Hirota, Simon A

    2015-01-01

    Rifaximin is a broad-spectrum oral antibiotic, exhibiting limited systemic absorption, that is used clinically to treat a variety of gastrointestinal disorders, including traveller's diarrhea, hepatic encephalopathy, irritable bowel syndrome, and the inflammatory bowel diseases. Rifaximin's antimicrobial properties, in the context of enteric infections, and its effects on the host's intestinal microbiota have been well characterized. More recently, it has been reported that rifaximin can modulate host tissue function through the activation of distinct molecular events. Within the gastrointestinal tract, rifaximin is a selective agonist of the pregnane X receptor (PXR), a nuclear receptor that regulates the expression of genes related to xenobiotic metabolism and drug detoxification. The PXR can also elicit immunomodulatory effects through its interaction with a variety of intracellular signaling cascades, including the nuclear factor kappa B and c-jun N-terminal kinase pathways. In this review, we will summarize the clinical uses of rifaximin and discuss its mechanism of action in relation to the modulation of the intestinal microbiota and the regulation of gastrointestinal host cell function, with a specific focus on PXR-dependent pathways.

  9. Characterization of effector mechanisms at the host: parasite interface during the immune response to tissue-dwelling intestinal nematode parasites

    Science.gov (United States)

    The protective immune response that develops following infection with many tissue dwelling intestinal nematode parasites is characterized by elevations in IL-4 and IL-13 and increased numbers of CD4+ T cells, granulocytes, and macrophages. These cells accumulate at the site of infection, and in many...

  10. Degradation characteristics, cell viability and host tissue responses of PDLLA-based scaffold with PRGD and β-TCP nanoparticles incorporation.

    Science.gov (United States)

    Yi, Jiling; Xiong, Feng; Li, Binbin; Chen, Heping; Yin, Yixia; Dai, Honglian; Li, Shipu

    2016-09-01

    This study is aimed to evaluate the degradation characteristics, cell viability and host tissue responses of PDLLA/PRGD/β-TCP (PRT) composite nerve scaffold, which was fabricated by poly(d, l-lactic acid) (PDLLA), RGD peptide(Gly-Arg-Gly-Asp-Tyr, GRGDY, abbreviated as RGD) modified poly-{(lactic acid)-co-[(glycolic acid)-alt-(l-lysine)]}(PRGD) and β-tricalcium phosphate (β-TCP). The scaffolds' in vitro degradation behaviors were investigated in detail by analysing changes in weight loss, pH and morphology. Then, the 3-(4,5-dimethyl-2-thiazolyl) -2,5-diphenyl-2 -H-tetrazolium bromide (MTT) assay and cell live/dead assay were carried out to assess their cell viability. Moreover, in vivo degradation patterns and host inflammation responses were monitored by subcutaneous implantation of PRT scaffold in rats. Our data showed that, among the tested scaffolds, the PRT scaffold had the best buffering capacity (pH = 6.1-6.3) and fastest degradation rate (12.4%, 8 weeks) during in vitro study, which was contributed by the incorporation of β-TCP nanoparticles. After in vitro and in vivo degradation, the high porosity structure of PRT could be observed using scanning electron microscopy. Meanwhile, the PRT scaffold could significantly promote cell survival. In the PRT scaffold implantation region, less inflammatory cells (especially for neutrophil and lymphocyte) could be detected. These results indicated that the PRT composite scaffold had a good biodegradable property; it could improve cells survival and reduced the adverse host tissue inflammation responses.

  11. Pseudomonas aeruginosa outer membrane vesicles triggered by human mucosal fluid and lysozyme can prime host tissue surfaces for bacterial adhesion

    Directory of Open Access Journals (Sweden)

    Matteo Maria Emiliano Metruccio

    2016-06-01

    Full Text Available Pseudomonas aeruginosa is a leading cause of human morbidity and mortality that often targets epithelial surfaces. Host immunocompromise, or the presence of indwelling medical devices, including contact lenses, can predispose to infection. While medical devices are known to accumulate bacterial biofilms, it is not well understood why resistant epithelial surfaces become susceptible to P. aeruginosa. Many bacteria, including P. aeruginosa, release Outer Membrane Vesicles (OMVs in response to stress that can fuse with host cells to alter their function. Here, we tested the hypothesis that mucosal fluid can trigger OMV release to compromise an epithelial barrier. This was tested using tear fluid and corneal epithelial cells in vitro and in vivo. After 1 h both human tear fluid, and the tear component lysozyme, greatly enhanced OMV release from P. aeruginosa strain PAO1 compared to PBS controls (~100 fold. TEM and SDS-PAGE showed tear fluid and lysozyme-induced OMVs were similar in size and protein composition, but differed from biofilm-harvested OMVs, the latter smaller with fewer proteins. Lysozyme-induced OMVs were cytotoxic to human corneal epithelial cells in vitro and murine corneal epithelium in vivo. OMV exposure in vivo enhanced Ly6G/C expression at the corneal surface, suggesting myeloid cell recruitment, and primed the cornea for bacterial adhesion (~4-fold, P < 0.01. Sonication disrupted OMVs retained cytotoxic activity, but did not promote adhesion, suggesting the latter required OMV-mediated events beyond cell killing. These data suggest that mucosal fluid induced P. aeruginosa OMVs could contribute to loss of epithelial barrier function during medical device-related infections.

  12. Tissue holding device for use during surgical procedure, has contact body with suction foot and suction mouth that is surrounded by rim, and suction pipe connected to suction chamber

    NARCIS (Netherlands)

    Vonck, D.; Goossens, R.H.M.; Flipsen, S.F.J.; Jakimowicz, J.J.; Van der Putten, E.P.W.

    2009-01-01

    The device has a locking ring (5), a connector (6), and a contact body (1) with a suction foot and a suction mouth (8), where the mouth is surrounded by a rim (10), which is substantially located in a plane of the suction foot. A suction chamber (9) has a sieve-shaped inner wall (2) and a

  13. The Importance of the KR-Rich Region of the Coat Protein of Ourmia melon virus for Host Specificity, Tissue Tropism, and Interference With Antiviral Defense.

    Science.gov (United States)

    Rossi, Marika; Vallino, Marta; Abbà, Simona; Ciuffo, Marina; Balestrini, Raffaella; Genre, Andrea; Turina, Massimo

    2015-01-01

    The N-terminal region of the Ourmia melon virus (OuMV) coat protein (CP) contains a short lysine/arginine-rich (KR) region. By alanine scanning mutagenesis, we showed that the KR region influences pathogenicity and virulence of OuMV without altering viral particle assembly. A mutant, called OuMV6710, with three basic residue substitutions in the KR region, was impaired in the ability to maintain the initial systemic infection in Nicotiana benthamiana and to infect both cucumber and melon plants systemically. The integrity of this protein region was also crucial for encapsidation of viral genomic RNA; in fact, certain mutations within the KR region partially compromised the RNA encapsidation efficiency of the CP. In Arabidopsis thaliana Col-0, OuMV6710 was impaired in particle accumulation; however, this phenotype was abolished in dcl2/dcl4 and dcl2/dcl3/dcl4 Arabidopsis mutants defective for antiviral silencing. Moreover, in contrast to CPwt, in situ immunolocalization experiments indicated that CP6710 accumulates efficiently in the spongy mesophyll tissue of infected N. benthamiana and A. thaliana leaves but only occasionally infects palisade tissues. These results provided strong evidence of a crucial role for OuMV CP during viral infection and highlighted the relevance of the KR region in determining tissue tropism, host range, pathogenicity, and RNA affinity, which may be all correlated with a possible CP silencing-suppression activity.

  14. High dietary level of synthetic vitamin E on lipid peroxidation, membrane fatty acid composition and cytotoxicity in breast cancer xenograft and in mouse host tissue

    Directory of Open Access Journals (Sweden)

    Barnes Christopher J

    2003-03-01

    Full Text Available Abstract Background d-α-tocopherol is a naturally occurring form of vitamin E not previously known to have antitumor activity. Synthetic vitamin E (sE is a commonly used dietary supplement consisting of a mixture of d-α-tocopherol and 7 equimolar stereoisomers. To test for antilipid peroxidation and for antitumor activity of sE supplementation, two groups of nude mice bearing a MDA-MB 231 human breast cancer tumor were fed an AIN-76 diet, one with and one without an additional 2000 IU/kg dry food (equivalent to 900 mg of all-rac-α-tocopherol or sE. This provided an intake of about 200 mg/kg body weight per day. The mice were killed at either 2 or 6 weeks after the start of dietary intervention. During necropsy, tumor and host tissues were excised for histology and for biochemical analyses. Results Tumor growth was significantly reduced by 6 weeks of sE supplementation. Thiobarbituric acid reactive substances, an indicator of lipid peroxidation, were suppressed in tumor and in host tissues in sE supplemented mice. In the sE treated mice, the fatty acid composition of microsomal and mitochondrial membranes of tumor and host tissues had proportionately less linoleic acid (n-6 C 18-2, similar levels of arachidonic acid (n-6 C 20-4, but more docosahexanoic acid (n-3 C 22-6. The sE supplementation had no significant effect on blood counts or on intestinal histology but gave some evidence of cardiac toxicity as judged by myocyte vacuoles and by an indicator of oxidative stress (increased ratio of Mn SOD mRNA over GPX1 mRNA. Conclusions At least one of the stereoisomers in sE has antitumor activity. Synthetic vitamin E appears to preferentially stabilize membrane fatty acids with more double bonds in the acyl chain. Although sE suppressed tumor growth and lipid peroxidation, it may have side-effects in the heart.

  15. Placenta Derived Mesenchymal Stem Cells Hosted on RKKP Glass-Ceramic: A Tissue Engineering Strategy for Bone Regenerative Medicine Applications

    Directory of Open Access Journals (Sweden)

    Mario Ledda

    2016-01-01

    Full Text Available In tissue engineering protocols, the survival of transplanted stem cells is a limiting factor that could be overcome using a cell delivery matrix able to support cell proliferation and differentiation. With this aim, we studied the cell-friendly and biocompatible behavior of RKKP glass-ceramic coated Titanium (Ti surface seeded with human amniotic mesenchymal stromal cells (hAMSCs from placenta. The sol-gel synthesis procedure was used to prepare the RKKP glass-ceramic material, which was then deposited onto the Ti surface by Pulsed Laser Deposition method. The cell metabolic activity and proliferation rate, the cytoskeletal actin organization, and the cell cycle phase distribution in hAMSCs seeded on the RKKP coated Ti surface revealed no significant differences when compared to the cells grown on the treated plastic Petri dish. The health of of hAMSCs was also analysed studying the mRNA expressions of MSC key genes and the osteogenic commitment capability using qRT-PCR analysis which resulted in being unchanged in both substrates. In this study, the combination of the hAMSCs’ properties together with the bioactive characteristics of RKKP glass-ceramics was investigated and the results obtained indicate its possible use as a new and interesting cell delivery system for bone tissue engineering and regenerative medicine applications.

  16. Placenta Derived Mesenchymal Stem Cells Hosted on RKKP Glass-Ceramic: A Tissue Engineering Strategy for Bone Regenerative Medicine Applications

    Science.gov (United States)

    Fosca, Marco; De Bonis, Angela; Curcio, Mariangela; Lolli, Maria Grazia; De Stefanis, Adriana; Marchese, Rodolfo; Rau, Julietta V.

    2016-01-01

    In tissue engineering protocols, the survival of transplanted stem cells is a limiting factor that could be overcome using a cell delivery matrix able to support cell proliferation and differentiation. With this aim, we studied the cell-friendly and biocompatible behavior of RKKP glass-ceramic coated Titanium (Ti) surface seeded with human amniotic mesenchymal stromal cells (hAMSCs) from placenta. The sol-gel synthesis procedure was used to prepare the RKKP glass-ceramic material, which was then deposited onto the Ti surface by Pulsed Laser Deposition method. The cell metabolic activity and proliferation rate, the cytoskeletal actin organization, and the cell cycle phase distribution in hAMSCs seeded on the RKKP coated Ti surface revealed no significant differences when compared to the cells grown on the treated plastic Petri dish. The health of of hAMSCs was also analysed studying the mRNA expressions of MSC key genes and the osteogenic commitment capability using qRT-PCR analysis which resulted in being unchanged in both substrates. In this study, the combination of the hAMSCs' properties together with the bioactive characteristics of RKKP glass-ceramics was investigated and the results obtained indicate its possible use as a new and interesting cell delivery system for bone tissue engineering and regenerative medicine applications. PMID:28078286

  17. Host Genetic Variations and Sex Differences Potentiate Predisposition, Severity, and Outcomes of Group A Streptococcus-Mediated Necrotizing Soft Tissue Infections

    Science.gov (United States)

    Mukundan, Santhosh; Alagarsamy, Jeyashree; Laturnus, Donna

    2015-01-01

    Host genetic variations play an important role in several pathogenic diseases, and we previously provided strong evidence that these genetic variations contribute significantly to differences in susceptibility and clinical outcomes of invasive group A Streptococcus (GAS) patients, including sepsis and necrotizing soft tissue infections (NSTIs). The goal of the present study was to investigate how genetic variations and sex differences among four commonly used mouse strains contribute to variation in severity, manifestations, and outcomes of NSTIs. DBA/2J mice were more susceptible to NSTIs than C57BL/6J, BALB/c, and CD-1 mice, as exhibited by significantly greater bacteremia, excessive dissemination to the spleen, and significantly higher mortality. Differences in the sex of the mice also contributed to differences in disease severity and outcomes: DBA/2J female mice were relatively resistant compared to their male counterparts. However, DBA/2J mice exhibited minimal weight loss and developed smaller lesions than did the aforementioned strains. Moreover, at 48 h after infection, compared with C57BL/6J mice, DBA/2J mice had increased bacteremia, excessive dissemination to the spleen, and excessive concentrations of inflammatory cytokines and chemokines. These results indicate that variations in the host genetic context as well as sex play a dominant role in determining the severity of and susceptibility to GAS NSTIs. PMID:26573737

  18. The spatial distribution of acid phosphatase activity in ectomycorrhizal tissues depends on soil fertility and morphotype, and relates to host plant phosphorus uptake.

    Science.gov (United States)

    Alvarez, Maricel; Huygens, Dries; Díaz, Leila Milena; Villanueva, Claudia Añazco; Heyser, Wolfgang; Boeckx, Pascal

    2012-01-01

    Acid phosphatase (ACP) enzymes are involved in the mobilization of soil phosphorus (P) and polyphosphate accumulated in the fungal tissues of ectomycorrhizal roots, thereby influencing the amounts of P that are stored in the fungus and transferred to the host plant. This study evaluated the effects of ectomycorrhizal morphotype and soil fertility on ACP activity in the extraradical mycelium (ACP(myc)), the mantle (ACP(mantle)) and the Hartig net region (ACP(Hartig)) of ectomycorrhizal Nothofagus obliqua seedlings. ACP activity was quantified in vivo using enzyme-labelled fluorescence-97 (ELF-97) substrate, confocal laser microscopy and digital image processing routines. There was a significant effect of ectomycorrhizal morphotype on ACP(myc), ACP(mantle) and ACP(Hartig), while soil fertility had a significant effect on ACP(myc) and ACP(Hartig). The relative contribution of the mantle and the Hartig net region to the ACP activity on the ectomycorrhizal root was significantly affected by ectomycorrhizal morphotype and soil fertility. A positive correlation between ACP(Hartig) and the shoot P concentration was found, providing evidence that ACP activity at the fungus:root interface is involved in P transfer from the fungus to the host. It is concluded that the spatial distribution of ACP in ectomycorrhizas varies as a function of soil fertility and colonizing fungus.

  19. Expanding the host range of small insect RNA viruses: Providence virus (Carmotetraviridae) infects and replicates in a human tissue culture cell line.

    Science.gov (United States)

    Jiwaji, Meesbah; Short, James Roswell; Dorrington, Rosemary Ann

    2016-10-01

    Tetraviruses are small, positive (+ve)-sense ssRNA viruses that infect the midgut cells of lepidopteran larvae. Providence virus (PrV) is the only member of the family Carmotetraviridae (previously Tetraviridae). PrV particles exhibit the characteristic tetraviral T=4 icosahedral symmetry, but PrV is distinct from other tetraviruses with respect to genome organization and viral non-structural proteins. Currently, PrV is the only tetravirus known to infect and replicate in lepidopteran cell culture lines. In this report we demonstrate, using immunofluorescence microscopy, that PrV infects and replicates in a human tissue culture cell line (HeLa), producing infectious virus particles. We also provide evidence for PrV replication in vitro in insect, mammalian and plant cell-free systems. This study challenges the long-held view that tetraviruses have a narrow host range confined to one or a few lepidopteran species and highlights the need to consider the potential for apparently non-infectious viruses to be transferred to new hosts in the laboratory.

  20. The White-Nose Syndrome Transcriptome: Activation of Anti-fungal Host Responses in Wing Tissue of Hibernating Little Brown Myotis.

    Directory of Open Access Journals (Sweden)

    Kenneth A Field

    2015-10-01

    Full Text Available White-nose syndrome (WNS in North American bats is caused by an invasive cutaneous infection by the psychrophilic fungus Pseudogymnoascus destructans (Pd. We compared transcriptome-wide changes in gene expression using RNA-Seq on wing skin tissue from hibernating little brown myotis (Myotis lucifugus with WNS to bats without Pd exposure. We found that WNS caused significant changes in gene expression in hibernating bats including pathways involved in inflammation, wound healing, and metabolism. Local acute inflammatory responses were initiated by fungal invasion. Gene expression was increased for inflammatory cytokines, including interleukins (IL IL-1β, IL-6, IL-17C, IL-20, IL-23A, IL-24, and G-CSF and chemokines, such as Ccl2 and Ccl20. This pattern of gene expression changes demonstrates that WNS is accompanied by an innate anti-fungal host response similar to that caused by cutaneous Candida albicans infections. However, despite the apparent production of appropriate chemokines, immune cells such as neutrophils and T cells do not appear to be recruited. We observed upregulation of acute inflammatory genes, including prostaglandin G/H synthase 2 (cyclooxygenase-2, that generate eicosanoids and other nociception mediators. We also observed differences in Pd gene expression that suggest host-pathogen interactions that might determine WNS progression. We identified several classes of potential virulence factors that are expressed in Pd during WNS, including secreted proteases that may mediate tissue invasion. These results demonstrate that hibernation does not prevent a local inflammatory response to Pd infection but that recruitment of leukocytes to the site of infection does not occur. The putative virulence factors may provide novel targets for treatment or prevention of WNS. These observations support a dual role for inflammation during WNS; inflammatory responses provide protection but excessive inflammation may contribute to mortality

  1. Clinical Application of Surrounding Puncture

    Institute of Scientific and Technical Information of China (English)

    GUO Yao-jie; HAN Chou-ping

    2003-01-01

    Surrounding puncture can stop pathogenic qi from spreading, consolidate the connection between local meridians and enrich local qi and blood, which can eventually supplement anti-pathogenic qi and remove pathogenic qi, and consequently remedy diseases. The author of this article summrized and analyzed the clinical application of surrounding puncture for the purpose of studying this technique and improving the therapeutic effect.

  2. Detection of Anoplophora glabripennis (Coleoptera: Cerambycidae) larvae in different host trees and tissues by automated analyses of sound-impulse frequency and temporal patterns.

    Science.gov (United States)

    Mankin, R W; Smith, M T; Tropp, J M; Atkinson, E B; Jong, D Y

    2008-06-01

    Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), an invasive pest quarantined in the United States, is difficult to detect because the larvae feed unseen inside trees. Acoustic technology has potential for reducing costs and hazards of tree inspection, but development of practical methods for acoustic detection requires the solution of technical problems involving transmission of resonant frequencies in wood and high background noise levels in the urban environments where most infestations have occurred. A study was conducted to characterize sounds from larvae of different ages in cambium, sapwood, and heartwood of bolts from three host tree species. Larval sounds in all of the tested trees and tissues consisted primarily of trains of brief, 3-10-ms impulses. There were no major differences in the spectral or temporal pattern characteristics of signals produced by larvae of different ages in each tissue, but larval sounds in sapwood often had fewer spectral peaks than sounds in cambium and heartwood. A large fraction, but not all background sounds could be discriminated from larval sounds by automated spectral analyses. In 3-min recordings from infested bolts, trains containing impulses in patterns called bursts occurred frequently, featuring 7-49 impulses separated by small intervals. Bursts were rarely detected in uninfested bolts. The occurrence of bursts was found to predict infestations more accurately than previously used automated spectral analyses alone. Bursts and other features of sounds that are identifiable by automated techniques may ultimately lead to improved pest detection applications and new insight into pest behavior.

  3. Visual surround suppression in schizophrenia

    Directory of Open Access Journals (Sweden)

    Marc Samuel Tibber

    2013-02-01

    Full Text Available Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with schizophrenia demonstrated weaker surround suppression compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation surround suppression in schizophrenia may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

  4. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  5. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  6. Multichannel spatial surround sound system

    Institute of Scientific and Technical Information of China (English)

    RAO Dan; XIE Bosun

    2004-01-01

    Based on the consideration of being compatible with 5.1 channel horizontal surround sound system, a spatial surround sound system is proposed. Theoretical and experimental results show that the system has a wide listening area. It can not only recreate stable image in the front and rear direction, but also eliminate the defect of poor lateral image of 5.1 channel system. The system can be used to reproduce special 3D sound effect and the spaciousness of hall.

  7. Distribution and coassociations of trace elements in soft tissue and byssus of Mytilus galloprovincialis relative to the surrounding seawater and suspended matter of the southern part of the Korean Peninsula.

    Science.gov (United States)

    Szefer, P; Kim, B-S; Kim, C-K; Kim, E-H; Lee, C-B

    2004-05-01

    The concentrations of Cd, Co, Cu, Cr, Fe, Hg, Mn, Ni, Pb, Sn, Ti and Zn were analyzed by AAS, ICP MS and AFS in soft tissues and byssal threads of Mytilus galloprovincialis from Masan Bay and Ulsan Bay, Korea. Spatial variations in metal concentrations were found. The levels of Cd, Pb, Hg, Cu, Zn, Co and Mn were very high in the mussels from Ulsan Bay (Sts. U1, U2) and comparable with elevated concentrations of these elements in Mytilus sp. reported to date for other geographical areas. Seasonal differences in some metal concentrations were also observed. These variations may be caused by factors such as: a large difference in seawater temperature, food supply for the mussel population and/or freshwater runoff of particulate metal to the coastal water and weight changes brought about by gonadal development and the release of sexual products. Pb, Cu, Zn, Co, Ni, Fe and Mn were more enriched in byssal threads than in the soft tissues, hence the byssus seems to be more sensitive in reflecting the availabilities of trace metals in the ambient waters. Concentrations of trace metals varied with respect to the size of mussels and season, depending on many factors like sexual development, and seawater temperature, etc. The levels of some trace metals in seawater, especially in suspended matter were correlated significantly with those in soft tissues and byssal threads. There were spatial variations in metal concentrations in the soft tissue and byssus attributed to different sources of trace elements located near the sampling sites. There were significant relationships between concentrations of some metals (Cd, Cu, Pb, and Zn) in mussel soft tissues and byssal threads and suspended matter. This suggests that M. galloprovincialis can be used as a sensitive biomonitor for the availabilities of trace elements in the coastal waters off Korea.

  8. Distribution and coassociations of trace elements in soft tissue and byssus of Mytilus galloprovincialis relative to the surrounding seawater and suspended matter of the southern part of the Korean Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Szefer, P.; Kim, B.-S.; Kim, C.-K.; Kim, E.-H.; Lee, C.-B

    2004-05-01

    The concentrations of Cd, Co, Cu, Cr, Fe, Hg, Mn, Ni, Pb, Sn, Ti and Zn were analyzed by AAS, ICP MS and AFS in soft tissues and byssal threads of Mytilus galloprovincialis from Masan Bay and Ulsan Bay, Korea. Spatial variations in metal concentrations were found. The levels of Cd, Pb, Hg, Cu, Zn, Co and Mn were very high in the mussels from Ulsan Bay (Sts. U1, U2) and comparable with elevated concentrations of these elements in Mytilus sp. reported to date for other geographical areas. Seasonal differences in some metal concentrations were also observed. These variations may be caused by factors such as: a large difference in seawater temperature, food supply for the mussel population and/or freshwater runoff of particulate metal to the coastal water and weight changes brought about by gonadal development and the release of sexual products. Pb, Cu, Zn, Co, Ni, Fe and Mn were more enriched in byssal threads than in the soft tissues, hence the byssus seems to be more sensitive in reflecting the availabilities of trace metals in the ambient waters. Concentrations of trace metals varied with respect to the size of mussels and season, depending on many factors like sexual development, and seawater temperature, etc. The levels of some trace metals in seawater, especially in suspended matter were correlated significantly with those in soft tissues and byssal threads. There were spatial variations in metal concentrations in the soft tissue and byssus attributed to different sources of trace elements located near the sampling sites. There were significant relationships between concentrations of some metals (Cd, Cu, Pb, and Zn) in mussel soft tissues and byssal threads and suspended matter. This suggests that M. galloprovincialis can be used as a sensitive biomonitor for the availabilities of trace elements in the coastal waters off Korea. - Mytilus galloprovincialis can be used as a biomonitor for trace elements in coastal waters off Korea.

  9. Links between cyclosporin exposure in tissues and graft-versus-host disease in pediatric bone marrow transplantation: analysis by a PBPK model.

    Science.gov (United States)

    Gérard, Cécile; Bleyzac, Nathalie; Girard, Pascal; Freyer, Gilles; Bertrand, Yves; Tod, Michel

    2011-03-01

    In hematopoietic stem cell transplantation (HSCT), cyclosporin is used to prevent graft-versus-host disease (GVHD). However, cyclosporin distribution in tissues is not linear, resulting in uncertainty regarding optimal dosing and monitoring. The objective of this study was to link the probability and severity of acute GVHD to cyclosporin exposure in blood, GVHD target organs, and lymphoid organs. A physiologically based pharmacokinetic model of cyclosporin disposition and logistic regression models were used. Sixty-one pediatric patients undergoing HSCT were studied. Cyclosporin was administered by intermittent (n = 31) or continuous infusion (n = 30). At steady state (1 day before acute GVHD), exposures in all organs were related with the probability and severity of acute GVHD. Average cyclosporin concentration or, equivalently, its area under the curve (AUC) was the pharmacokinetic index best correlated with the anti-GVHD effect. Cyclosporin AUC in interstitial fluid of lymphoid organs was a superior index than that in blood, but marginally. Hence, AUC in blood maybe used as an index of cyclosporin efficacy. Using our model, target AUCs in blood could be defined for malignant and non-malignant diseases, as well as the equivalent target values for C(2) and C(0) concentrations.

  10. Baculovirus Host-Range

    Institute of Scientific and Technical Information of China (English)

    Suzanne M. Thiem; Xiao-Wen Cheng

    2009-01-01

    Baculoviruses are used as microbial insecticides, protein expression vectors, epitope display platforms, and most recently as vectors for gene therapy. Understanding the mechanisms that control baculovirus host-range and tissue tropisms are important for assessing their safety and for improving their properties for these biotechnology applications. In the past two decades some progress has been made and several baculovirus genes that influence host-range have been identified. Despite this progress, our understanding of the underlying mechanisms that restrict baculovirus host-range is still limited. Here we review what is currently known about baculovirus genes that influence virus host-range.

  11. 三种抗尿失禁合成吊带兔原位植入后的宿主反应研究%Host tissue reaction in situ to three synthetic anti-incontinence slings in a rabbit model

    Institute of Scientific and Technical Information of China (English)

    邓谋; 罗新; 丁静; 徐弢; 袁玉宇; 王国帅; 刘曼; 赖奎霖; 朱兰

    2015-01-01

    目的采用兔作为动物模型,评估三种不同的抗尿失禁合成吊带原位植入后的宿主反应及安全性。方法45只清洁级新西兰大白兔被随机分为3组,每组15只,A 组采用三维静电仿生聚偏二氟乙烯( polyvinylidene fluoride,PVDF)吊带,B组采用聚丙烯( polypropylene, PP)吊带,C组采用单丝编织聚偏二氟乙烯吊带,分别将三种吊带材料原位植入兔阴道与尿道间隙,于术后4、12和26 w进行观察。结果3组动物术后均无排尿异常情况,大体观察各组材料均与植入前差异不大,各组材料均未出现侵蚀和暴露现象。 A组中形成薄层纤维包裹,轻度炎性细胞浸润,大量血管再生,有少量细胞长入材料内部;B组和C组中材料周围形成较厚的纤维包裹,伴较少炎性细胞浸润,长期观察见增生的纤维组织局部长入周围组织。3组在4w、12 w和26 w的组织病理学评分比较差异均无统计学意义(P>0.05)。结论三种吊带原位植入后均较安全。三维仿生PVDF吊带可能成为一种治疗女性压力性尿失禁的理想吊带。%Objective To evaluate the host tissue reaction and safety in a rabbit model after in situ implantation of three different synthetic anti-incontinence slings.MethodS A total of 45 clean female New Zealand rabbits were randomized into three groups with 15 in each group, group A used three -dimensional electrospinning Polyvinylidene fluoride ( PVDF ) sling, ( group B used polypropylene ( PP) sling, and group C used traditional technique PVDF sling.In each group, a piece of implant was placed into the space between urethra and vagina of the rabbits.Animals were sacrificed at week 4, 12, 26 after implantation for gross observation and histopathologic study.Results Postoperative abnormal urination, sling erosion or retraction were not observed in 3 groups.No obvious difference was observed in 3 groups under gross observation before and after

  12. Visual Surround Suppression in Schizophrenia

    Science.gov (United States)

    Tibber, Marc S.; Anderson, Elaine J.; Bobin, Tracy; Antonova, Elena; Seabright, Alice; Wright, Bernice; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast – a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with SZ demonstrated weaker SS compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation SS in SZ may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies. PMID:23450069

  13. Effects of plant tissue factors of the acceptance of four greenhouse vegetable host plants by the greenhouse whitefly: an electrical penetration graph (EPG) study

    NARCIS (Netherlands)

    Lei, H.; Lenteren, van J.C.; Xu, R.M.

    2001-01-01

    A combination of biological control and host-plant resistance is needed to control greenhouse whitefly, Trialeurodes vaporariorum (Westwood). The high level of susceptibility of several host plants to whitefly, based on their performance on these plants, is well documented. These studies only

  14. Enhancerless cytomegalovirus is capable of establishing a low-level maintenance infection in severely immunodeficient host tissues but fails in exponential growth.

    Science.gov (United States)

    Podlech, Jürgen; Pintea, Rares; Kropp, Kai A; Fink, Annette; Lemmermann, Niels A W; Erlach, Katja C; Isern, Elena; Angulo, Ana; Ghazal, Peter; Reddehase, Matthias J

    2010-06-01

    Major immediate-early transcriptional enhancers are genetic control elements that act, through docking with host transcription factors, as a decisive regulatory unit for efficient initiation of the productive virus cycle. Animal models are required for studying the function of enhancers paradigmatically in host organs. Here, we have sought to quantitatively assess the establishment, maintenance, and level of in vivo growth of enhancerless mutants of murine cytomegalovirus in comparison with those of an enhancer-bearing counterpart in models of the immunocompromised or immunologically immature host. Evidence is presented showing that enhancerless viruses are capable of forming restricted foci of infection but fail to grow exponentially.

  15. The controversy surrounding bone morphogenetic proteins in the spine: a review of current research.

    Science.gov (United States)

    Hustedt, Joshua W; Blizzard, Daniel J

    2014-12-01

    Bone morphogenetic proteins have been in use in spinal surgery since 2002. These proteins are members of the TGF-beta superfamily and guide mesenchymal stem cells to differentiate into osteoblasts to form bone in targeted tissues. Since the first commercial BMP became available in 2002, a host of research has supported BMPs and they have been rapidly incorporated in spinal surgeries in the United States. However, recent controversy has arisen surrounding the ethical conduct of the research supporting the use of BMPs. Yale University Open Data Access (YODA) recently teamed up with Medtronic to offer a meta-analysis of the effectiveness of BMPs in spinal surgery. This review focuses on the history of BMPs and examines the YODA research to guide spine surgeons in their use of BMP in spinal surgery.

  16. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    Background: The placenta is the base for the exchange of nutrients, oxygen and waste products for the fetus. The placental vessels hold a crucial role in regulation the blood flow, and a compromised placental function leads to serious complications such as fetal death or growth retardation. An in...

  17. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    Background. The placenta is the base for the exchange of nutrients, oxygen and waste products for the fetus.The placental vessels hold a crucial role in regulation the blood flow, and a compromised placental function leads to serious complications such as fetal death or growth retardation...

  18. Preparation of monoclonal antibodies to nuclear matrix proteins of tissues surrounding esophagus cancer and its preliminary identification%食管癌旁组织核基质蛋白单克隆抗体的制备及初步鉴定

    Institute of Scientific and Technical Information of China (English)

    张新梅; 林汉良; 刘乐和; 张昌卿; 钟叔平; 曾金云; 郑克立

    2000-01-01

    目的 制备抗食管癌旁组织核基质蛋白的特异性单抗。方法 SDS-PAGE分析正常食管组织、食管癌旁组织及 食管癌组织核基质蛋白间的差异。用食管癌旁组织核基质蛋白做免疫原免疫Balb/c小鼠,利用杂交瘤技术制备了5株能稳定 分泌单克隆抗体的杂交瘤细胞株,并对9-1-2/D、9-1-7/D 2株细胞作了初步鉴定。结果 免疫组化分析发现9-1-2/D单抗与食管 癌及正常食管组织均有反应,而9-1-7/D单抗只与食管癌组织反应,与正常食管组织无反应。Western Blotting分析显示: 9-1-2/D单抗与电泳图谱上正常食管组织核基质和食管癌旁组织核基质52 kD的蛋白反应,而与食管癌组织核基质55 kD的蛋 白反应。9-1-7/D单抗只与电泳图谱上食管癌旁组织及癌组织核基质46 kD的蛋白反应,与正常食管组织核基质无反应。结论 本实验为食管癌的早期诊断作了初步有意义的探讨。%Objective To prepare anti-nuclear matrix proteins of tissues surrounding esophagus cancer monoclonal anti- bodies. Methods Differences among nuclear matrix proteins (NMPS) of normal esophagus tissues, esophagus cancer tissues and tissues adjacent to cancer were identified by SDS-PAGE. Balb/c mouse were hyperimmunized with NMPS of tissues adja- cent to esophagus cancer. Five mouse lymphocyte hybridoma cell lines were established and preliminary identification of cell lines 9-1-2/D, 9-1-7/D were made. Results Immunohistochemical analysis showed monoclonal antibody 9-1-2/D reacted both with esophagus cancer and normal esophageal tissues; monoclonal antibody 9-1-7/D reacted only with nucleoli of esophagus cancer cells. Western Blotting analysis showed monoclonal antibody 9-1-2/D reacted with 52 kD NMPS of normal esophagus tissues and tissues adjacent to esophagus cancer and reacted with 55 kD NMP of esophagus cancer tissue. Monoclonal anti- body 9-1-7/D reacted only with 46 kD protein of esophagus cancer

  19. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  20. Reduced surround inhibition in musicians.

    Science.gov (United States)

    Shin, Hae-Won; Kang, Suk Y; Hallett, Mark; Sohn, Young H

    2012-06-01

    To investigate whether surround inhibition (SI) in the motor system is altered in professional musicians, we performed a transcranial magnetic stimulation (TMS) study in 10 professional musicians and 15 age-matched healthy non-musicians. TMS was set to be triggered by self-initiated flexion of the index finger at different intervals ranging from 3 to 1,000 ms. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest and expressed as a percentage. Normalized MEP amplitudes of the abductor digiti minimi (ADM) muscles were compared between the musicians and non-musicians with the primary analysis being the intervals between 3 and 80 ms (during the movement). A mixed-design ANOVA revealed a significant difference in normalized ADM MEPs during the index finger flexion between groups, with less SI in the musicians. This study demonstrated that the functional operation of SI is less strong in musicians than non-musicians, perhaps due to practice of movement synergies involving both muscles. Reduced SI, however, could lead susceptible musicians to be prone to develop task-specific dystonia.

  1. Binaural Rendering in MPEG Surround

    Science.gov (United States)

    Breebaart, Jeroen; Villemoes, Lars; Kjörling, Kristofer

    2008-12-01

    This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  2. 生物全降解聚左旋乳酸/无定形磷酸钙支架植入大鼠体内后周围组织的钙化%Effect of poly-L-lactic acid/amorphous calcium phosphate scaffold on the surrounding tissue calcification after implantation into the rats

    Institute of Scientific and Technical Information of China (English)

    秦超师; 李晓艳; 冯高科; 蒋学俊; 卢钊; 李君

    2015-01-01

    背景:新型生物全降解聚左旋乳酸/无定形磷酸钙支架展现了良好的应用前景,但支架材料植入后是否引起周围组织钙化尚不明确.目的:观察聚左旋乳酸/无定形磷酸钙支架植入SD大鼠肌内组织后对周围组织钙化的影响.方法:将48只SD大鼠随机均分为实验组与对照组,在实验组大鼠背部肌肉组织中植入聚左旋乳酸/无定形磷酸钙支架,在对照组大鼠背部肌肉组织中植入聚左旋乳酸支架.植入后1,2,4,12周,分别检测肝肾功能及血钙、磷、碱性磷酸酶水平;取支架及周围肌肉组织进行苏木精-伊红染色、钙化Von kossa染色、碱性磷酸酶染色及免疫组织化学核因子κB染色,Western blot检测周围肌肉组织白细胞介素6、骨形成蛋白2水平,并检测组织匀浆钙、碱性磷酸酶含量.结果与结论:两组支架植入未造成大鼠肝肾功能的改变,并且随着植入时间延长亦无明显变化.实验组植入后2,4,12周的白细胞介素6表达少于对照组(P 0.05).表明聚左旋乳酸/无定形磷酸钙支架具有良好的安全性及生物相容性,未引起周围组织钙化.%BACKGROUND:Novel fuly biodegradable poly-L-lactic acid/amorphous calcium phosphate (PLLA/ACP) scaffold shows a good prospect of application, but whether the scaffold material has impact on the surrounding tissue calcification is unknown. OBJECTIVE: To observe the influence of PLLA/ACP scaffold material on the calcification of surrounding tissue after implantation of PLLA/ACP scaffold into rats. METHODS:A total of 48 SD rats were divided into experimental group and control group randomly. The experimental group was implanted with PLLA/ACP scaffold material, while the control group was implanted with PLLA scaffold material. At 1, 2, 4, 12 weeks after implantation, the liver function, kidney function and concentrations of calcium, phosphorus, alkaline phosphatase in serum were detected; the muscle tissue around the scaffold

  3. 负压创伤治疗糖尿病足溃疡及对周围组织氧分压的作用研究%Effect of Negative-pressure Wound Therapy for Diabetic Foot Ulcers and Oxygen Partial Pressure for Surrounding Tissue

    Institute of Scientific and Technical Information of China (English)

    颜晓东; 徐国玲; 钟玫; 莫建明; 路文胜; 黄秀禄; 谭小燕; 农月稠

    2012-01-01

    目的 观察负压创伤治疗技术(NPWT)对糖尿病足溃疡的治疗效果.方法 36例糖尿病足溃疡患者采用智能NPWT治疗,22例采用常规清创、换药方法 治疗.两组均辅以控制血糖、血压、抗凝、抗感染及对症支持治疗.观察疗效,并测定溃疡周围组织氧分压.结果 NPWT组总有效率为94.44%,常规治疗组总有效率为81.81%,NPWT组疗效优于常规治疗组(P<0.05).NPWT组治疗后经皮氧分压较治疗前明显提高(P<0.05);常规治疗组治疗后2周无明显提高(P>0.05).结论 NPWT治疗糖尿病足溃疡疗效显著,能提高溃疡周边组织氧分压,这可能是促进创面愈合的重要原因之一.%Objective To discuss thc efficacy of negative-pressure wound therapy( MPWT ) for treatment of diabetic foot utcers. Methods Thirty six patients vvith diabetic foot utcer underwent. MPW'tt MPWT gmup ),22 patients vvkh diabetic foot underwent, conventionat treatment(conventionat treatment gmup). Adjuvant therapy of Wood sugar and Wood pressure controt,anticoagutation,anti-infection and supporting treatment was performed in the two groups. The efficacy was observed and oxygen partiat pressure for surrounding tissue was measured. Resutts The totat effective rate was 94. 44% in MPWT group,which was 81. 81% in conventionat treatment gmup. The efficacy of MPWT gmup was superior to that of conventionat treatment group( P <0. 05 ). Percutaneous oxygen partiat pressure showed a significant improvement in the MPWT group after treatment( P <0. 05 ), which showed no significant improvement in the conventionat treatment group after two-week treatment( P >0. 05 ). Conctusion MPWT for treatment of diabetic foot utcers shows a good effectiveness, which can improve oxygen partiat pressure for surrounding tissue of diabetic foot utcers. It may be one of the important causes to promote wound heating.

  4. Contour detection by surround suppression of texture

    NARCIS (Netherlands)

    Petkov, Nicolai; Tavares, JMRS; Jorge, RMN

    2007-01-01

    Based on a keynote lecture at Complmage 2006, Coimbra, Oct. 20-21, 2006, an overview is given of our activities in modelling and using surround inhibition for contour detection. The effect of suppression of a line or edge stimulus by similar surrounding stimuli is known from visual perception studie

  5. Cystoisospora canis (Apicomplexa: Sarcocystidae): development of monozoic tissue cysts in human cells, demonstration of egress of zoites from tissue cysts, and demonstration of repeat monozoic tissue cyst formation by zoites.

    Science.gov (United States)

    Houk, Alice E; Lindsay, David S

    2013-11-01

    Sporozoites of Cystoisospora canis penetrated and developed to monozoic tissue cysts in 4 human, 1 monkey, 1 bovine and 2 canine cell lines. No asexual division was documented although multiple infection of a single cell was observed. Examination of cultures using transmission electron microscopy demonstrated that they were monozoic tissue cysts and contained a single sporozoite. The appearance of monozoic tissue cysts in all cell lines was similar but the parasitophorous vacuole surrounding some sporozoites in DH82 dog macrophages was swollen. Monozoic tissue cysts were observed for up to 127 days in human pigmented retinal epithelial cells. Treatment of cell cultures containing monozoic tissue cysts with 0.75 sodium taurocholic acid and 0.25% trypsin stimulated egress of zoites (former sporozoites) from tissue cysts. Zoites collected from monozoic tissue cysts were able to penetrate and develop to monozoic tissue cysts in new host cells. Monozoic tissue cysts survived exposure to acid pepsin solution indicating that they would be orally infectious. The tissue cyst wall surrounding zoites did not autofluoresce as did oocyst and sporocyst walls exposed to UV light. We believe that C. canis can be used as a model system to study extra-intestinal monozoic tissue cysts stages of Cystoisospora belli of humans.

  6. Histological comparison of the effect of immediate loading on the surrounding tissue of stainless steel and Ti-alloy micro-implants%组织学比较即刻负载对不锈钢及钛合金微种植体周围组织的影响

    Institute of Scientific and Technical Information of China (English)

    陈岩; Shin Hong-in; 邓耀强; 赵文婷; Kyung Hee-moon

    2014-01-01

    目的 临床与组织学比较即刻负载对正畸用不锈钢及钛合金微种植体及周围组织的影响.方法 不锈钢及钛合金微种植体各24枚,植入于3头18个月龄的微型猪上颌骨内.相邻两枚种植体之间用镍钛闭合弹簧即刻加载约150克左右的水平力.十周后检查微种植体的稳定性.每组选择8枚稳定性好的微种植体进行不脱钙处理,制作组织学磨片,在光学及荧光光学显微镜下观察.用组织测量学图像分析软件测量两组微种植体的骨结合率.P<0.05有统计学意义.结果 1.植入时折断微种植体:不锈钢组2枚,折断率为7.7%;钛合金组9枚,折断率为27.3%;P>0.05.2.临床成功率:不锈钢组75.0%,钛合金组83.3%;P>0.05.3.骨结合率:不锈钢组平均值16.94%,钛合金组37.33%,P<0.05.结论 不锈钢微种植体在即刻负载水平力的条件下有较高的临床成功率和骨结合率,但是,明显的低于钛合金微种植体.%Objective The aim of this study was to investigate the effect of immediate loading on the surrounding tissues of the stainless steel and Ti-alloy micro-implants in mini-pigs clinically and histologically.Methods 24 stainless steel and Ti-alloy micro-implants were planted by self-drilling in the buccal side of the maxillae of three 18 months old mini-pigs.Approximately 150 g constant and continuous force by stretching closed nickel-titanium springs were immediately loaded for every two adjacent micro-implants for ten weeks.Undecalcified section of micro-implants and surrounding tissues were studied with optical microscope and fluorescent microscope.With iMT software,miniscrew-bone integration values were calculated.Results 1.During insertion,two stainless steel miniscrews fractured (7.7%) and 9 Ti-alloy micro-implants fractured (27.30%) (P>0.05).2.The clinical successful placement rate was 75% for stainless steel microimplant group and 83.3% for Ti-alloy group,(P>0.05).3.The integration

  7. On the environment surrounding close-in exoplanets

    CERN Document Server

    Vidotto, A A; Jardine, M; Moutou, C; Donati, J -F

    2015-01-01

    Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e., the stellar wind) much denser than the local conditions encountered around the solar system planets. The environment surrounding these exoplanets also differs in terms of dynamics (slower stellar winds, but higher Keplerian velocities) and ambient magnetic fields (likely higher for host stars more active than the Sun). Here, we quantitatively investigate the nature of the interplanetary media surrounding the hot Jupiters HD46375b, HD73256b, HD102195b, HD130322b, HD179949b. We simulate the three-dimensional winds of their host stars, in which we directly incorporate their observed surface magnetic fields. With that, we derive mass-loss rates (1.9 to 8.0 $\\times 10^{-13} M_{\\odot}$/yr) and the wind properties at the position of the hot-Jupiters' orbits (temperature, velocity, magnetic field intensity and pressure). We show that these exoplanets' orbits are super-magnetosonic, indicating that bow shocks are formed surrou...

  8. Polypyrimidine tract binding protein-1 (PTB1 is a determinant of the tissue and host tropism of a human rhinovirus/poliovirus chimera PV1(RIPO.

    Directory of Open Access Journals (Sweden)

    Nusrat Jahan

    Full Text Available The internal ribosomal entry site (IRES of picornavirus genomes serves as the nucleation site of a highly structured ribonucleoprotein complex essential to the binding of the 40S ribosomal subunit and initiation of viral protein translation. The transition from naked RNA to a functional "IRESome" complex are poorly understood, involving the folding of secondary and tertiary RNA structure, facilitated by a tightly concerted binding of various host cell proteins that are commonly referred to as IRES trans-acting factors (ITAFs. Here we have investigated the influence of one ITAF, the polypyrimidine tract-binding protein 1 (PTB1, on the tropism of PV1(RIPO, a chimeric poliovirus in which translation of the poliovirus polyprotein is under the control of a human rhinovirus type 2 (HRV2 IRES element. We show that PV1(RIPO's growth defect in restrictive mouse cells is partly due to the inability of its IRES to interact with endogenous murine PTB. Over-expression of human PTB1 stimulated the HRV2 IRES-mediated translation, resulting in increased growth of PV1(RIPO in murine cells and human neuronal SK-N-MC cells. Mutations within the PV1(RIPO IRES, selected to grow in restrictive mouse cells, eliminated the human PTB1 supplementation requirement, by restoring the ability of the IRES to interact with endogenous murine PTB. In combination with our previous findings these results give a compelling insight into the thermodynamic behavior of IRES structures. We have uncovered three distinct thermodynamic aspects of IRES formation which may independently contribute to overcome the observed PV1(RIPO IRES block by lowering the free energy δG of the IRESome formation, and stabilizing the correct and functional structure: 1 lowering the growth temperature, 2 modifying the complement of ITAFs in restricted cells, or 3 selection of adaptive mutations. All three mechanisms can conceivably modulate the thermodynamics of RNA folding, and thus facilitate and stabilize

  9. Polypyrimidine tract binding protein-1 (PTB1) is a determinant of the tissue and host tropism of a human rhinovirus/poliovirus chimera PV1(RIPO).

    Science.gov (United States)

    Jahan, Nusrat; Wimmer, Eckard; Mueller, Steffen

    2013-01-01

    The internal ribosomal entry site (IRES) of picornavirus genomes serves as the nucleation site of a highly structured ribonucleoprotein complex essential to the binding of the 40S ribosomal subunit and initiation of viral protein translation. The transition from naked RNA to a functional "IRESome" complex are poorly understood, involving the folding of secondary and tertiary RNA structure, facilitated by a tightly concerted binding of various host cell proteins that are commonly referred to as IRES trans-acting factors (ITAFs). Here we have investigated the influence of one ITAF, the polypyrimidine tract-binding protein 1 (PTB1), on the tropism of PV1(RIPO), a chimeric poliovirus in which translation of the poliovirus polyprotein is under the control of a human rhinovirus type 2 (HRV2) IRES element. We show that PV1(RIPO)'s growth defect in restrictive mouse cells is partly due to the inability of its IRES to interact with endogenous murine PTB. Over-expression of human PTB1 stimulated the HRV2 IRES-mediated translation, resulting in increased growth of PV1(RIPO) in murine cells and human neuronal SK-N-MC cells. Mutations within the PV1(RIPO) IRES, selected to grow in restrictive mouse cells, eliminated the human PTB1 supplementation requirement, by restoring the ability of the IRES to interact with endogenous murine PTB. In combination with our previous findings these results give a compelling insight into the thermodynamic behavior of IRES structures. We have uncovered three distinct thermodynamic aspects of IRES formation which may independently contribute to overcome the observed PV1(RIPO) IRES block by lowering the free energy δG of the IRESome formation, and stabilizing the correct and functional structure: 1) lowering the growth temperature, 2) modifying the complement of ITAFs in restricted cells, or 3) selection of adaptive mutations. All three mechanisms can conceivably modulate the thermodynamics of RNA folding, and thus facilitate and stabilize the

  10. A permeability barrier surrounds taste buds in lingual epithelia.

    Science.gov (United States)

    Dando, Robin; Pereira, Elizabeth; Kurian, Mani; Barro-Soria, Rene; Chaudhari, Nirupa; Roper, Stephen D

    2015-01-01

    Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003-1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste.

  11. On the environment surrounding close-in exoplanets

    Science.gov (United States)

    Vidotto, A. A.; Fares, R.; Jardine, M.; Moutou, C.; Donati, J.-F.

    2015-06-01

    Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e. the stellar wind) much denser than the local conditions encountered around the Solar system planets. The environment surrounding these exoplanets also differs in terms of dynamics (slower stellar winds, but higher Keplerian velocities) and ambient magnetic fields (likely higher for host stars more active than the Sun). Here, we quantitatively investigate the nature of the interplanetary media surrounding the hot Jupiters HD 46375b, HD 73256b, HD 102195b, HD 130322b and HD 179949b. We simulate the three-dimensional winds of their host stars, in which we directly incorporate their observed surface magnetic fields. With that, we derive mass-loss rates (1.9-8.0 × 10-13 M⊙ yr-1) and the wind properties at the position of the hot Jupiters' orbits (temperature, velocity, magnetic field intensity and pressure). We show that these exoplanets' orbits are supermagnetosonic, indicating that bow shocks are formed surrounding these planets. Assuming planetary magnetic fields similar to Jupiter's, we estimate planetary magnetospheric sizes of 4.1-5.6 planetary radii. We also derive the exoplanetary radio emission released in the dissipation of the stellar wind energy. We find radio fluxes ranging from 0.02 to 0.13 mJy, which are challenging to be observed with present-day technology, but could be detectable with future higher sensitivity arrays (e.g. Square Kilometre Array). Radio emission from systems having closer hot Jupiters, such as from τ Boo b or HD 189733b, or from nearby planetary systems orbiting young stars, are likely to have higher radio fluxes, presenting better prospects for detecting exoplanetary radio emission.

  12. Agroforestry practice in villages surrounding Nyamure former ...

    African Journals Online (AJOL)

    cntaganda

    Key words: Agroforestry, fuel wood, tree products, woodlot, forest plantation. INTRODUCTION ... The study area included three administrative cells in the surroundings of Nyamure ..... Table 6: Distance and time spent on firewood collection.

  13. Explaining preferences for home surroundings and locations

    Directory of Open Access Journals (Sweden)

    Hans Skifter Andersen

    2011-01-01

    Full Text Available This article is based on a survey carried out in Denmark that asked a random sample of the population about their preferences for home surroundings and locations. It shows that the characteristics of social surroundings are very important and can be divided into three independent dimensions: avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific preferences for surroundings.

  14. Three-Dimensional Human Bronchial-Tracheal Epithelial Tissue-Like Assemblies (TLAs) as Hosts For Severe Acute Respiratory Syndrome (SARS)-CoV Infection

    Science.gov (United States)

    Suderman, M. T.; McCarthy, M.; Mossell, E.; Watts, D. M.; Peters, C. J.; Shope, R.; Goodwin, T. J.

    2006-01-01

    A three-dimensional (3-D) tissue-like assembly (TLA) of human bronchial-tracheal mesenchymal (HBTC) cells with an overlay of human bronchial epithelial (BEAS-2B) cells was constructed using a NASA Bioreactor to survey the infectivity of SARS-CoV. This TLA was inoculated with a low passage number Urbani strain of SARS-CoV. At selected intervals over a 10-day period, media and cell aliquots of the 3-D TLA were harvested for viral titer assay and for light and electron microscopy examination. All viral titer assays were negative in both BEAS-2B two-dimensional monolayer and TLA. Light microscopy immunohistochemistry demonstrated antigen-antibody reactivity with anti-SARS-CoV polyclonal antibody to spike and nuclear proteins on cell membranes and cytoplasm. Coronavirus Group 2 cross-reactivity was demonstrated by positive reaction to anti-FIPV 1 and anti-FIPV 1 and 2 antibodies. TLA examination by transmission electron microscopy indicated increasing cytoplasmic vacuolation with numerous electron-dense bodies measuring 45 to 270 nm from days 4 through 10. There was no evidence of membrane blebbing, membrane duplication, or fragmentation of organelles in the TLAs. However, progressive disruption of endoplasmic reticulum was observed throughout the cells. Antibody response to SARS-CoV specific spike and nucleocapsid glycoproteins, cross-reactivity with FIPV antibodies, and the cytoplasmic pathology suggests this HBTE TLA model is permissive to SARS-CoV infection.

  15. Surround-Masking Affects Visual Estimation Ability

    Science.gov (United States)

    Jastrzebski, Nicola R.; Hugrass, Laila E.; Crewther, Sheila G.; Crewther, David P.

    2017-01-01

    Visual estimation of numerosity involves the discrimination of magnitude between two distributions or perceptual sets that vary in number of elements. How performance on such estimation depends on peripheral sensory stimulation is unclear, even in typically developing adults. Here, we varied the central and surround contrast of stimuli that comprised a visual estimation task in order to determine whether mechanisms involved with the removal of unessential visual input functionally contributes toward number acuity. The visual estimation judgments of typically developed adults were significantly impaired for high but not low contrast surround stimulus conditions. The center and surround contrasts of the stimuli also differentially affected the accuracy of numerosity estimation depending on whether fewer or more dots were presented. Remarkably, observers demonstrated the highest mean percentage accuracy across stimulus conditions in the discrimination of more elements when the surround contrast was low and the background luminance of the central region containing the elements was dark (black center). Conversely, accuracy was severely impaired during the discrimination of fewer elements when the surround contrast was high and the background luminance of the central region was mid level (gray center). These findings suggest that estimation ability is functionally related to the quality of low-order filtration of unessential visual information. These surround masking results may help understanding of the poor visual estimation ability commonly observed in developmental dyscalculia.

  16. Do symbiotic bacteria subvert host immunity?

    Science.gov (United States)

    Hooper, Lora V

    2009-05-01

    The mammalian intestine is home to dense and complex indigenous bacterial communities. Most of these bacteria establish beneficial symbiotic relationships with their hosts, making important contributions to host metabolism and digestive efficiency. The vast numbers of intestinal bacteria and their proximity to host tissues raise the question of how symbiotic host-bacterial relationships are established without eliciting potentially harmful immune responses. In light of the varied ways in which pathogenic bacteria manipulate host immunity, this Opinion article explores the role of immune suppression, subversion and evasion in the establishment of symbiotic host-bacterial associations.

  17. Meningococcal interactions with the host.

    Science.gov (United States)

    Carbonnelle, Etienne; Hill, Darryl J; Morand, Philippe; Griffiths, Natalie J; Bourdoulous, Sandrine; Murillo, Isabel; Nassif, Xavier; Virji, Mumtaz

    2009-06-24

    Neisseria meningitidis interacts with host tissues through hierarchical, concerted and co-ordinated actions of a number of adhesins; many of which undergo antigenic and phase variation, a strategy that helps immune evasion. Three major structures, pili, Opa and Opc predominantly influence bacterial adhesion to host cells. Pili and Opa proteins also determine host and tissue specificity while Opa and Opc facilitate efficient cellular invasion. Recent studies have also implied a role of certain adhesin-receptor pairs in determining increased host susceptibility to infection. This chapter examines our current knowledge of meningococcal adhesion and invasion mechanisms particularly related to human epithelial and endothelial cells which are of primary importance in the disease process.

  18. Role of porcine serum haptoglobin in the host-parasite relationship of Taenia solium cysticercosis.

    Science.gov (United States)

    Navarrete-Perea, José; Toledano-Magaña, Yanis; De la Torre, Patricia; Sciutto, Edda; Bobes, Raúl José; Soberón, Xavier; Laclette, Juan Pedro

    2016-06-01

    Human and porcine cysticercosis is a parasitic disease caused by the larval stage (cysts) of the tapeworm Taenia solium. Cysts may live in several host tissues such as skeletal muscle or brain. We have previously described the presence of host haptoglobin (Hp) and hemoglobin (Hb) in different protein extracts of the T. solium cysts. Here, we report the binding of host Hp and Hb to a number of cyst proteins, evaluated through measuring electrophoretic and light absorbance changes. In the sera obtained from 18 cysticercotic pigs, Hp-Hb complexes were abundant, whereas free Hp was undetectable. In contrast, in the sera from non 18 cysticercotic pigs, Hp-Hb and free Hp were found. In the soluble protein fraction of cysts tissue, free Hp was detected showing a considerable Hb-binding ability, whereas in the vesicular fluid, Hp is mainly bound to Hb. Interestingly, assays carried out with the insoluble fraction of T. solium cysts tissue, showed binding of Hp and Hp-Hb in a saturable way, suggesting the existence of specific interactions. Our results suggested that the parasite can take advantage of the uptaken host Hp and Hb, either free or in complexes, as a source of iron or as a way to modulate the inflammatory response surrounding the T. solium cysts.

  19. 切口周围组织中白细胞介素-1β参与尼古丁戒断大鼠术后切口痛痛觉过敏的研究%Interleukin-1β in the surrounding incision tissues is involved in postoperative hyperalgesia in rats with nicotine withdrawal

    Institute of Scientific and Technical Information of China (English)

    逯素芬; 于爱兰; 刘献文; 张宗旺

    2014-01-01

    目的 探讨切口周围组织中白细胞介素(interleukin,IL)-1β在尼古丁戒断大鼠术后切口痛痛觉过敏中的作用.方法 SD大鼠96只,按随机数字表法分为4组:正常对照组(Naive组,6只)、尼古丁戒断组(NT组,30只)、切口痛组(IP组,30只)和尼古丁戒断切口痛组(NT+IP组,30只).NT组、IP组和NT+IP组大鼠按术前2h和术后2、24、48、72 h分为5个亚组,每个亚组6只.观察各组大鼠上述时间点机械刺激缩足阈值(paw mechanical withdrawal threshold,MWT)、热刺激缩足潜伏期(paw thermal withdrawal latency,TWL)和后爪水肿的变化;取大鼠术侧后爪切口周围皮肤组织,应用酶联免疫分析法检测IL-1β含量.结果 与IP组比较,NT+IP组大鼠术后2、24、48、72 h MwT和TWL均降低(P<0.05),且术侧后爪水肿明显,其中以术后24 h水肿最为显著(P<0.01).与IP组各时间点比较,NT+IP组大鼠相应时间点切口周围组织中IL-1β水平明显增高(P<0.01).与术前2 h(19.7±1.9) ng/L比较,NT+IP组大鼠切口周围组织中IL-1β水平术后各时间点均明显升高(P<0.01);术后2h(62.2±3.7) ng/L开始升高,至术后48 h(129.5±6.3) ng/L达高峰,术后72 h开始回降.结论 尼古丁戒断引起大鼠术后痛觉敏感性增高,局部水肿明显;IL-1β参与了尼古丁戒断大鼠术后切口痛痛觉过敏.%Objective To explore the contribution of interleukin (IL)-1β in surrounding incision tissues to postoperative hyperalgesia in rats with nicotine withdrawal.Methods Ninety-six SD rats were randomly divided into Naive group (n=6),NT group (n=30),IP group (n=30) and NT+IP group (n=30).The rats in NT group,IP group and NT+IP group were divided into 5 subgroups by preoperative 2 h,postoperative 2,24,48 h and 72 h,six in each subgroup.Both paw mechanical withdrawal threshold (MWT) and paw thermal withdrawal latency (TWL) were determined at above time points for every rats.The hind paw edema was also observed.The level of IL-1β in the

  20. Tissue formation and tissue engineering through host cell recruitment or a potential injectable cell-based biocomposite with replicative potential: Molecular mechanisms controlling cellular senescence and the involvement of controlled transient telomerase activation therapies.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2015-12-01

    . Nuclear export is initiated by ROS-induced phosphorylation of tyrosine 707 within hTERT by the Src kinase family. It might be presumed that protection of mitochondria against oxidative stress is an important telomere length-independent function for telomerase in cell survival. Biotechnology companies are focused on development of therapeutic telomerase vaccines, telomerase inhibitors, and telomerase promoter-driven cell killing in oncology, have a telomerase antagonist in late preclinical studies. Anti-aging medicine-oriented groups have intervened on the market with products working on telomerase activation for a broad range of degenerative diseases in which replicative senescence or telomere dysfunction may play an important role. Since oxidative damage has been shown to shorten telomeres in tissue culture models, the adequate topical, transdermal, or systemic administration of antioxidants (such as, patented ocular administration of 1% N-acetylcarnosine lubricant eye drops in the treatment of cataracts) may be beneficial at preserving telomere lengths and delaying the onset or in treatment of disease in susceptible individuals. Therapeutic strategies toward controlled transient activation of telomerase are targeted to cells and replicative potential in cell-based therapies, tissue engineering and regenerative medicine.

  1. Smart Chips for Smart Surroundings - 4S

    NARCIS (Netherlands)

    Schuler, Eberhard; König, Ralf; Becker, Jürgen; Rauwerda, Gerard; Burgwal, van de Marcel; Smit, Gerard J.M.; Cardoso, João M.P.; Hübner, Michael

    2011-01-01

    The overall mission of the 4S project (Smart Chips for Smart Surroundings) was to define and develop efficient flexible, reconfigurable core building blocks, including the supporting tools, for future Ambient System Devices. Reconfigurability offers the needed flexibility and adaptability, it provid

  2. Host response mechanisms in periodontal diseases

    Science.gov (United States)

    SILVA, Nora; ABUSLEME, Loreto; BRAVO, Denisse; DUTZAN, Nicolás; GARCIA-SESNICH, Jocelyn; VERNAL, Rolando; HERNÁNDEZ, Marcela; GAMONAL, Jorge

    2015-01-01

    Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4+ T-cells (T-helper cells). Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs) and bone-resorbing osteoclasts (OCLs). This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as a stage that

  3. Host response mechanisms in periodontal diseases

    Directory of Open Access Journals (Sweden)

    Nora SILVA

    2015-06-01

    Full Text Available Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4+ T-cells (T-helper cells. Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs and bone-resorbing osteoclasts (OCLs. This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as

  4. Multifunctional Hydrogel with Good Structure Integrity, Self-Healing, and Tissue-Adhesive Property Formed by Combining Diels-Alder Click Reaction and Acylhydrazone Bond.

    Science.gov (United States)

    Yu, Feng; Cao, Xiaodong; Du, Jie; Wang, Gang; Chen, Xiaofeng

    2015-11-04

    Hydrogel, as a good cartilage tissue-engineered scaffold, not only has to possess robust mechanical property but also has to have an intrinsic self-healing property to integrate itself or the surrounding host cartilage. In this work a double cross-linked network (DN) was designed and prepared by combining Diels-Alder click reaction and acylhydrazone bond. The DA reaction maintained the hydrogel's structural integrity and mechanical strength in physiological environment, while the dynamic covalent acylhydrazone bond resulted in hydrogel's self-healing property and controlled the on-off switch of network cross-link density. At the same time, the aldehyde groups contained in hydrogel further promote good integration of the hydrogel to surrounding tissue based on aldehyde-amine Schiff-base reaction. This kind of hydrogel has good structural integrity, autonomous self-healing, and tissue-adhesive property and simultaneously will have a good application in tissue engineering and tissue repair field.

  5. Host epithelial geometry regulates breast cancer cell invasiveness

    Science.gov (United States)

    Boghaert, Eline; Gleghorn, Jason P.; Lee, KangAe; Gjorevski, Nikolce; Radisky, Derek C.; Nelson, Celeste M.

    2012-01-01

    Breast tumor development is regulated in part by cues from the local microenvironment, including interactions with neighboring nontumor cells as well as the ECM. Studies using homogeneous populations of breast cancer cell lines cultured in 3D ECM have shown that increased ECM stiffness stimulates tumor cell invasion. However, at early stages of breast cancer development, malignant cells are surrounded by normal epithelial cells, which have been shown to exert a tumor-suppressive effect on cocultured cancer cells. Here we explored how the biophysical characteristics of the host microenvironment affect the proliferative and invasive tumor phenotype of the earliest stages of tumor development, by using a 3D microfabrication-based approach to engineer ducts composed of normal mammary epithelial cells that contained a single tumor cell. We found that the phenotype of the tumor cell was dictated by its position in the duct: proliferation and invasion were enhanced at the ends and blocked when the tumor cell was located elsewhere within the tissue. Regions of invasion correlated with high endogenous mechanical stress, as shown by finite element modeling and bead displacement experiments, and modulating the contractility of the host epithelium controlled the subsequent invasion of tumor cells. Combining microcomputed tomographic analysis with finite element modeling suggested that predicted regions of high mechanical stress correspond to regions of tumor formation in vivo. This work suggests that the mechanical tone of nontumorigenic host epithelium directs the phenotype of tumor cells and provides additional insight into the instructive role of the mechanical tumor microenvironment. PMID:23150585

  6. The Interstellar Cloud Surrounding the Solar System

    Science.gov (United States)

    Frisch, P. C.

    Ultraviolet spectral data of nearby stars indicate that the cloud surrounding the solar system has an average neutral density n(HI)~0.1 cm-3, temperature ~6800 K, and turbulence ~1.7 km/s. Comparisons between the anomalous cosmic ray data and ultraviolet data suggest that the electron density is in the range n(e-)~0.22 to 0.44 cm-3. This cloud is flowing past the Sun from a position centered in the Norma-Lupis region. The cloud properties are consistent with interstellar gas which originated as material evaporated from the surfaces of embedded clouds in the Scorpius-Centaurus Association, and which was then displaced towards the Sun by a supernova event about 4 Myrs ago. The Sun and surrounding cloud velocities are nearly perpendicular in space, and this cloud is sweeping past the Sun. The morphology of this cloud can be reconstructed by assuming that the cloud moves in a direction parallel to the surface normal. With this assumption, the Sun entered the surrounding cloud 2000 to 8000 years ago, and is now about 0.05 to 0.16 pc from the cloud surface. Prior to its recent entry into the surrounding cloud complex, the Sun was embedded in a region of space with average density lower than 0.0002 cm-3. If a denser cloud velocity component seen towards alpha Cen A,B is real, it will encounter the solar system within 50,000 yr. The nearby magnetic field seen upwind has a spatial orientation that is parallel to the cloud surface. The nearby star Sirius is viewed through the wake of the solar system, but this direction also samples the hypothetical cloud interface. Comparisons of anomalous cosmic ray and interstellar absorption line data suggest that trace elements in the surrounding cloud are in ionization equilibrium. Data towards nearby white dwarfs indicate partial helium ionization, N(N(HI)(/N(HeI)>~13.7, which is consistent with pickup ion data within the solar system if less than 40% hydrogen ionization occurs in the heliopause region. However, the white dwarfs may

  7. Persistent Confusion and Controversy Surrounding Gene Patents

    Science.gov (United States)

    Guerrini, Christi J.; Majumder, Mary A.; McGuire, Amy L.

    2016-01-01

    There is persistent confusion and controversy surrounding basic issues of patent law relevant to the genomics industry. Uncertainty and conflict can lead to the adoption of inefficient practices and exposure to liability. The development of patent-specific educational resources for industry members, as well as the prompt resolution of patentability rules unsettled by recent U.S. Supreme Court decisions, are therefore urgently needed. PMID:26849516

  8. Host conservatism or host specialization? Patterns of fungal diversification are influenced by host specificity in Ophiognomonia (Gnomoniaceae, Diaporthales)

    Science.gov (United States)

    Species of Ophiognomonia (Gnomoniaceae) are perithecial fungi that occur as endophytes, pathogens, and latent saprobes on leaf and stem tissue of plants in the Betulaceae, Fagaceae, Juglandaceae, Lauraceae, Malvaceae, Platanaceae, Rosaceae, Salicaceae, and Sapindaceae. In this study host plant patte...

  9. Identification of -SiC surrounded by relatable surrounding diamond medium using weak Raman surface phonons

    Indian Academy of Sciences (India)

    Mohan Kumar Kuntumalla; Harish Ojha; Vadali Venkata Satya Siva Srikanth

    2013-11-01

    It is difficult to detect -SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, -SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/-SiC nanocomposite thin film system is considered in which nanosized -SiC crystallites are surrounded by a relatable nanodiamond medium that leads to the appearance of a weak Raman surface phonon band at about 855 cm-1. Change in the nature of the surrounding material structure and its volume content when relatable, will affect the resultant Raman response of -SiC phase as seen in the present case of diamond/-SiC nanocomposite thin films.

  10. Differences in inferred genome-wide signals of positive selection during the evolution of Trypanosoma cruzi and Leishmania spp. lineages: A result of disparities in host and tissue infection ranges?

    Science.gov (United States)

    Flores-López, Carlos A; Machado, Carlos A

    2015-07-01

    Trypanosoma cruzi and Leishmania spp. are kinetoplastids responsible for Chagas disease and Leishmaniasis, neglected tropical diseases for which there are no effective methods of control. These two human pathogens differ widely in the range of mammal species they can infect, their cell/tissue tropism and cell invasion mechanisms. Whether such major biological differences have had any impact on genome-wide patterns of genetic diversification in both pathogens has not been explored. The recent genome sequencing projects of medically important species of Leishmania and T. cruzi lineages provide unique resources for performing comparative evolutionary analyses to address that question. We show that inferred genome-wide signals of positive selection are higher in T. cruzi proteins than in Leishmania spp. proteins. We report significant differences in the fraction of protein-coding genes showing evidence of positive selection in the two groups of parasites, and also report that the intensity of positive selection and the proportion of sites under selection are higher in T. cruzi than in Leishmania spp. The pattern is unlikely to be the result of confounding factors like differences in GC content, average gene length or differences in reproductive mode between the two taxa. We propose that the greater versatility of T. cruzi in its host range, cell tropism and cell invasion mechanisms may explain the observed differences between the two groups of parasites. Genes showing evidence of positive selection within each taxonomic group may be under diversifying selection to evade the immune system and thus, depending on their functions, could represent viable candidates for the development of drugs or vaccines for these neglected human diseases.

  11. Explaining preferences for home surroundings and locations

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter

    2011-01-01

    : avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places...... with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific...

  12. Role of constitutive behavior and tumor-host mechanical interactions in the state of stress and growth of solid tumors.

    Directory of Open Access Journals (Sweden)

    Chrysovalantis Voutouri

    Full Text Available Mechanical forces play a crucial role in tumor patho-physiology. Compression of cancer cells inhibits their proliferation rate, induces apoptosis and enhances their invasive and metastatic potential. Additionally, compression of intratumor blood vessels reduces the supply of oxygen, nutrients and drugs, affecting tumor progression and treatment. Despite the great importance of the mechanical microenvironment to the pathology of cancer, there are limited studies for the constitutive modeling and the mechanical properties of tumors and on how these parameters affect tumor growth. Also, the contribution of the host tissue to the growth and state of stress of the tumor remains unclear. To this end, we performed unconfined compression experiments in two tumor types and found that the experimental stress-strain response is better fitted to an exponential constitutive equation compared to the widely used neo-Hookean and Blatz-Ko models. Subsequently, we incorporated the constitutive equations along with the corresponding values of the mechanical properties - calculated by the fit - to a biomechanical model of tumor growth. Interestingly, we found that the evolution of stress and the growth rate of the tumor are independent from the selection of the constitutive equation, but depend strongly on the mechanical interactions with the surrounding host tissue. Particularly, model predictions - in agreement with experimental studies - suggest that the stiffness of solid tumors should exceed a critical value compared with that of the surrounding tissue in order to be able to displace the tissue and grow in size. With the use of the model, we estimated this critical value to be on the order of 1.5. Our results suggest that the direct effect of solid stress on tumor growth involves not only the inhibitory effect of stress on cancer cell proliferation and the induction of apoptosis, but also the resistance of the surrounding tissue to tumor expansion.

  13. Adipose tissue fibrosis

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The increasing prevalence of obesity causes a majorinterest in white adipose tissue biology. Adipose tissuecells are surrounded by extracellular matrix proteinswhose composition and remodeling is of crucial importancefor cell function. The expansion of adipose tissue inobesity is linked to an inappropriate supply with oxygenand hypoxia development. Subsequent activation ofhypoxia inducible factor 1 (HIF-1) inhibits preadipocytedifferentiation and initiates adipose tissue fibrosis. Therebyadipose tissue growth is limited and excess triglyceridesare stored in ectopic tissues. Stressed adipocytes andhypoxia contribute to immune cell immigration andactivation which further aggravates adipose tissuefibrosis. There is substantial evidence that adipose tissuefibrosis is linked to metabolic dysfunction,both in rodentmodels and in the clinical setting. Peroxisome proliferatoractivated receptor gamma agonists and adiponectin bothreduce adipose tissue fibrosis, inflammation and insulinresistance. Current knowledge suggests that antifibroticdrugs, increasing adipose tissue oxygen supply or HIF-1antagonists will improve adipose tissue function andthereby ameliorate metabolic diseases.

  14. Laser/tissue interaction.

    Science.gov (United States)

    Dederich, D N

    1991-01-01

    When laser light impinges on tissue, it can reflect, scatter, be absorbed, or transmit to the surrounding tissue. Absorption controls to a great degree the extent to which reflection, scattering and transmission occur, and wavelength is the primary determinant of absorption. The CO2 laser is consistently absorbed by most materials and tissues and the Nd-YAG laser wavelength is preferentially absorbed in pigmented tissues. The factors which determine the initial tissue effect include the laser wavelength, laser power, laser waveform, tissue optical properties, and tissue thermal properties. There are almost an infinite number of combinations of these factors possible, many of which would result in unacceptable damage to the tissues. This underscores the need to thoroughly test any particular combination of these factors on the conceptual, in-vitro, and in-vivo level before a treatment is offered.

  15. IN VITRO INOCULATION OF ASPARAGUS OFFICINALIS TISSUE CULTURE SHOOTS WITH FUSARIUM PROLIFERA TUM

    Directory of Open Access Journals (Sweden)

    A.K.MoHD OMAR

    1999-01-01

    Full Text Available Artificially inoculated asparagus tissue culture plantlets with a virulent fungus, Fusarium proliferatum showed signs of infection as early as 4 days after inoculat ion. Macroscopic observations revealed presence of early symptoms such as necrotic lesions at the affected area and light microscopic examinations clearly revealed the post-penetration events that took place including the destruction of surrounding cells. However, little is known of the hyphal activity or advancement on the host's surface at the initial stage after inoculation. Scanning electron microscopic examination clearly revealed the hyphal advancement on the surface and the mode of entrance into the host tissues beneath. Four days after inoculation, the fungi proceeded to spread out from the inoculation point onto the host surface which eventually developed into a sparse network of both aerial and non-aerial hyphae. Non-aerial hyphae form a network of mycelium that adheres to the surface and it's movement appeared to be oriented towards the stomata. Hyphal penetration occurs more often through the stomata, natural openings or wounds. In some cases, the hyphae crossed over the stomatal opening w ithout entering the host tissues. At places where the cuticle layer is absent or not well developed the hyphae successfully grew in between the epidermal cells into the tissues beneath.

  16. Characterizing the Microenvironment Surrounding Phosphorylated Protein Sites

    Institute of Scientific and Technical Information of China (English)

    Shi-Cai Fan; Xue-Gong Zhang

    2005-01-01

    Protein phosphorylation plays an important role in various cellular processes. Due to its high complexity, the mechanism needs to be further studied. In the last few years, many methods have been contributed to this field, but almost all of them investigated the mechanism based on protein sequences around protein sites. In this study, we implement an exploration by characterizing the microenvironment surrounding phosphorylated protein sites with a modified shell model, and obtain some significant properties by the rank-sum test, such as the lack of some classes of residues, atoms, and secondary structures. Furthermore, we find that the depletion of some properties affects protein phosphorylation remarkably. Our results suggest that it is a meaningful direction to explore the mechanism of protein phosphorylation from microenvironment and we expect further findings along with the increasing size of phosphorylation and protein structure data.

  17. Opportunity's Surroundings After Sol 1820 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  18. Exploiting Surrounding Text for Retrieving Web Images

    Directory of Open Access Journals (Sweden)

    S. A. Noah

    2008-01-01

    Full Text Available Web documents contain useful textual information that can be exploited for describing images. Research had been focused on representing images by means of its content (low level description such as color, shape and texture, little research had been directed to exploiting such textual information. The aim of this research was to systematically exploit the textual content of HTML documents for automatically indexing and ranking of images embedded in web documents. A heuristic approach for locating and assigning weight surrounding web images and a modified tf.idf weighting scheme was proposed. Precision-recall measures of evaluation had been conducted for ten queries and promising results had been achieved. The proposed approach showed slightly better precision measure as compared to a popular search engine with an average of 0.63 and 0.55 relative precision measures respectively.

  19. Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Tyler R Schleicher

    Full Text Available The beneficial symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium, Vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. Colonization of the squid light organ by V. fischeri begins a lifelong association with a regulated daily rhythm. Each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial cells. We analyzed the host and symbiont proteomes of adult squid exudate and surrounding light organ epithelial tissue using 1D- and 2D-polyacrylamide gel electrophoresis and multidimensional protein identification technology (MudPIT in an effort to understand the contribution of both partners to the maintenance of this association. These proteomic analyses putatively identified 1581 unique proteins, 870 proteins originating from the symbiont and 711 from the host. Identified host proteins indicate a role of the innate immune system and reactive oxygen species (ROS in regulating the symbiosis. Symbiont proteins detected enhance our understanding of the role of quorum sensing, two-component signaling, motility, and detoxification of ROS and reactive nitrogen species (RNS inside the light organ. This study offers the first proteomic analysis of the symbiotic microenvironment of the adult light organ and provides the identification of proteins important to the regulation of this beneficial association.

  20. The lithosphere-asthenosphere Italy and surroundings

    CERN Document Server

    Panza, G F; Chimera, G; Pontevivo, A; Raykova, R

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineat...

  1. The lithosphere-asthenosphere: Italy and surroundings

    Institute of Scientific and Technical Information of China (English)

    GiulianoF.Panza; AntonellaPontevivo; GiordanoChimera; RenetaRaykova; AbdelkrimAoudia

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by sur-face wave velocity tomography and non-linear inversion.Maps of the Moho depth, of the thickness of the lithos-phere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, iden-tified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the prmctpat recent votca-noes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria, a lithospheric dou-bling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenos-phere properties delineate a differentiation between the northern and the southern sectors of the Adriatic Sea,likely attesting the fragmentation of Adria.

  2. Preliminary design of surrounding heliostat fields

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Francisco J. [Zaragoza University, Dpto. de Ingenieria Mecanica, CPS-B, Maria de Luna 3, 50018 Zaragoza (Spain)

    2009-05-15

    Recently, the author has shown elsewhere a simplified model that allows quick evaluations of the annual overall energy collected by a surrounding heliostat field. This model is the combination of an analytical flux density function produced by a heliostat, developed by the own author, and an optimized mirror density distribution developed by University of Houston for the Solar One Project. As main conclusion of this previous work, it was recognized that such pseudo-continuous simplified model should not substitute much more accurate discrete evaluations, which manage thousands of individual heliostat coordinates. Here in this work, the difficulty of generating a preliminary discrete layout of a large number of heliostats is addressed. The main novelty is the direct definition of thousands of heliostat coordinates through basically two parameters i.e. a simplified blocking factor and an additional security distance. Such procedure, which was formerly theoretically suggested by the author, is put into practice here, showing examples and commenting their problems and advantages. Getting a previous set of thousands of heliostat coordinates would be a major first step in the complex process of designing solar power tower (SPT). (author)

  3. Quasars Probing Quasars VIII. The Physical Properties of the Cool Circumgalactic medium Surrounding z ~ 2-3 Massive Galaxies

    CERN Document Server

    Lau, Marie Wingyee; Hennawi, Joseph F

    2015-01-01

    We characterize the physical properties of the cool T ~ 10^4 K circumgalactic medium surrounding z ~ 2-3 quasar host galaxies, which are predicted to evolve into present day massive ellipticals. Using a statistical sample of 14 quasar pairs with projected separation 100 cm^-3 and subparsec scale gas clumps.

  4. Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131-36)

    NARCIS (Netherlands)

    Emonts, B. H. C.; Morganti, R.; Oosterloo, T. A.; Holt, J.; Tadhunter, C. N.; van der Hulst, J. M.; Ojha, R.; Sadler, E. M.

    2008-01-01

    We present the detection of an enormous disc of cool neutral hydrogen (HI) gas surrounding the S0 galaxy NGC612, which hosts one of the nearest powerful radio sources (PKS 0131-36). Using the Australia Telescope Compact Array, we detect MHI = 1.8 x 10(9) M(circle dot) of HI emission-line gas that is

  5. Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131-36)

    NARCIS (Netherlands)

    Emonts, B. H. C.; Morganti, R.; Oosterloo, T. A.; Holt, J.; Tadhunter, C. N.; van der Hulst, J. M.; Ojha, R.; Sadler, E. M.

    2008-01-01

    We present the detection of an enormous disc of cool neutral hydrogen (HI) gas surrounding the S0 galaxy NGC612, which hosts one of the nearest powerful radio sources (PKS 0131-36). Using the Australia Telescope Compact Array, we detect MHI = 1.8 x 10(9) M(circle dot) of HI emission-line gas that is

  6. Optimum and maximum host size at parasitism for the endoparasitoid Hyposoter didymator (Hymenoptera: Ichneumonidae) differ greatly between two host species

    NARCIS (Netherlands)

    Reudler Talsma, J.H.; Elzinga, J.A.; Harvey, J.A.; Biere, A.

    2007-01-01

    Host size is considered a reliable indicator of host quality and an important determinant of parasitoid fitness. Koinobiont parasitoids attack hosts that continue feeding and growing during parasitism. In contrast with hemolymph-feeding koinobionts, tissue-feeding koinobionts face not only a minimum

  7. A Stellar Stream Surrounds the Whale Galaxy

    Science.gov (United States)

    Kohler, Susanna

    2015-10-01

    The -cold dark matter cosmological model predicts that galaxies are assembled through the disruption and absorption of small satellite dwarf galaxies by their larger hosts. A recent study argues that NGC 4631, otherwise known as the Whale galaxy, shows evidence of such a recent merger in the form of an enormous stellar stream extending from it.Stream SignaturesAccording to the -CDM model, stellar tidal streams should be a ubiquitous feature among galaxies. When satellite dwarf galaxies are torn apart, they spread out into such streams before ultimately feeding the host galaxy. Unfortunately, these streams are very faint, so were only recently starting to detect these features.Stellar tidal streams have been discovered around the Milky Way and Andromeda, providing evidence of these galaxies growth via recent (within the last 8 Gyr) mergers. But discovering stellar streams around other Milky Way-like galaxies would help us to determine if the model of hierarchical galaxy assembly applies generally.To this end, the Stellar Tidal Stream Survey, led by PI David Martnez-Delgado (Center for Astronomy of Heidelberg University), is carrying out the first systematic survey of stellar tidal streams. In a recent study, Martnez-Delgado and collaborators present their detection of a giant (85 kpc long!) stellar tidal stream extending into the halo of NGC 4631, the Whale galaxy.Modeling a SatelliteThe top image is a snapshot from an N-body simulation of a single dwarf satellite, 3.5 Gyr after it started interacting with the Whale galaxy. The satellite has been torn apart and spread into a stream that reproduces observations, which are shown in the lower image (scale is not the same). [Martnez-Delgado et al. 2015]The Whale galaxy is a nearby edge-on spiral galaxy interacting with a second spiral, NGC 4656. But the authors dont believe that the Whale galaxys giant tidal stellar stream is caused by its interactions with NGC 4656. Instead, based on their observations, they believe

  8. Impacts of Artificial Reefs on Surrounding Ecosystems

    Science.gov (United States)

    Manoukian, Sarine

    Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation. Acoustic systems like high-frequency multibeam sonar are efficient tools in monitoring the environmental evolution around artificial reefs, whereas water turbidity can limit visual dive and ROV inspections. A high-frequency multibeam echo sounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. How do artificial reefs change over time in relation to the coastal processes? How accurately does multibeam technology map different typologies of artificial modules of known size and shape? How do artificial reefs affect fish school behavior? What are the limitations of multibeam technology for investigating fish school distribution as well as spatial and temporal changes? This study addresses the above questions and presents results of a new approach for artificial reef seafloor mapping over time, based upon an integrated analysis of multibeam swath bathymetry data and geoscientific information (backscatter data analysis, SCUBA observations, physical oceanographic data, and previous findings on the geology and sedimentation processes, integrated with unpublished data) from Senigallia artificial reef, northwestern Adriatic Sea (Italy) and St. Petersburg Beach Reef, west-central Florida continental shelf. A new approach for observation of fish

  9. An HST study of three very faint GRB host galaxies

    DEFF Research Database (Denmark)

    Jaunsen, A.O.; Andersen, M.I.; Hjorth, J.;

    2003-01-01

    . (2002). We obtain a revised and much higher probability that the galaxies identified as hosts indeed are related to the GRBs (P(n(chance))=0.69, following Bloom et al. 2002), thereby strengthening the conclusion that GRBs are preferentially located in star-forming regions in their hosts. Apart from......As part of the HST/STIS GRB host survey program we present the detection of three faint gamma-ray burst (GRB) host galaxies based on an accurate localisation using ground-based data of the optical afterglows (OAs). A common property of these three hosts is their extreme faintness. The location...... at which GRBs occur with respect to their host galaxies and surrounding environments are robust indicators of the nature of GRB progenitors. The bursts studied here are among the four most extreme outliers, in terms of relative distance from the host center, in the recent comprehensive study of Bloom et al...

  10. Atmospheric mercury emissions from mine wastes and surrounding geologically enriched terrains

    Science.gov (United States)

    Gustin, M.S.; Coolbaugh, M.F.; Engle, M.A.; Fitzgerald, B.C.; Keislar, R.E.; Lindberg, S.E.; Nacht, D.M.; Quashnick, J.; Rytuba, J.J.; Sladek, C.; Zhang, H.; Zehner, R.E.

    2003-01-01

    Waste rock and ore associated with Hg, precious and base metal mining, and their surrounding host rocks are typically enriched in mercury relative to natural background concentrations (soil:air interface, and photo reduction of mercury containing phases. To determine the need for and effectiveness of regulatory controls on short-lived anthropogenic point sources the contribution of mercury from geologic non-point sources to the atmospheric mercury pool needs to be quantified. The atmospheric mercury contribution from small areas of mining disturbance with relatively high mercury concentrations are, in general, less than that from surrounding large areas of low levels of mercury enrichment. In the arid to semi-arid west-ern United States volatilization is the primary means by which mercury is released from enriched sites.

  11. Resolved Host Studies of Stellar Explosions

    CERN Document Server

    Levesque, Emily M

    2016-01-01

    The host galaxies of nearby (z<0.3) core-collapse supernovae and long-duration gamma-ray bursts offer an excellent means of probing the environments and populations that produce these events' varied massive progenitors. These same young stellar progenitors make LGRBs and SNe valuable and potentially powerful tracers of star formation, metallicity, the IMF, and the end phases of stellar evolution. However, properly utilizing these progenitors as tools requires a thorough understanding of their formation and, consequently, the physical properties of their parent host environments. This review looks at some of the recent work on LGRB and SN hosts with resolved environments that allows us to probe the precise explosion sites and surrounding environments of these events in incredible detail.

  12. Tissue integration of polyacrylamide hydrogel: an experimental study of periurethral, perivesical, and mammary gland tissue in the pig

    DEFF Research Database (Denmark)

    Christensen, Lise H; Nielsen, John B; Mouritsen, Lone

    2008-01-01

    and regional lymph nodes were examined at 1, 1 1/2, 3, 3 1/2, 6, 12, and 14 months, and other lymph nodes and organs were examined at 1, 6, 12, and 14 months. RESULTS PAAG was invaded by macrophages and giant cells that were gradually replaced by a network of fibrous tissue. Silicone gel was seen inside...... With silicone gel as reference, PAAG tissue integration and migration was studied in a longitudinal study of the pig. MATERIALS AND METHODS Forty-one pigs were used. PAAG and silicone gel were injected into mammary tissue, and PAAG was injected into urethral or bladder wall or the anal canal. Tissues...... these cells or as large vacuoles, surrounded by a fibrous capsule. Regional lymph nodes contained PAAG only at 1 1/2 months and silicone gel at 12 months. CONCLUSION PAAG is a stable, viscoelastic bulking agent, which unlike silicone gel is slowly integrated within its host tissue via a thin fibrous network...

  13. Using host response modifiers in the treatment of periodontal disease.

    Science.gov (United States)

    Novak, M John; Donley, Timothy G

    2002-01-01

    Periodontal disease is the result of a complex interaction between microbial plaque, the host's inflammatory response to the plaque, and host modifying factors (e.g., smoking, diabetes, genetics) that may have an impact on the disease process. It is known that plaque initiates periodontal disease but that the host response is responsible for the destruction of periodontal tissues. This article describes why host response modifiers may be used to help control inflammation and tissue destruction as part of the initial phase of periodontal therapy in selected patient groups.

  14. THE CLASSIFICATION OF THE SURROUNDINGS OF COAL MINING ROADWAYS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 侯朝炯; 李华祥

    1996-01-01

    This introduces the calculation of opaper the deformationg .the Surroundings of coaowaysand the divisi of surroundings into 5 levels by means or !fuzzy integral assess mairrx, wnlcnserves-asthe scientific basis for selecting supporting pattern of roadways and determining the, pa-rameters of support.

  15. MicroCT Bone Densitometry: Context Sensitivity, Beam Hardening Correction and the Effect of Surrounding Media

    Directory of Open Access Journals (Sweden)

    Philip L. Salmon

    2014-12-01

    Full Text Available The context-sensitivity of microCT bone densitometry due to beam hardening artefacts was assessed. Bones and teeth are scanned with varying thickness of surrounding media (water, alcohol, biological tissue and it is important to understand how this affects reconstructed attenuation (“density” of the mineralized tissue. Aluminium tubes and rods with thickness 0.127mm–5mm were scanned both in air or surrounded by up to 2cm of water. Scans were performed with different energy filters and degrees of software beam hardening correction (BHC. Also tested were the effects of signal-to-noise ratio, magnification and truncation. The thickness of an aluminium tube significantly affected its mean reconstructed attenuation. This effect of thickness could be reduced substantially by BHC for scans in air, but not for scans in water. Varying thickness of surrounding water also changed the mean attenuation of an aluminium tube. This artefact could be almost eliminated by an optimal BHC value. The “cupping” artefact of heterogeneous attenuation (elevated at outer surfaces could be corrected if aluminium was scanned in air, but in water BHC was much less effective. Scan truncation, changes to magnification and signal-to-noise ratio also caused artificial changes to measured attenuation. Measurement of bone mineral density by microCT is highly context sensitive. A surrounding layer of liquid or biological tissue reduces the ability of software BHC to remove bone density artefacts. Sample thickness, truncation, magnification and signal to noise ratio also affect reconstructed attenuation. Thus it is important for densitometry that sample and calibration phantom dimensions and mounting materials are standardised.

  16. Incorporation by host tissue of two biomaterials used as repair of defects produced in abdominal wall of rats Incorporação por tecido do hospedeiro de dois biomateriais usados como reparo de defeitos produzido em parede abdominal de ratos

    Directory of Open Access Journals (Sweden)

    Suyiene Cordeiro Falcão

    2008-02-01

    Full Text Available PURPOSE: Biomaterials may be used as treatment of great abdominal wall defects to avoid tension during repair. In the present research we intended to investigate incorporation type by host tissue of membranes of microbial cellulose (MC, produced by the bacteria Zoogloea sp., and of polytetrafluoroethylene (ePTFE in abdominal wall defects of rats. METHODS: Sixty male rats Wistar, anesthetized by ketamine (5mg/100g and xylazine (2mg/100g, were submitted to a rectangular excision (2x3cm of the abdominal wall, including fascia, muscles and peritoneum and further treated with implants of microbial cellulose (MC Group - 30 animals or expanded polytetrafluoroethylene ( ePTFE Group- 30 animals. Each group was subdivided in 14th DPO, 28th DPO and 60th DPO Subgroups. RESULTS: Incorporation of biomaterials was observed by wrapping and infiltration by host tissue. It has been found that wrapping associated to infiltration of host connective tissue in implants of ePTFE were present in 100% of the observed samples, and this may be responsible for increase resistance to traction. Inversely, wrapping without host tissue infiltration was seen in 100% of examined specimens of MC implants. CONCLUSION: Wrapping and host tissue infiltration is seen only in ePTFE implants.OBJETIVO: Biomateriais podem ser usados como tratamento de grandes defeitos da parede abdominal para evitar tensão durante reparo. Na presente pesquisa pretendeu-se investigar o tipo de incorporação pelo tecido do hospedeiro de membranas de celulose microbiana (CM, produzidas pela bactérias Zoogloea sp., e de politetrafluoretileno (PTFEe em defeitos da parede abdominal de ratos. MÉTODOS: Sessenta ratos machos Wistar, anestesiados através de cetamina (5mg/100g e xilazina (2mg/100g, foram submetidos a uma excisão retangular (2x3cm da parede abdominal, incluindo fascia, músculos e peritoneum e posteriormente tratadas com implantes de celulose microbiana (Groupo CM - 30 animais ou

  17. Black hole solutions surrounded by perfect fluid in Rastall theory

    Science.gov (United States)

    Heydarzade, Y.; Darabi, F.

    2017-08-01

    In this work, we obtain uncharged∖charged Kiselev-like black holes as a new class of black hole solutions surrounded by perfect fluid in the context of Rastall theory. Then, we study the specific cases of the uncharged∖charged black holes surrounded by regular matter like dust and radiation, or exotic matter like quintessence, cosmological constant and phantom fields. By comparing the Kiselev-like black hole solutions in Rastall theory with the Kiselev black hole solutions in GR, we find an effective perfect fluid behavior for the black hole's surrounding field. It is shown that the corresponding effective perfect fluid has interesting characteristic features depending on the different ranges of the parameters in Rastall theory. For instance, Kiselev-like black holes surrounded by regular matter in Rastall theory may be considered as Kiselev black holes surrounded by exotic matter in GR, or Kiselev-like black holes surrounded by exotic matter in Rastall theory may be considered as Kiselev black holes surrounded by regular matter in GR.

  18. Surround suppression and sparse coding in visual and barrel cortices

    Directory of Open Access Journals (Sweden)

    Robert N S Sachdev

    2012-07-01

    Full Text Available During natural vision the entire retina is stimulated. Likewise, during natural tactile behaviors, spatially extensive regions of the somatosensory surface are co-activated. The large spatial extent of naturalistic stimulation means that surround suppression, a phenomenon whose neural mechanisms remain a matter of debate, must arise during natural behavior. To identify common neural motifs that might instantiate surround suppression across modalities, we review models of surround suppression and compare the evidence supporting the competing ideas that surround suppression has either cortical or sub-cortical origins in visual and barrel cortex. In the visual system there is general agreement lateral inhibitory mechanisms contribute to surround suppression, but little direct experimental evidence that intracortical inhibition plays a major role. Two intracellular recording studies of V1, one using naturalistic stimuli (Haider et al., 2010, the other sinusoidal gratings (Ozeki et al., 2009, sought to identify the causes of reduced activity in V1 with increasing stimulus size, a hallmark of surround suppression. The former attributed this effect to increased inhibition, the latter to largely balanced withdrawal of excitation and inhibition. In rodent primary somatosensory barrel cortex, multi-whisker responses are generally weaker than single whisker responses, suggesting multi-whisker stimulation engages similar surround suppressive mechanisms. The origins of suppression in S1 remain elusive: studies have implicated brainstem lateral/internuclear interactions and both thalamic and cortical inhibition. Although the anatomical organization and instantiation of surround suppression in the visual and somatosensory systems differ, we consider the idea that one common function of surround suppression, in both modalities, is to remove the statistical redundancies associated with natural stimuli by increasing the sparseness or selectivity of sensory

  19. Geometric control of tissue morphogenesis

    Science.gov (United States)

    Nelson, Celeste M.

    2009-01-01

    Summary Morphogenesis is the dynamic and regulated change in tissue form that leads to creation of the body plan and development of mature organs. Research over the past several decades has uncovered a multitude of genetic factors required for morphogenesis in animals. The behaviors of individual cells within a developing tissue are determined by combining these genetic signals with information from the surrounding microenvironment. At any point in time, the local microenvironment is influenced by macroscale tissue geometry, which sculpts long range signals by affecting gradients of morphogens and mechanical stresses. The geometry of a tissue thus acts as both a template and instructive cue for further morphogenesis. PMID:19167433

  20. Acute graft versus host disease

    Directory of Open Access Journals (Sweden)

    Vogelsang Georgia B

    2007-09-01

    Full Text Available Abstract Acute graft-versus-host disease (GVHD occurs after allogeneic hematopoietic stem cell transplant and is a reaction of donor immune cells against host tissues. Activated donor T cells damage host epithelial cells after an inflammatory cascade that begins with the preparative regimen. About 35%–50% of hematopoietic stem cell transplant (HSCT recipients will develop acute GVHD. The exact risk is dependent on the stem cell source, age of the patient, conditioning, and GVHD prophylaxis used. Given the number of transplants performed, we can expect about 5500 patients/year to develop acute GVHD. Patients can have involvement of three organs: skin (rash/dermatitis, liver (hepatitis/jaundice, and gastrointestinal tract (abdominal pain/diarrhea. One or more organs may be involved. GVHD is a clinical diagnosis that may be supported with appropriate biopsies. The reason to pursue a tissue biopsy is to help differentiate from other diagnoses which may mimic GVHD, such as viral infection (hepatitis, colitis or drug reaction (causing skin rash. Acute GVHD is staged and graded (grade 0-IV by the number and extent of organ involvement. Patients with grade III/IV acute GVHD tend to have a poor outcome. Generally the patient is treated by optimizing their immunosuppression and adding methylprednisolone. About 50% of patients will have a solid response to methylprednisolone. If patients progress after 3 days or are not improved after 7 days, they will get salvage (second-line immunosuppressive therapy for which there is currently no standard-of-care. Well-organized clinical trials are imperative to better define second-line therapies for this disease. Additional management issues are attention to wound infections in skin GVHD and fluid/nutrition management in gastrointestinal GVHD. About 50% of patients with acute GVHD will eventually have manifestations of chronic GVHD.

  1. Reconstructing the sequence of events surrounding body disposition based on color staining of bone*.

    Science.gov (United States)

    Huculak, Meaghan A; Rogers, Tracy L

    2009-09-01

    Literature regarding bone color is limited to determining location of primary and secondary dispositions. This research is the first to use bone color to interpret the sequence of events surrounding body disposition. Two scenarios were compared-bones buried and then exposed on the ground surface and bones exposed then buried. Forty juvenile pig humeri with minimal tissue were used in each scenario with an additional 20 controls to determine if decomposing tissue affects bone color. Munsell Color Charts were used to record bone color of surface and 2.5 cm cross-sections. Results reveal five main surface colors attributed to soil, sun, hemolysis, decomposition, and fungi. Fungi on buried bones suggests prior surface exposure. Cross-sections of strictly buried bones are identical to buried then exposed bone, stressing the importance of bone surface analysis. Cross-sectioning may help verify remains have been exposed then buried. Decomposition of excess tissue creates minimal color staining.

  2. Biomimetic injectable HUVEC-adipocytes/collagen/alginate microsphere co-cultures for adipose tissue engineering.

    Science.gov (United States)

    Yao, Rui; Zhang, Renji; Lin, Feng; Luan, Jie

    2013-05-01

    Engineering adipose tissue that has the ability to engraft and establish a vascular supply is a laudable goal that has broad clinical relevance, particularly for tissue reconstruction. In this article, we developed novel microtissues from surface-coated adipocyte/collagen/alginate microspheres and human umbilical vein endothelial cells (HUVECs) co-cultures that resembled the components and structure of natural adipose tissue. Firstly, collagen/alginate hydrogel microspheres embedded with viable adipocytes were obtained to mimic fat lobules. Secondly, collagen fibrils were allowed to self-assemble on the surface of the microspheres to mimic collagen fibrils surrounding the fat lobules in the natural adipose tissue and facilitate HUVEC attachment and co-cultures formation. Thirdly, the channels formed by the gap among the microspheres served as the room for in vitro prevascularization and in vivo blood vessel development. The endothelial cell layer outside the microspheres was a starting point of rapid vascular ingrowth. Adipose tissue formation was analyzed for 12 weeks at 4-week intervals by subcutaneous injection into the head of node mice. The vasculature in the regenerated tissue showed functional anastomosis with host blood vessels. Long-term stability of volume and weight of the injection was observed, indicating that the vasculature formed within the constructs benefited the formation, maturity, and maintenance of adipose tissue. This study provides a microsurgical method for adipose regeneration and construction of biomimetic model for drug screening studies.

  3. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real‐world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  4. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real-world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  5. Traditional Indian custOInS surrounding birth

    African Journals Online (AJOL)

    traditional custOIns surrounding birth in Indian culture. ... conception, pregnancy, birth and the early months ofparenthood. .... house attended by a traditional birth attendant of a ..... Spiritual components play a dominant role in traditional.

  6. Glow phenomenon surrounding the vertical stabilizer and OMS pods

    Science.gov (United States)

    1994-01-01

    This 35mm frame, photographed as the Space Shuttle Columbia was orbiting Earth during a 'night' pass, documents the glow phenomenon surrounding the vertical stabilizer and the Orbital Maneuvering System (OMS) pods of the spacecraft.

  7. Insights on Metal Based Dental Implants and their Interaction with the Surrounding Tissues.

    Science.gov (United States)

    Popa, Marcela; Hussien, Mohamed D; Cirstea, Alexandra; Grigore, Raluca; Lazar, Veronica; Bezirtzoglou, Eugenia; Chifiriuc, Mariana Carmen; Sakizlian, Monica; Stavropoulou, Elisavet; Bertesteanu, Serban

    2015-01-01

    At present, the use of dental implants is a very common practice as tooth loss is a frequent problem and can occur as a result of disease or trauma. An implant is usually made of biocompatible materials that do not cause rejection reactions and allow the implant union with the respective bone. To achieve this goal, the implant surface may have different structures and coatings, generally used to increase the adherence of the implant to the bone and to decrease the risk of the periimplantar inflammatory reactions. This review gives some insights of the metal based materials used for dental implants, their limits, improvement strategies as well as the pathophysiology, diagnosis, treatment and prevention of periimplantary diseases.

  8. The structures of eye and surrounding tissues of Longman's beaked whale, Indopacetus pacificus

    Institute of Scientific and Technical Information of China (English)

    ZHU Qian; Tadasu K.YAMADA; LI Xiang

    2008-01-01

    Observations were made on one eye from a Longman's beaked whale Indopacetus pacificus,which was probably one of the least known extant cetaceans.The whale died shortly after swimming aground on the coast in the Nishikata Beach,Sendai-shi,Kagoshima-ken Prefecture,Japan,on July 26,2002.It was a mature female with body length 6.45 m.This paper documented the basic structural characteristics of her visual organ of the whale in order to better understand this animal.

  9. HAM56 and CD68 antigen presenting cells surrounding a sarcoidal granulomatous tattoo

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2011-01-01

    Full Text Available Context : Tattoos are produced by introducing colorants of various compositions into the skin, either accidentally or for cosmetic purposes. Case Report: A 62-year-old male presented with a cosmetic tattoo and requested a total excision of the lesion. Dermatopathologic analysis of the excised tissue with hematoxylin and eosin examination, as well as immunohistochemistry was performed. H&E staining demonstrated classic histologic features of a tattoo. Utilizing immunohistochemistry, dermal histiocytic antigen presenting cells stained with HAM56 and CD68 antibodies; the staining was present surrounding the tattoo pigment. Conclusions : We identified two macrophage markers (HAM56 and CD68 surrounding dermal tattoo pigment. A minimal dermal inflammatory immune was noted to the tattoo pigment. Moreover, the immune response and/or tolerance to tattoos is not well characterized. We suggest that tattoo materials and techniques could be utilized in therapeutic delivery for diseases such recessive dystrophic epidermolysis bullosa, potentially preventing immune rejection of gene therapy agents.

  10. Structure and function of the interphotoreceptor matrix surrounding retinal photoreceptor cells.

    Science.gov (United States)

    Ishikawa, Makoto; Sawada, Yu; Yoshitomi, Takeshi

    2015-04-01

    The interphotoreceptor matrix (IPM) is a highly organized structure with interconnected domains surrounding cone and rod photoreceptor cells and extends throughout the subretinal space. Based on known roles of the extracellular matrix in other tissues, the IPM is thought to have several prominent functions including serving as a receptor for growth factors, regulating retinoid transport, participating in cytoskeletal organization in surrounding cells, and regulation of oxygen and nutrient transport. In addition, a number of studies suggest that the IPM also may play a significant role in the etiology of retinal degenerative disorders. In this review, we describe the present knowledge concerning the structure and function of the IPM under physiological and pathological conditions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    OpenAIRE

    Hao Sun; Huanxin Zou; Shilin Zhou; Cheng Wang; Naser El-Sheimy

    2013-01-01

    Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searc...

  12. Cytokines in lethal graft-versus-host disease

    NARCIS (Netherlands)

    Knulst, A.C.; Bril-Bazuin, C.; Tibbe, G.J.M.; Oudenaren, van A.; Savelkoul, H.F.J.; Benner, R.

    1992-01-01

    Graft-versus-host disease (GVHD) is caused by donor T lymphocytes that recognize foreign antigens on host tissues. This leads to T cell activation, which involves a cascade of events including the transcription of genes for cytokines and their receptors and the production of cytokines. One of the fi

  13. "Tilt" in color space: Hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2015-01-01

    The perceived color of a chromatic stimulus is influenced by the chromaticity of its surround. To investigate these influences along the dimension of hue, we measured hue changes induced in stimuli of different hues by isoluminant chromatic surrounds. Generally, induced hue changes were directed in color space away from the hue of the inducing surround and depended on the magnitude on the hue difference between stimulus and surround. With increasing difference in hue between stimulus and surround, induced hue changes increased up to a maximum and then decreased for larger differences. This qualitative pattern was similar for different inducers, but quantitatively, induction was weaker along some directions in cone-opponent color space than along other directions. The strongest induction effects were found along an oblique, blue-yellow axis that corresponds to the daylight axis. The overall pattern of the induction effect shows similarities to the well-known tilt effect, where shifts in perceived angle of oriented stimuli are induced by oriented surrounds. This suggests analogous neural representations and similar mechanisms of contextual processing for different visual features such as orientation and color.

  14. Control of Formation of Lithological Reservoirs by Surrounding Mudstone

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and the analysis of oil & gas accumulation mechanism. Geological statistical shows that the major burial depth and interval of lithological reservoirs in the Jiyang depression are related to the hydrocarbon generation in and expulsion from the Lower Tertiary source rocks and the time of the formation of most lithological reservoirs coincides with the peak of hydrocarbon generation and expulsion. The lithological traps located in the center of effective source rocks are propitious to high oil saturation than those located on the margin of effective source rocks. The hydrocarbon charge degree of the lithological reservoir has a positive correlation with the intensity of hydrocarbon expulsion from surrounding source rocks.Geological analyses and NMR experiments also show that the oil saturation of surrounding source rocks control the hydrocarbon potential of lithological traps, and a critical value for oil saturation of surrounding mudstone is required, that is, when the oil saturation of surrounding mudstone is lower than this critical value, no oil and gas accumulate in the lithological trap. The control of surrounding mudstone on the oil-bearing properties of lithological reservoirs is also analyzed by the mechanisms of hydrocarbon generation and expulsion as well as accumulation.

  15. Circumstances surrounding dying in the paediatric intensive care unit

    Directory of Open Access Journals (Sweden)

    Plötz Frans B

    2006-08-01

    Full Text Available Abstract Background Death is inevitable in the paediatric intensive care unit (PICU. We aimed to describe the circumstances surrounding dying in a PICU. Method The chart records of all patients less than 18 years of age who died at the PICU between January first 2000 and July first 2005 were retrospectively analyzed. Information regarding sex, age, length of stay, admission, diagnosis, and the way a patient died was registered. Post mortem information regarding natural versus unnatural death, autopsy and donation was obtained. Non-survivors were allocated in five groups: do-not-resuscitate (DNR, withholding and/or withdrawal of therapy (W/W, failed cardiopulmonary resuscitation (failed CPR, brain death (BD, and terminal organ failure (TOF. Results During the study period 87 (4.4% of the 1995 admitted patients died. Non-survivors were more often admitted during the day (54% and the week (68%. W/W was found in 27.6%, TOF in 26.4%, BD in 23.0%, failed CPR in 18.4%, and DNR in 4.6%. Forty-three percent died in the first two days, of which BD (40.5% and failed CPR (37.8% were most common. Seventy-five children (86% died due to a natural cause. Autopsy permission was obtained in 19 of 54 patients (35%. The autopsies confirmed the clinical diagnosis in 11 patients, revealed new information in 5 patients, and in 3 patients the autopsy did not provide additional information. Nine patients were medically suitable for organ donation and 24 patients for tissue donation, whereas consent was only obtained in 2 cases in both groups. Conclusion We observed that 43% of the patients died within the first two days of admission due to BD and failed CPR, whereas after 4 days most patients died after W/W. Autopsy remains an useful tool to confirm clinical diagnoses or to provide new information. Only a small percentage of the deceased children is suitable for organ donation.

  16. An Efficient Strategy Developed for Next-Generation Sequencing of Endosymbiont Genomes Performed Using Crude DNA Isolated from Host Tissues: A Case Study of Blattabacterium cuenoti Inhabiting the Fat Bodies of Cockroaches.

    Science.gov (United States)

    Kinjo, Yukihiro; Saitoh, Seikoh; Tokuda, Gaku

    2015-01-01

    Whole-genome sequencing has emerged as one of the most effective means to elucidate the biological roles and molecular features of obligate intracellular symbionts (endosymbionts). However, the de novo assembly of an endosymbiont genome remains a challenge when host and/or mitochondrial DNA sequences are present in a dataset and hinder the assembly of the genome. By focusing on the traits of genome evolution in endosymbionts, we herein developed and investigated a genome-assembly strategy that consisted of two consecutive procedures: the selection of endosymbiont contigs from an output obtained from a de novo assembly performed using a TBLASTX search against a reference genome, named TBLASTX Contig Selection and Filtering (TCSF), and the iterative reassembling of the genome from reads mapped on the selected contigs, named Iterative Mapping and ReAssembling (IMRA), to merge the contigs. In order to validate this approach, we sequenced two strains of the cockroach endosymbiont Blattabacterium cuenoti and applied this strategy to the datasets. TCSF was determined to be highly accurate and sensitive in contig selection even when the genome of a distantly related free-living bacterium was used as a reference genome. Furthermore, the use of IMRA markedly improved sequence assemblies: the genomic sequence of an endosymbiont was almost completed from a dataset containing only 3% of the sequences of the endosymbiont's genome. The efficiency of our strategy may facilitate further studies on endosymbionts.

  17. Nitric oxide production by necrotrophic pathogen Macrophomina phaseolina and the host plant in charcoal rot disease of jute: complexity of the interplay between necrotroph-host plant interactions.

    Directory of Open Access Journals (Sweden)

    Tuhin Subhra Sarkar

    Full Text Available M. phaseolina, a global devastating necrotrophic fungal pathogen causes charcoal rot disease in more than 500 host plants. With the aim of understanding the plant-necrotrophic pathogen interaction associated with charcoal rot disease of jute, biochemical approach was attempted to study cellular nitric oxide production under diseased condition. This is the first report on M. phaseolina infection in Corchorus capsularis (jute plants which resulted in elevated nitric oxide, reactive nitrogen species and S nitrosothiols production in infected tissues. Time dependent nitric oxide production was also assessed with 4-Amino-5-Methylamino-2',7'-Difluorofluorescein Diacetate using single leaf experiment both in presence of M. phaseolina and xylanases obtained from fungal secretome. Cellular redox status and redox active enzymes were also assessed during plant fungal interaction. Interestingly, M. phaseolina was found to produce nitric oxide which was detected in vitro inside the mycelium and in the surrounding medium. Addition of mammalian nitric oxide synthase inhibitor could block the nitric oxide production in M. phaseolina. Bioinformatics analysis revealed nitric oxide synthase like sequence with conserved amino acid sequences in M. phaseolina genome sequence. In conclusion, the production of nitric oxide and reactive nitrogen species may have important physiological significance in necrotrophic host pathogen interaction.

  18. Nitric oxide production by necrotrophic pathogen Macrophomina phaseolina and the host plant in charcoal rot disease of jute: complexity of the interplay between necrotroph-host plant interactions.

    Science.gov (United States)

    Sarkar, Tuhin Subhra; Biswas, Pranjal; Ghosh, Subrata Kumar; Ghosh, Sanjay

    2014-01-01

    M. phaseolina, a global devastating necrotrophic fungal pathogen causes charcoal rot disease in more than 500 host plants. With the aim of understanding the plant-necrotrophic pathogen interaction associated with charcoal rot disease of jute, biochemical approach was attempted to study cellular nitric oxide production under diseased condition. This is the first report on M. phaseolina infection in Corchorus capsularis (jute) plants which resulted in elevated nitric oxide, reactive nitrogen species and S nitrosothiols production in infected tissues. Time dependent nitric oxide production was also assessed with 4-Amino-5-Methylamino-2',7'-Difluorofluorescein Diacetate using single leaf experiment both in presence of M. phaseolina and xylanases obtained from fungal secretome. Cellular redox status and redox active enzymes were also assessed during plant fungal interaction. Interestingly, M. phaseolina was found to produce nitric oxide which was detected in vitro inside the mycelium and in the surrounding medium. Addition of mammalian nitric oxide synthase inhibitor could block the nitric oxide production in M. phaseolina. Bioinformatics analysis revealed nitric oxide synthase like sequence with conserved amino acid sequences in M. phaseolina genome sequence. In conclusion, the production of nitric oxide and reactive nitrogen species may have important physiological significance in necrotrophic host pathogen interaction.

  19. Nitric Oxide Production by Necrotrophic Pathogen Macrophomina phaseolina and the Host Plant in Charcoal Rot Disease of Jute: Complexity of the Interplay between Necrotroph–Host Plant Interactions

    Science.gov (United States)

    Sarkar, Tuhin Subhra; Biswas, Pranjal; Ghosh, Subrata Kumar; Ghosh, Sanjay

    2014-01-01

    M. phaseolina, a global devastating necrotrophic fungal pathogen causes charcoal rot disease in more than 500 host plants. With the aim of understanding the plant-necrotrophic pathogen interaction associated with charcoal rot disease of jute, biochemical approach was attempted to study cellular nitric oxide production under diseased condition. This is the first report on M. phaseolina infection in Corchorus capsularis (jute) plants which resulted in elevated nitric oxide, reactive nitrogen species and S nitrosothiols production in infected tissues. Time dependent nitric oxide production was also assessed with 4-Amino-5-Methylamino-2′,7′-Difluorofluorescein Diacetate using single leaf experiment both in presence of M. phaseolina and xylanases obtained from fungal secretome. Cellular redox status and redox active enzymes were also assessed during plant fungal interaction. Interestingly, M. phaseolina was found to produce nitric oxide which was detected in vitro inside the mycelium and in the surrounding medium. Addition of mammalian nitric oxide synthase inhibitor could block the nitric oxide production in M. phaseolina. Bioinformatics analysis revealed nitric oxide synthase like sequence with conserved amino acid sequences in M. phaseolina genome sequence. In conclusion, the production of nitric oxide and reactive nitrogen species may have important physiological significance in necrotrophic host pathogen interaction. PMID:25208092

  20. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  1. Dual perfluorocarbon method to noninvasively monitor dissolved oxygen concentration in tissue engineered constructs in vitro and in vivo.

    Science.gov (United States)

    Goh, Fernie; Long, Robert; Simpson, Nicholas; Sambanis, Athanassios

    2011-07-01

    Noninvasive in vivo monitoring of tissue implants provides important correlations between construct function and the observed physiologic effects. As oxygen is a key parameter affecting cell and tissue function, we established a monitoring method that utilizes (19) F nuclear magnetic resonance (NMR) spectroscopy, with perfluorocarbons (PFCs) as oxygen concentration markers, to noninvasively monitor dissolved oxygen concentration (DO) in tissue engineered implants. Specifically, we developed a dual PFC method capable of simultaneously measuring DO within a tissue construct and its surrounding environment, as the latter varies among animals and with physiologic conditions. In vitro studies using an NMR-compatible bioreactor demonstrated the feasibility of this method to monitor the DO within alginate beads containing metabolically active murine insulinoma βTC-tet cells, relative to the DO in the culture medium, under perfusion and static conditions. The DO profiles obtained under static conditions were supported by mathematical simulations of the system. In vivo, the dual PFC method was successful in tracking the oxygenation state of entrapped βTC-tet cells and the surrounding peritoneal DO over 16 days in normal mice. DO measurements correlated well with the extent of cell growth and host cell attachment examined postexplantation. The peritoneal oxygen environment was found to be variable and hypoxic, and significantly lower in the presence of metabolically active cells. The significance of the dual PFC system in providing critical DO measurements for entrapped cells and other tissue constructs, in vitro and in vivo, is discussed. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  2. Wolbachia-Host Interactions: Host Mating Patterns Affect Wolbachia Density Dynamics.

    Science.gov (United States)

    Zhao, Dong-Xiao; Zhang, Xiang-Fei; Chen, Da-Song; Zhang, Yan-Kai; Hong, Xiao-Yue

    2013-01-01

    Wolbachia are maternally inherited intracellular bacteria that infect a wide range of arthropods and cause an array of effects on host reproduction, fitness and mating behavior. Although our understanding of the Wolbachia-associated effects on hosts is rapidly expanding, our knowledge of the host factors that mediate Wolbachia dynamics is rudimentary. Here, we explore the interactions between Wolbachia and its host, the two-spotted spider mite Tetranychus urticae Koch. Our results indicate that Wolbachia induces strong cytoplasmic incompatibility (CI), increases host fecundity, but has no effects on the longevity of females and the mating competitiveness of males in T. urticae. Most importantly, host mating pattern was found to affect Wolbachia density dynamics during host aging. Mating of an uninfected mite of either sex with an infected mite attenuates the Wolbachia density in the infected mite. According to the results of Wolbachia localization, this finding may be associated with the tropism of Wolbachia for the reproductive tissue in adult spider mites. Our findings describe a new interaction between Wolbachia and their hosts.

  3. Comparative genomic analysis identifies divergent genomic features of pathogenic Enterococcus cecorum including a type IC CRISPR-Cas system, a capsule locus, an epa-like locus, and putative host tissue binding proteins.

    Science.gov (United States)

    Borst, Luke B; Suyemoto, M Mitsu; Scholl, Elizabeth H; Fuller, Fredrick J; Barnes, H John

    2015-01-01

    Enterococcus cecorum (EC) is the dominant enteric commensal of adult chickens and contributes to the gut consortia of many avian and mammalian species. While EC infection is an uncommon zoonosis, like other enterococcal species it can cause life-threating nosocomial infection in people. In contrast to other enterococci which are considered opportunistic pathogens, emerging pathogenic strains of EC cause outbreaks of musculoskeletal disease in broiler chickens. Typical morbidity and mortality is comparable to other important infectious diseases of poultry. In molecular epidemiologic studies, pathogenic EC strains were found to be genetically clonal. These findings suggested acquisition of specific virulence determinants by pathogenic EC. To identify divergent genomic features and acquired virulence determinants in pathogenic EC; comparative genomic analysis was performed on genomes of 3 pathogenic and 3 commensal strains of EC. Pathogenic isolates had smaller genomes with a higher GC content, and they demonstrated large regions of synteny compared to commensal isolates. A molecular phylogenetic analysis demonstrated sequence divergence in pathogenic EC genomes. At a threshold of 98% identity, 414 predicted proteins were identified that were highly conserved in pathogenic EC but not in commensal EC. Among these, divergent CRISPR-cas defense loci were observed. In commensal EC, the type IIA arrangement typical for enterococci was present; however, pathogenic EC had a type IC locus, which is novel in enterococci but commonly observed in streptococci. Potential mediators of virulence identified in this analysis included a polysaccharide capsular locus similar to that recently described for E. faecium, an epa-like locus, and cell wall associated proteins which may bind host extracellular matrix. This analysis identified specific genomic regions, coding sequences, and predicted proteins which may be related to the divergent evolution and increased virulence of emerging

  4. Migraine increases centre-surround suppression for drifting visual stimuli.

    Directory of Open Access Journals (Sweden)

    Josephine Battista

    Full Text Available BACKGROUND: The pathophysiology of migraine is incompletely understood, but evidence points to hyper-responsivity of cortical neurons being a key feature. The basis of hyper-responsiveness is not clear, with an excitability imbalance potentially arising from either reduced inhibition or increased excitation. In this study, we measure centre-surround contrast suppression in people with migraine as a perceptual analogue of the interplay between inhibition and excitation in cortical areas responsible for vision. We predicted that reduced inhibitory function in migraine would reduce perceptual surround suppression. Recent models of neuronal surround suppression incorporate excitatory feedback that drives surround inhibition. Consequently, an increase in excitation predicts an increase in perceptual surround suppression. METHODS AND FINDINGS: Twenty-six people with migraine and twenty approximately age- and gender-matched non-headache controls participated. The perceived contrast of a central sinusoidal grating patch (4 c/deg stationary grating, or 2 c/deg drifting at 2 deg/sec, 40% contrast was measured in the presence and absence of a 95% contrast annular grating (same orientation, spatial frequency, and drift rate. For the static grating, similar surround suppression strength was present in control and migraine groups with the presence of the surround resulting in the central patch appearing to be 72% and 65% of its true contrast for control and migraine groups respectively (t(44 = 0.81, p = 0.42. For the drifting stimulus, the migraine group showed significantly increased surround suppression (t(44 = 2.86, p<0.01, with perceived contrast being on average 53% of actual contrast for the migraine group and 68% for non-headache controls. CONCLUSIONS: In between migraines, when asymptomatic, visual surround suppression for drifting stimuli is greater in individuals with migraine than in controls. The data provides evidence for a

  5. Solar Proton Transport within an ICRU Sphere Surrounded by a Complex Shield: Combinatorial Geometry

    Science.gov (United States)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-01-01

    The 3DHZETRN code, with improved neutron and light ion (Z (is) less than 2) transport procedures, was recently developed and compared to Monte Carlo (MC) simulations using simplified spherical geometries. It was shown that 3DHZETRN agrees with the MC codes to the extent they agree with each other. In the present report, the 3DHZETRN code is extended to enable analysis in general combinatorial geometry. A more complex shielding structure with internal parts surrounding a tissue sphere is considered and compared against MC simulations. It is shown that even in the more complex geometry, 3DHZETRN agrees well with the MC codes and maintains a high degree of computational efficiency.

  6. Ethical and regulatory issues surrounding umbilical cord blood ...

    African Journals Online (AJOL)

    Recent medical advances in the field of regenerative medicine and tissue ... from fetal tissue, the practice of UCB biobanking presents several ethical and ... of haematopoietic stem cells for research and therapeutic uses, and increase the ...

  7. 6.1 channel general planar surround sound system

    Institute of Scientific and Technical Information of China (English)

    XIE Bosun

    2001-01-01

    A new 6.1 channel surround sound system and its two signal mixing methods are proposed. Theoretical and experimental results show that the system is able to recreate 360°sound image in horizontal plane. Especially, compared with current 5.1 channel system, lateral and rear image of the new system is improved obviously. Therefore it is suitable to be used as a general surround sound system. It is also proved that, the new system is fully compatible with 5.1 channel system, and current methods are available to record 6.1 channel signals.

  8. Linking disadvantaged housing areas to the surrounding city

    DEFF Research Database (Denmark)

    Stender, Marie

    Several disadvantaged social housing areas in Denmark are currently undergo-ing thorough physical refurbishments, aiming to integrate them better with the surrounding city. The ambition is to attract new users and residents by opening up the borders of the area and establish attractive, new...... that especially eve-ryday-route strategies adding new public functions within the area can pave the way for integration with the surroundings. The applicability of such strategies is however highly dependent on the context, location and existing image of the ar-ea. Social distance may sustain though physical...

  9. Association and host selectivity in multi-host pathogens.

    Directory of Open Access Journals (Sweden)

    José M Malpica

    Full Text Available The distribution of multi-host pathogens over their host range conditions their population dynamics and structure. Also, host co-infection by different pathogens may have important consequences for the evolution of hosts and pathogens, and host-pathogen co-evolution. Hence it is of interest to know if the distribution of pathogens over their host range is random, or if there are associations between hosts and pathogens, or between pathogens sharing a host. To analyse these issues we propose indices for the observed patterns of host infection by pathogens, and for the observed patterns of co-infection, and tests to analyse if these patterns conform to randomness or reflect associations. Applying these tests to the prevalence of five plant viruses on 21 wild plant species evidenced host-virus associations: most hosts and viruses were selective for viruses and hosts, respectively. Interestingly, the more host-selective viruses were the more prevalent ones, suggesting that host specialisation is a successful strategy for multi-host pathogens. Analyses also showed that viruses tended to associate positively in co-infected hosts. The developed indices and tests provide the tools to analyse how strong and common are these associations among different groups of pathogens, which will help to understand and model the population biology of multi-host pathogens.

  10. The baculovirus uses a captured host phosphatase to induce enhanced locomotory activity in host caterpillars.

    Directory of Open Access Journals (Sweden)

    Susumu Katsuma

    Full Text Available The baculovirus is a classic example of a parasite that alters the behavior or physiology of its host so that progeny transmission is maximized. Baculoviruses do this by inducing enhanced locomotory activity (ELA that causes the host caterpillars to climb to the upper foliage of plants. We previously reported that this behavior is not induced in silkworms that are infected with a mutant baculovirus lacking its protein tyrosine phosphatase (ptp gene, a gene likely captured from an ancestral host. Here we show that the product of the ptp gene, PTP, associates with baculovirus ORF1629 as a virion structural protein, but surprisingly phosphatase activity associated with PTP was not required for the induction of ELA. Interestingly, the ptp knockout baculovirus showed significantly reduced infectivity of larval brain tissues. Collectively, we show that the modern baculovirus uses the host-derived phosphatase to establish adequate infection for ELA as a virion-associated structural protein rather than as an enzyme.

  11. Ecological mechanisms linking protected areas to surrounding lands.

    Science.gov (United States)

    Hansen, Andrew J; DeFries, Ruth

    2007-06-01

    Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.

  12. Metrizamide demonstration of the subarachnoid space surrounding the Gasserian ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, D.; Babin, E.

    1980-05-01

    The chance opacification of the subarachnoid space surrounding the Gasserian ganglion, observed during metrizamide basal cisternography, is reported. This is compared to similar demonstrations of the optic subarachnoid space. Such infrequently observed images should be known because they may be related to the occurrence of trigeminal neuralgia.

  13. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  14. Challenges Surrounding the Education of Children with Chronic Diseases

    Science.gov (United States)

    Gordon, Maria, Ed.

    2016-01-01

    While governing bodies have mandated that all students have the right to an education, with disabled students treated to the same rights and opportunities as non-disabled students, policymakers do not always agree on what all-inclusive education should look like. "Challenges Surrounding the Education of Children with Chronic Diseases"…

  15. Host density increases parasite recruitment but decreases host risk in a snail-trematode system.

    Science.gov (United States)

    Buck, J C; Hechinger, R F; Wood, A C; Stewart, T E; Kuris, A M; Lafferty, K D

    2017-08-01

    Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk at local scales. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail-density-trematode-prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (California, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective

  16. Host density increases parasite recruitment but decreases host risk in a snail-trematode system

    Science.gov (United States)

    Buck, Julia C; Hechinger, R.F.; Wood, A.C.; Stewart, T.E.; Kuris, A.M.; Lafferty, Kevin D.

    2017-01-01

    Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally-transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail density-trematode prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (CA, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail-biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail-biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective-stage input, but this was

  17. Parasite host range and the evolution of host resistance

    NARCIS (Netherlands)

    Gorter, F.A.; Hall, A.R.; A., Buckling; P.D., Scanlan

    2015-01-01

    Parasite host range plays a pivotal role in the evolution and ecology of hosts
    and the emergence of infectious disease. Although the factors that promote
    host range and the epidemiological consequences of variation in host range
    are relatively well characterized, the effect of parasite

  18. Military installation sequestered more carbon than surrounding areas

    Science.gov (United States)

    Zhao, S.; Liu, S.; Li, Z.; Sohl, T.

    2008-12-01

    Land use activities greatly affect the temporal trends and spatial patterns of regional land-atmospheric exchange of carbon. Military installations generally have drastically different land management strategies from surrounding areas, and the carbon consequences have never been quantified and assessed. Here, we used the General Ensemble Biogeochemical Modeling System (GEMS) to simulate and compare ecosystem carbon dynamics between Fort Benning and surrounding areas from 1992 to 2050. GEMS was driven by unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes (predicted by FOREcasting SCEnarios of land cover change (FORE-SCE)). Our results indicated that the military installation sequestered more carbon than surrounding areas (0.77 vs. 0.16 Mg C ha-1 y-1 averaged from 1992 to 2007). Differences in land use activities were the primary cause behind the difference in carbon sequestration rates. From 1992 to 2007, no urban/residential expansion occurred at the installation, and transitional barren (primarily caused by forest harvesting) slightly increased from 0 to 0.2%. In contrast, urban land increased from 5.6 to 7.6% and transitional barren increased from 0.1 to 0.7% in the surrounding areas. Live biomass accumulation accounted for most of the carbon sink in both Fort Benning and surrounding areas (0.75 vs. 0.15 Mg C ha-1 y-1), while soil organic carbon accumulation was small (0.02 vs. 0.01 Mg C ha- 1 y-1), suggesting biomass removal caused by urbanization and harvesting resulted in much less carbon sequestration in surrounding areas. Fort Benning is likely to sequester more carbon in the future, although the rate of carbon sequestered per year will gradually reduce. The future carbon source/sink strength in the surrounding areas varied greatly, from a small sink to a strong source, depending on the path of land use change (e.g., increase of clear

  19. Lensed Quasar Hosts

    CERN Document Server

    Peng, C Y; Rix, H W; Keeton, C R; Falco, E E; Kochanek, C S; Lehár, J; McLeod, B A; Peng, Chien Y.; Impey, Chris D.; Rix, Hans-Walter; Keeton, Charles R.; Falco, Emilio E.; Kochanek, Chris S.; Lehar, Joseph; Leod, Brian A. Mc

    2006-01-01

    Gravitational lensing assists in the detection of quasar hosts by amplifying and distorting the host light away from the unresolved quasar core images. We present the results of HST observations of 30 quasar hosts at redshifts 1 1.7 is a factor of 3--6 higher than the local value. But, depending on the stellar content the ratio may decline at z>4 (if E/S0-like), flatten off to 6--10 times the local value (if Sbc-like), or continue to rise (if Im-like). We infer that galaxy bulge masses must have grown by a factor of 3--6 over the redshift range 3>z>1, and then changed little since z~1. This suggests that the peak epoch of galaxy formation for massive galaxies is above z~1. We also estimate the duty cycle of luminous AGNs at z>1 to be ~1%, or 10^7 yrs, with sizable scatter.

  20. How detrimental are seed galls to their hosts? Plant performance, germination, developmental instability and tolerance to herbivory in Inga laurina, a leguminous tree.

    Science.gov (United States)

    Santos, J C; de Araujo, N A V; Venâncio, H; Andrade, J F; Alves-Silva, E; Almeida, W R; Carmo-Oliveira, R

    2016-11-01

    Gall inducers use these structures as shelters and sources of nutrition. Consequently, they cause multiple physiological changes in host plants. We studied the impact caused by seed coat galls of a braconid wasp on the performance of fruits, seeds and seedlings of tree Inga laurina. We tested whether these seed galls are 'nutrient sinks' with respect to the fruit/seed of host plant, and so constrain the reproductive ability and reduce seedling longevity. We measured the influence of such galls on the secondary compounds, fruit and seed parameters, seed viability and germination and seedling performance. Inga laurina has indehiscent legumes with polyembryonic seeds surrounded by a fleshy sarcotesta rich in sugars. The galls formed inside the seed coat and galled tissues presented higher phenol concentrations, around 7-fold that of ungalled tissues. Galls caused a significant reduction in parameters such as fruit and seed size, seed weight and the number of embryos. Fluctuating asymmetry (a stress indicator) was 31% higher in leaves of galled seed plants in comparison to ungalled seed plants. However, the negative effects on fruit and seed parameters were not sufficient to reduce seed germination (except the synchronization index) or seedling performance (except leaf area and chlorophyll content). We attributed these results to the ability of I. laurina to tolerate gall attack on seeds without a marked influence on seedling performance. Moreover, because of the intensity of seed galling on host plant, we suggest that polyembryony may play a role in I. laurina reproduction increasing tolerance to seed damage.

  1. Hosting the World

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Hangzhou and surrounding communities open their doors to leisure and tourism The 2006 World Leisure Expo opens its doors in the scenic city of Hangzhou, in east China’s Zhejiang Province, from April 22 to October 22. The Expo, which was co-sponsored by the World Leisure Organization (WLO), National Tourism Administration and the Zhejiang Provincial Government, highlights the many recreational facets of Hangzhou.

  2. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    徐峰; 文婷; 卢天健; Seffen; Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great...

  3. Acupuncture, connective tissue, and peripheral sensory modulation.

    Science.gov (United States)

    Langevin, Helene M

    2014-01-01

    Although considerable controversy surrounds the legitimacy of acupuncture as a treatment, a growing literature on the physiological effects of acupuncture needling in animals and humans is providing new insights into basic cellular mechanisms including connective tissue mechanotransduction and purinergic signaling. This review summarizes these findings and proposes a model combining connective tissue plasticity and peripheral sensory modulation in response to the sustained stretching of tissue that results from acupuncture needle manipulation.

  4. Tissue tests

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    Tissue tests are widely used in horticulture practice and have in comparison with soil or substrate testing advantages as well disadvantages in comparison with soil testing. One of the main advantages of tissue tests is the certainty that analysed nutrients in plant tissues are really present in the

  5. Tissue tests

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    Tissue tests are widely used in horticulture practice and have in comparison with soil or substrate testing advantages as well disadvantages in comparison with soil testing. One of the main advantages of tissue tests is the certainty that analysed nutrients in plant tissues are really present in the

  6. Heterogeneity in friction strength of an active fault by incorporation of fragments of the surrounding host rock

    Science.gov (United States)

    Kato, Naoki; Hirono, Tetsuro

    2016-07-01

    To understand the correlation between the mesoscale structure and the frictional strength of an active fault, we performed a field investigation of the Atera fault at Tase, central Japan, and made laboratory-based determinations of its mineral assemblages and friction coefficients. The fault zone contains a light gray fault gouge, a brown fault gouge, and a black fault breccia. Samples of the two gouges contained large amounts of clay minerals such as smectite and had low friction coefficients of approximately 0.2-0.4 under the condition of 0.01 m s-1 slip velocity and 0.5-2.5 MP confining pressure, whereas the breccia contained large amounts of angular quartz and feldspar and had a friction coefficient of 0.7 under the same condition. Because the fault breccia closely resembles the granitic rock of the hangingwall in composition, texture, and friction coefficient, we interpret the breccia as having originated from this protolith. If the mechanical incorporation of wall rocks of high friction coefficient into fault zones is widespread at the mesoscale, it causes the heterogeneity in friction strength of fault zones and might contribute to the evolution of fault-zone architectures.

  7. Myoepithelioma of soft tissue

    Directory of Open Access Journals (Sweden)

    Pai Mukhta

    2009-01-01

    Full Text Available Myoepitheliomas and mixed tumors involving deep subcutaneous and subfascial soft tissues of limb or limb girdle are rare lesions as against salivary lesions that are well established conditions. Here, we report a 22-year-old female who presented with painful hard swelling in the left gluteal region of 1½ year duration. MRI showed a large ill-defined heterogeneous mass lesion measuring about 7-8 cm. in the left sacral region eroding the left sacroiliac region and left sacroiliac joint. With a clinical diagnosis of chondrosarcoma, the tumor with the surrounding tissue was resected in segments at surgery. Histomorphology revealed nests, sheets and cords of round to spindled cells with extensive squamous metaplasia in a myxoid to fibrous stroma. These cells extensively infiltrated muscle and bone. The tumor cells expressed immunoreactivity for cytokeratin (AE1/AE3 and S-100.

  8. Avian host defense peptides

    NARCIS (Netherlands)

    Cuperus, Tryntsje; Coorens, M.; van Dijk, A.; Haagsman, H.P.

    2013-01-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense

  9. SARS Pathogenesis: Host Factors

    NARCIS (Netherlands)

    A. de Lang (Anna)

    2012-01-01

    textabstractWhile it is hypothesized that Sever Acute Respiratory Syndrome (SARS) in humans is caused by a disproportional immune response illustrated by inappropriate induction of inflammatory cytokines, the exact nature of the host response to SARS coronavirus (CoV) infection causing severe

  10. Variable Ly alpha sheds light on the environment surrounding GRB 090426

    CERN Document Server

    Thöne, C C; Lazzati, D; Postigo, A de Ugarte; Fynbo, J P U; Christensen, L; Levan, A J; Aloy, M A; Hjorth, J; Jakobsson, P; Levesque, E M; Malesani, D; Milvang-Jensen, B; Roming, P W A; Tanvir, N R; Wiersema, K; Gladders, M; Wuyts, E; Dahle, H

    2011-01-01

    Long duration gamma-ray bursts are commonly associated with the deaths of massive stars. Spectroscopic studies using the afterglow as a light source provide a unique opportunity to unveil the medium surrounding it, probing the densest region of their galaxies. This material is usually in a low ionisation state and at large distances from the burst site, hence representing the normal interstellar medium in the galaxy. Here we present the case of GRB 090426 at z=2.609, whose optical spectrum indicates an almost fully ionised medium together with a low column density of neutral hydrogen. For the first time, we also observe variations in the Ly alpha absorption line. Photoionisation modeling shows that we are probing material from the vicinity of the burst (~80 pc). The host galaxy is a complex of two luminous interacting galaxies, which might suggest that this burst could have occurred in an isolated star-forming region outside its host galaxy created in the interaction of the two galaxies.

  11. Clustering of supernova Ia host galaxies

    CERN Document Server

    Carlberg, R G; Le Borgne, D; Conley, A; Howell, D A; Perrett, K; Astier, Pierre; Balam, D; Balland, C; Basa, S; Hardin, D; Fouchez, D; Guy, J; Hook, I; Pain, R; Pritchet, C J; Regnault, N; Rich, J; Perlmutter, S

    2008-01-01

    For the first time the cross-correlation between type Ia supernova host galaxies and surrounding field galaxies is measured using the Supernova Legacy Survey sample. Over the z=0.2 to 0.9 redshift range we find that supernova hosts are correlated an average of 60% more strongly than similarly selected field galaxies over the 3-100 arcsec range and about a factor of 3 more strongly below 10 arcsec. The correlation errors are empirically established with a jackknife analysis of the four SNLS fields. The hosts are more correlated than the field at a significance of 99% in the fitted amplitude and slope, with the point-by-point difference of the two correlation functions having a reduced $\\chi^2$ for 8 degrees of freedom of 4.3, which has a probability of random occurrence of less than 3x10^{-5}. The correlation angle is 1.5+/-0.5 arcsec, which deprojects to a fixed co-moving correlation length of approximately 6.5+/- 2/h mpc. Weighting the field galaxies with the mass and star formation rate supernova frequencie...

  12. Host Phylogeny Determines Viral Persistence and Replication in Novel Hosts

    Science.gov (United States)

    Longdon, Ben; Hadfield, Jarrod D.; Webster, Claire L.

    2011-01-01

    Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae) to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts. PMID:21966271

  13. Dynamics of two-component membranes surrounded by viscoelastic media.

    Science.gov (United States)

    Komura, Shigeyuki; Yasuda, Kento; Okamoto, Ryuichi

    2015-11-01

    We discuss the dynamics of two-component fluid membranes which are surrounded by viscoelastic media. We assume that membrane-embedded proteins can diffuse laterally and induce a local membrane curvature. The mean squared displacement of a tagged membrane segment is obtained as a generalized Einstein relation. When the elasticity of the surrounding media obeys a power-law behavior in frequency, an anomalous diffusion of the membrane segment is predicted. We also consider the situation where the proteins generate active non-equilibrium forces. The generalized Einstein relation is further modified by an effective temperature that depends on the force dipole energy. The obtained generalized Einstein relations are useful for membrane microrheology experiments.

  14. Study on Temperature Fieldof Surrounding Rock with BEM

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The authors analyzed the characteristic of surrounding rock temperature field around a drifting face, setup its mathematic model, and got its numerical result with the boundary element method(BEM). To calculate in-tra-domain integral, it was transformed into boundary integration with the DRM method. Using the similitude the-ory, the dimensionless differential equation was educed. Finally, the authors calculated two drifting faces of San-hejian Coal Mine using the computer software developed by authors based on the above principium, and got the dis-tribution characteristic of surrounding rock temperature field around a drifting face and the periodic variation intemperature with its periodic moving forward. Comparing the calculated heat dissipating-capacity of surroundingrock with the measured data shows that the computer software is proper.

  15. Experimental Study of Deformation of Surrounding Rock with Infrared Radiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-jun; AN Li-qian; REN Run-hou; FAN Shi-min; MA Nian-jie; LI Jian-hui; JI Yuan-ming

    2005-01-01

    According to the practical conditions of coal roadway in Changcun Coal Mine of Lu'an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared (TIR) imaging system in the process of confined compressions. It is found that the model surface TIR temperature (TIRT) changes with the increase of load. Furthermore, TIRT changes non-synchronously in different ranges such as the roof, floor, wall, corners and bolted ranges. The TIRT is higher in the location of stress concentration and bolted ranges than that in the location of stress relaxation and broken ranges. The interaction ranges of bolt and rock are determined preliminarily according to the corresponding relationship of TIRT fields and the strain fields of the surrounding rock. The new method of TIR image processing has been proved to be effective for the study of bolt support and observation of roadway stability under mine pressure.

  16. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    Xu Feng; Wen Ting; Lu Tianjian; Seffen Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great problem for burn patients. Thus, it is of great importance to quantify the thermal damage in skin tissue. In this paper, the available models and experimental methods for quantification of thermal damage in skin tissue are discussed.

  17. High resolution bathymetry of China seas and their surroundings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the oceanic lithospheric flexure and the worldwide bathymetric data ETOPO5, the high resolu tion bathymetry of the China seas and their surroundings is computed from altimeter derived gravity anomalies. The new bathymetry obtained by this study is higher resolution and accuracy than the widely used ETOPO5 data, mean while it shows clearly the seafioor, the tectonic characteristics and the geodynamical processes in the China seas.

  18. Thermodynamic stability of black holes surrounded by quintessence

    OpenAIRE

    Ma, Meng-Sen; Zhao, Ren; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic q...

  19. Hidden History: A Mobile Application for Discovering Surrounding Landscapes

    OpenAIRE

    2016-01-01

    This thesis work describes the design, development and evaluation of a mobile application called Hidden History. This application lets users discover and explore three types of landscapes (Historic, Scenic and Cultural) using three different modes of discovery (Route, Explore and Tour). Before designing Hidden History, the feature set of other applications that help users explore surrounding landscapes were identified and analyzed. Hidden History was then designed to implement the best fea...

  20. Treatment of Postherpetic Neuralgia by Surround Needling with Electric Stimulation

    Institute of Scientific and Technical Information of China (English)

    FAN Jin; YANG Qin-hua

    2005-01-01

    运用电针围刺法治疗带状疱疹后遗神经痛29例,获得较好疗效,总有效率为93.1%.%Twenty-nine cases of postherpetic neuralgia of herpes zoster were treated by the surround needling with electric stimulation, and the better therapeutic effect was obtained, the total effective rate was 93.1%.

  1. Belief and Attitudes surrounding Childhood Autism in Ghana

    OpenAIRE

    2012-01-01

    Autism is a life-long invisible impairment with an unknown etiology. Current literature shows an increase in the diagnosis of autism worldwide. This qualitative study explores the attitudes and beliefs which surround childhood autism in Ghana. In-depth interviews were conducted with four (4) parents whose children have autism and three (3) key informants; a Religious Leader, a Health Worker and an Administrator of a Special school in Accra, Ghana. A semi-structured interview guide was used fo...

  2. THE DESIGN OF DYNAMIC SIMULATION SYSTEM ON EARTHQUAKE SURROUNDINGS

    Institute of Scientific and Technical Information of China (English)

    沈毅力; 杨云; 李天石

    2003-01-01

    Objective To design a system that can simulate earthquake surroundings. In the surroundings, people can be familiar with the omen, strong shock and aftershock of earthquake, thus make right choices and get away when the disaster occurs. Methods The system consists of an electro-hydraulic servo system, a whole-information sound system and some lighting device; By using the adaptive inverse control method and LMS algorithms, the inverse model (I.e. The controller) is convergent rapidly; The software based on LabVIEW makes the parameters can be modified easily; There is a double closed-loop structure in the system: an analog closed-loop and a digital closed-loop, and their parameters can be inspected in real time. Results The system is of very high reliability, and the desired vibration signal can be tracked exactly by output. Conclusion Earthquake surroundings is simulated vividly. Through the system, people can be familiar with earthquake phenomena, and know lots of knowledge of earthquake.

  3. "Tissue" transglutaminase in AIDS.

    Science.gov (United States)

    Amendola, Alessandra; Fesus, Laszlo; Piacentini, Mauro; Szondy, Zsuzsa

    2002-07-01

    Apoptosis or programmed cell death (PCD) is an active process of cellular self-destruction, essential for embryonic development and maintenance of homeostasis of multicellular organisms. Programmed cell death induction can serve as a defence mechanism of the host against intracellular microbes. Virus infections trigger host cell apoptosis, which can either limit virus production or contribute directly to viral pathogenesis. Several independent laboratories have identified "tissue" transglutaminase (tTG) as a potentially important player of the cell death program(s). This gene is specifically expressed in cells dying during mammalian development as well as in those undergoing apoptosis in various patho-physiological and experimental settings [Eur. J. Cell Biol. 56 (1991) 170; Piacentini, M., Davies, P.J.A., Fesus, L., 1994. Tissue transglutaminase in cells undergoing apoptosis. In: Tomei, L.D., Cope, F.O. (Eds.), Apoptosis II: The molecular basis of apoptosis in disease. Cold Spring Harbor Lab. Press, pp. 143-165.]. This chapter reviews recent studies concerning the expression and the possible role of "tissue" transglutaminase (tTG) in apoptotic cells; particular emphasis is given to its expression in the cell death pathways associated with HIV infection in the immune system. We propose here that the induction of the tTG gene in cells of the immune system, as well as the detection of the isodipeptide epsilon(gamma-glutamyl)lysine in plasma, are useful markers of apoptosis and might make it possible to monitor disease progression in HIV-infected individuals.

  4. Microsatellite analysis reveals strong but differential impact of a social parasite on its two host species.

    Science.gov (United States)

    Fischer-Blass, Birgit; Heinze, Jürgen; Foitzik, Susanne

    2006-03-01

    The speed and the dynamics of the co-evolutionary process strongly depend on the relative strengths of reciprocal selection pressures exerted by the interacting species. Here, we investigate the influence of an obligate social parasite, the slave-making ant Harpagoxenus sublaevis, on populations of the two main host species Leptothorax acervorum and Leptothorax muscorum from a German ant community. A combination of genetic and demographic data allowed us to analyse the consequences of raiding pressure on the hosts' life history and possible host preferences of the parasite. We can demonstrate that slave raids during which the social parasite pillages brood from neighbouring host colonies are both frequent and extremely destructive for both host species. Microsatellite analysis showed that, on average, a single slave-maker colony conducts more than three raids per year and that host colonies mostly perish in the aftermath of these parasite attacks. Only in few cases, surviving nests of previously raided host colonies were found in the surroundings of slave-maker colonies. As a consequence of the high prevalence of parasites and their recurrent and devastating slave raids on host colonies, the life expectancy of host colonies was severely reduced. Combining our results on host-specific parasitic colony founding and raiding frequencies with the post-raid survival rate, we can demonstrate an overall higher mortality rate for the smaller host species L. muscorum. This might be caused by a preference of H. sublaevis for this secondary host species as demographic data on host species usage indicate.

  5. CHARACTERIZATION OF HOST PLANT DEFENSE RESPONSES TO PARASITIZATION BY Orobanche aegyptiaca

    OpenAIRE

    2001-01-01

    Orobanche (spp.) are parasitic plants that attack the roots of many important crops. O. aegyptiaca penetrates the host root (aided by digestive enzymes) and forms connections to the host vascular tissue, from which it will withdraw all of its water and nutrient requirements. In order to control this weed, it is important to understand the relationship between the host and the parasite. To investigate how parasitism effects host defense pathways, we are studying the patterns of expression o...

  6. Microbiome Profiles in Periodontitis in Relation to Host and Disease Characteristics

    Science.gov (United States)

    Hong, Bo-Young; Furtado Araujo, Michel V.; Strausbaugh, Linda D.; Terzi, Evimaria; Ioannidou, Effie; Diaz, Patricia I.

    2015-01-01

    Periodontitis is an inflammatory condition that affects the supporting tissues surrounding teeth. The occurrence of periodontitis is associated with shifts in the structure of the communities that inhabit the gingival sulcus. Although great inter-subject variability in the subgingival microbiome has been observed in subjects with periodontitis, it is unclear whether distinct community types exist and if differences in microbial signatures correlate with host characteristics or with the variable clinical presentations of periodontitis. Therefore, in this study we explored the existence of different community types in periodontitis and their relationship with host demographic, medical and disease-related clinical characteristics. Clustering analyses of microbial abundance profiles suggested two types of communities (A and B) existed in the 34 subjects with periodontitis evaluated. Type B communities harbored greater proportions of certain periodontitis-associated taxa, including species historically associated with the disease, such as Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, and taxa recently linked to periodontitis. In contrast, subjects with type A communities had increased proportions of different periodontitis-associated species, and were also enriched for health-associated species and core taxa (those equally prevalent in health and periodontitis). Periodontitis subgingival clusters were not associated with demographic, medical or disease-specific clinical parameters other than periodontitis extent (proportion of sites affected), which positively correlated with the total proportion of cluster B signature taxa. In conclusion, two types of microbial communities were detected in subjects with periodontitis. Host demographics and underlying medical conditions did not correlate with these profiles, which instead appeared to be related to periodontitis extent, with type B communities present in more widespread disease cases. The two

  7. Microbiome profiles in periodontitis in relation to host and disease characteristics.

    Directory of Open Access Journals (Sweden)

    Bo-Young Hong

    Full Text Available Periodontitis is an inflammatory condition that affects the supporting tissues surrounding teeth. The occurrence of periodontitis is associated with shifts in the structure of the communities that inhabit the gingival sulcus. Although great inter-subject variability in the subgingival microbiome has been observed in subjects with periodontitis, it is unclear whether distinct community types exist and if differences in microbial signatures correlate with host characteristics or with the variable clinical presentations of periodontitis. Therefore, in this study we explored the existence of different community types in periodontitis and their relationship with host demographic, medical and disease-related clinical characteristics. Clustering analyses of microbial abundance profiles suggested two types of communities (A and B existed in the 34 subjects with periodontitis evaluated. Type B communities harbored greater proportions of certain periodontitis-associated taxa, including species historically associated with the disease, such as Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, and taxa recently linked to periodontitis. In contrast, subjects with type A communities had increased proportions of different periodontitis-associated species, and were also enriched for health-associated species and core taxa (those equally prevalent in health and periodontitis. Periodontitis subgingival clusters were not associated with demographic, medical or disease-specific clinical parameters other than periodontitis extent (proportion of sites affected, which positively correlated with the total proportion of cluster B signature taxa. In conclusion, two types of microbial communities were detected in subjects with periodontitis. Host demographics and underlying medical conditions did not correlate with these profiles, which instead appeared to be related to periodontitis extent, with type B communities present in more widespread disease

  8. Messages from the Other Side: Parasites Receive Damage Cues from their Host Plants.

    Science.gov (United States)

    Tjiurutue, Muvari Connie; Stevenson, Philip C; Adler, Lynn S

    2016-08-01

    As sessile organisms, plants rely on their environment for cues indicating imminent herbivory. These cues can originate from tissues on the same plant or from different individuals. Since parasitic plants form vascular connections with their host, parasites have the potential to receive cues from hosts that allow them to adjust defenses against future herbivory. However, the role of plant communication between hosts and parasites for herbivore defense remains poorly investigated. Here, we examined the effects of damage to lupine hosts (Lupinus texensis) on responses of the attached hemiparasite (Castilleja indivisa), and indirectly, on a specialist herbivore of the parasite, buckeyes (Junonia coenia). Lupines produce alkaloids that act as defenses against herbivores that can be taken up by the parasite. We found that damage to lupine host plants by beet armyworm (Spodoptera exigua) significantly increased jasmonic acid (JA) levels in both the lupine host and parasite, suggesting uptake of phytohormones or priming of parasite defenses by using host cues. However, lupine host damage did not induce changes in alkaloid levels in the hosts or parasites. Interestingly, the parasite had substantially higher concentrations of JA and alkaloids compared to lupine host plants. Buckeye herbivores consumed more parasite tissue when attached to damaged compared to undamaged hosts. We hypothesize that increased JA due to lupine host damage induced higher iridoid glycosides in the parasite, which are feeding stimulants for this specialist herbivore. Our results demonstrate that damage to hosts may affect both parasites and associated herbivores, indicating cascading effects of host damage on multiple trophic levels.

  9. Characterization of exoplanet hosts

    Directory of Open Access Journals (Sweden)

    Valenti Jeff A.

    2013-04-01

    Full Text Available Spectroscopic analysis of exoplanet hosts and the stellar sample from which they are drawn provides abundances and other properties that quantitively constrain models of planet formation. The program Spectroscopy Made Easy (SME determines stellar parameters by fitting observed spectra, though line lists must be selected wisely. For giant planets, it is now well established that stars with higher metallicity are more likely to have detected companions. Stellar metallicity does not seem to affect the formation and/or migration of detectable planets less massive than Neptune, especially when considering only the most massive planet in the system. In systems with at least one planet less than 10 times the mass of Earth, the mass of the most massive planet increases dramatically with host star metallicity. This may reflect metallicity dependent timescales for core formation, envelope accretion, and/or migration into the detection zone.

  10. HostPhinder: A Phage Host Prediction Tool

    DEFF Research Database (Denmark)

    Villarroel, Julia; Kleinheinz, Kortine Annina; Jurtz, Vanessa Isabell

    2016-01-01

    The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within...... reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference...... phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k) is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST...

  11. An anatomical and histological study of the structures surrounding the proximal attachment of the hamstring muscles.

    Science.gov (United States)

    Pérez-Bellmunt, Albert; Miguel-Pérez, Maribel; Brugué, Marc Blasi; Cabús, Juan Blasi; Casals, Martí; Martinoli, Carlo; Kuisma, Raija

    2015-06-01

    The proximal attachment of hamstring muscles has a very high incidence of injuries due to a wide number of factors and its morphology may be one of the underlying factors as scientific literature points out. The connective tissue component of the attachment of hamstring muscles is not well known. For this reason the aim of this study is to describe the anatomy and histology surrounding the proximal attachment of the hamstring muscles (PAHM) and its direct anatomic relations. Forty-eight cryopreserved lower limbs have sequentially been studied by means of dissection, anatomical sections and histology. All specimens studied presented an annular connective tissue structure that resembles a retinaculum, which covers and adapts to the attachment of hamstring muscles on the ischial tuberosity. The results show how this retinaculum is continuous with the long head of biceps femoris muscle, however there is a layer of loose connective tissue between the retinaculum and the semitendinosus muscle. Furthermore, this structure receives expansions of the anterior epimysium of the gluteus maximus muscle (GIM). Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Tissue types (image)

    Science.gov (United States)

    There are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue ... and binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of ...

  13. INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

    2016-02-10

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

  14. Issues surrounding record keeping in district nursing practice.

    Science.gov (United States)

    Anderson, E E

    2000-07-01

    This article examines some aspects of nursing documentation following the publication of the document 'Guidelines for Records and Record Keeping' (UKCC, 1998). The importance of nursing documentation in patient care, in guiding practice and in providing information for members of the interprofessional healthcare team is highlighted. Record keeping forms an important part of the clinical governance initiative in terms of quality improvement and risk management. The issues surrounding the legal requirements of record keeping in district nursing practice are discussed. Suggestions are made for assessing the quality of nursing documentation by audit and research, in order to establish the suitability of using the present systems in the community setting.

  15. Induced radioactivity in a 4 MW target and its surroundings

    CERN Document Server

    Agosteo, Stefano; Otto, Thomas; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation.

  16. Mutual seismic interaction between tunnels and the surrounding granular soil

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Abdel-Motaal

    2014-12-01

    Study results show that the maximum exerted straining actions in tunnel lining are directly proportional to the relative stiffness between tunnel and surrounding soil (lining thickness and soil shear modulus. Moreover, it is highly affected by the peak ground acceleration and the tunnel location (embedment depth. A comprehensive study is performed to show the effect of tunnel thickness and tunnel diameter on both the induced bending moment and lining deformation. In general, it is concluded that seismic analysis should be considered in regions subjected to peak ground acceleration greater than 0.15g.

  17. Problems Surrounding Probation In The South African Public Service

    Directory of Open Access Journals (Sweden)

    Z. Baloyi

    2006-11-01

    Full Text Available The aim of the study was to investigate problems surrounding probation periods in the South African Public Service. A qualitative study was conducted to determine the views of both probationers and supervisors managing the probation process. Data was gathered by means of focus groups and individual interviews. Nine key areas were identified as being problematic, viz. clarity regarding the purpose of probation, lack of proper guidelines, the duration of probation, rotation during probation, lack of training, poor management of probation, performance management, anxiety and stress, power and authority. Recommendations are made concerning possible interventions.

  18. Estimation of Specific Effective Energy of Surrounding Organs with Prostate as the Source Organ

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon; Lim, Chang Seon; Whang, Joo Ho [Kyunghee Univ., Konyang (Korea, Republic of)

    2008-10-15

    The incidence of prostate cancer has increased rapidly due to such as aging population and western dietary habits and it is the fifth most common cancer among male cancers and the most common cancer in urinary system. Prostate cancer is treated in various ways, but suitable treatments are selected case by case instead of particularly superior treatments chosen. One of them is cancer treatment via irradiation and it is widely available because of its simplicity and outstanding effectiveness; however compromised local selectivity inevitably results in side effects in surrounding tissues like bladder, urethra and rectum. These tough problems have been able to be solved since mid-1980s when radioisotope seeds such as {sup 1}'2{sup 5}I or {sup 103}Pd which could be implanted in the body were produced, and now much less invasive brachytherapy is widely used in the US and Europe. But there is a lack of investigations related to this therapy in Korea. In the present study, we intend to estimate specific effective energy of prostate and surrounding organs using {sup 125}I and {sup 103}Pd and thus provide basic data of radiation exposure assessments during prostate brachytherapy.

  19. Toxoplasma exports dense granule proteins beyond the vacuole to the host cell nucleus and rewires the host genome expression.

    Science.gov (United States)

    Bougdour, Alexandre; Tardieux, Isabelle; Hakimi, Mohamed-Ali

    2014-03-01

    Toxoplasma gondii is the most widespread apicomplexan parasite and occupies a large spectrum of niches by infecting virtually any warm-blooded animals. As an obligate intracellular parasite, Toxoplasma has evolved a repertoire of strategies to fine-tune the cellular environment in an optimal way to promote growth and persistence in host tissues hence increasing the chance to be transmitted to new hosts. Short and long-term intracellular survival is associated with Toxoplasma ability to both evade the host deleterious immune defences and to stimulate a beneficial immune balance by governing host cell gene expression. It is only recently that parasite proteins responsible for driving these transcriptional changes have been identified. While proteins contained in the apical secretory Rhoptry organelle have already been identified as bona fide secreted effectors that divert host signalling pathways, recent findings revealed that dense granule proteins should be added to the growing list of effectors as they reach the host cell cytoplasm and nucleus and target various host cell pathways in the course of cell infection. Herein, we emphasize on a novel subfamily of dense granule residentproteins, exemplified with the GRA16 and GRA24 members we recently discovered as both are exported beyond the vacuole-containing parasites and reach the host cell nucleus to reshape the host genome expression.

  20. Muscle biopsies off-set normal cellular signaling in surrounding musculature

    DEFF Research Database (Denmark)

    Krag, Thomas O; Hauerslev, Simon; Dahlqvist, Julia R

    2013-01-01

    muscle tissue for at least 3 weeks after the biopsy was performed and magnetic resonance imaging suggests that an effect of a biopsy may persist for at least 5 months. Cellular signaling after a biopsy resembles what is seen in severe limb-girdle muscular dystrophy type 2I with respect to protein......Studies of muscle physiology and muscular disorders often require muscle biopsies to answer questions about muscle biology. In this context, we have often wondered if muscle biopsies, especially if performed repeatedly, would affect interpretation of muscle morphology and cellular signaling. We...... hypothesized that muscle morphology and cellular signaling involved in myogenesis/regeneration and protein turnover can be changed by a previous muscle biopsy in close proximity to the area under investigation. Here we report a case where a past biopsy or biopsies affect cellular signaling of the surrounding...

  1. Capillarity-induced mechanical behaviors of a polymer microtube surrounded by a droplet

    Directory of Open Access Journals (Sweden)

    Yue Mei

    2014-12-01

    Full Text Available The capillary force of a liquid drop has a great impact on the mechanical behaviors of a polymer microtube. To further explore this capillary effect, we examine the buckling condition and finite deformation of a hollow microfiber surrounded by a droplet. The Eulerian rod model and thin-walled shell model are both adopted to predict the critical value of the capillary force acting on the microfiber. According to the Mooney-Rivlin model, we calculate the true axial stress of the microtube under the combined action of surface tension and Laplace pressure. The numerical results show that the value of the true axial stress is closely related to the Young’s contact angle, droplet volume and characteristic sizes of the microtube. Our findings address that proper control over surface wettability may improve the performance optimization of micro-devices, and these analyses may produce ideas in the areas of nanofabrication, electrospinning and tissue engineering.

  2. Chronic Effect of Transrectal Split-Focus Ultrasonic Ablation on Canine Prostatic Tissue

    National Research Council Canada - National Science Library

    SASAKI, Kazuaki; AZUMA, Takashi; KAWABATA, Ken-ichi; UMEMURA, Shin-ichiro; TANAKA, Ryou; YAMANE, Yoshihisa; SHIMODA, Minoru

    2006-01-01

    ... prostatic tissue without injuring surrounding tissues. The prostates of 5 dogs were transrectally treated with split-focus ablation at a peak intensity in the water of 1.7 kW/cm2 for 4 s (4 shots...

  3. Differential expression of tissue repair genes in the pathogenesis of chronic obstructive pulmonary disease

    National Research Council Canada - National Science Library

    Gosselink, John V; Hayashi, Shizu; Elliott, W Mark; Xing, Li; Chan, Becky; Yang, Luojia; Wright, Claire; Sin, Don; Paré, Peter D; Pierce, John A; Pierce, Richard A; Patterson, Alex; Cooper, Joel; Hogg, James C

    2010-01-01

    .... The expression of 54 genes associated with repair of repetitively damaged tissue was measured in 136 paired samples of small bronchioles and surrounding lung tissue separated by laser capture microdissection...

  4. Illuminating coronavirus-host interactions

    NARCIS (Netherlands)

    Raaben, M.

    2009-01-01

    Viruses are infectious agents incapable of growing or reproducing outside a host cell. They are completely dependent on the cellular machinery of the host for their multiplication. On the other hand, however, viruses also have to deal with the immune defences of the host. Apparently, viruses are wal

  5. Interactions of the Infrared bubble N4 with the surroundings

    CERN Document Server

    Liu, Hong-Li; Wu, Yuefang; Yuan, Jing-Hua; Liu, Tie; Dubner, G; Paron, S; Ortega, M E; Molinari, Sergio; Huang, Maohai; Zavagno, Annie; Samal, Manash R; Huang, Ya-Fang; Zhang, Si-Ju

    2016-01-01

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with HII regions have been considered to be a good sample to investigate triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the HII region G11.898+0.747, analyzing its interaction with the surroundings and star formation histories therein, aiming at determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 $\\times10^{22}$ cm$^{-2}$, mean volume density of about 4.4 $\\times10^{4}$ cm$^{-3}$, and a mean mass of 320 $M_{\\odot}$. In addition, from PAH emission seen at 8 $\\mu$m, ...

  6. Radio observations of Supernova Remnants and the surrounding molecular gas

    CERN Document Server

    Dubner, G

    2011-01-01

    Supernova Remnants (SNRs) are believed to be the main source of Galactic cosmic rays (CR). The strong SNR shocks provide ideal acceleration sites for particles of at least 10^14 eV/nucleon. Radio continuum studies of SNRs carried out with good sensitivity and high angular resolution convey information about three main aspects of the SNRs: morphology, polarization and spectrum. Based on this information it is possible to localize sites of higher compression and particle acceleration as well as the orientation and degree of order of the magnetic fields, and in some cases even its intensity. All this information, when complemented with the study of the distribution and kinematics of the surrounding interstellar gas, results in a very useful dataset to investigate the role of SNRs as cosmic ray accelerators. In this presentation, I analyze the radio observations of SNRs and surrounding molecular clouds, showing the contribution of these studies to the understanding of the role of SNRs as factories of CRs.

  7. Triggered Star Formation Surrounding Wolf-Rayet Star HD 211853

    Science.gov (United States)

    Liu, Tie; Wu, Yuefang; Zhang, Huawei; Qin, Sheng-Li

    2012-05-01

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 103 cm-3 and kinematic temperature ~20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core "A," which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the "collect and collapse" process functions in this region. The star-forming activities in core "A" seem to be affected by the "radiation-driven implosion" process.

  8. Triggered star formation surrounding Wolf-Rayet star HD 211853

    CERN Document Server

    Liu, Tie; Zhang, Huawei; Qin, Sheng-Li

    2012-01-01

    The environment surrounding Wolf-Rayet star HD 211853 is studied in molecular emission, infrared emission, as well as radio and HI emission. The molecular ring consists of well-separated cores, which have a volume density of 10$^{3}$ cm$^{-3}$ and kinematic temperature $\\sim$20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From SED modeling towards the young stellar objects (YSOs), sequential star formation is revealed on a large scale in space spreading from the Wolf-Rayet star to the molecular ring. A small scale sequential star formation is revealed towards core A, which harbors a very young star cluster. Triggered star formations is thus suggested. The presence of PDR, the fragmentation of the molecular ring, the collapse of the cores, the large scale sequential star formation indicate the "Collect and Collapse" process functions in this region. The star forming activities in core A seem to be affected by the "Radiation-Driven Implosion" (...

  9. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-05-20

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  10. HostPhinder: A Phage Host Prediction Tool

    Directory of Open Access Journals (Sweden)

    Julia Villarroel

    2016-05-01

    Full Text Available The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST and significantly outperforming BLAST on phages for which both had predictions. HostPhinder predictions on phage draft genomes from the INTESTI phage cocktail corresponded well with the advertised targets of the cocktail. Our study indicates that for most phages genomic similarity correlates well with related bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2].

  11. INVASIVE WEEDS IN BOGOR BOTANIC GARDENS, INDONESIA AND ITS IMPLICATION ON SURROUNDING LANDSCAPES

    Directory of Open Access Journals (Sweden)

    Edi Santosa

    2014-07-01

    Full Text Available Conservation areas with the objective for collection and exchange plant materials have been speculated as weed bank for surrounding areas. Objective of this study was to identify and characterize ruderal invasive weeds in the Bogor Botanic Gardens (BBG. Observations were conducted in all vak (collection blocks in the BBG in order to identify the weeds species, determine their invasiveness, dominance and distribution. Weeds associations with host plants were observed. Current weed control program and data of dead trees collection were analyzed in relevant to weed. Distribution of weeds outside BBG was observed by transects method following river and road directions. Results showed that there were seven invasive weeds, i.e., Cecropia adenopus (Cecropiaceae, Cissus nodosa Blume (Vitaceae, Cissus sicyoides Blume (Vitaceae, Dioscorea bulbifera L. (Dioscoreaceae, Ficus elastica Roxb. (Moraceae, Mikania micrantha H.B.K. (Asteraceae and Paraserianthes falcataria (L. Nielsen (Fabaceae. These seven weeds species invaded 41 out of 215 plant families in BBG. Six species of weeds, i.e., C. adenopus, C. nodosa Blume., C. sicyoides Blume., D. bulbifera L., M. micrantha H.B.K. and P. falcataria (L. Nielsen, were introduced as BBG collections for the first time while the F. elastica Roxb was considered as native. It is most likely that the weeds dispersal agents are the wind, birds, bats, visitors, and waters. All of these weeds existed in surrounding areas outside BBG. Given the detrimental impact of invasive weeds on the plant collection in BBG, it is necessary to develop long–term comprehensive control measures both inside and neighboring areas by involving other government authorities beyond BBG.

  12. Entomopathogenic Fungi: New Insights into Host-Pathogen Interactions.

    Science.gov (United States)

    Butt, T M; Coates, C J; Dubovskiy, I M; Ratcliffe, N A

    2016-01-01

    Although many insects successfully live in dangerous environments exposed to diverse communities of microbes, they are often exploited and killed by specialist pathogens. Studies of host-pathogen interactions (HPI) provide valuable insights into the dynamics of the highly aggressive coevolutionary arms race between entomopathogenic fungi (EPF) and their arthropod hosts. The host defenses are designed to exclude the pathogen or mitigate the damage inflicted while the pathogen responds with immune evasion and utilization of host resources. EPF neutralize their immediate surroundings on the insect integument and benefit from the physiochemical properties of the cuticle and its compounds that exclude competing microbes. EPF also exhibit adaptations aimed at minimizing trauma that can be deleterious to both host and pathogen (eg, melanization of hemolymph), form narrow penetration pegs that alleviate host dehydration and produce blastospores that lack immunogenic sugars/enzymes but facilitate rapid assimilation of hemolymph nutrients. In response, insects deploy an extensive armory of hemocytes and macromolecules, such as lectins and phenoloxidase, that repel, immobilize, and kill EPF. New evidence suggests that immune bioactives work synergistically (eg, lysozyme with antimicrobial peptides) to combat infections. Some proteins, including transferrin and apolipophorin III, also demonstrate multifunctional properties, participating in metabolism, homeostasis, and pathogen recognition. This review discusses the molecular intricacies of these HPI, highlighting the interplay between immunity, stress management, and metabolism. Increased knowledge in this area could enhance the efficacy of EPF, ensuring their future in integrated pest management programs.

  13. Biological therapy of strontium-substituted bioglass for soft tissue wound-healing: responses to oxidative stress in ovariectomised rats.

    Science.gov (United States)

    Jebahi, S; Oudadesse, H; Jardak, N; Khayat, I; Keskes, H; Khabir, A; Rebai, T; El Feki, H; El Feki, A

    2013-07-01

    New synthetic biomaterials are constantly being developed for wound repair and regeneration. Bioactive glasses (BG) containing strontium have shown successful applications in tissue engineering account of their biocompatibility and the positive biological effects after implantation. This study aimed to assess whether BG-Sr was accepted by the host tissue and to characterize oxidative stress biomarker and antioxidant enzyme profiles during muscle and skin healing. Wistar rats were divided into five groups (six animals per group): the group (I) was used as negative control (T), after ovariectomy, groups II, III, IV and V were used respectively as positive control (OVX), implanted tissue with BG (OVX-BG), BG-Sr (OVX-BG-Sr) and presented empty defects (OVX-NI). Soft tissues surrounding biomaterials were used to estimate superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) concentration. Our results show that 60 days after operation, treatment of rats with BG-Sr significantly increased MDA concentration and caused an increase of SOD, CAT and GPx activities in both skin and muscular tissues. BG-Sr revealed maturation of myotubes followed a normal appearance of muscle regenerated with high density and mature capillary vessels. High wound recovery with complete re-epithelialization and regeneration of skin was observed. The results demonstrate that the protective action against reactive oxygen species (ROS) was clearly observed in soft tissue surrounding BG-Sr. Moreover, the potential use of BG-Sr rapidly restores the wound skin and muscle structural and functional properties. The BG advantages such as ion release might make BG-Sr an effective biomaterial choice for antioxidative activity.

  14. Medical image of the week: granulation tissue

    Directory of Open Access Journals (Sweden)

    Ganesh A

    2014-03-01

    Full Text Available A 57 year old woman presented with a tickling sensation in the back of throat and intermittent bleeding from the healing stoma one month after decannulation of her tracheostomy tube. On bronchoscopy a granuloma with surrounding granulation tissue was present in the subglottic space (Figure 1. Argon plasma coagulation (APC was performed to cauterize the granulation tissue (Figure 2. Formation of granulation tissue after tracheostomy is a common complication which can result in tracheal stenosis. APC and electrocautery using flexible bronchoscopy has been shown to safely and effectively remove the granulation tissue.

  15. Tissue Classification

    DEFF Research Database (Denmark)

    Van Leemput, Koen; Puonti, Oula

    2015-01-01

    Computational methods for automatically segmenting magnetic resonance images of the brain have seen tremendous advances in recent years. So-called tissue classification techniques, aimed at extracting the three main brain tissue classes (white matter, gray matter, and cerebrospinal fluid), are now...... well established. In their simplest form, these methods classify voxels independently based on their intensity alone, although much more sophisticated models are typically used in practice. This article aims to give an overview of often-used computational techniques for brain tissue classification...

  16. Soft tissue digestion of Paradiplozoon vaalense for SEM of sclerites and simultaneous molecular analysis.

    Science.gov (United States)

    Dos Santos, Q M; Avenant-Oldewage, A

    2015-02-01

    Classification of most monogeneans is primarily based on size, shape, and arrangement of haptoral sclerites. These structures are often obscured or misinterpreted when studied using light microscopy, leading to confusion regarding defining characters. Scanning electron microscopy (SEM) has predominantly been used to study haptoral sclerites in smaller monogeneans, focusing on hooks and anchors. In the Diplozoidae, SEM has not been used to study haptoral sclerites. Using new and modified techniques, the sclerites of diplozoids collected in South Africa were successfully studied using SEM. The digestion buffer from a DNA extraction kit was used to digest the surrounding tissue, and Poly-L-lysine-coated and concavity slides were employed to limit the movement and loss of sclerites, with the latter being more user-friendly. In addition to the success of visualizing the sclerites using SEM, the digested tissue from as little as half of the haptor provided viable genetic material for molecular characterization. From the results presented here, the study of the sclerites of larger monogeneans using SEM, including those bearing clamps, is a viable possibility for future research. Also, this method may be beneficial for the study of other, non-haptoral sclerites, such as cirri in other families of monogeneans. During this study, Labeo capensis was noted as a valid host of Paradiplozoon vaalense in a region of the Vaal River where the type host, Labeo umbratus, appears to be absent.

  17. The Drosophila melanogaster host model

    Science.gov (United States)

    Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

  18. The Drosophila melanogaster host model

    Directory of Open Access Journals (Sweden)

    Christina O. Igboin

    2012-02-01

    Full Text Available The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

  19. Host niches and defensive extended phenotypes structure parasitoid wasp communities.

    Directory of Open Access Journals (Sweden)

    Richard Bailey

    2009-08-01

    Full Text Available Oak galls are spectacular extended phenotypes of gallwasp genes in host oak tissues and have evolved complex morphologies that serve, in part, to exclude parasitoid natural enemies.Parasitoids and their insect herbivore hosts have coevolved to produce diverse communities comprising about a third of all animal species. The factors structuring these communities, however, remain poorly understood. An emerging theme in community ecology is the need to consider the effects of host traits, shaped by both natural selection and phylogenetic history, on associated communities of natural enemies. Here we examine the impact of host traits and phylogenetic relatedness on 48 ecologically closed and species-rich communities of parasitoids attacking gall-inducing wasps on oaks. Gallwasps induce the development of spectacular and structurally complex galls whose species- and generation-specific morphologies are the extended phenotypes of gallwasp genes. All the associated natural enemies attack their concealed hosts through gall tissues, and several structural gall traits have been shown to enhance defence against parasitoid attack. Here we explore the significance of these and other host traits in predicting variation in parasitoid community structure across gallwasp species. In particular, we test the "Enemy Hypothesis," which predicts that galls with similar morphology will exclude similar sets of parasitoids and therefore have similar parasitoid communities. Having controlled for phylogenetic patterning in host traits and communities, we found significant correlations between parasitoid community structure and several gall structural traits (toughness, hairiness, stickiness, supporting the Enemy Hypothesis. Parasitoid community structure was also consistently predicted by components of the hosts' spatiotemporal niche, particularly host oak taxonomy and gall location (e.g., leaf versus bud versus seed. The combined explanatory power of structural and

  20. An analysis of amino acid sequences surrounding archaeal glycoprotein sequons.

    Science.gov (United States)

    Abu-Qarn, Mehtap; Eichler, Jerry

    2007-05-01

    Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.

  1. An analysis of amino acid sequences surrounding archaeal glycoprotein sequons

    Directory of Open Access Journals (Sweden)

    Mehtap Abu-Qarn

    2006-01-01

    Full Text Available Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.

  2. Wave rectification in plasma sheaths surrounding electric field antennas

    Science.gov (United States)

    Boehm, M. H.; Carlson, C. W.; Mcfadden, J. P.; Clemmons, J. H.; Ergun, R. E.; Mozer, F. S.

    1994-01-01

    Combined measurements of Langmuir or broadband whistler wave intensity and lower-frequency electric field waveforms, all at 10-microsecond time resolution, were made on several recent sounding rockets in the auroral ionosphere. It is found that Langmuir and whistler waves are partically rectified in the plasma sheaths surrounding the payload and the spheres used as antennas. This sheath rectification occurs whenever the high frequency (HF) potential across the sheath becomes of the same order as the electron temperature or higher, for wave frequencies near or above the ion plasma frequency. This rectification can introduce false low-frequency waves into measurements of electric field spectra when strong high-frequency waves are present. Second harmonic signals are also generated, although at much lower levels. The effect occurs in many different plasma conditions, primarily producing false waves at frequencies that are low enough for the antenna coupling to the plasma to be resistive.

  3. The nature of plerions surrounding soft gamma-ray repeaters

    CERN Document Server

    Harding, A K

    1995-01-01

    Compact steady sources of X-ray emission have been detected at the positions of at least two soft gamma-ray repeaters (SGRs). These sources have been interpreted as synchrotron nebulae powered by the neutron star that is causing the bursts. We explore a plerion model for the sources surrounding SGRs where the steady observed emission is powered by the SGR bursts rather than by the spin-down of a pulsar. In this case there is no limit on the neutron star magnetic field. We find that the synchrotron lifetime of the particles injected into the plerion around SGR1806-20 is long enough to smear out nebular emission from individual bursts. Transient nebular emission would therefore not be detected following an SGR burst. The combined radio emission from multiple burst injections is expected to have a steeper spectrum than that of a typical plerion.

  4. Casimir Effect in the Kerr Spacetime Surrounded by Quintessence

    CERN Document Server

    Bezerra, V B; Freitas, L F F; Muniz, C R

    2016-01-01

    We calculate the Casimir energy of a massless scalar field in a cavity formed by nearby parallel plates orbiting a rotating spherical body surrounded by quintessence, investigating the influence of the gravitational field on that energy, at zero temperature. This influence includes the effects due to the spacetime dragging caused by the source rotation as well as those ones due to the quintessence. We show that the energy depends on all the involved parameters, as source mass, angular momentum and quintessence state parameter, for any radial coordinate and polar angle. We show that at the north pole the Casimir energy is not influenced by the quintessential matter. At the equatorial plane, when the quintessence is canceled, the result obtained in the literature is recovered. Finally, constraints in the quintessence parameters are obtained from the uncertainty in the current measurements of Casimir effect.

  5. Ozone bioindication in Barcelona and surrounding area of Catalonia

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, A.; Penuelas, J. [Univ. Autonoma de Barcelona, Barcelona (Spain). Ecophysiology Unit of CSIC

    2002-07-01

    A field study was conducted from July to September 2000 to assess ozone (O{sub 3}) phytotoxicity in Barcelona and surrounding areas of Catalonia (NE Spain) by using tobacco plants Bel-W3 and Populus nigra 'Brandaris' as bioindicators. The study was conducted simultaneously at eight sites where ozone concentrations and meteorological variables were continuously monitored. The ozone levels correlated well with ozone injury on the Bel-W3 cultivar, especially at stations established in the urban area of Barcelona, and in the first months of summer. In the second half of summer plants showed a decreasing efficiency in its biomonitoring capacity. The behaviour of Populus as bioindicator or biomonitor was less satisfactory. For both species it is necessary to improve cultivation conditions since water deficits seem to play an important role in bioindication in the Mediterranean region. (orig.)

  6. Physical Coupling of Kazarian Galaxies with Surrounding Galaxies

    Science.gov (United States)

    Kazarian, M. A.; Martirosian, J. R.

    2003-04-01

    Results from a statistical study of Kazarian galaxies and the objects surrounding them are presented. It is shown that: (1) the sample of Kazarian galaxies up to 16m.0 is complete. (2) Roughly 35.7% of the Kazarian galaxies are members of clusters, 14.0% of groups, and 13.6% of binary systems, while 36.7% are single galaxies. (3) Of the 580 Kazarian galaxies, roughly 61.2% are infrared, 8.8% radio, and 2.8% x-ray sources. (4) The relative numbers of Kazarian galaxies for complete samples of I, R, and X in the different groups are systematically higher than the corresponding numbers for samples of all Kazarian galaxies.

  7. On radial oscillations in viscous accretion discs surrounding neutron stars

    Science.gov (United States)

    Chen, Xingming; Taam, Ronald E.

    1992-01-01

    Radial oscillations resulting from axisymmetric perturbations in viscous accretion disks surrounding neutron stars in X-ray binary systems have been investigated. Within the framework of the alpha-viscosity model a series of hydrodynamic calculations demonstrates that the oscillations are global for alpha of about 1. On the other hand, for alpha of 0.4 or less, the oscillations are local and confined to the disk boundaries. If viscous stresses acting in the radial direction are included, however, it is found that the disk can be stabilized. The application of such instabilities in accretion disks, without reference to the boundary layer region between the neutron star (or magnetosphere) and the inner edge of the disk, to the phenomenology of quasi-periodic oscillations is brought into question.

  8. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O`Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-09-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  9. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O' Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-01-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  10. Rotation of the Warm Molecular Gas Surrounding Ultracompact HII Regions

    CERN Document Server

    Klaassen, P D; Keto, E R; Zhang, Q

    2009-01-01

    We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by SO_2 and OCS) appears to be undergoing bulk rotation. From the molecular line emission and thermal component of the continuum emission, we independently derived gas masses for each region which are consistent with each other. From the free-free component of the continuum emission we estimate the minimum stellar mass required to power the HII region and find that this mass, when added to the derived gas mass, is a significant fraction of the dynamical mass for that region.

  11. A 500 Parsec Halo Surrounding the Galactic Globular NGC 1851

    CERN Document Server

    Olszewski, Edward W; Knezek, Patricia; Subramaniam, Annapurni; de Boer, Thomas; Seitzer, Patrick

    2009-01-01

    Using imaging that shows four magnitudes of main sequence stars, we have discovered that the Galactic globular cluster NGC 1851 is surrounded by a halo that is visible from the tidal radius of 700 arcsec (41 pc) to more than 4500 arcsec (>250 pc). This halo is symmetric and falls in density as a power law of $r^{-1.24}$. It contains approximately 0.1% of the dynamical mass of NGC 1851. There is no evidence for tidal tails. Current models of globular cluster evolution do not explain this feature, although simulations of tidal influences on dwarf spheroidal galaxies qualitatively mimic these results. Given the state of published models it is not possible to decide between creation of this halo from isolated cluster evaporation, or from tidal or disk shocking, or from destruction of a dwarf galaxy in which this object may have once been embedded.

  12. Thermodynamic stability of black holes surrounded by quintessence

    CERN Document Server

    Ma, Meng-Sen; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there is a great deal of difference on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  13. Thermodynamic stability of black holes surrounded by quintessence

    Science.gov (United States)

    Ma, Meng-Sen; Zhao, Ren; Ma, Ya-Qin

    2017-06-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence ω _q is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there are several differences on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  14. Impact-Generated Dust Clouds Surrounding the Galilean Moons

    CERN Document Server

    Krüger, H; Grün, E; Kr\\"uger, Harald~; Krivov, Alexander V.; Gr\\"un, Eberhard

    2003-01-01

    Tenuous dust clouds of Jupiter's Galilean moons Io, Europa, Ganymede and Callisto have been detected with the in-situ dust detector on board the Galileo spacecraft. The majority of the dust particles have been sensed at altitudes below five radii of these lunar-sized satellites. We identify the particles in the dust clouds surrounding the moons by their impact direction, impact velocity, and mass distribution. Average particle sizes are 0.5 to $\\rm 1 \\mu m$, just above the detector threshold, indicating a size distribution with decreasing numbers towards bigger particles. Our results imply that the particles have been kicked up by hypervelocity impacts of micrometeoroids onto the satellites' surfaces. The measured radial dust density profiles are consistent with predictions by dynamical modeling for satellite ejecta produced by interplanetary impactors (Krivov et al., PSS, 2003, 51, 251--269), assuming yield, mass and velocity distributions of the ejecta from laboratory measurements. The dust clouds of the th...

  15. COMMUNICATION: Electrochemical polymerization of conducting polymers in living neural tissue

    Science.gov (United States)

    Richardson-Burns, Sarah M.; Hendricks, Jeffrey L.; Martin, David C.

    2007-06-01

    A number of biomedical devices require extended electrical communication with surrounding tissue. Significant improvements in device performance would be achieved if it were possible to maintain communication with target cells despite the reactive, insulating scar tissue that forms at the device-tissue interface. Here, we report that the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) can be polymerized directly within living neural tissue resulting in an electrically conductive network that is integrated within the tissue. Nano and microscale PEDOT filaments extend out from electrode sites, presumably forming within extracellular spaces. The cloud of PEDOT filaments penetrates out into the tissue far enough that it should be possible to bypass fibrous scar tissue and contact surrounding healthy neurons. These electrically functional, diffuse conducting polymer networks grown directly within tissue signify a new paradigm for creating soft, low impedance implantable electrodes.

  16. Chitin Scaffolds in Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Tetsuya Furuike

    2011-03-01

    Full Text Available Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine.

  17. Avian host defense peptides.

    Science.gov (United States)

    Cuperus, Tryntsje; Coorens, Maarten; van Dijk, Albert; Haagsman, Henk P

    2013-11-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense of many organisms. It is becoming increasingly clear that in the animal kingdom the functions of HDPs are not confined to direct antimicrobial actions. Research in mammals has indicated that HDPs have many immunomodulatory functions and are also involved in other physiological processes ranging from development to wound healing. During the past five years our knowledge about avian HDPs has increased considerably. This review addresses our current knowledge on the evolution, regulation and biological functions of HDPs of birds.

  18. Host Integration Server 2004

    Institute of Scientific and Technical Information of China (English)

    PaulThurrott; 杨岩

    2005-01-01

    微软发布的Host Integration Server(HIS)2004,是IBM大型主机集成服务器的一个重要的更新,添加了一些重要的新特点和改进。与大多数微软公司协同工作的产品不同,HIS 2004的设计目的是为了移植,而不是纯粹的集成,事实上它将会帮助客户从现有的传统平台中得到更多的价值——在这种情况下,所指的产品就是IBM大型主机和iSeries(也就是以前的AS/400)系列机型。

  19. The in vivo performance of plasmonic nanobubbles as cell theranostic agents in zebrafish hosting prostate cancer xenografts.

    Science.gov (United States)

    Wagner, Daniel S; Delk, Nikki A; Lukianova-Hleb, Ekaterina Y; Hafner, Jason H; Farach-Carson, Mary C; Lapotko, Dmitri O

    2010-10-01

    Cell theranostics is a new approach that unites diagnosis, therapy and confirmation (guidance) of the results of therapy in one single process at cell level, thus principally improving both the rapidity and precision of treatment. The ideal theranostic agent will support all three of the above functions in vivo with cellular resolution, allowing individual assessment of disease state and the elimination of diseased cells while leaving healthy cells intact. We have developed and evaluated plasmonic nanobubbles (PNBs) as an in vivo tunable theranostic cellular agent in zebrafish hosting prostate cancer xenografts. PNBs were selectively generated around gold nanoparticles in cancer cells in the zebrafish with short single laser pulses. By varying the energy of the laser pulse, we dynamically tuned the PNB size in a theranostic sequence of two PNBs: an initial small PNB detected a cancer cell through optical scattering, followed by a second bigger PNB, which mechanically ablated this cell without damage to surrounding tissue, while its optical scattering confirmed the destruction of the cell. Thus PNBs supported the diagnosis and guided ablation of individual human cancer cells in a living organism without damage to the host.

  20. Transplantation of three-dimensional artificial human vascular tissues fabricated using an extracellular matrix nanofilm-based cell-accumulation technique.

    Science.gov (United States)

    Asano, Yoshiya; Shimoda, Hiroshi; Okano, Daisuke; Matsusaki, Michiya; Akashi, Mitsuru

    2017-04-01

    We have established a novel three-dimensional (3D) tissue-constructing technique, referred to as the 'cell-accumulation method', which is based on the self-assembly of cultured human cells. In this technique, cells are coated with fibronectin and gelatin to construct extracellular matrix (ECM) nanofilms and cultured to form multi-layers in vitro. By using this method, we have successfully fabricated artificial tissues with vascular networks constructed by co-cultivation of human umbilical vein-derived vascular endothelial cells between multi-layers of normal human dermal fibroblasts. In this study, to assess these engineered vascular tissues as therapeutic implants, we transplanted the 3D human tissues with microvascular networks, fabricated based on the cell-accumulation method, onto the back skin of nude mice. After the transplantation, we found vascular networks with perfusion of blood in the transplanted graft. At the boundary between host and implanted tissue, connectivity between murine and human vessels was found. Transmission electron microscopy of the implanted artificial vascular tubules demonstrated the ultrastructural features of blood capillaries. Moreover, maturation of the vascular tissues after transplantation was shown by the presence of pericyte-like cells and abundant collagen fibrils in the ECM surrounding the vasculature. These results demonstrated that artificial human vascular tissues constructed by our method were engrafted and matured in animal skin. In addition, the implanted artificial human vascular networks were connected with the host circulatory system by anastomosis. This method is an attractive technique for engineering prevascularized artificial tissues for transplantation. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Titanium implant impairment and surrounding muscle cell death following neuro-myoelectrostimulation: An in vivo study.

    Science.gov (United States)

    Lecocq, Mathieu; Félix, Marie-Solenne; Linares, Jean-Marc; Chaves-Jacob, Julien; Decherchi, Patrick; Dousset, Erick

    2015-11-01

    Electrical currents have deleterious effects on biomedical metallic implants. However, following arthroplasty, neuro-myoelectrostimulation (NMES) is often used in patient rehabilitation. Such a rehabilitation technique could compromise patient recovery through deleterious effects on metallic alloys and biological tissues. The purpose of our study was to assess the effects of NMES on a Ti6Al4V implant placed in a rat tibial crest and the surrounding muscle tissues. This in vivo study allowed to bring to the fore the prosthesis behavior under mechanical and electromagnetic loads induced by NEMS stimulation. After 3 weeks, implant-to-bone adhesion significantly decreased in stimulated animals compared with nonstimulated animals. Surface mapping indicated titanium implant degradation after NMES. Furthermore, NMES alone did not induce muscle damage contrary to that found in implanted animals. The muscle damage rate was significantly higher in implanted and stimulated animals compared with implanted-only animals. It seems obvious that rehabilitation programs using the NMES technique could induce early deterioration of biomaterial employed for surgical implants. Clinicians should reconsider the use of NMES as a rehabilitation technique for patients with titanium prostheses.

  2. Maximum geometrical hindrance to diffusion in brain extracellular space surrounding uniformly spaced convex cells.

    Science.gov (United States)

    Tao, L; Nicholson, C

    2004-07-07

    Brain extracellular space (ECS) constitutes a porous medium in which diffusion is subject to hindrance, described by tortuosity, lambda = (D/D*)1/2, where D is the free diffusion coefficient and D* is the effective diffusion coefficient in brain. Experiments show that lambda is typically 1.6 in normal brain tissue although variations occur in specialized brain regions. In contrast, different theoretical models of cellular assemblies give ambiguous results: they either predict lambda-values similar to experimental data or indicate values of about 1.2. Here we constructed three different ECS geometries involving tens of thousands of cells and performed Monte Carlo simulation of 3-D diffusion. We conclude that the geometrical hindrance in the ECS surrounding uniformly spaced convex cells is independent of the cell shape and only depends on the volume fraction alpha (the ratio of the ECS volume to the whole tissue volume). This dependence can be described by the relation lambda = ((3-alpha)/2)1/2, indicating that the geometrical hindrance in such ECS cannot account for lambda > 1.225. Reasons for the discrepancy between the theoretical and experimental tortuosity values are discussed.

  3. Association of GM4 ganglioside with the membrane surrounding lipid droplets in shark liver.

    Science.gov (United States)

    Li, Yu-Teh; Sugiyama, Eiko; Ariga, Toshio; Nakayama, Jun; Hayama, Masayoshi; Hama, Yoichiro; Nakagawa, Hiroki; Tai, Tadashi; Maskos, Karol; Li, Su-Chen; Kasama, Takeshi; Ksama, Takeshi

    2002-07-01

    By TLC, GM4 was found to be the major ganglioside in the liver of six shark species examined: Odontaspis taurus, Negaprion brevirostris, Sphyrna lewini, Mustelus griseus, Mustelus manazo, and Prionace glauca. A detailed analysis of the glycosphingolipids (GSLs) in the liver of O. taurus (sand tiger shark) showed that it contained approximately 110 nmol of lipid-bound sialic acid per gram of wet tissue, of which 80% was GM4. By extracting the liver of O. taurus with chloroform/methanol, followed by chromatographic separation of GSLs using DEAE-Sephadex A-25 and Iatrobeads columns, we have isolated GM4 in pure form with a yield of approximately 5 mg per 100 g of wet tissue. The structures of both the sugar chain and the ceramide moiety of this GM4 were analyzed by chemical analysis, mass spectrometry, and NMR spectroscopy. Similar to GM4 isolated from other sources, 92% of fatty acids in the ceramide of this GM4 were 2-hydroxylated. However, unlike the long-chain bases found in other GSLs, the total long-chain bases in this GM4 were found to contain 43% octadecasphingenine and 50% nonadecasphingenine. Immunohistochemical analysis using a monoclonal antibody against GM4 revealed that the hepatocytes of both M. griseus (spotless smooth hound) and M. manazo (smooth hound) were filled with lipid droplets and GM4 was primarily associated with the membrane structure surrounding lipid droplets.

  4. [Vitamin D metabolism and signaling in human hepatocellular carcinoma and surrounding non-tumorous liver].

    Science.gov (United States)

    Horváth, Evelin; Balla, Bernadett; Kósa, János; Lakatos, Péter András; Lazáry, Áron; Németh, Dániel; Jozilan, Hasan; Somorácz, Áron; Korompay, Anna; Gyöngyösi, Benedek; Borka, Katalin; Kiss, András; Kupcsulik, Péter; Schaff, Zsuzsa; Szalay, Ferenc

    2016-11-01

    1,25-Dihydroxy vitamin D3 mediates antitumor effects in hepatocellular carcinoma. We examined mRNA and protein expression differences in 1,25-Dihydroxy vitamin D3-inactivating CYP24A1, mRNA of activating CYP27B1 enzymes, and that of VDR between human hepatocellular carcinoma and surrounding non-tumorous liver. Snap-frozen tissues from 13 patients were studied for mRNA and protein expression of CYP24A1. Paraffin-embedded tissues from 36 patients were used to study mRNA of VDR and CYP27B1. mRNA expression was measured by RT-PCR, CYP24A1 protein was detected by immunohistochemistry. Expression of VDR and CYP27B1 was significantly lower in hepatocellular carcinoma compared with non-tumorous liver (p<0.05). The majority of the HCC samples expressed CYP24A1 mRNA, but neither of the non-tumorous liver. The gene activation was followed by CYP24A1 protein synthesis. The presence of CYP24A1 mRNA and the reduced expression of VDR and CYP27B1 mRNA in human hepatocellular carcinoma samples indicate decreased bioavailability of 1,25-Dihydroxy vitamin D3, providing an escape mechanism from the anti-tumor effect. Orv. Hetil., 2016, 157(48), 1910-1918.

  5. Host responses to the pathogen Mycobacterium avium subsp. paratuberculosis and beneficial microbes exhibit host sex specificity.

    Science.gov (United States)

    Karunasena, Enusha; McMahon, K Wyatt; Chang, David; Brashears, Mindy M

    2014-08-01

    Differences between microbial pathogenesis in male and female hosts are well characterized in disease conditions connected to sexual transmission. However, limited biological insight is available on variances attributed to sex specificity in host-microbe interactions, and it is most often a minimized variable outside these transmission events. In this work, we studied two gut microbes-a pathogen, Mycobacterium avium subsp. paratuberculosis, and a probiotic, Lactobacillus animalis NP-51-and the interaction between each agent and the male and female gastrointestinal systems. This trial was conducted in BALB/c mice (n=5 per experimental group and per sex at a given time point), with analysis at four time points over 180 days. Host responses to M.avium subsp. paratuberculosis and L. animalis were sensitive to sex. Cytokines that were significantly different (P ≤ 0.05) betweenthe sexes included interleukin-1α/β (IL-1α/β), IL-17, IL-6, IL-10, IL-12, and gamma interferon (IFN-) and were dependent on experimental conditions. However, granulocyte-macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), and IL-13/23 showed no sex specificity. A metabolomics study indicated a 0.5- to 2.0-fold (log2 scale) increase in short-chain fatty acids (butyrate and acetate) in males and greater increases in o-phosphocholine or histidine from female colon tissues; variances distinct to each sex were observed with age or long-term probiotic consumption. Two genera, Staphylococcus and Roseburia, were consistently overrepresented in females compared to males; other species were specific to one sex but fluctuated depending on experimental conditions. The differences observed suggest that male and female gut tissues and microbiota respond to newly introduced microorganisms differently and that gut-associated microorganisms with host immune system responses and metabolic activity are supported by biology distinct to the host sex.

  6. Whyever bladder tissue engineering clinical applications still remain unusual even though many intriguing technological advances have been reached?

    Science.gov (United States)

    Alberti, C

    2016-01-01

    To prevent problematic outcomes of bowel-based bladder reconstructive surgery, such as prosthetic tumors and systemic metabolic complications, research works, to either regenerate and strengthen failing organ or build organ replacement biosubstitute, have been turned, from 90s of the last century, to both regenerative medicine and tissue engineering.Various types of acellular matrices, naturally-derived materials, synthetic polymers have been used for either "unseeded" (cell free) or autologous "cell seeded" tissue engineering scaffolds. Different categories of cell sources - from autologous differentiated urothelial and smooth muscle cells to natural or laboratory procedure-derived stem cells - have been taken into consideration to reach the construction of suitable "cell seeded" templates. Current clinically validated bladder tissue engineering approaches essentially consist of augmentation cystoplasty in patients suffering from poorly compliant neuropathic bladder. No clinical applications of wholly tissue engineered neobladder have been carried out to radical-reconstructive surgical treatment of bladder malignancies or chronic inflammation-due vesical coarctation. Reliable reasons why bladder tissue engineering clinical applications so far remain unusual, particularly imply the risk of graft ischemia, hence its both fibrous contraction and even worse perforation. Therefore, the achievement of graft vascular network (vasculogenesis) could allow, together with the promotion of host surrounding vessel sprouting (angiogenesis), an effective graft blood supply, so avoiding the ischemia-related serious complications.

  7. The tidally disturbed luminous compact blue galaxy Mkn 1087 and its surroundings

    CERN Document Server

    Lopez-Sanchez, A R; Rodríguez, M; Lopez-Sanchez, Angel R.; Esteban, Cesar; Rodriguez, Monica

    2004-01-01

    We present new broad-band optical and near-infrared CCD imaging together with deep optical intermediate-resolution spectroscopy of Mkn 1087 and its surrounding objects. We analyze the morphology and colors of the stellar populations of the brightest objects, some of them star-formation areas, as well as the kinematics, physical conditions and chemical composition of the ionized gas associated with them. Mkn 1087 does not host an Active Galactic Nucleus, but it could be a Luminous Compact Blue Galaxy. Although it was classified as a suspected Wolf-Rayet galaxy, we do not detect the spectral features of these sort of massive stars. Mkn 1087 shows morphological and kinematical features that can be explained assuming that it is in interaction with two nearby galaxies: the bright KPG 103a and a dwarf ($M_B\\sim-18$) star-forming companion. We argue that this dwarf companion is not a tidal object but an external galaxy because of its low metallicity [12+log(O/H) = 8.24] with respect to the one derived for Mkn 1087 [...

  8. Automated spectroscopic tissue classification in colorectal surgery

    NARCIS (Netherlands)

    Schols, R.M.; Alic, L.; Beets, G.L.; Breukink, S.O.; Wieringa, F.P.; Stassen, L.P.S.

    2015-01-01

    In colorectal surgery, detecting ureters and mesenteric arteries is of utmost importance to prevent iatrogenic injury and to facilitate intraoperative decision making. A tool enabling ureter- and artery-specific image enhancement within (and possibly through) surrounding adipose tissue would facilit

  9. Guiding Neuronal Growth in Tissues with Light

    Science.gov (United States)

    2010-02-27

    and structural properties of their surroundings in addition to the biochemical properties. Furthermore, three-dimensional biopolymer matrices provide...Properties of Biopolymer Networks Biopolymer networks exhibit unique nonlinear rheological behavior that differs dramatically from most synthetic...and provide bio-compatible scaffolds for tissue growth and organ regeneration. Unleashing the full potential of these applications requires an

  10. Tomography images of the Alpine roots and surrounding upper mantle

    Science.gov (United States)

    Plomerova, Jaroslava; Babuska, Vladislav

    2017-04-01

    Teleseismic body-wave tomography represents powerful tool to study regional velocity structure of the upper mantle and to image velocity anomalies, such as subducted lithosphere plates in collisional zones. In this contribution, we recapitulate 3D models of the upper mantle beneath the Alps, which developed at a collision zone of the Eurasian and African plates. Seismic tomography studies indicate a leading role of the rigid mantle lithosphere that functioned as a major stress guide during the plate collisions. Interactions of the European lithosphere with several micro-plates in the south resulted in an arcuate shape of this mountain range on the surface and in a complicated geometry of the Alpine subductions in the mantle. Early models with one bended lithosphere root have been replaced with more advanced models showing two separate lithosphere roots beneath the Western and Eastern Alps (Babuska et al., Tectonophysics 1990; Lippitsch et al., JGR 2003). The standard isotropic velocity tomography, based on pre-AlpArray data (the currently performed passive seismic experiment in the Alps and surroundings) images the south-eastward dipping curved slab of the Eurasian lithosphere in the Western Alps. On the contrary, beneath the Eastern Alps the results indicate a very steep northward dipping root that resulted from the collision of the European plate with the Adriatic microplate. Dando et al. (2011) interpret high-velocity heterogeneities at the bottom of their regional tomographic model as a graveyard of old subducted lithospheres. High density of stations, large amount of rays and dense ray-coverage of the volume studied are not the only essential pre-requisites for reliable tomography results. A compromise between the amount of pre-processed data and the high-quality of the tomography input (travel-time residuals) is of the high importance as well. For the first time, the existence of two separate roots beneath the Alps has been revealed from carefully pre

  11. The water exchange between Chinchorro Bank and its surroundings

    Science.gov (United States)

    Candela, Julio; Ochoa, Jose Luis; Sheinbaum, Julio; Lopez, Manuel; Cornado, Cesar

    2015-04-01

    Chinchorro Bank is a relatively large (~500 km^ 2) atoll situated 33 km in front of the Yucatan Peninsula in the Caribbean coast of Mexico. Two years of continuous measurements of the subsurface pressure field inside and around Chinchorro Bank, along with currents and waves observed outside, suggest four major processes governing the water exchange of the Bank with its surroundings: 1) surface wave pumping of water into the Bank through its eastern edge, 2) the large scale circulation in the region that drives the sea level changes through geostrophy, 3) the tidal pumping with imposed cyclic flows into and out of the Bank and 4) the imposed drift by the wind. Waves impinging all along the eastern barrier reef induce water inflows (from overtopping the reef) and generate a pressure gradient that drives a drift from east to west throughout the Bank. This western drift can normally replenish the water over the Bank with a time scale of ~10 days. However, extreme wave events, lasting around 24 hours, can replenish the whole Bank's water in the order of day. The region's large scale circulation is dominated by the zonal Cayman Current impinging on the Yucatan Peninsula becoming the Yucatan Current as it turns northward. Variability in the strength and impacting latitude of this current causes sea level gradients within the Bank, i.e., a Yucatan Current increase of 1 m/s, over a period of a couple of weeks, sets up a zonal sea level gradient within that can replenish the whole Bank's water in a time scale of ~14 days. At such times, the large scale current around the Bank is at a maximum thus ensuring an effective removal and dispersal of the exported waters. The Bank has a micro-tidal regime with a semidiurnal amplitude of ~12 cm during spring tides and a diurnal of ~2 cm, these imply that the Bank is exchanging ~10% of its waters with its surroundings daily. However small, this tidal pumping is effective for the ventilation of the Banks' waters in ~10 days due to the

  12. Tissue Classification

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, David Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    The project began as a e ort to support InLight and Lumidigm. With the sale of the companies to a non-New Mexico entity, the project then focused on supporting a new company Medici Technologies. The Small Business (SB) is attempting to quantify glucose in tissue using a series of short interferometer scans of the nger. Each scan is produced from a novel presentation of the nger to the device. The intent of the project is to identify and, if possible, implement improved methods for classi cation, feature selection, and training to improve the performance of predictive algorithms used for tissue classi cation.

  13. The structural feature surrounding glycated lysine residues in human hemoglobin.

    Science.gov (United States)

    Ito, Shigenori; Nakahari, Takashi; Yamamoto, Daisuke

    2011-06-01

    Complications derived from diabetes mellitus are caused by nonenzymatic protein glycation at the specific sites. LC/MS/MS was performed for the identification of the tryptic peptides of glycated hemoglobins using glyceraldehyde. After the identification of the glycation or non-glycation site, computer analysis of the structure surrounding the sites was carried out using PDB data (1BZ0). Five glycated lysine residues (Lys-16(α), -56(α), -8(β), -82(β), and -144(β)) and four non-glycated lysine residues (Lys-7(α), -40(α), -99(α), and -132(β)) were identified. The non-glycated lysine residues, Lys-7(α), -40(α), and -132(β), are most likely to form electrostatic interactions with the β carboxyl group of Asp-74(α), C-terminal His-146(β), and Glu-7(β) by virtue of their proximity, which is 2.67-2.91 Å (N-O). Additionally, there are histidine residues within 4.55-7.38 Å (N-N) around eight sites except for Lys-7(α). We conclude that the following factors seem to be necessary for glycation of lysine residues: (i) the apparent absence of aspartate or glutamate residues to inhibit the glycation reaction by forming an electrostatic interaction, (ii) the presence of histidine residues for acid-base catalysis of the Amadori rearrangement, and (iii) the presence of an amino acid residue capable of stabilizing a phosphate during proton transfer.

  14. Dilemmas surrounding passive euthanasia--a Malaysian perspective.

    Science.gov (United States)

    Talib, Norchaya

    2005-09-01

    In western societies where the principle of autonomy is jealously guarded, perhaps active euthanasia is more often the focus of public concern and debates rather than any other forms of euthanasia. However due to the advance in technology and its corresponding ability in prolonging life, in Malaysia passive euthanasia presents more of a dilemma. For those concerned and involved with end of life decision-making, it is generally agreed that this is an area fraught with not only medical but legal and ethical issues. In Malaysia where the society is not homogenous but is multi-cultural and multi-religious, in addition to medical, legal and ethical issues, religious principles and cultural norms further impact and play significant roles in end of life decision-making. This paper seeks to identify the issues surrounding the practice of passive euthanasia in Malaysia. It will be shown that despite applicable legal provisions, current practice of the medical profession combined with religious and cultural values together affect decision-making which involves the withholding and/or withdrawing of life-saving treatment.

  15. Mercury's interior, surface, and surrounding environment latest discoveries

    CERN Document Server

    Clark, Pamela Elizabeth

    2015-01-01

    This SpringerBrief details the MESSENGER Mission, the findings of which present challenges to widely held conventional views and remaining mysteries surrounding the planet. The work answers the question of why Mercury is so dense, and the implications from geochemical data on its planetary formation. It summarizes imaging and compositional data from the terrestrial planet surface processes and explains the geologic history of Mercury.  It also discusses the lack of southern hemisphere coverage. Our understanding of the planet Mercury has been in a transitional phase over the decades since Mariner 10. The influx of new data from the NASA MESSENGER Mission since it was inserted into the orbit of Mercury in March of 2011 has greatly accelerated that shift. The combined compositional data of relatively high volatiles (S, K), relatively low refractories (Al, Ca), and low crustal iron, combined with an active, partially molten iron rich core, has major implications for Mercury and Solar System formation. From a s...

  16. Zonal disintegration phenomenon in rock mass surrounding deep tunnels

    Institute of Scientific and Technical Information of China (English)

    WU Hao; FANG Qin; GUO Zhi-kun

    2008-01-01

    Zonal disintegration is a typical static phenomenon of deep rock masses. It has been defined as alternating regions of fractured and relatively intact rock mass that appear around or in front of the working stope during excavation of a deep tunnel. Zonal disintegration phenomenon was successfully demonstrated in the laboratory with 3D tests on analogous gypsum models, two circular cracked zones were observed in the test. The linear Mohr-Coulomb yield criterion was used with a constitutive model that showed linear softening and ideal residual plastic to analyze the elasto-plastic field of the enclosing rock mass around a deep tunnel. The results show that tunneling causes a maximum stress zone to appear between an elastic and plastic zone in the surrounding rock. The zonal disintegration phenomenon is analyzed by considering the stress-strain state of the rock mass in the vicinity of the maximum stress zone. Creep instability failure of the rock due to the development of the plastic zone, and transfer of the maximum stress zone into the rock mass, are the cause of zonal disintegration. An analytical criterion for the critical depth at which zonal disintegration can occur is derived. This depth depends mainly on the character and stress concentration coefficient of the rock mass.

  17. Beliefs and practices surrounding postpartum period among Myanmar women.

    Science.gov (United States)

    Sein, Kyi Kyi

    2013-11-01

    to examine the postpartum beliefs and practices among young women (15-24 years) both quantitative and qualitative approaches were used: a cross-sectional comparative study using a semi-structured questionnaire and focus group discussions (FGDs). Kyimyindaing Township in the western district of Yangon, Myanmar. young women (15-24 years) who had experience of at least one live birth were included. A total of 196 women for a quantitative survey and 31 women for FGDs were recruited. postpartum beliefs and practices at the last childbirth were explored by a pretested semi-structured questionnaire and four FGDs (two in urban and two in rural areas). The survey questionnaire covered socio-demographic data, food and behavioural restrictions and observances during the last postpartum period and underlying reasons for those practices. Majority of participants followed the traditional postpartum practices regardless of the area of residence and education level. Notion of 'dirty lochia' was identified. traditional beliefs and practices surrounding post partum were highly prevalent among young women. Variation in degree and duration of adherence to postpartum taboos was noted. These beliefs and practices were imparted and perpetuated by women's close social network. the findings point out the importance of awareness of postpartum beliefs and practices among health staff for providing culturally sensitive health care and gaining better co-operation and mutual understanding in giving health care. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Unilateral lung agenesis--detrimental roles of surrounding vessels.

    Science.gov (United States)

    Chou, An-Kou; Huang, Shu-Chien; Chen, Shyh-Jye; Huang, Pei-Ming; Wang, Jou-Kou; Wu, Mei-Hwan; Chen, Yih-Sharng; Chang, Chung-I; Chiu, Ing-Sh; Wu, En-Ting

    2007-03-01

    Unilateral lung agenesis is a rare congenital defect and could be associated with multiple abnormalities. The patients usually have poor long-term outcomes especially in those with right lung agenesis. We reviewed the 10-year experience in our hospital to describe special clinical features and try to delineate the causes of poor outcomes. From 1995 to 2005, 14 patients less than 18 years of age with unilateral lung agenesis (4 with left agenesis, 10 with right agenesis) were enrolled. Medical records reviewed included diagnosis, presentation, chromosome anomalies, cardiovascular anomalies and interventions, outcomes. We found that the mechanisms of severe airway disease in right lung agenesis included (1) trachea compression by the aortic arch, (2) the presence of "pseudo-ring-sling complex," (3) distended pulmonary artery due to left to right shunt which impinged the only bronchus, and finally (4) the persistent LSVC that restricts the growth of trachea. The etiologies of airway complication in left lung agenesis included anomalous aortic arch compression on trachea and the coexisting heart disease with significant left to right shunt, which impinged on the bronchus. In conclusion, unilateral lung agenesis has frequently associated airway problems due to its surrounding vessels. Satisfactory airway intervention remains challenging. This disease still requires great effort to improve patient outcomes.

  19. The interstellar cloud surrounding the Sun -- a new perspective

    CERN Document Server

    Gry, Cecile

    2014-01-01

    Aims: We offer a new, simpler picture of the local interstellar medium around the Sun (LISM) made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected properties. Methods: We re-examine the kinematics and abundances of the local interstellar medium, as revealed by the published results for the ultraviolet absorption lines of MgII, FeII and HI. Results: In contrast to previous representations, our new picture of the LISM consists of a single, monolithic cloud that surrounds the Sun in all directions and accounts for most of the matter present in the first 50 parsecs around the Sun. The cloud fills the space around us out to about 9 pc in most directions, although its boundary is very irregular with possibly a few extensions up to 20 pc. The cloud does not behave like a rigid body: gas within the cloud is being differentially decelerated in the direction of motion, and the cloud is expanding in directions per...

  20. Dense Ionized and Neutral Gas Surrounding Sgr A*

    CERN Document Server

    Shukla, Hemant; Scoville, N Z

    2004-01-01

    We present high resolution H41a hydrogen recombination line observations of the 1.2' (3 pc) region surrounding Sgr A* at 92 GHz using the OVRO Millimeter Array with an angular resolution of 7" x 3" and velocity resolution of 13 km/s. New observations of H31a, H35a, H41a, and H44a lines were obtained using the NRAO 12-m telescope, and their relative line strengths are interpreted in terms of various emission mechanisms. These are the most extensive and most sensitive observations of recombination line to date. Observations of HCO+ (1 - 0) transition at 89 GHz are also obtained simultaneously with a 40% improved angular resolution and 4-15 times improved sensitivity over previous observations, and the distribution and kinematics of the dense molecular gas in the circumnuclear disk (CND) are mapped and compared with those of the ionized gas. The line brightness ratios of the hydrogen recombination lines are consistent with purely spontaneous emission from 7000 K gas with n_e = 20,000 cm$^{-3}$ near LTE condition...

  1. Instability of Magnetized Ionization Fronts Surrounding H II Regions

    CERN Document Server

    Kim, Jeong-Gyu

    2014-01-01

    An ionization front (IF) surrounding an H II region is a sharp interface where a cold neutral gas makes transition to a warm ionized phase by absorbing UV photons from central stars. We investigate the instability of a plane-parallel D-type IF threaded by parallel magnetic fields, by neglecting the effects of recombination within the ionized gas. We find that weak D-type IFs always have the post-IF magnetosonic Mach number $\\mathcal{M}_{\\rm M2} \\leq 1$. For such fronts, magnetic fields increase the maximum propagation speed of the IFs, while reducing the expansion factor $\\alpha$ by a factor of $1+1/(2\\beta_1)$ compared to the unmagnetized case, with $\\beta_1$ denoting the plasma beta in the pre-IF region. IFs become unstable to distortional perturbations due to gas expansion across the fronts, exactly analogous to the Darrieus-Landau instability of ablation fronts in terrestrial flames. The growth rate of the IF instability is proportional linearly to the perturbation wavenumber as well as the upstream flow ...

  2. An insight in the surroundings of HR4796

    CERN Document Server

    Lagrange, A -M; Boccaletti, A; Lacour, S; Thebault, P; Chauvin, G; Mouillet, D; Augereau, J C; Bonnefoy, M; Ehrenreich, D; Kral, Q

    2012-01-01

    HR4796 is a young, early A-type star harbouring a well structured debris disk, shaped as a ring with sharp inner edges. It forms with the M-type star HR4796B a binary system, with a proj. sep. ~560 AU. Our aim is to explore the surroundings of HR4796A and B, both in terms of extended or point-like structures. Adaptive optics images at L'-band were obtained with NaCo in Angular Differential Mode and with Sparse Aperture Masking (SAM). We analyse the data as well as the artefacts that can be produced by ADI reduction on an extended structure with a shape similar to that of HR4796A dust ring. We determine constraints on the presence of companions using SAM and ADI on HR4796A, and ADI on HR4796B. We also performed dynamical simulations of a disk of planetesimals and dust produced by collisions, perturbed by a planet located close to the disk outer edge. The disk ring around HR4796A is well resolved. We highlight the potential effects of ADI reduction of the observed disk shape and surface brightness distribution,...

  3. Dead discs, unstable discs and the stars they surround

    Directory of Open Access Journals (Sweden)

    D’Angelo Caroline

    2014-01-01

    Full Text Available Strong stellar magnetic fields significantly alter the behaviour of surrounding accretion discs. Recent work has demonstrated that at low accretion rates a large amount of mass can remain confined in the disc, contrary to the standard assumption that the magnetic field will expel the disc in an outflow (the “propeller regime”. These “dead discs” often become unstable, causing cycles of accretion onto the central star. Here I present the main predictions of this model, and argue that it provides a good explanation for the peculiar behaviour seen in several accreting sources with strong magnetic fields. I will focus in particular on three accreting millisecond X-ray pulsars: SAX J1808.4-3658, NGC 6440 X-2 and IGR J00291+5934. These sources all show low-frequency quasi-periodic oscillations consistent with a variable accretion rate, as well as unusual outburst patterns that suggest gas is confined in the inner disc regions during quiescence.

  4. Preliminary Analysis of Slope Stability in Kuok and Surrounding Areas

    Directory of Open Access Journals (Sweden)

    Dewandra Bagus Eka Putra

    2016-12-01

    Full Text Available The level of slope influenced by the condition of the rocks beneath the surface. On high level of slopes, amount of surface runoff and water transport energy is also enlarged. This caused by greater gravity, in line with the surface tilt from the horizontal plane. In other words, topsoil eroded more and more. When the slope becomes twice as steep, then the amount of erosion per unit area be 2.0 - 2.5 times more. Kuok and surrounding area is the road access between the West Sumatra and Riau which plays an important role economies of both provinces. The purpose of this study is to map the locations that have fairly steep slopes and potential mode of landslides. Based on SRTM data obtained,  the roads in Kuok area has a minimum elevation of + 33 m and a maximum  + 217.329 m. Rugged road conditions with slope ranging from 24.08 ° to 44.68 ° causing this area having frequent landslides. The result of slope stability analysis in a slope near the Water Power Plant Koto Panjang, indicated that mode of active failure is toppling failure or rock fall and the potential zone of failure is in the center part of the slope.

  5. Expression of zebrafish nos2b surrounds oral cavity.

    Science.gov (United States)

    Poon, Kar-Lai; Richardson, Michael; Korzh, Vladimir

    2008-06-01

    Inducible nitric oxide synthase (NOS2) catalyzes the production of nitric oxide (NO), and is one of the factors establishing innate immunity. In zebrafish, Nos2 is represented by nos2a and nos2b. Here, we report the cloning and expression pattern of the zebrafish nos2b gene, which does not seem to participate in induced immune response. nos2b was mapped to zebrafish linkage group 15. The spatial and temporal expression pattern of nos2b in embryonic zebrafish was analyzed by whole-mount in situ hybridization. nos2b is expressed constitutively in two primordia located along the ventral midline. The first group of cells contributes to the neurohypophysis. Initially at the level of the ventral hindbrain, the second group of cells migrates closely with the thyroid primordium to its final position at the basihyal by 3 dpf. Thus, the analysis of expression pattern of nos2b reveals complex morphogenetic movements resulting in its expression surrounding the oral cavity.

  6. Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

    Science.gov (United States)

    Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

    2011-01-01

    Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

  7. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  8. Representing the egocentric auditory space: relationships of surrounding region concepts.

    Science.gov (United States)

    Campos, Marcella C; Hermann, Thomas; Schack, Thomas; Bläsing, Bettina

    2013-03-01

    We investigated the representation of azimuthal directions of sound sources under two different conditions. In the first experiment, we examined the participants' mental representation of sound source directions via similarity judgments. Auditory stimuli originating from sixteen loudspeakers positioned equidistantly around the participant were presented in pairs, with the first stimulus serving as the anchor, and thereby providing the context for the second stimulus. For each pair of stimuli, participants had to rate the sound source directions as either similar or dissimilar. In the second experiment, the same participants categorized single sound source directions using verbal direction labels (front, back, left, right, and combinations of any two of these). In both experiments, the directions within the front and back regions were more distinctively categorized than those on the sides, and the sides' categories included more directions than those of the front or back. Furthermore, we found evidence that the left-right decision comprises the basic differentiation of the surrounding regions. These findings illustrate what seem to be central features of the representation of directions in auditory space.

  9. New mechanisms of disease and parasite-host interactions.

    Science.gov (United States)

    de Souza, Tiago Alves Jorge; de Carli, Gabriel Jose; Pereira, Tiago Campos

    2016-09-01

    An unconventional interaction between a patient and parasites was recently reported, in which parasitic cells invaded host's tissues, establishing several tumors. This finding raises various intriguing hypotheses on unpredicted forms of interplay between a patient and infecting parasites. Here we present four unusual hypothetical host-parasite scenarios with intriguing medical consequences. Relatively simple experimental designs are described in order to evaluate such hypotheses. The first one refers to the possibility of metabolic disorders in parasites intoxicating the host. The second one is on possibility of patients with inborn errors of metabolism (IEM) being more resistant to parasites (due to accumulation of toxic compounds in the bloodstream). The third one refers to a mirrored scenario: development of tumors in parasites due to ingestion of host's circulating cancer cells. The last one describes a complex relationship between parasites accumulating a metabolite and supplying it to a patient with an IEM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Root-associated fungal communities in three Pyroleae species and their mycobiont sharing with surrounding trees in subalpine coniferous forests on Mount Fuji, Japan.

    Science.gov (United States)

    Jia, Shuzheng; Nakano, Takashi; Hattori, Masahira; Nara, Kazuhide

    2017-07-13

    Pyroleae species are perennial understory shrubs, many of which are partial mycoheterotrophs. Most fungi colonizing Pyroleae roots are ectomycorrhizal (ECM) and share common mycobionts with their Pyroleae hosts. However, such mycobiont sharing has neither been examined in depth before nor has the interspecific variation in sharing among Pyroleae species. Here, we examined root-associated fungal communities in three co-existing Pyroleae species, including Pyrola alpina, Pyrola incarnata, and Orthilia secunda, with reference to co-existing ECM fungi on the surrounding trees in the same soil blocks in subalpine coniferous forests. We identified 42, 75, and 18 fungal molecular operational taxonomic units in P. alpina, P. incarnata, and O. secunda roots, respectively. Mycobiont sharing with surrounding trees, which was defined as the occurrence of the same mycobiont between Pyroleae and surrounding trees in each soil block, was most frequent among P. incarnata (31 of 44 plants). In P. alpina, sharing was confirmed in 12 of 37 plants, and the fungal community was similar to that of P. incarnata. Mycobiont sharing was least common in O. secunda, found in only 5 of 32 plants. Root-associated fungi of O. secunda were dominated by Wilcoxina species, which were absent from the surrounding ECM roots in the same soil blocks. These results indicate that mycobiont sharing with surrounding trees does not equally occur among Pyroleae plants, some of which may develop independent mycorrhizal associations with ECM fungi, as suggested in O. secunda at our research sites.

  11. Intracellular accommodation of rhizobia in legume host cell: the fine-tuning of the endomembrane system

    NARCIS (Netherlands)

    Gavrin, A.Y.

    2015-01-01

    The symbiosis of legumes with rhizobia leads to the formation of root nodules. Rhizobia which are hosted inside specialized infected cells are surrounded by hostderived membranes, forming symbiosomes. Although it is known that symbiosome formation involves proliferation of membranes and changing of

  12. Microbiota and host immune responses: a love-hate relationship.

    Science.gov (United States)

    Tomkovich, Sarah; Jobin, Christian

    2016-01-01

    A complex relationship between the microbiota and the host emerges early at birth and continues throughout life. The microbiota includes the prokaryotes, viruses and eukaryotes living among us, all of which interact to different extents with various organs and tissues in the body, including the immune system. Although the microbiota is most dense in the lower intestine, its influence on host immunity extends beyond the gastrointestinal tract. These interactions with the immune system operate through the actions of various microbial structures and metabolites, with outcomes ranging from beneficial to deleterious for the host. These differential outcomes are dictated by host factors, environment, and the type of microbes or products present in a specific ecosystem. It is also becoming clear that the microbes are in turn affected and respond to the host immune system. Disruption of this complex dialogue between host and microbiota can lead to immune pathologies such as inflammatory bowel diseases, diabetes and obesity. This review will discuss recent advances regarding the ways in which the host immune system and microbiota interact and communicate with one another.

  13. Simultaneous transcriptional profiling of bacteria and their host cells.

    Directory of Open Access Journals (Sweden)

    Michael S Humphrys

    Full Text Available We developed an RNA-Seq-based method to simultaneously capture prokaryotic and eukaryotic expression profiles of cells infected with intracellular bacteria. As proof of principle, this method was applied to Chlamydia trachomatis-infected epithelial cell monolayers in vitro, successfully obtaining transcriptomes of both C. trachomatis and the host cells at 1 and 24 hours post-infection. Chlamydiae are obligate intracellular bacterial pathogens that cause a range of mammalian diseases. In humans chlamydiae are responsible for the most common sexually transmitted bacterial infections and trachoma (infectious blindness. Disease arises by adverse host inflammatory reactions that induce tissue damage & scarring. However, little is known about the mechanisms underlying these outcomes. Chlamydia are genetically intractable as replication outside of the host cell is not yet possible and there are no practical tools for routine genetic manipulation, making genome-scale approaches critical. The early timeframe of infection is poorly understood and the host transcriptional response to chlamydial infection is not well defined. Our simultaneous RNA-Seq method was applied to a simplified in vitro model of chlamydial infection. We discovered a possible chlamydial strategy for early iron acquisition, putative immune dampening effects of chlamydial infection on the host cell, and present a hypothesis for Chlamydia-induced fibrotic scarring through runaway positive feedback loops. In general, simultaneous RNA-Seq helps to reveal the complex interplay between invading bacterial pathogens and their host mammalian cells and is immediately applicable to any bacteria/host cell interaction.

  14. Bubble dynamics in perfused tissue undergoing decompression.

    Science.gov (United States)

    Meisel, S; Nir, A; Kerem, D

    1981-02-01

    A mathematical model describing bubble dynamics in a perfused tissue undergoing decompression is presented, taking into account physical expansion and inward diffusion from surrounding supersaturated tissue as growth promoting factors and tissue gas elimination by perfusion, tissue elasticity, surface tension and inherent unsaturation as resolving driving forces. The expected behavior after a step reduction of pressure of a bubble initially existing in the tissue, displaying both growth and resolution has been demonstrated. A strong perfusion-dependence of bubble resolution time at low perfusion rates is apparent. The model can account for various exposure pressures and saturation fractions of any inert gas-tissue combination for which a set of physical and physiological parameters is available.

  15. Hard-Soft Tissue Interface Engineering.

    Science.gov (United States)

    Armitage, Oliver E; Oyen, Michelle L

    2015-01-01

    The musculoskeletal system is comprised of three distinct tissue categories: structural mineralized tissues, actuating muscular soft tissues, and connective tissues. Where connective tissues - ligament, tendon and cartilage - meet with bones, a graded interface in mechanical properties occurs that allows the transmission of load without creating stress concentrations that would cause tissue damage. This interface typically occurs over less than 1 mm and contains a three order of magnitude difference in elastic stiffness, in addition to changes in cell type and growth factor concentrations among others. Like all engineered tissues, the replication of these interfaces requires the production of scaffolds that will provide chemical and mechanical cues, resulting in biologically accurate cellular differentiation. For interface tissues however, the scaffold must provide spatially graded chemical and mechanical cues over sub millimetre length scales. Naturally, this complicates the manufacture of the scaffolds and every stage of their subsequent cell seeding and growth, as each region has different optimal conditions. Given the higher degree of difficulty associated with replicating interface tissues compared to surrounding homogeneous tissues, it is likely that the development of complex musculoskeletal tissue systems will continue to be limited by the engineering of connective tissues interfaces with bone.

  16. Prokaryotes Versus Eukaryotes: Who is Hosting Whom?

    Science.gov (United States)

    Tellez, Guillermo

    2014-01-01

    Microorganisms represent the largest component of biodiversity in our world. For millions of years, prokaryotic microorganisms have functioned as a major selective force shaping eukaryotic evolution. Microbes that live inside and on animals outnumber the animals' actual somatic and germ cells by an estimated 10-fold. Collectively, the intestinal microbiome represents a "forgotten organ," functioning as an organ inside another that can execute many physiological responsibilities. The nature of primitive eukaryotes was drastically changed due to the association with symbiotic prokaryotes facilitating mutual coevolution of host and microbe. Phytophagous insects have long been used to test theories of evolutionary diversification; moreover, the diversification of a number of phytophagous insect lineages has been linked to mutualisms with microbes. From termites and honey bees to ruminants and mammals, depending on novel biochemistries provided by the prokaryotic microbiome, the association helps to metabolize several nutrients that the host cannot digest and converting these into useful end products (such as short-chain fatty acids), a process, which has huge impact on the biology and homeostasis of metazoans. More importantly, in a direct and/or indirect way, the intestinal microbiota influences the assembly of gut-associated lymphoid tissue, helps to educate immune system, affects the integrity of the intestinal mucosal barrier, modulates proliferation and differentiation of its epithelial lineages, regulates angiogenesis, and modifies the activity of enteric as well as the central nervous system. Despite these important effects, the mechanisms by which the gut microbial community influences the host's biology remain almost entirely unknown. Our aim here is to encourage empirical inquiry into the relationship between mutualism and evolutionary diversification between prokaryotes and eukaryotes, which encourage us to postulate: who is hosting whom?

  17. Evaluation on potential of wild hosts as trap plants for managing gramineous stemborers in maize based-agroecosystem.

    Science.gov (United States)

    Yewhalaw, Delenasaw; Getu, Emana; Seyoum, Emiru

    2008-02-01

    As part of habitat management system to control cereal stemborers, various wild hosts used as trap plants were studied during the dry season from November 2003 to March 2004 at Melkassa, central Ethiopia. Five wild hosts of the family Poaceae [Pennisetum purpurum (Schumach), Sorghum vulgare variety sudanense (Pers.), Panicum coloratum L., Sorghum arundinaceum Stapf, and Hyperrhania rufa (Nees)] were evaluated as trap plants in maize, Zea mays L.,-based agroecosystem. The results of the study showed that maize plots surrounded by all tested wild hosts had significantly lower mean percentage of foliage damage and stemborer density than maize monocrop plots 15 m away from the treatment blocks. Interestingly, mean foliar damage and stemborer density between maize plots surrounded by wild hosts and maize monocrop plots within the treatment blocks was not significant. Percentage of tunneled stalks was significantly greater in maize monocrop plots 15 m away from the treatment blocks than in maize plots surrounded by all tested wild host plant species. Moreover, the highest mean percentage of parasitism (62%) of Chilo partellus (Swinhoe) by Cotesia flavipes (Cameron) was recorded in maize plots surrounded by P. purpureum. Therefore, the findings revealed that these wild hosts have considerable merit to be used as trap plants in the development of strategies for managing cereal stemborers in maize crops.

  18. Host factors in nidovirus replication

    NARCIS (Netherlands)

    Wilde, Adriaan Hugo de

    2013-01-01

    The interplay between nidoviruses and the infected host cell was investigated. Arterivirus RNA-synthesising activity was shown to depend on intact membranes and on a cytosolic host protein which does not cosediment with the RTC. Furthermore, the immunosuppressant drug cyclosporin A (CsA) blocks repl

  19. Host Adaptation of Staphylococcal Leukocidins

    NARCIS (Netherlands)

    Vrieling, M.

    2016-01-01

    Staphylococcus aureus is a human and animal pathogen of global importance and has the capacity to cause disease in distinct host populations, using a large arsenal of secreted proteins to evade the host immune response. Amongst the immune evasion proteins of S. aureus, secreted cytotoxins play a pre

  20. Stennis hosts 2010 Special Olympics

    Science.gov (United States)

    2010-01-01

    Sarah Johnson, 28, of Gulfport, carries in the Olympic torch to signal the start of the 2010 Area III Special Olympic games at NASA's John C. Stennis Space Center on March 27. Stennis volunteers hosted special needs athletes from across the area for the event. Stennis is an annual host of the games.

  1. GIANT Hα NEBULA SURROUNDING THE STARBURST MERGER NGC 6240

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yagi, Masafumi; Komiyama, Yutaka; Kashikawa, Nobunari [Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Ohyama, Youichi [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C. (China); Tanaka, Hisashi [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Okamura, Sadanori, E-mail: yoshidam@hiroshima-u.ac.jp [Department of Advanced Sciences, Faculty of Science and Engineering, Hosei University, Koganei, Tokyo 184-8584 (Japan)

    2016-03-20

    We revealed the detailed structure of a vastly extended Hα-emitting nebula (“Hα nebula”) surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is ∼90 kpc in diameter and the total Hα luminosity amounts to L{sub Hα} ≈ 1.6 × 10{sup 42} erg s{sup −1}. The volume filling factor and the mass of the warm ionized gas are ∼10{sup −4}–10{sup −5} and ∼5 × 10{sup 8} M{sub ⊙}, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the Hα nebula and the extended soft-X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bipolar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebula was formed by intense outflows—superwinds—driven by starbursts. We also found three bright knots embedded in a looped filament of ionized gas that show head-tail morphologies in both emission-line and continuum, suggesting close interactions between the outflows and star-forming regions. Based on the morphology and surface brightness distribution of the Hα nebula, we propose the scenario that three major episodes of starburst/superwind activities, which were initiated ∼10{sup 2} Myr ago, formed the extended ionized gas nebula of NGC 6240.

  2. IRIS Observation of a Sunspot and the Surrounding Plage Region

    Science.gov (United States)

    TIAN, H.; DeLuca, E. E.; Mcintosh, S. W.; Reeves, K. K.; McKillop, S.; Weber, M.; Saar, S.; Golub, L.; Testa, P.

    2013-12-01

    NASA's IRIS mission is providing high-cadence and high-resolution observations of the solar transition region and chromosphere. We present preliminary results from IRIS observation of a sunspot and the surrounding plage region. The major findings in this observation can be summarized as following: (1) The slit jaw images in the filters of 1400Å and 1330Å reveal the presence of many rapidly evolving fibril-like structures in the transition region for the first time. These thin and long structures mainly reside in the plage region. They could be strands of low-lying cool transition region loops or the transition region counterpart of chromospheric spicules. (2) The C II and Mg II line profiles are almost Gaussian in the sunspot umbra and clearly exhibit a deep reversal at the line center in the plage region, suggesting a greatly reduced opacity in the sunspot atmosphere. (3) Bidirectional jets are frequently occurring mainly in the plage region immediately outside the sunspot throughout the observation. Triple or double Gaussian fit to the line profiles of Si IV suggests a velocity as high as 100 km/s. These velocity values are of the same order of the Alfven speed in the transition region. (4)Three-minute oscillation is clearly present in the sunspot umbra. The oscillation is identified in not only the slit jaw images of 2796Å, 1400Å and 1330Å, but also in spectra of the bright Mg II, C II and Si IV lines. Strong non-linearity is clearly seen in the intensity and Doppler shift oscillations. Interestingly, the obvious increase of the line width only occurs at the times of largest blue shift. The correlated change of the intensity and Doppler shift suggests an upward propagating magneto-acoustic shock wave.

  3. Isoperimetric inequalities in surround system and space science

    Directory of Open Access Journals (Sweden)

    JiaJin Wen

    2016-02-01

    Full Text Available Abstract By means of the algebraic, analysis, convex geometry, computer, and inequality theories we establish the following isoperimetric inequality in the centered 2-surround system S ( 2 { P , Γ , l } $S^{(2} \\{P,\\varGamma ,l \\}$ : ( 1 | Γ | ∮ Γ r ¯ P p 1 / p ⩽ | Γ | 4 π sin l π | Γ | [ csc l π | Γ | + cot 2 l π | Γ | ln ( tan l π | Γ | + sec l π | Γ | ] , ∀ p ⩽ − 2 . $$\\begin{aligned}& \\biggl(\\frac{1}{|\\varGamma |} \\oint_{\\varGamma }\\bar{r}_{P}^{p} \\biggr^{1/p}\\leqslant\\frac{|\\varGamma |}{4\\pi}\\sin\\frac{l\\pi}{|\\varGamma |} \\biggl[ \\csc \\frac{l\\pi}{|\\varGamma |}+\\cot^{2} \\frac{l\\pi}{|\\varGamma |} \\ln \\biggl(\\tan \\frac{l\\pi}{|\\varGamma |}+\\sec\\frac{l\\pi}{|\\varGamma |} \\biggr \\biggr], \\\\& \\quad \\forall p\\leqslant -2. \\end{aligned}$$ As an application of the inequality in space science, we obtain the best lower bounds of the mean λ-gravity norm ∥ F λ ( Γ , P ∥ ‾ $\\overline{\\Vert {\\mathbf{F}}_{\\lambda} ( \\varGamma ,P \\Vert }$ as follows: ∥ F λ ( Γ , P ∥ ‾ ≜ 1 | Γ | ∮ Γ 1 ∥ A − P ∥ λ ⩾ ( 2 π | Γ | λ , ∀ λ ⩾ 2 . $$\\overline{\\bigl\\Vert {\\mathbf{F}}_{\\lambda} ( \\varGamma ,P \\bigr\\Vert } \\triangleq\\frac{1}{|\\varGamma |} \\oint_{\\varGamma }\\frac{1}{\\|A-P\\|^{\\lambda }}\\geqslant \\biggl(\\frac{2\\pi}{|\\varGamma |} \\biggr^{\\lambda},\\quad \\forall \\lambda\\geqslant2. $$

  4. The interstellar cloud surrounding the Sun: a new perspective

    Science.gov (United States)

    Gry, Cécile; Jenkins, Edward B.

    2014-07-01

    Aims: We offer a new, simpler picture of the local interstellar medium, made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected properties. Methods: We re-examine the kinematics and abundances of the local interstellar gas, as revealed by the published results for the ultraviolet absorption lines of Mg II, Fe II, and H I. Results: In contrast to previous representations, our new picture of the local interstellar medium consists of a single, monolithic cloud that surrounds the Sun in all directions and accounts for most of the matter present in the first 50 parsecs around the Sun. The cloud fills the space around us out to about 9 pc in most directions, although its boundary is very irregular with possibly a few extensions up to 20 pc. The cloud does not behave like a rigid body: gas within the cloud is being differentially decelerated in the direction of motion, and the cloud is expanding in directions perpendicular to this flow, much like a squashed balloon. Average H I volume densities inside the cloud vary between 0.03 and 0.1 cm-3 over different directions. Metals appear to be significantly depleted onto grains, and there is a steady increase in depletion from the rear of the cloud to the apex of motion. There is no evidence that changes in the ionizing radiation influence the apparent abundances. Secondary absorption components are detected in 60% of the sight lines. Almost all of them appear to be interior to the volume occupied by the main cloud. Half of the sight lines exhibit a secondary component moving at about -7.2 km s-1 with respect to the main component, which may be the signature of a shock propagating toward the cloud's interior.

  5. DEFORMATION OF MOISTURE FLUX CIRCULATION SURROUNDING THE LANDFALL TYPHOON "BILIS"

    Institute of Scientific and Technical Information of China (English)

    RAN Ling-kun; YANG Wen-xia; HONG Yan-chao

    2009-01-01

    The deformation parameter (DP), which is defined as the product of shear deformation and stretching deformation of moisture flux circulation, is introduced. The tendency equation of DP is derived in pressure coordinates. Furthermore, DP is used to diagnose the deformation character of moisture flux circulation in the periphery of Bilis. The analysis showed that before Bilis landed, DP presented eight abnormal areas, which distributed alternately and closely encircled the low-pressure center. This indicated that the moisture flux circulation in the periphery of Bilis rotated counterclockwise and stretched longitudinally and latitudinally to deform. After Bilis landed, DP weakened gradually and its regular pattern of horizontal distribution loosened. The shear and stretching deformations of moisture flux circulation surrounding Bilis weakened after the typhoon landed. The deformation of moisture flux circulation in the periphery of Bilis mainly appeared in the middle-lower troposphere. There existed 1/2 phase difference between the shear and stretching deformations in the vertical-latitudinal cross section and a π/4 phase difference between them on the horizontal plane. As Bilis landed and further moved inland of China, the intensities of DP, shear and stretching deformations decreased, meanwhile their vertical and horizontal structures became irregular. The chief dynamic factors responsible for the deformation of moisture flux circulation in the periphery of Bilis were the three terms associated with the three-dimensional advection transportation of DP, square difference between shear and stretching deformations coupling with Coriolis parameter, and horizontal gradient of geopotential height before Bilis landed. The last two dynamic factors impacted jointly on the deformation of moisture flux circulation after Bilis landed.

  6. Rain Simulation for the Test of Automotive Surround Sensors

    Science.gov (United States)

    Hasirlioglu, Sinan; Riener, Andreas; Doric, Igor

    2017-04-01

    The WHO Global Health Observatory data indicates that over 1.25 million people die in traffic accidents annually. To save lives, car manufacturers spend lot of efforts on the development of novel safety systems aiming to avoid or mitigate accidents and provide maximum protection for vehicle occupants as well as vulnerable road users. All the safety features mainly rely on data from surround sensors such as radar, lidar and camera and intelligent vehicles today use these environmental data for instant decision making and vehicle control. As already small errors in sensor data measurements could lead to catastrophes like major injuries or road traffic fatalities, it is of utmost importance to ensure high reliability and accuracy of sensors and safety systems. This work focuses on the influence of environmental factors such as rain conditions, as it is known that rain drops scatter the electromagnetic waves. The result is incorrect measurements with a direct negative impact on environment detection. To identify potential problems of sensors under varying environmental conditions, systems are today tested in real-world settings with two main problems: First, tests are time-consuming and second, environmental conditions are not reproducible. Our approach to test the influence of weather on automotive sensors is to use an indoor rain simulator. Our artificial rain maker, installed at CARISSMA (Center of Automotive Research on Integrated Safety Systems and Measurement Area), is parametrized with rain characteristics measured in the field using a standard disdrometer. System behavior on artificial rain is compared and validated with natural rainfall. With this simulator it is finally possible to test environmental influence at various levels and under reproducible conditions. This saves lot of efforts required for the test process itself and furthermore has a positive impact on the reliability of sensor systems due to the fact that test driven development is enabled.

  7. Messages from the other side: parasites receive damage cues from their host plants

    OpenAIRE

    Tjiurutue, Muvari Connie; Stevenson, Philip C.; Lynn S. Adler

    2016-01-01

    As sessile organisms, plants rely on their environment for cues indicating imminent herbivory. These cues can originate from tissues on the same plant or from different individuals. Since parasitic plants form vascular connections with their host, parasites have the potential to receive cues from hosts that allow them to adjust defenses against future herbivory. However, the role of plant communication between hosts and parasites for herbivore defense remains poorly investigated. Here we exam...

  8. The interactions of intracellular Protista and their host cells, with special reference to heterotrophic organisms.

    Science.gov (United States)

    Bannister, L H

    1979-04-11

    Intracellular genera are found in all the major groups of Protista, but are particularly common among the dinoflagellates, trypanosomatid zooflagellates and suctorian ciliates; the Sporozoa are nearly all intracellular at some stage of their life, and the Microspora entirely so. Intracellular forms can dwell in the nucleus, within phagosomal or other vacuoles or may lie free in the hyaloplasm of their host cells. Organisms tend to select their hosts from a restricted taxonomic range although there are some notable exceptions. There is also great variation in the types of host cell inhabited. There are various reasons for both host and cell selectivity including recognition phenomena at the cell surfaces. Invasion of host cells is usually preceded by surface interactions with the invader. Some organisms depend upon phagocytosis for entry, but others induce host cells to engulf them by non-phagocytic means or invade by microinjection through the host plasma membrane. Protista avoid lysosomal destruction by their resistance to enzyme attack, by surrounding themselves with lysosome-inhibiting vacuoles, by escaping from the phagosomal system into the hyaloplasm and by choosing host cells which lack lysosomes. Nutrition of intracellular heterotrophic organisms involves some degree of competition with the host cell's metabolism as well as erosion of host cell cytoplasm. In Plasmodium infections, red cells are made more permeable to required nutrients by the action of the parasite on the host cell membrane. The parasite is often dependent upon the host cell for complex nutrients which it cannot synthesize for itself. Intracellular forms often profoundly modify the structure and metabolism of the host cell or interfere with its growth and multiplication. This may result in the final lysis of the host cell at the end of the intracellular phase or before the infection of other cells. Certain types of intracellular organisms may have arisen initially as forms attached to the

  9. Larval helminths in intermediate hosts

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2005-01-01

    a reduction in size, caused by crowding, virtually nothing is known about longer-lasting effects after transmission to the definitive host. This study is the first to use in vitro cultivation with feeding of adult trematodes to investigate how numbers of parasites in the intermediate host affect the size......Density-dependent effects on parasite fitness have been documented from adult helminths in their definitive hosts. There have, however, been no studies on the cost of sharing an intermediate host with other parasites in terms of reduced adult parasite fecundity. Even if larval parasites suffer...... and fecundity of adult parasites. For this purpose, we examined two different infracommunities of parasites in crustacean hosts. Firstly, we used experimental infections of Maritrema novaezealandensis in the amphipod, Paracalliope novizealandiae, to investigate potential density-dependent effects in single...

  10. Salmonellae interactions with host processes.

    Science.gov (United States)

    LaRock, Doris L; Chaudhary, Anu; Miller, Samuel I

    2015-04-01

    Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.

  11. Endothelial cells, tissue factor and infectious diseases

    Directory of Open Access Journals (Sweden)

    Lopes-Bezerra L.M.

    2003-01-01

    Full Text Available Tissue factor is a transmembrane procoagulant glycoprotein and a member of the cytokine receptor superfamily. It activates the extrinsic coagulation pathway, and induces the formation of a fibrin clot. Tissue factor is important for both normal homeostasis and the development of many thrombotic diseases. A wide variety of cells are able to synthesize and express tissue factor, including monocytes, granulocytes, platelets and endothelial cells. Tissue factor expression can be induced by cell surface components of pathogenic microorganisms, proinflammatory cytokines and membrane microparticles released from activated host cells. Tissue factor plays an important role in initiating thrombosis associated with inflammation during infection, sepsis, and organ transplant rejection. Recent findings suggest that tissue factor can also function as a receptor and thus may be important in cell signaling. The present minireview will focus on the role of tissue factor in the pathogenesis of septic shock, infectious endocarditis and invasive aspergillosis, as determined by both in vivo and in vitro models.

  12. Bidirectional extracellular matrix signaling during tissue morphogenesis

    Science.gov (United States)

    Gjorevski, Nikolce; Nelson, Celeste M.

    2009-01-01

    Normal tissue development and function are regulated by the interplay between cells and their surrounding extracellular matrix (ECM). The ECM provides biochemical and mechanical contextual information that is conveyed from the cell membrane through the cytoskeleton to the nucleus to direct cell phenotype. Cells, in turn, remodel the ECM and thereby sculpt their local microenvironment. Here we review the mechanisms by which cells interact with, respond to, and influence the ECM, with particular emphasis placed on the role of this bidirectional communication during tissue morphogenesis. We also discuss the implications for successful engineering of functional tissues ex vivo. PMID:19896886

  13. Quantification and validation of soft tissue deformation

    DEFF Research Database (Denmark)

    Mosbech, Thomas Hammershaimb; Ersbøll, Bjarne Kjær; Christensen, Lars Bager

    2009-01-01

    markers are easy to distinguish from the surrounding soft tissue in 3D computed tomography images. By tracking corresponding markers using methods from point-based registration, we are able to accurately quantify the magnitude and propagation of the induced deformation. The deformation is parameterised......We present a model for soft tissue deformation derived empirically from 10 pig carcases. The carcasses are subjected to deformation from a known single source of pressure located at the skin surface, and the deformation is quantified by means of steel markers injected into the tissue. The steel...

  14. Controlling the 3D architecture of Self-Lifting Auto-generated Tissue Equivalents (SLATEs) for optimized corneal graft composition and stability.

    Science.gov (United States)

    Gouveia, Ricardo M; González-Andrades, Elena; Cardona, Juan C; González-Gallardo, Carmen; Ionescu, Ana M; Garzon, Ingrid; Alaminos, Miguel; González-Andrades, Miguel; Connon, Che J

    2017-03-01

    Ideally, biomaterials designed to play specific physical and physiological roles in vivo should comprise components and microarchitectures analogous to those of the native tissues they intend to replace. For that, implantable biomaterials need to be carefully designed to have the correct structural and compositional properties, which consequently impart their bio-function. In this study, we showed that the control of such properties can be defined from the bottom-up, using smart surface templates to modulate the structure, composition, and bio-mechanics of human transplantable tissues. Using multi-functional peptide amphiphile-coated surfaces with different anisotropies, we were able to control the phenotype of corneal stromal cells and instruct them to fabricate self-lifting tissues that closely emulated the native stromal lamellae of the human cornea. The type and arrangement of the extracellular matrix comprising these corneal stromal Self-Lifting Analogous Tissue Equivalents (SLATEs) were then evaluated in detail, and was shown to correlate with tissue function. Specifically, SLATEs comprising aligned collagen fibrils were shown to be significantly thicker, denser, and more resistant to proteolytic degradation compared to SLATEs formed with randomly-oriented constituents. In addition, SLATEs were highly transparent while providing increased absorption to near-UV radiation. Importantly, corneal stromal SLATEs were capable of constituting tissues with a higher-order complexity, either by creating thicker tissues through stacking or by serving as substrate to support a fully-differentiated, stratified corneal epithelium. SLATEs were also deemed safe as implants in a rabbit corneal model, being capable of integrating with the surrounding host tissue without provoking inflammation, neo-vascularization, or any other signs of rejection after a 9-months follow-up. This work thus paves the way for the de novo bio-fabrication of easy-retrievable, scaffold-free human

  15. Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bernard Jones; J. Blair Briggs; Leland Monteirth

    2007-05-01

    A series of experiments was performed at Los Alamos Scientific Laboratory in 1958 to determine critical masses of cylinders of Oralloy (Oy) reflected by a number of materials. The experiments were all performed on the Comet Universal Critical Assembly Machine, and consisted of discs of highly enriched uranium (93.3 wt.% 235U) reflected by half-inch and one-inch-thick cylindrical shells of various reflector materials. The experiments were performed by members of Group N-2, particularly K. W. Gallup, G. E. Hansen, H. C. Paxton, and R. H. White. This experiment was intended to ascertain critical masses for criticality safety purposes, as well as to compare neutron transport cross sections to those obtained from danger coefficient measurements with the Topsy Oralloy-Tuballoy reflected and Godiva unreflected critical assemblies. The reflector materials examined in this series of experiments are as follows: magnesium, titanium, aluminum, graphite, mild steel, nickel, copper, cobalt, molybdenum, natural uranium, tungsten, beryllium, aluminum oxide, molybdenum carbide, and polythene (polyethylene). Also included are two special configurations of composite beryllium and iron reflectors. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to the uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities. In addition to the idealizations made by the experimenters (removal of the platen and diaphragm), two simplifications were also made to the benchmark models that resulted in a small bias and additional uncertainty. First of all, since impurities in core and reflector materials are only estimated, they are not included in the benchmark models. Secondly, the room, support structure, and other possible surrounding equipment were not included in the model. Bias values that result from these two simplifications were determined and associated

  16. Behavioural aspects surrounding medicine purchases from pharmacies in Australia

    Directory of Open Access Journals (Sweden)

    Emmerton L

    2008-09-01

    Full Text Available Objective: This study aimed to produce current data regarding behavioural aspects of non-prescription (over-the-counter medicine purchases, in light of changes in the pharmaceutical market and increasing provision of professional services in pharmacies.Methods: Data were collected in 15 community pharmacies in South-East Queensland, Australia, over 540 hours in five days in August, 2006. The method, previously validated, involved documentation of both observational and interview data. Fifteen trained researchers were stationed in a selected pharmacy each to unobtrusively observe all eligible sales of non-prescription medicines, and, where possible, interview the purchasers post-sale. Non-response was supplemented by observational data and recall by the salesperson. The data included details of the purchase and purchasing behaviour, while new questions addressed issues of topical importance, including customers’ privacy concerns. A selection of the analyses is reported here.Results: In total, 3470 purchases were documented (135-479 per pharmacy, with customers of 67.5% of purchases (74.7% excluding an outlier pharmacy participating in the survey. Customers averaged 1.2 non-prescription medicines per transaction. Two-thirds (67.2% of customers were female, and 38.8% of the customers were aged 31-45 years. Analgesics and respiratory medicines accounted for two-thirds of the sales data (33.4% and 32.4%, respectively. Intended-brand purchases comprised 71% of purchases (2004/2824; in-store substitution then occurred in 8.8% of these cases, mainly following recommendations by pharmacy staff. Medicines intended for self-use comprised 62.9% of purchases (1752/2785. First-time purchases (30.8%, 799/2594 were more commonly influenced by pharmacy staff than by advertising.Conclusions: This study used validated methods adapted to a changing marketplace, thus providing data that both confirm and add to knowledge surrounding medicine purchases. Despite the

  17. Reliability analysis of tunnel surrounding rock stability by Monte-Carlo method

    Institute of Scientific and Technical Information of China (English)

    XI Jia-mi; YANG Geng-she

    2008-01-01

    Discussed advantages of improved Monte-Carlo method and feasibility aboutproposed approach applying in reliability analysis for tunnel surrounding rock stability. Onthe basis of deterministic parsing for tunnel surrounding rock, reliability computing methodof surrounding rock stability was derived from improved Monte-Carlo method. The com-puting method considered random of related parameters, and therefore satisfies relativityamong parameters. The proposed method can reasonably determine reliability of sur-rounding rock stability. Calculation results show that this method is a scientific method indiscriminating and checking surrounding rock stability.

  18. Clinical Observation of Vascular Dementia Treated by Surrounding-acupuncture of the CT-located Area

    Institute of Scientific and Technical Information of China (English)

    LUN Xin; FENG Bi-fang; RONG Li; YANG Wen-hui

    2003-01-01

    Purpose To observe the clinical effect of "Surrounding Needling Technigue through CT Location" in treating vascular dementia. Method Fifty cases of vascular dementia were randomly divided into surrounding Needling Technigue through CT location and routine acupuncture groups, 25 cases in each group,and were given surrounding Needling Technigue through CT location and routine acupuncture respectively. Results The effective rates in surrounding Needling Technigue through CT location and routine acupuncture groups were 88% and 60% respectively, and there was significant difference between the two groups, P < 0.01.Conclusion Therapeutic effect of surrounding Needling Technigue through CT location in treating vascular dementia was satisfactory, and better than that of routine acupuncture.

  19. Misconceptions Surrounding Climate Change: A Review of the Literature

    Science.gov (United States)

    Templeton, C. M.; McNeal, K. S.; Libarkin, J.

    2011-12-01

    Misconceptions about climate change abound in every corner of society. The result manifests itself ranging from apprehension to total disregard for climate change conditions. According to several sources, however, a large percentage of the U. S. population do, indeed indicate some concern over global warming and climate change in general. These climate change misconceptions are numerous and include, to name a few; confusion between weather and climate, how greenhouse gases are affecting the earth, the effects of ozone depletion, earth's natural cycles, volcanic activity, nuclear waste and a host of other anthropogenic influences. This paper is a review of the current research literature relating to climate change misconceptions. These errant views will be addressed, cataloged, enumerated, and ranked to get a grasp on where the general population, politicians, scientists, and educators as well as students stand on informed climate change information. The categories where misconceptions arise have been identified in this literature review study and include the following: Natural cycles of the earth, ecological which include deforestation, urban development and any human intervention on the environment, educational - including teacher strategies, student understanding and textbook updates, emotional, ozone layer and its interactions, polar ice, political regulations, mandates and laws, pollution from human sources as well as from nature, religious beliefs and dogma and social beliefs. We suggest appropriate solutions for addressing these misconceptions, especially in the classroom setting, and broadly include available funding sources for work in climate change education. Some solutions include need for compilation of appropriate education resources and materials for public use, need for the development of educational materials that appropriately address the variety of publics, and need for programs that are conducting climate change education research and EPO work to

  20. Host Specialization in the Charcoal Rot Fungus, Macrophomina phaseolina.

    Science.gov (United States)

    Su, G; Suh, S O; Schneider, R W; Russin, J S

    2001-02-01

    ABSTRACT To investigate host specialization in Macrophomina phaseolina, the fungus was isolated from soybean, corn, sorghum, and cotton root tissue and soil from fields cropped continuously to these species for 15 years in St. Joseph, LA. Chlorate phenotype of each isolate was determined after growing on a minimal medium containing 120 mM potassium chlorate. Consistent differences in chlorate sensitivity were detected among isolates from different hosts and from soil versus root. To further explore genetic differentiation among fungal isolates from each host, these isolates were examined by restriction fragment length polymorphism and random amplified polymorphic DNA (RAPD) analysis. No variations were observed among isolates in restriction patterns of DNA fragments amplified by polymerase chain reaction covering the internal transcribed spacer region, 5.8S rRNA and part of 25S rRNA, suggesting that M. phaseolina constitutes a single species. Ten random primers were used to amplify the total DNA of 45 isolates, and banding patterns resulting from RAPD analysis were compared with the neighbor-joining method. Isolates from a given host were genetically similar to each other but distinctly different from those from other hosts. Chlorate-sensitive isolates were distinct from chlorate-resistant isolates within a given host. In greenhouse tests, soybean, sorghum, corn, and cotton were grown separately in soil infested with individual isolates of M. phaseolina that were chosen based on their host of origin and chlorate phenotype. Root colonization and plant weight were measured after harvesting. More colonization of corn roots occurred when corn was grown in soil containing corn isolates compared with isolates from other hosts. However, there was no host specialization in isolates from soybean, sorghum, or cotton. More root colonization in soybean occurred with chlorate-sensitive than with chlorate-resistant isolates.

  1. Towards host-to-host meeting scheduling negotiation

    Directory of Open Access Journals (Sweden)

    Rani Megasari

    2015-03-01

    Full Text Available This paper presents a different scheme of meeting scheduling negotiation among a large number of personnel in a heterogeneous community. This scheme, named Host-to-Host Negotiation, attempts to produce a stable schedule under uncertain personnel preferences. By collecting information from hosts’ inter organizational meeting, this study intends to guarantee personnel availability. As a consequence, personnel’s and meeting’s profile in this scheme are stored in a centralized manner. This study considers personnel preferences by adapting the Clarke Tax Mechanism, which is categorized as a non manipulated mechanism design. Finally, this paper introduces negotiation strategies based on the conflict handling mode. A host-to-host scheme can give notification if any conflict exist and lead to negotiation process with acceptable disclosed information. Nevertheless, a complete negotiation process will be more elaborated in the future works.

  2. Differential survival of Ichthyophonus isolates indicates parasite adaptation to its host environment

    Science.gov (United States)

    Hershberger, P.K.; Pacheco, C.A.; Gregg, J.L.; Purcell, M.K.; LaPatra, S.E.

    2008-01-01

    In vitro viability of Ichthyophonus spp. spores in seawater and freshwater corresponded with the water type of the host from which the spores were isolated. Among Ichthyophonus spp. spores from both marine and freshwater fish hosts (Pacific herring, Clupea pallasii, and rainbow trout, Oncorhynchus mykiss, respectively), viability was significantly greater (P < 0.05) after incubation in seawater than in freshwater at all time points from 1 to 60 min after immersion; however, magnitude of the spore tolerances to water type differed with host origin. Ichthyophonus sp. adaptation to its host environment was indicated by greater seawater tolerance of spores from the marine host and greater freshwater tolerance of spores from the freshwater host. Prolonged aqueous survival of Ichthyophonus spp. spores in the absence of a host provides insight into routes of transmission, particularly among planktivorous fishes, and should be considered when designing strategies to dispose of infected fish carcasses and tissues.

  3. Host factors influencing viral persistence

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Nansen, A; Ørding Andreasen, Susanne

    2000-01-01

    host were used. Our results reveal that very different outcomes may be observed depending on virus strain and immunocompetence of the host. Thus while CD4+ cells are not critical during the initial phase of virus control, infectious virus reappear in mice lacking CD4+ cells, B cells or CD40 ligand...... that these different outcomes may be explained in relatively simple mathematical terms. This suggests that modelling may be used as a means to predict critical host and virus parameters. Therefore, combining mathematical modelling with precise, quantitative, in vivo analyses looks to be a promising approach...

  4. Enhanced tissue integration of implantable electrodes for sensing, and stimulation, via radio frequency glow discharge

    Science.gov (United States)

    O'Connor, Laurie M.

    Biopotential electrodes are conductive materials that convert electronic currents to or from ionic currents for sensing, and stimulating specific tissue sites for medical applications. Implanted electrodes become "walled off" by the foreign body tissue reactions producing poorly attached scar capsules dominated by surrounding dense collagenous lamellae and source fibroblasts which are electrically resistive. The conductive interstitial fluid that is typical between an electrode and the resistive capsule allows spurious current paths. The insulating layer increases the distance between the electrode and the target sites and poor attachment often results in electrode migration within the host tissue. This investigation tested the hypothesis that surface-energy modulation of electrodes, via Radio Frequency Glow Discharge Treatment (RFGDT), can improve the performance of tissue-implantable electrodes by reducing the foreign body tissue reaction and enhancing interfacial bonding between the tissue and electrode material. Previously published findings were reproduced in a pilot study of explanted reference grade medical-grade methyl silicone (PDMS) and commercially pure titanium (cpTi) materials and their tissue capsules from 30-day subcutaneous exposures in Balb/C mice. The low-critical surface tension PDMS produced thick, dense, poorly attached scar capsules while the higher-surface-energy commercially pure titanium (cpTi) produced more cellular and strongly attached tissue layers difficult to delaminate from the biomaterial. For the main body of work, cpTi, capacitor-grade Tantalum (Ta), and synthetic heart valve-quality Pyrolytic Carbon (PyC) were evaluated, representative of potential high-surface-energy implant electrode materials. Their surface characteristics were determined as-manufactured and after Radio Frequency Glow Discharge Treatment (RFGDT) by Critical Surface Tension (CST) measurement, Scanning Electron Microscopy (SEM), Energy Dispersive X

  5. Transcriptional adaptation of Mycosphaerella graminicola to programmed cell death (PCD) of its susceptible wheat host.

    Science.gov (United States)

    Keon, John; Antoniw, John; Carzaniga, Raffaella; Deller, Siân; Ward, Jane L; Baker, John M; Beale, Michael H; Hammond-Kosack, Kim; Rudd, Jason J

    2007-02-01

    Many important fungal pathogens of plants spend long periods (days to weeks) of their infection cycle in symptomless association with living host tissue, followed by a sudden transition to necrotrophic feeding as host tissue death occurs. Little is known about either the host responses associated with this sudden transition or the specific adaptations made by the pathogen to invoke or tolerate it. We are studying a major host-specific fungal pathogen of cultivated wheat, Septoria tritici (teleomorph Mycosphaerella graminicola). Here, we describe the host responses of wheat leaves infected with M. graminicola during the development of disease symptoms and use microarray transcription profiling to identify adaptive responses of the fungus to its changing environment. We show that symptom development on a susceptible host genotype has features reminiscent of the hypersensitive response, a rapid and strictly localized form of host programmed cell death (PCD) more commonly associated with disease-resistance mechanisms. The initiation and advancement of this host response is associated with a loss of cell-membrane integrity and dramatic increases in apoplastic metabolites and the rate of fungal growth. Microarray analysis of the fungal genes differentially expressed before and after the onset of host PCD supports a transition to more rapid growth. Specific physiological adaptation of the fungus is also revealed with respect to membrane transport, chemical and oxidative stress mechanisms, and metabolism. Our data support the hypothesis that host plant PCD plays an important role in susceptibility towards fungal pathogens with necrotrophic lifestyles.

  6. Mistletoe ecophysiology: Host-parasite interactions

    Science.gov (United States)

    G. Glatzel; B. W. Geils

    2009-01-01

    Mistletoes are highly specialized perennial flowering plants adapted to parasitic life on aerial parts of their hosts. In our discussion on the physiological interactions between parasite and host, we focus on water relations, mineral nutrition, and the effect of host vigour. When host photosynthesis is greatest, the xylem water potential of the host is most negative....

  7. The Effect of Superstructures Connected to Implants with Different Surface Properties on the Surrounding Bone

    Directory of Open Access Journals (Sweden)

    Katsunori Koretake

    2015-07-01

    Full Text Available The objective of this study was to investigate how the connection of superstructures to implants with different surface properties affects the surrounding bone. The right and left mandibular premolars and molars of 5 dogs were extracted. After 12 weeks, a machined implant was placed mesially and an anodized implant was placed distally on one side of the edentulous jaw, with the positions reversed on the opposite side. Twelve weeks after implantation, splinted superstructures were set to the implants. At 24 weeks after implantation, the implant stability quotient (ISQ was measured, radiographs were obtained. Removal torque values were measured and histologic observation was performed. The ISQ values at 24 weeks after implantation were not significantly different between the groups. The removal torque values were significantly different between the distal anodized and distal machined implants (p < 0.05. From 12 to 24 weeks, marginal bone losses were not significantly different between the groups. Fluorescent observation of tissue samples revealed bone-remodeling activity around all of the implants. The results of this study suggest that when implants with different surface properties are connected, machined implants at the most distal sites might be a potential risk factor for implant-bone binding.

  8. Evans Blue Staining Reveals Vascular Leakage Associated with Focal Areas of Host-Parasite Interaction in Brains of Pigs Infected with Taenia solium

    Science.gov (United States)

    Paredes, Adriana; Cangalaya, Carla; Rivera, Andrea; Gonzalez, Armando E.; Mahanty, Siddhartha; Garcia, Hector H.; Nash, Theodore E.

    2014-01-01

    Cysticidal drug treatment of viable Taenia solium brain parenchymal cysts leads to an acute pericystic host inflammatory response and blood brain barrier breakdown (BBB), commonly resulting in seizures. Naturally infected pigs, untreated or treated one time with praziquantel were sacrificed at 48 hr and 120 hr following the injection of Evans blue (EB) to assess the effect of treatment on larval parasites and surrounding tissue. Examination of harvested non encapsulated muscle cysts unexpectedly revealed one or more small, focal round region(s) of Evans blue dye infiltration (REBI) on the surface of otherwise non dye-stained muscle cysts. Histopathological analysis of REBI revealed focal areas of eosinophil-rich inflammatory infiltrates that migrated from the capsule into the tegument and internal structures of the parasite. In addition some encapsulated brain cysts, in which the presence of REBI could not be directly assessed, showed histopathology identical to that of the REBI. Muscle cysts with REBI were more frequent in pigs that had received praziquantel (6.6% of 3736 cysts; n = 6 pigs) than in those that were untreated (0.2% of 3172 cysts; n = 2 pigs). Similar results were found in the brain, where 20.7% of 29 cysts showed histopathology identical to muscle REBI cysts in praziquantel-treated pigs compared to the 4.3% of 47 cysts in untreated pigs. Closer examination of REBI infiltrates showed that EB was taken up only by eosinophils, a major component of the cellular infiltrates, which likely explains persistence of EB in the REBI. REBI likely represent early damaging host responses to T. solium cysts and highlight the focal nature of this initial host response and the importance of eosinophils at sites of host-parasite interaction. These findings suggest new avenues for immunomodulation to reduce inflammatory side effects of anthelmintic therapy. PMID:24915533

  9. Evans blue staining reveals vascular leakage associated with focal areas of host-parasite interaction in brains of pigs infected with Taenia solium.

    Science.gov (United States)

    Marzal, Miguel; Guerra-Giraldez, Cristina; Paredes, Adriana; Cangalaya, Carla; Rivera, Andrea; Gonzalez, Armando E; Mahanty, Siddhartha; Garcia, Hector H; Nash, Theodore E

    2014-01-01

    Cysticidal drug treatment of viable Taenia solium brain parenchymal cysts leads to an acute pericystic host inflammatory response and blood brain barrier breakdown (BBB), commonly resulting in seizures. Naturally infected pigs, untreated or treated one time with praziquantel were sacrificed at 48 hr and 120 hr following the injection of Evans blue (EB) to assess the effect of treatment on larval parasites and surrounding tissue. Examination of harvested non encapsulated muscle cysts unexpectedly revealed one or more small, focal round region(s) of Evans blue dye infiltration (REBI) on the surface of otherwise non dye-stained muscle cysts. Histopathological analysis of REBI revealed focal areas of eosinophil-rich inflammatory infiltrates that migrated from the capsule into the tegument and internal structures of the parasite. In addition some encapsulated brain cysts, in which the presence of REBI could not be directly assessed, showed histopathology identical to that of the REBI. Muscle cysts with REBI were more frequent in pigs that had received praziquantel (6.6% of 3736 cysts; n = 6 pigs) than in those that were untreated (0.2% of 3172 cysts; n = 2 pigs). Similar results were found in the brain, where 20.7% of 29 cysts showed histopathology identical to muscle REBI cysts in praziquantel-treated pigs compared to the 4.3% of 47 cysts in untreated pigs. Closer examination of REBI infiltrates showed that EB was taken up only by eosinophils, a major component of the cellular infiltrates, which likely explains persistence of EB in the REBI. REBI likely represent early damaging host responses to T. solium cysts and highlight the focal nature of this initial host response and the importance of eosinophils at sites of host-parasite interaction. These findings suggest new avenues for immunomodulation to reduce inflammatory side effects of anthelmintic therapy.

  10. Host associations between fungal root endophytes and boreal trees.

    Science.gov (United States)

    Kernaghan, Gavin; Patriquin, Glenn

    2011-08-01

    Fungal root endophytes colonize root tissue concomitantly with mycorrhizal fungi, but their identities and host preferences are largely unknown. We cultured fungal endophytes from surface-sterilized Cenococcum geophilum ectomycorrhizae of Betula papyrifera, Abies balsamea, and Picea glauca from two boreal sites in eastern Canada. Isolates were initially grouped on the basis of cultural morphology and then identified by internal transcribed spacer ribosomal DNA sequencing or by PCR restriction fragment length polymorphism. Phylogenetic analysis of the sequence data revealed 31 distinct phylotypes among the isolates, comprising mainly members of the ascomycete families Helotiaceae, Dermateaceae, Myxotrichaceae, and Hyaloscyphaceae, although other fungi were also isolated. Multivariate analyses indicate a clear separation among the endophyte communities colonizing each host tree species. Some phylotypes were evenly distributed across the roots of all three host species, some were found preferentially on particular hosts, and others were isolated from single hosts only. The results indicate that fungal root endophytes of boreal trees are not randomly distributed, but instead form relatively distinct assemblages on different host tree species.

  11. Resident microbiota affect Bordetella pertussis infectious dose and host specificity.

    Science.gov (United States)

    Weyrich, Laura S; Feaga, Heather A; Park, Jihye; Muse, Sarah J; Safi, Chetan Y; Rolin, Olivier Y; Young, Sarah E; Harvill, Eric T

    2014-03-01

    Before contacting host tissues, invading pathogens directly or indirectly interact with host microbiota, but the effects of such interactions on the initial stages of infection are poorly understood. Bordetella pertussis is highly infectious among humans but requires large doses to colonize rodents, unlike a closely related zoonotic pathogen, Bordetella bronchiseptica, raising important questions about the contributions of bacterial competition to initial colonization and host selection. We observed that <100 colony-forming units (CFU) of B. bronchiseptica efficiently infected mice and displaced culturable host microbiota, whereas 10 000 CFU of B. pertussis were required to colonize murine nasal cavities and did not displace host microorganisms. Bacteria isolated from murine nasal cavities but not those from the human lower respiratory tract limited B. pertussis growth in vitro, indicating that interspecies competition may limit B. pertussis colonization of mice. Further, a broad-spectrum antibiotic treatment delivered before B. pertussis inoculation reduced the infectious dose to <100 CFU, and reintroduction of single Staphylococcus or Klebsiella species was sufficient to inhibit B. pertussis colonization of antibiotic-treated mice. Together, these results reveal that resident microorganisms can prevent B. pertussis colonization and influence host specificity, and they provide rationale for manipulating microbiomes to create more-accurate animal models of infectious diseases.

  12. Cellular proliferation and regeneration following tissue damage. Progress report. [Eyes

    Energy Technology Data Exchange (ETDEWEB)

    Harding, C.V.

    1976-10-01

    Results are reported from a study of wound healing in tissues of the eye, particularly lens, cornea, and surrounding tissues. The reactions of these tissues to mechanical injuries, as well as injuries induced by chemotoxic agents were studied. It is postulated that a better understanding of the basic reactions of the eye to injurious agents may be of importance in the evaluation of potential environmental hazards.

  13. Use of biosynthetic cellulose membrane in the guided tissue regeneration

    OpenAIRE

    Iamaguti, Luciana Santini; Universidade Estadual Paulista; Brandão, Cláudia Valéria Seullner; Universidade Estadual Paulista

    2007-01-01

    Guided Tissue Regeneration (GTR) is a regenerative treatment modality that requires the placement of a physical barrier over a bone defect in such a way that the proliferation of the surrounding soft tissues into the barrier-protected area is prevented. Thereby in the guided osseous regeneration allowing boneforming cells from the existent bone edges to invade the space and produce bone. The physical barriers should be biocompatible, allow cellular occlusion, maintain adequate space, tissue i...

  14. [Scaffold-based Bone Tissue Engineering].

    Science.gov (United States)

    Holzapfel, B M; Rudert, M; Hutmacher, D W

    2017-08-01

    Tissue engineering provides the possibility of regenerating damaged or lost osseous structures without the need for permanent implants. Within this context, biodegradable and bioresorbable scaffolds can provide structural and biomechanical stability until the body's own tissue can take over their function. Additive biomanufacturing makes it possible to design the scaffold's architectural characteristics to specifically guide tissue formation and regeneration. Its nano-, micro-, and macro-architectural properties can be tailored to ensure vascularization, oxygenation, nutrient supply, waste exchange, and eventually ossification not only in its periphery but also in its center, which is not in direct contact with osteogenic elements of the surrounding healthy tissue. In this article we provide an overview about our conceptual design and process of the clinical translation of scaffold-based bone tissue engineering applications.

  15. Inhibition of the dorsal premotor cortex does not repair surround inhibition in writer's cramp patients.

    Science.gov (United States)

    Veugen, Lidwien C; Hoffland, Britt S; Stegeman, Dick F; van de Warrenburg, Bart P

    2013-03-01

    Writer's cramp is a task-specific form of focal dystonia, characterized by abnormal movements and postures of the hand and arm during writing. Two consistent abnormalities in its pathophysiology are a loss of surround inhibition and overactivity of the dorsal premotor cortex (PMd). This study aimed to assess a possible link between these two phenomena by investigating whether PMd inhibition leads to an improvement of surround inhibition, in parallel with previously demonstrated writing improvement. Fifteen writer's cramp patients and ten controls performed a simple motor hand task during which surround inhibition was measured using transcranial magnetic stimulation. Motor cortical excitability was measured of the active and surround muscles at three phases of the task. Surround inhibition and writing performance were assessed before and after PMd inhibitory continuous theta burst stimulation. In contrast to healthy controls, patients did not show inhibition of the abductor digiti minimi muscle during movement initiation of the first dorsal interosseus muscle, confirming the loss of surround inhibition. PMd inhibition led to an improvement of writing speed in writer's cramp patients. However, in both groups, no changes in surround inhibition were observed. The results confirm a role for the PMd in the pathophysiology of writer's cramp. We show that PMd inhibition does not lead to restoration of the surround inhibition defect in writer's cramp, despite the improvement in writing. This questions the involvement of the PMd in the loss of surround inhibition, and perhaps also the direct link between surround inhibition and dystonia.

  16. TOF-Secondary Ion Mass Spectrometry Imaging of Polymeric Scaffolds with Surrounding Tissue after in Vivo Implantation

    NARCIS (Netherlands)

    Klerk, Leendert A.; Dankers, Patricia Y. W.; Popa, Eliane R.; Bosman, Anton W.; Sanders, Marjolein E.; Reedquist, Kris A.; Heeren, Ron M. A.

    2010-01-01

    Supramolecular polymeric materials are of increasing interest for the use as drug delivery carriers. A thorough insight in the biocompatibility and the degradation of these materials in vivo are of fundamental importance to further their development and application in medical practice. Molecular ima

  17. Frequencies, bandwidths and magnitudes of vocal tract and surrounding tissue resonances, measured through the lips during phonation.

    Science.gov (United States)

    Hanna, Noel; Smith, John; Wolfe, Joe

    2016-05-01

    The frequencies, magnitudes, and bandwidths of vocal tract resonances are all important in understanding and synthesizing speech. High precision acoustic impedance spectra of the vocal tracts of 10 subjects were measured from 10 Hz to 4.2 kHz by injecting a broadband acoustic signal through the lips. Between 300 Hz and 4 kHz the acoustic resonances R (impedance minima measured through the lips) and anti-resonances R¯ (impedance maxima) associated with the first three voice formants, have bandwidths of ∼50 to 90 Hz for men and ∼70 to 90 Hz for women. These acoustic resonances approximate those of a smooth, dry, rigid cylinder of similar dimensions, except that their bandwidths indicate higher losses in the vocal tract. The lossy, inertive load and airflow caused by opening the glottis further increase the bandwidths observed during phonation. The vocal tract walls are not rigid and measurements show an acousto-mechanical resonance R0 ∼ 20 Hz and anti-resonance R¯0∼200 Hz. These give an estimate of wall inertance consistent with an effective thickness of 1-2 cm and a wall stiffness of 2-4 kN m(-1). The non-rigidity of the tract imposes a lower limit of the frequency of the first acoustic resonance fR1 and the first formant F1.

  18. TOF-secondary ion mass spectrometry imaging of polymeric scaffolds with surrounding tissue after in vivo implantation.

    Science.gov (United States)

    Klerk, Leendert A; Dankers, Patricia Y W; Popa, Eliane R; Bosman, Anton W; Sanders, Marjolein E; Reedquist, Kris A; Heeren, Ron M A

    2010-06-01

    Supramolecular polymeric materials are of increasing interest for the use as drug delivery carriers. A thorough insight in the biocompatibility and the degradation of these materials in vivo are of fundamental importance to further their development and application in medical practice. Molecular imaging techniques are powerful tools that enable the elucidation of molecular distributions in and around such polymer implants. A supramolecular polymeric hydrogel was implanted under the renal capsule to study its biocompatibility with TOF-SIMS. This results in a molecular cartography of the polymer implant combined with the cellular signature of the implantation environment. In this experiment, molecular signals are observed from cells that are involved in the biological response to the implant, e.g., macrophages. These molecular signatures are compared with macrophage standards cultured in different polarization environments. On the basis of this comparison, information can be acquired on the various macrophage differentiations that are connected to different stages in the foreign body response. Mass spectrometric imaging techniques offer the opportunity to visualize different histological phenomena in a single experiment without the need for specific immunohistochemical markers. Cellular infiltration into the polymer is visualized, offering a clear view on both biological and polymer features in a single imaging experiment.

  19. Mathematical modeling of cancer cell invasion of tissue: biological insight from mathematical analysis and computational simulation.

    Science.gov (United States)

    Andasari, Vivi; Gerisch, Alf; Lolas, Georgios; South, Andrew P; Chaplain, Mark A J

    2011-07-01

    The ability of cancer cells to break out of tissue compartments and invade locally gives solid tumours a defining deadly characteristic. One of the first steps of invasion is the remodelling of the surrounding tissue or extracellular matrix (ECM) and a major part of this process is the over-expression of proteolytic enzymes, such as the urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs), by the cancer cells to break down ECM proteins. Degradation of the matrix enables the cancer cells to migrate through the tissue and subsequently to spread to secondary sites in the body, a process known as metastasis. In this paper we undertake an analysis of a mathematical model of cancer cell invasion of tissue, or ECM, which focuses on the role of the urokinase plasminogen activation system. The model consists of a system of five reaction-diffusion-taxis partial differential equations describing the interactions between cancer cells, uPA, uPA inhibitors, plasmin and the host tissue. Cancer cells react chemotactically and haptotactically to the spatio-temporal effects of the uPA system. The results obtained from computational simulations carried out on the model equations produce dynamic heterogeneous spatio-temporal solutions and using linear stability analysis we show that this is caused by a taxis-driven instability of a spatially homogeneous steady-state. Finally we consider the biological implications of the model results, draw parallels with clinical samples and laboratory based models of cancer cell invasion using three-dimensional invasion assay, and go on to discuss future development of the model.

  20. Prokaryotes versus Eukaryotes: Who is hosting whom?

    Directory of Open Access Journals (Sweden)

    Guillermo eTellez

    2014-10-01

    Full Text Available Microorganisms represent the largest component of biodiversity in our world. For millions of years, prokaryotic microorganisms have functioned as a major selective force shaping eukaryotic evolution. Microbes that live inside and on animals outnumber the animals’ actual somatic and germ cells by an estimated 10-fold. Collectively, the intestinal microbiome represents a ‘forgotten organ’, functioning as an organ inside another that can execute many physiological responsibilities. The nature of primitive eukaryotes was drastically changed due to the association with symbiotic prokaryotes facilitating mutual coevolution of host and microbe. Phytophagous insects have long been used to test theories of evolutionary diversification; moreover, the diversification of a number of phytophagous insect lineages has been linked to mutualisms with microbes. From termites and honey bees to ruminants and mammals, depending on novel biochemistries provided by the prokaryotic microbiome, the association helps to metabolize several nutrients that the host cannot digest and converting these into useful end products (such as short chain fatty acids, a process which has huge impact on the biology and homeostasis of metazoans. More importantly, in a direct and/or indirect way, the intestinal microbiota influences the assembly of gut-associated lymphoid tissue, helps to educate immune system, affects the integrity of the intestinal mucosal barrier, modulates proliferation and differentiation of its epithelial lineages, regulates angiogenesis, and modifies the activity of enteric as well as the central nervous system,. Despite these important effects, the mechanisms by which the gut microbial community influences the host’s biology remains almost entirely unknown. Our aim here is to encourage empirical inquiry into the relationship between mutualism and evolutionary diversification between prokaryotes and eukaryotes which encourage us to postulate: Who is

  1. A decade of progress in tissue engineering.

    Science.gov (United States)

    Khademhosseini, Ali; Langer, Robert

    2016-10-01

    Tremendous progress has been achieved in the field of tissue engineering in the past decade. Several major challenges laid down 10 years ago, have been studied, including renewable cell sources, biomaterials with tunable properties, mitigation of host responses, and vascularization. Here we review advancements in these areas and envision directions of further development.

  2. The use of germ line-mutated mice in understanding host-pathogen interactions.

    Science.gov (United States)

    Yap, George S; Sher, Alan

    2002-10-01

    Microbial pathogenesis reflects an imbalance between parasite and host factors that favour pathogen multiplication and tissue destruction over those required for microbial elimination and preservation of the integrity of host tissues. In vivo analysis of host-pathogen interactions has been revolutionized by the ability to engineer specific genetic alterations including loss of function mutations and transgenes into the mouse germline. This brief review recapitulates what we have learned about the host response to Toxoplasma gondii infection to illustrate the usefulness of gene-altered mice in microbial pathogenesis research. A consideration of the pitfalls and limitations of experiments in knockout mice and ways of addressing these concerns are discussed. Finally, advances in inducible and tissue-restricted alterations in gene function are presented and their possible applications to microbiology research are considered.

  3. Chew on this: Amoebic trogocytosis and host cell killing by Entamoeba histolytica

    Science.gov (United States)

    Ralston, Katherine S.

    2015-01-01

    Entamoeba histolytica was named “histolytica” (histo-: tissue; lytic-: dissolving) for its ability to destroy host tissues. Direct killing of host cells by the amoebae is likely to be the driving factor that underlies tissue destruction, but the mechanism was unclear. We recently showed that after attaching to host cells, amoebae bite off and ingest distinct host cell fragments, and that this contributes to cell killing. Here we review this process, termed “amoebic trogocytosis” (trogo-: nibble), and how this process interplays with phagocytosis, or whole cell ingestion, in this organism. “Nibbling” processes have been described in other microbes and in multicellular organisms. The discovery of amoebic trogocytosis in E. histolytica may also shed light on an evolutionarily conserved process for intercellular exchange. PMID:26070402

  4. Numerical analysis of tunnel reinforcing influences on failure process of surrounding rock under explosive stress waves

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-jun; TANG Chun-an; ZHU Wan-cheng; LI Di-yuan; LI Shu-cai

    2008-01-01

    Based on mesoscopic damage mechanics, numerical code RFPA2D (dynamic edition) was developed to analyze the influence of tunnel reinforcing on failure process of surrounding rock under explosive stress waves. The results show that the propagation phenomenon of stress wave in the surrounding rock of tunnel and the failure process of surrounding rock under explosive stress waves are reproduced realistically by using numerical code RFPAED; from the failure process of surrounding rock,the place at which surrounding rock fractures is transferred because of tunnel reinforcing, and the rockfall and collapse caused by failure of surrounding rock are restrained by tunnel reinforcing; furthermore, the absolute values of peak values of major principal stress, and the minimal principal stress and shear stress at center point of tunnel roof are reduced because of tunnel reinforcing, and the displacement at center point of tunnel roof is reduced as well, consequently the stability of tunnel increases.

  5. Photochemical tissue bonding

    Science.gov (United States)

    Redmond, Robert W.; Kochevar, Irene E.

    2012-01-10

    Photochemical tissue bonding methods include the application of a photosensitizer to a tissue and/or tissue graft, followed by irradiation with electromagnetic energy to produce a tissue seal. The methods are useful for tissue adhesion, such as in wound closure, tissue grafting, skin grafting, musculoskeletal tissue repair, ligament or tendon repair and corneal repair.

  6. Soluble Host Defense Lectins in Innate Immunity to Influenza Virus

    Directory of Open Access Journals (Sweden)

    Wy Ching Ng

    2012-01-01

    Full Text Available Host defenses against viral infections depend on a complex interplay of innate (nonspecific and adaptive (specific components. In the early stages of infection, innate mechanisms represent the main line of host defense, acting to limit the spread of virus in host tissues prior to the induction of the adaptive immune response. Serum and lung fluids contain a range of lectins capable of recognizing and destroying influenza A viruses (IAV. Herein, we review the mechanisms by which soluble endogenous lectins mediate anti-IAV activity, including their role in modulating IAV-induced inflammation and disease and their potential as prophylactic and/or therapeutic treatments during severe IAV-induced disease.

  7. TRANSPLANTATION AND POTENTIAL IMMORTALITY OF MAMMALIAN TISSUES

    Science.gov (United States)

    Loeb, Leo

    1926-01-01

    1. Serial transplantation of tumors made it possible in 1901 and following years to draw the conclusion that various mammalian tissues have potential immortality. Serial transplantations of normal tissues did not succeed at first, because the homoioreaction on the part of the lymphocytes and connective tissue of the host injures the transplant. 2. In continuation of these experiments we found that cartilage of the rat can be transplanted serially to other rats at least for a period of 3 years. At the end of that time great parts of the transplanted cartilage and perichondrium are alive. 3. Not only the cartilage of young rats can be homoiotransplanted, but also the cartilage of very old rats which are nearing the end of life. By using such animals we have been able to obtain cartilage and perichondrium approaching an age of 6 years which is almost double the average age of a rat. 4. We found that cartilage can be homoiotransplanted more readily than other tissues for the following reasons: (a) While in principle the homoioreaction towards cartilage is the same as against other tissues, cartilage elicits this reaction with less intensity; (b) cartilage is better able to resist the invasion of lymphocytes and connective tissue than the majority of other tissues; (c) a gradual adaptation between transplant and host seems to take place in the case of cartilage transplantation, as a result of which the lymphocytic reaction on the part of the host tissue decreases progressively the longer the cartilage is kept in the strange host. 5. At time of examination we not only found living transplanted cartilage tissue, but also perichondrial tissue, which in response to a stimulus apparently originating in the necrotic central cartilage, had been proliferating and replacing it. These results suggest that it may perhaps be possible under favorable conditions to keep cartilage alive indefinitely through serial transplantations. 6. At the same time these experiments permit the

  8. Ex-vivo evaluation of gene therapy vectors in human pancreatic (cancer) tissue slices

    NARCIS (Netherlands)

    van Geer, M.A.; Kuhlmann, K.F.D.; Bakker, C.T.; ten Kate, F.J.W.; Oude Elferink, R.P.J.; Bosma, P.J.

    2009-01-01

    AIM: To culture human pancreatic tissue obtained from small resection specimens as a pre-clinical model for examining virus-host interactions. METHODS: Human pancreatic tissue samples (malignant and normal) were obtained from surgical specimens and processed immediately to tissue slices. Tissue slic

  9. Ex-vivo evaluation of gene therapy vectors in human pancreatic (cancer) tissue slices

    NARCIS (Netherlands)

    van Geer, M.A.; Kuhlmann, K.F.D.; Bakker, C.T.; ten Kate, F.J.W.; Oude Elferink, R.P.J.; Bosma, P.J.

    2009-01-01

    AIM: To culture human pancreatic tissue obtained from small resection specimens as a pre-clinical model for examining virus-host interactions. METHODS: Human pancreatic tissue samples (malignant and normal) were obtained from surgical specimens and processed immediately to tissue slices. Tissue slic

  10. Connective tissue regeneration in skeletal muscle after eccentric contraction-induced injury

    DEFF Research Database (Denmark)

    Mackey, Abigail Louise; Kjaer, Michael

    2016-01-01

    the adaptation throughout this process of both the connective tissue structures surrounding the myofibres, and the fibroblasts, the cells responsible for synthesising this connective tissue. However, the few studies investigating muscle connective tissue remodelling demonstrate a strong response that appears...... when the muscle connective tissue responses are compared, although further work is required to confirm this. Pharmacological agents (growth hormone and angiotensin II type I receptor blockers) are considered in the context of accelerating the muscle connective tissue adaptation to loading. Cautioning...

  11. The cross-correlation of signals and spatial impression in surround sound reproduction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The relationship between the cross-correlation coefficients of feeding signals and auditory spatial impression(ASI) which are created by the left,right,left surround and right surround loudspeakers in 5.1 channel surround sound system is investigated by psychoacoustic experiments.The results show that for reproducing by the front left-right or left-right surround loudspeakers pair,the auditory source width(ASW) can be broadened by controlling the crosscorrelation coefficients of feeding signals to some e...

  12. [Impact of microsporidia on hormonal balance in insect hosts].

    Science.gov (United States)

    Issi, I V; Tokarev, Iu S

    2002-01-01

    Microsporidia (M) is a phylum of protists parasitizing obligatory in animal cells. Long way of adaptation of M to intracellular parasitism resulted in establishment of quite close relationships between the parasite and its host. Different species of M induce in their hosts symptoms similar to those caused by misbalance of juvenile hormone (JH) and ecdysone. M infection leads to pathology of different hormone-dependent functions such as cell differentiation and specialization, molting, metamorphosis, diapause and reproduction of insects. The signs of hormonal dysfunction evidence for elevated titer of JH in M-infected insects. Two possible explanation of this could be offered: JH secretion by M or specific influence of the parasites on the insect endocrine systems. Impact on insect endogenous JH titer by M could be mediated by affection of secretory activity of corpora allata or by suppression of enzymatic degradation of JH. According to different hypotheses, insect hormonal status during microsporidiosis could be modified by a) insect host stress-reaction, b) exhaustion of insect host reserves, characteristic for acute phase of the disease, c) destruction of infected insect cells and tissues during mass sporogenesis of M. Data found in literature and provided by our experiments evidence for presence of JH analogues or juvenilizing substance in the extracts of M spores. From detailed examination of pathological process it is also seen that juvenilizing effect of M infection is usually restricted to the invaded regions of tissues (i.e. expressed locally) but not a systemic one. Ability of M to modify morpho-functional features of infected tissues at the level of hormonal regulation is undoubtfully a prominent adaptation for stabilizing "microsporidia-insect" parasite-host systems.

  13. Tissue Photolithography

    Science.gov (United States)

    Wade, Lawrence A.; Kartalov, Emil; Shibata, Darryl; Taylor, Clive

    2011-01-01

    Tissue lithography will enable physicians and researchers to obtain macromolecules with high purity (greater than 90 percent) from desired cells in conventionally processed, clinical tissues by simply annotating the desired cells on a computer screen. After identifying the desired cells, a suitable lithography mask will be generated to protect the contents of the desired cells while allowing destruction of all undesired cells by irradiation with ultraviolet light. The DNA from the protected cells can be used in a number of downstream applications including DNA sequencing. The purity (i.e., macromolecules isolated form specific cell types) of such specimens will greatly enhance the value and information of downstream applications. In this method, the specific cells are isolated on a microscope slide using photolithography, which will be faster, more specific, and less expensive than current methods. It relies on the fact that many biological molecules such as DNA are photosensitive and can be destroyed by ultraviolet irradiation. Therefore, it is possible to protect the contents of desired cells, yet destroy undesired cells. This approach leverages the technologies of the microelectronics industry, which can make features smaller than 1 micrometer with photolithography. A variety of ways has been created to achieve identification of the desired cell, and also to designate the other cells for destruction. This can be accomplished through chrome masks, direct laser writing, and also active masking using dynamic arrays. Image recognition is envisioned as one method for identifying cell nuclei and cell membranes. The pathologist can identify the cells of interest using a microscopic computerized image of the slide, and appropriate custom software. In one of the approaches described in this work, the software converts the selection into a digital mask that can be fed into a direct laser writer, e.g. the Heidelberg DWL66. Such a machine uses a metalized glass plate (with

  14. Comparison of Socioeconomic Factors between Surrounding and Non-Surrounding Areas of the Qinghai–Tibet Railway before and after Its Construction

    Directory of Open Access Journals (Sweden)

    Shicheng Li

    2016-08-01

    Full Text Available As the world’s highest railway, and the longest highland railway, the Qinghai–Tibet Railway (QTR has been paid considerable attention by researchers. However, most attention has been paid to the ecological and environmental issues affecting it, and sustainable ecological, social, and economic development-related studies of the QTR are rare. In this study, by analyzing the passenger traffic, freight traffic, passenger-kilometers, and freight-kilometers of the QTR for the period 1982–2013 and the transport structure of the Tibetan Plateau (TP for 1990–2013, the evolutionary process of the transport system in the TP following the construction of the QTR has been revealed. Subsequently, by comparing Gross Domestic Product (GDP, population, industrial structure, and urbanization level at the county and 1 km scales between surrounding and non-surrounding areas of the QTR, the differences in socioeconomic performance before and after its construction were detected. The results show that (1 in the TP, the highway-dominated transport system will break up and an integrated and sustainable transport system will form; (2 at the county scale, the annual growth rates of GDP of counties surrounding the QTR were greater than those of non-surrounding counties for the period 2000–2010. At the 1 km scale, following the opening of the completed line, the GDP of surrounding areas had a greater growth rate than before; (3 analysis at the county and 1 km scales indicated that population was not aggregated into the surrounding areas of the QTR in the period 2000–2010; (4 in terms of industrial structure, the proportion of primary industry decreased continuously, while the proportion of secondary and tertiary industries increased overall in the period 1984–2012. The QTR had no obvious impact on changes in the urbanization level of its surrounding areas.

  15. Vibrio fischeri-derived outer membrane vesicles trigger host development.

    Science.gov (United States)

    Aschtgen, Marie-Stephanie; Wetzel, Keith; Goldman, William; McFall-Ngai, Margaret; Ruby, Edward

    2016-04-01

    Outer membrane vesicles (OMV) are critical elements in many host-cell/microbe interactions. Previous studies of the symbiotic association between Euprymna scolopes and Vibrio fischeri had shown that within 12 h of colonizing crypts deep within the squid's light organ, the symbionts trigger an irreversible programme of tissue development in the host. Here, we report that OMV produced by V. fischeri are powerful contributors to this process. The first detectable host response to the OMV is an increased trafficking of macrophage-like cells called haemocytes into surface epithelial tissues. We showed that exposing the squid to other Vibrio species fails to induce this trafficking; however, addition of a high concentration of their OMV, which can diffuse into the crypts, does. We also provide evidence that tracheal cytotoxin released by the symbionts, which can induce haemocyte trafficking, is not part of the OMV cargo, suggesting two distinct mechanisms to induce the same morphogenesis event. By manipulating the timing and localization of OMV signal delivery, we showed that haemocyte trafficking is fully induced only when V. fischeri, the sole species able to reach and grow in the crypts, succeeds in establishing a sustained colonization. Further, our data suggest that the host's detection of OMV serves as a symbiotic checkpoint prior to inducing irreversible morphogenesis. © 2015 John Wiley & Sons Ltd.

  16. Exploring the Islamic Perspective on Tissue Engineering Principles and Practice

    Directory of Open Access Journals (Sweden)

    Munirah, S.

    2014-12-01

    Full Text Available Tissue engineering is related to the replacement, restoration, repair and/or regeneration of tissues/organs that are tailored to the needs of the individual patient. The potential applications of tissue engineering are being unveiled with much hype and expectations among the scientists and the public at large. The demand for engineered tissues may increase considerably, but the progress has been slow due to scientific and technical challenges that linked to moral, religious, philosophical, political and economic aspects. There are ongoing debates on certain aspects that seem to indicate that scientists maybe “playing God”. This article briefly analyses tissue engineering principles and the discourse surrounding it. Subsequently, the author briefly reflects on the Islamic perspectives, both for and against the technology. The discussions serve to provide a platform on how best to achieve a consensus that adequately deals with the scientific reality and the Islamic moral and legal jurisprudence that surrounds the technology.

  17. The Smallest AGN Host Galaxies

    CERN Document Server

    Greene, J E; Ho, L C

    2005-01-01

    We describe our efforts to study dwarf galaxies with active nuclei, whose black holes, with masses < 10^6 M_sun, provide the best current observational constraints on the mass distribution of primordial seed black holes. Although these low-mass galaxies do not necessarily contain classical bulges, Barth, Greene, & Ho (2005) show that their stellar velocity dispersions and black hole masses obey the same relation as more massive systems. In order to characterize the properties of the dwarf hosts without the glare of the active nucleus, we have compiled a complementary sample of narrow-line active galaxies with low-mass hosts. The host galaxy properties, both their structures and stellar populations, are consistent with the general properties of low-mass, blue galaxies from Sloan. The black holes in these galaxies are probably radiating close to their Eddington limits, suggesting we may have found Type 2 analogues of narrow-line Seyfert 1 galaxies.

  18. Asteroseismology of Exoplanet Host Stars

    CERN Document Server

    Huber, Daniel

    2015-01-01

    Asteroseismology is among the most powerful observational tools to determine fundamental properties of stars. Space-based photometry has recently enabled the systematic detection of oscillations in exoplanet host stars, allowing a combination of asteroseismology with transit and radial-velocity measurements to characterize planetary systems. In this contribution I will review the key synergies between asteroseismology and exoplanet science such as the precise determination of radii and ages of exoplanet host stars, as well as applications of asteroseismology to measure spin-orbit inclinations in multiplanet systems and orbital eccentricities of small planets. Finally I will give a brief outlook on asteroseismic studies of exoplanet hosts with current and future space-based missions such as K2 and TESS.

  19. Impact of fluorescence emission from gold atoms on surrounding biological tissue—implications for nanoparticle radio-enhancement

    Science.gov (United States)

    Byrne, H. L.; Gholami, Y.; Kuncic, Z.

    2017-04-01

    The addition of gold nanoparticles within target tissue (i.e. a tumour) to enhance the delivered radiation dose is a well studied radiotherapy treatment strategy, despite not yet having been translated into standard clinical practice. While several studies have used Monte Carlo simulations to investigate radiation dose enhancement by Auger electrons emitted from irradiated gold nanoparticles, none have yet considered the effects due to escaping fluorescence photons. Geant4 was used to simulate a water phantom containing 10 mg ml‑1 uniformly dispersed gold (1% by mass) at 5 cm depth. Incident monoenergetic photons with energies either side of the gold K-edge at 73 keV and 139.5 keV were chosen to give the same attenuation contrast against water, where water is used as a surrogate for biological tissue. For 73 keV incident photons, adding 1% gold into the water phantom enhances the energy deposited in the phantom by a factor of  ≈1.9 while 139.5 keV incident photons give a lower enhancement ratio of  ≈1.5. This difference in enhancement ratio, despite the equivalent attenuation ratios, can be attributed to energy carried from the target into the surrounding volume by fluorescence photons for the higher incident photon energy. The energy de-localisation is maximal just above the K-edge with 36% of the initial energy deposit in the phantom lost to escaping fluorescence photons. Conversely we find that the absorption of more photons by gold in the phantom reduces the number of scattered photons and hence energy deposited in the surrounding volume by up to 6% for incident photons below the K-edge. For incident photons above the K-edge this is somewhat offset by fluorescence. Our results give new insight into the previously unstudied centimetre scale energy deposition outside a target, which will be valuable for the future development of treatment plans using gold nanoparticles. From these results, we can conclude that gold nanoparticles

  20. The Inflammasome in Host Defense

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2009-12-01

    Full Text Available Nod-like receptors have emerged as an important family of sensors in host defense. These receptors are expressed in macrophages, dendritic cells and monocytes and play an important role in microbial immunity. Some Nod-like receptors form the inflammasome, a protein complex that activates caspase-1 in response to several stimuli. Caspase-1 activation leads to processing and secretion of pro-inflammatory cytokines such as interleukin (IL-1β and IL-18. Here, we discuss recent advances in the inflammasome field with an emphasis on host defense. We also compare differential requirements for inflammasome activation in dendritic cells, macrophages and monocytes.

  1. Host parasite communications-Messages from helminths for the immune system: Parasite communication and cell-cell interactions.

    Science.gov (United States)

    Coakley, Gillian; Buck, Amy H; Maizels, Rick M

    2016-07-01

    Helminths are metazoan organisms many of which have evolved parasitic life styles dependent on sophisticated manipulation of the host environment. Most notably, they down-regulate host immune responses to ensure their own survival, by exporting a range of immuno-modulatory mediators that interact with host cells and tissues. While a number of secreted immunoregulatory parasite proteins have been defined, new work also points to the release of extracellular vesicles, or exosomes, that interact with and manipulate host gene expression. These recent results are discussed in the overall context of how helminths communicate effectively with the host organism.

  2. Non-invasive microelectrode potassium flux measurements as a potential tool for early recognition of virus-host compatibility in plants

    Science.gov (United States)

    Understanding mechanisms of virus-host compatibility and its early recognition is of significant economic importance. Net Ca2+ and K+ fluxes were measured from mesophyll tissue of host (potato, tomato, tobacco) and non-host (sugar beet and periwinkle) plants in response to infection with Potato viru...

  3. err aA spatial evaluation of socio demographics surrounding National Priorities List sites in Florida using a distance-based approach

    Directory of Open Access Journals (Sweden)

    Kiros Gebre-Egziabher

    2009-06-01

    Full Text Available Abstract Background Over the last two decades, various spatial techniques have been demonstrated using geographical information systems (GIS to adequately estimate and characterize inequities of minority populations living near environmentally hazardous facilities. However, these methods have produced mixed results. In this study, we use recently developed variations of the "distance based" approach to spatially evaluate and compare demographic and socioeconomic disparities surrounding the worst hazardous waste sites in Florida. Methods We used data from the 2000 US Census Bureau and the Florida Department of Environmental Protection to identify selected socio and economic variables within one (1 mile of 71 National Priorities List (NPL or Superfund sites in Florida. ArcMap (ESRI, v. 9.2 was used to map the centroid locations of each of the NPL sites as well as identify and estimate the number of host and non-host tracts. The unit of analysis in this study was at the census tract level. Logistic regression (SAS v9.1.3 was used to determine if race/ethnicity and socioeconomic indicators are significant predictors of the location of NPL sites. Results There were significant differences in race/ethnicity composition and socio-economic factors between NPL host census tracts and non-host census tracts in Florida. The percentages of Blacks (OR = 5.7, p Conclusion The recently developed distance-based method supports previous studies and suggests that race and ethnicity play substantial roles in where hazardous facilities are located in Florida. Recommendations include using distance-based methods to evaluate socio and demographic characteristics surrounding other less known environmental hazardous facilities, such as landfills, or Toxic Release Inventory (TRI sites.

  4. Histology of Phytophthora ramorum in Notholithocarpus densiflorus bark tissues

    Science.gov (United States)

    Molly Botts Giesbrecht; Everett M. Hansen; Peter Kitin

    2011-01-01

    Colonisation of Notholithocarpus densiflorus (Hook. and Arn.) Rehder tissues by Phytophthora ramorum Werres, De Cock & Man in't Veld is not well understood. The pathogen is able to colonise nearly all tissues of this host but it is unclear how a tree is ultimately killed. In this research,

  5. Histological Examination of Phytophthora ramorum in Notholithocarpus densiflorus Bark Tissues

    Science.gov (United States)

    M. Botts

    2010-01-01

    Colonization of N. densiflorus tissues by P. ramorum is not well understood. The pathogen is able to colonize nearly all tissues of this host but it is unclear how a tree is ultimately killed. Because this is such a destructive invasive pathogen, it is important to investigate its pathogenic strategy. Microscopic investigation of xylem colonization has been conducted,...

  6. Interleukin (IL)-8 immunoreactivity of injured axons and surrounding oligodendrocytes in traumatic head injury.

    Science.gov (United States)

    Hayashi, Takahito; Ago, Kazutoshi; Nakamae, Takuma; Higo, Eri; Ogata, Mamoru

    2016-06-01

    Interleukin (IL)-8 has been suggested to be a positive regulator of myelination in the central nervous system, in addition to its principal role as a chemokine for neutrophils. Immunostaining for beta-amyloid precursor protein (AβPP) is an effective tool for detecting traumatic axonal injury, although AβPP immunoreactivity can also indicate axonal injury due to hypoxic causes. In this study, we examined IL-8 and AβPP immunoreactivity in sections of corpus callosum obtained from deceased patients with blunt head injury and from equivalent control tissue. AβPP immunoreactivity was detected in injured axons, such as axonal bulbs and varicose axons, in 24 of 44 head injury cases. These AβPP immunoreactive cases had survived for more than 3h. The AβPP immunostaining pattern can be classified into two types: traumatic (Pattern 1) and non-traumatic (Pattern 2) axonal injuries, which we described previously [Hayashi et al. Int. J. Legal Med. 129 (2015) 1085-1090]. Three of 44 control cases also showed AβPP immunoreactive injured axons as Pattern 2. In contrast, IL-8 immunoreactivity was detected in 7 AβPP immunoreactive and in 2 non-AβPP immunoreactive head injury cases, but was not detected in any of the 44 control cases, including the 3 AβPP immunoreactive control cases. The IL-8 immunoreactive cases had survived from 3 to 24 days, whereas those cases who survived less than 3 days (n=29) and who survived 90 days (n=1) were not IL-8 immunoreactive. Moreover, IL-8 was detected as Pattern 1 axons only. In addition, double immunofluorescence analysis showed that IL-8 is expressed by oligodendrocytes surrounding injured axons. In conclusion, our results suggest that immunohistochemical detection of IL-8 may be useful as a complementary diagnostic marker of traumatic axonal injury.

  7. Recognition of upper airway and surrounding structures at MRI in pediatric PCOS and OSAS

    Science.gov (United States)

    Tong, Yubing; Udupa, J. K.; Odhner, D.; Sin, Sanghun; Arens, Raanan

    2013-03-01

    Obstructive Sleep Apnea Syndrome (OSAS) is common in obese children with risk being 4.5 fold compared to normal control subjects. Polycystic Ovary Syndrome (PCOS) has recently been shown to be associated with OSAS that may further lead to significant cardiovascular and neuro-cognitive deficits. We are investigating image-based biomarkers to understand the architectural and dynamic changes in the upper airway and the surrounding hard and soft tissue structures via MRI in obese teenage children to study OSAS. At the previous SPIE conferences, we presented methods underlying Fuzzy Object Models (FOMs) for Automatic Anatomy Recognition (AAR) based on CT images of the thorax and the abdomen. The purpose of this paper is to demonstrate that the AAR approach is applicable to a different body region and image modality combination, namely in the study of upper airway structures via MRI. FOMs were built hierarchically, the smaller sub-objects forming the offspring of larger parent objects. FOMs encode the uncertainty and variability present in the form and relationships among the objects over a study population. Totally 11 basic objects (17 including composite) were modeled. Automatic recognition for the best pose of FOMs in a given image was implemented by using four methods - a one-shot method that does not require search, another three searching methods that include Fisher Linear Discriminate (FLD), a b-scale energy optimization strategy, and optimum threshold recognition method. In all, 30 multi-fold cross validation experiments based on 15 patient MRI data sets were carried out to assess the accuracy of recognition. The results indicate that the objects can be recognized with an average location error of less than 5 mm or 2-3 voxels. Then the iterative relative fuzzy connectedness (IRFC) algorithm was adopted for delineation of the target organs based on the recognized results. The delineation results showed an overall FP and TP volume fraction of 0.02 and 0.93.

  8. Salmonella's long-term relationship with its host.

    Science.gov (United States)

    Ruby, Thomas; McLaughlin, Laura; Gopinath, Smita; Monack, Denise

    2012-05-01

    Host-adapted strains of Salmonella enterica cause systemic infections and have the ability to persist systemically for long periods of time and pose significant public-health problems. Multidrug-resistant S. enterica serovar Typhi (S. Typhi) and nontyphoidal Salmonella (NTS) are on the increase and are often associated with HIV infection. Chronically infected hosts are often asymptomatic and transmit disease to naïve hosts via fecal shedding of bacteria, thereby serving as a critical reservoir for disease. Salmonella utilizes multiple ways to evade and modulate host innate and adaptive immune responses in order to persist in the presence of a robust immune response. Survival in macrophages and modulation of immune cells migration allow Salmonella to evade various immune responses. The ability of Salmonella to persist depends on a balance between immune responses that lead to the clearance of the pathogen and avoidance of damage to host tissues. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  9. Mycobacterium tuberculosis Transcription Machinery: Ready To Respond to Host Attacks.

    Science.gov (United States)

    Flentie, Kelly; Garner, Ashley L; Stallings, Christina L

    2016-05-01

    Regulating responses to stress is critical for all bacteria, whether they are environmental, commensal, or pathogenic species. For pathogenic bacteria, successful colonization and survival in the host are dependent on adaptation to diverse conditions imposed by the host tissue architecture and the immune response. Once the bacterium senses a hostile environment, it must enact a change in physiology that contributes to the organism's survival strategy. Inappropriate responses have consequences; hence, the execution of the appropriate response is essential for survival of the bacterium in its niche. Stress responses are most often regulated at the level of gene expression and, more specifically, transcription. This minireview focuses on mechanisms of regulating transcription initiation that are required by Mycobacterium tuberculosis to respond to the arsenal of defenses imposed by the host during infection. In particular, we highlight how certain features of M. tuberculosis physiology allow this pathogen to respond swiftly and effectively to host defenses. By enacting highly integrated and coordinated gene expression changes in response to stress,M. tuberculosis is prepared for battle against the host defense and able to persist within the human population.

  10. An oxygen-rich dust disk surrounding an evolved star in the Red Rectangle

    NARCIS (Netherlands)

    Waters, LBFM; Waelkens, C; van Winckel, H; Molster, FJ; Tielens, AGGM; van Loon, JT; Morris, PW; Cami, J; Bouwman, J; de Koter, A; de Jong, T; de Graauw, T

    1998-01-01

    The Red Rectangle(1) is the prototype of a class of carbon-rich reflection nebulae surrounding low-mass stars in the final stages of evolution. The central star of this nebula has ejected most of its layers (during the red-giant phase), which now form the surrounding cloud, and is rapidly evolving t

  11. The Space of an Object: Object Attention Alters the Spatial Gradient in the Surround

    Science.gov (United States)

    Kravitz, Dwight Jacob; Behrmann, Marlene

    2008-01-01

    Although object-based attention enhances perceptual processing of information appearing within the boundaries of a selected object, little is known about the consequences for information in the object's surround. The authors show that distance from an attended object's center of mass determines reaction time (RT) to targets in the surround. Of 2…

  12. Different surrounding landscapes may result in different fish assemblages in East African seagrass beds

    NARCIS (Netherlands)

    Dorenbosch, M.; Grol, M.G.G.; Nagelkerken, I.; Velde, G. van der

    2006-01-01

    Few studies have considered how seagrass fish assemblages are influenced by surrounding habitats. This information is needed for a better understanding of the connectivity between tropical coastal ecosystems. To study the effects of surrounding habitats on the composition, diversity and densities of

  13. Surround modulation characteristics of local field potential and spiking activity in primary visual cortex of cat.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available In primary visual cortex, spiking activity that evoked by stimulus confined in receptive field can be modulated by surround stimulus. This center-surround interaction is hypothesized to be the basis of visual feature integration and segregation. Spiking output has been extensively reported to be surround suppressive. However, less is known about the modulation properties of the local field potential (LFP, which generally reflects synaptic inputs. We simultaneously recorded spiking activity and LFP in the area 17 of anesthetized cats to examine and compare their modulation characteristics. When the stimulus went beyond the classical receptive field, LFP exhibited decreased power along the gamma band (30-100 Hz in most of our recording sites. Further investigation revealed that suppression of the LFP gamma mean power (gLFP depended on the angle between the center and surround orientations. The strongest suppression was induced when center and surround orientations were parallel. Moreover, the surround influence of the gLFP exhibited an asymmetric spatial organization. These results demonstrate that the gLFP has similar but not identical surround modulation properties, as compared to the spiking activity. The spatiotemporal integration of LFP implies that the oscillation and synchronization of local synaptic inputs may have important functions in surround modulation.

  14. Acanthamoeba induces cell-cycle arrest in host cells.

    Science.gov (United States)

    Sissons, James; Alsam, Selwa; Jayasekera, Samantha; Kim, Kwang Sik; Stins, Monique; Khan, Naveed Ahmed

    2004-08-01

    Acanthamoeba can cause fatal granulomatous amoebic encephalitis (GAE) and eye keratitis. However, the pathogenesis and pathophysiology of these emerging diseases remain unclear. In this study, the effects of Acanthamoeba on the host cell cycle using human brain microvascular endothelial cells (HBMEC) and human corneal epithelial cells (HCEC) were determined. Two isolates of Acanthamoeba belonging to the T1 genotype (GAE isolate) and T4 genotype (keratitis isolate) were used, which showed severe cytotoxicity on HBMEC and HCEC, respectively. No tissue specificity was observed in their ability to exhibit binding to the host cells. To determine the effects of Acanthamoeba on the host cell cycle, a cell-cycle-specific gene array was used. This screened for 96 genes specific for host cell-cycle regulation. It was observed that Acanthamoeba inhibited expression of genes encoding cyclins F and G1 and cyclin-dependent kinase 6, which are proteins important for cell-cycle progression. Moreover, upregulation was observed of the expression of genes such as GADD45A and p130 Rb, associated with cell-cycle arrest, indicating cell-cycle inhibition. Next, the effect of Acanthamoeba on retinoblastoma protein (pRb) phosphorylation was determined. pRb is a potent inhibitor of G1-to-S cell-cycle progression; however, its function is inhibited upon phosphorylation, allowing progression into S phase. Western blotting revealed that Acanthamoeba abolished pRb phosphorylation leading to cell-cycle arrest at the G1-to-S transition. Taken together, these studies demonstrated for the first time that Acanthamoeba inhibits the host cell cycle at the transcriptional level, as well as by modulating pRb phosphorylation using host cell-signalling mechanisms. A complete understanding of Acanthamoeba-host cell interactions may help in developing novel strategies to treat Acanthamoeba infections.

  15. Visual mimicry of host nestlings by cuckoos

    Science.gov (United States)

    Langmore, Naomi E.; Stevens, Martin; Maurer, Golo; Heinsohn, Robert; Hall, Michelle L.; Peters, Anne; Kilner, Rebecca M.

    2011-01-01

    Coevolution between antagonistic species has produced instances of exquisite mimicry. Among brood-parasitic cuckoos, host defences have driven the evolution of mimetic eggs, but the evolutionary arms race was believed to be constrained from progressing to the chick stage, with cuckoo nestlings generally looking unlike host young. However, recent studies on bronze-cuckoos have confounded theoretical expectations by demonstrating cuckoo nestling rejection by hosts. Coevolutionary theory predicts reciprocal selection for visual mimicry of host young by cuckoos, although this has not been demonstrated previously. Here we show that, in the eyes of hosts, nestlings of three bronze-cuckoo species are striking visual mimics of the young of their morphologically diverse hosts, providing the first evidence that coevolution can select for visual mimicry of hosts in cuckoo chicks. Bronze-cuckoos resemble their own hosts more closely than other host species, but the accuracy of mimicry varies according to the diversity of hosts they exploit. PMID:21227972

  16. Effects of surrounding elements on city image in the sample of Erzurum city

    Directory of Open Access Journals (Sweden)

    S. Ozer

    2010-05-01

    Full Text Available Structural elements which are the parts of city identities are shaped as the result of social and cultural characteristics and natural factors. In order to increase visual quality of cities and make cities more liveable landscape architects use not only living materials such as plants but also nonliving materials. This study was carried out to investigate the effects of surrounding elements which are vertical elements in landscape designs, on functional and city aesthetics. With this aim, materials used in surrounding elements around houses in Erzurum, houses surrounded by these elements and their harmony with their surroundings, aesthetics and functional effects were investigated and their contributions to city image were determined. While surrounding elements are mainly adequate in functions, they are lower quality in aesthetics. Some suggestions were offered for the city images that local councils should be careful on and due to Universiade in 2011.

  17. Catastrophe mechanism and disaster countermeasure for soft rock roadway surrounding rock in Meihe mine

    Institute of Scientific and Technical Information of China (English)

    Yu Yang⇑; Zhu Caikun; Chong Deyu; Liu Yang; Li Sichao

    2015-01-01

    The soft rock’s heterogeneity and nonlinear mechanical behavior cause extremely difficult maintenance on the soft rock roadway. Aiming at the asymmetric deformation and destruction phenomenon appearing after excavating and supporting the 7101 air return way in Meihe mine, this paper comprehensively adopted a variety of methods to analyze the roadway surrounding rock deformation rule, obtaining the roadway surrounding rock stress and plastic zone distribution rule under no supporting condition and the roadway surrounding rock deformation features under original symmetric supporting condition. Furthermore, this paper revealed the catastrophe mechanism, and proposed the concept of‘weak struc-ture’ and the disaster countermeasure of‘overall stabilizing the roadway and strengthening the support of weak structure’ . The industrial test shows that the disaster control technology can realize the coordination deformation of the supporting structure and roadway surrounding rock, thus significantly controlling the deformation of roadway surrounding rock.

  18. Effect of longwall length on mechanical characteristics of surrounding rock stress shell in mining face

    Energy Technology Data Exchange (ETDEWEB)

    Guang-Xiang Xie; Lei Wang [Anhui University of Science and Technology, Huainan (China)

    2008-12-15

    The mechanical characteristics of surrounding rock stress shell in longwall mining face were studied, based on the results of in-situ measurement combined with numerical simulation, and the effect of longwall length on mechanical characteristics of surrounding rock stress shell was discovered. The results show that the mechanical characteristics of surrounding rock stress shell are influenced by the length of the face. With an increase of mining face length, the level of concentration of shell stress located in the front face and surrounding rock of roadway is amplified and the three- dimensional stress is focused in the working face. The damage lies in the head entry corner of face and the vertical displacement is reduced but horizontal displacement is enlarged. The dynamic balance of surrounding rock stress shell is improved with rational adjustment of face length. It is effective in protecting the working face and controlling strata behavior. 5 refs., 7 figs.

  19. Stability classification model of mine-lane surrounding rock based on distance discriminant analysis method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; LI Xi-bing; GONG Feng-qiang

    2008-01-01

    Based on the principle of Mahalanobis distance discriminant analysis (DDA) theory, a stability classification model for mine-lane surrounding rock was established, including six indexes of discriminant factors that reflect the engineering quality of surrounding rock: lane depth below surface, span of lane, ratio of directly top layer thickness to coal thickness, uniaxial comprehensive strength of surrounding rock, development degree coefficient of surrounding rock joint and range of broken surrounding rock zone. A DDA model was obtained through training 15 practical measuring samples. The re-substitution method was introduced to verify the stability of DDA model and the ratio of mis-discrimination is zero. The DDA model was used to discriminate3 new samples and the results are identical with actual rock kind. Compared with the artificial neural network method and support vector mechanic method, the results show that this model has high prediction accuracy and can be used in practical engineering.

  20. Varieties of Quest and the Religious Openness Hypothesis within Religious Fundamentalist and Biblical Foundationalist Ideological Surrounds

    Directory of Open Access Journals (Sweden)

    P. J. Watson

    2013-12-01

    Full Text Available According to the Religious Openness Hypothesis, the religious and psychological openness of American Christians is obscured by a defensive ghettoization of thought associated with a Religious Fundamentalist Ideological Surround and can be discovered instead within a Biblical Foundationalist Ideological Surround. A test of this claim examined Religious Fundamentalism, Biblical Foundationalism, Quest, and Multidimensional Quest Scales in 432 undergraduates. Christian Religious Reflection, Religious Schema, and Religious Orientation measures clarified these two ideological surrounds. Partial correlations controlling for Biblical Foundationalism described a Religious Fundamentalist Ideological Surround that more strongly rejected Quest and that more generally displayed a failure to integrate faith with intellect. Partial correlations controlling for Religious Fundamentalism revealed a Biblical Foundationalist Ideological Surround that was more open to Quest and that offered numerous demonstrations of an ability to unite faith with intellect. These data supplemented previous investigations in demonstrating that Christianity and other traditional religions have ideological resources for promoting a faithful intellect.

  1. Biosignatures of Pathogen and Host

    Energy Technology Data Exchange (ETDEWEB)

    Fitch, J P; Chromy, B A; Forde, C E; Garcia, E; Gardner, S N; Gu, P P; Kuczmarksi, T A; Melius, C F; McCutchen-Maloney, S L; Milanovich, F P; Motin, V L; Ott, L L; Quong, A A; Quong, J N; Rocco, J M; Slezak, T R; Sokhansanj, B A; Vitalis, E A; Zemla, A T; McCready, P M

    2002-08-27

    In information theory, a signature is characterized by the information content as well as noise statistics of the communication channel. Biosignatures have analogous properties. A biosignature can be associated with a particular attribute of a pathogen or a host. However, the signature may be lost in backgrounds of similar or even identical signals from other sources. In this paper, we highlight statistical and signal processing challenges associated with identifying good biosignatures for pathogens in host and other environments. In some cases it may be possible to identify useful signatures of pathogens through indirect but amplified signals from the host. Discovery of these signatures requires new approaches to modeling and data interpretation. For environmental biosignal collections, it is possible to use signal processing techniques from other applications (e.g., synthetic aperture radar) to track the natural progression of microbes over large areas. We also present a computer-assisted approach to identify unique nucleic-acid based microbial signatures. Finally, an understanding of host-pathogen interactions will result in better detectors as well as opportunities in vaccines and therapeutics.

  2. Gastrointestinal mucormycosis in immunocompromised hosts.

    Science.gov (United States)

    Dioverti, M Veronica; Cawcutt, Kelly A; Abidi, Maheen; Sohail, M Rizwan; Walker, Randall C; Osmon, Douglas R

    2015-12-01

    Invasive mucormycosis is a rare fungal infection in immunocompromised hosts, but it carries a high mortality rate. Primary gastrointestinal disease is the least frequent form of presentation. Early diagnosis and treatment are critical in the management; however, symptoms are typically non-specific in gastrointestinal disease, leading to delayed therapy. To describe the clinical presentation, diagnosis, treatment and outcomes of gastrointestinal mucormycosis in immunocompromised hosts, we reviewed all cases of primary gastrointestinal mucormycosis in immunocompromised hosts reported in English literature as well as in our Institution from January 1st 1991 to December 31st 2013 for a total of 31 patients. About 52% of patients underwent solid organ transplant (SOT), while the rest had an underlying haematologic malignancy. Abdominal pain was the most common presenting symptom, followed by gastrointestinal bleeding and fever. Gastric disease was more common in SOT, whereas those with haematologic malignancy presented with intestinal disease (P = 0.002). Although gastrointestinal mucormycosis remains an uncommon condition in immunocompromised hosts, it carries significant morbidity and mortality, particularly in cases with intestinal involvement. A high index of suspicion is of utmost importance to institute early and appropriate therapy and improve outcomes.

  3. Host Defence to Pulmonary Mycosis

    Directory of Open Access Journals (Sweden)

    Christopher H Mody

    1999-01-01

    Full Text Available OBJECTIVE: To provide a basic understanding of the mechanisms of host defense to pathogenic fungi. This will help physicians understand why some patients are predisposed to fungal infections and update basic scientists on how microbial immunology applies to fungal disease.

  4. Host Event Based Network Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Jonathan Chugg

    2013-01-01

    The purpose of INL’s research on this project is to demonstrate the feasibility of a host event based network monitoring tool and the effects on host performance. Current host based network monitoring tools work on polling which can miss activity if it occurs between polls. Instead of polling, a tool could be developed that makes use of event APIs in the operating system to receive asynchronous notifications of network activity. Analysis and logging of these events will allow the tool to construct the complete real-time and historical network configuration of the host while the tool is running. This research focused on three major operating systems commonly used by SCADA systems: Linux, WindowsXP, and Windows7. Windows 7 offers two paths that have minimal impact on the system and should be seriously considered. First is the new Windows Event Logging API, and, second, Windows 7 offers the ALE API within WFP. Any future work should focus on these methods.

  5. Microbial Protection and Virulence in Periodontal Tissue as a Function of Polymicrobial Communities: Symbiosis and Dysbiosis

    OpenAIRE

    Roberts, Frank A; Darveau, Richard P.

    2015-01-01

    This review discusses polymicrobial interactions with the host in both health and disease. As our ability improves to identify specific bacterial clonal types both with respect to abundance and location in the oral biofilm we will learn more concerning their contribution to both oral health and disease. Recent studies examining host-bacterial interactions have revealed that commensal bacteria not only protect the host simply by niche occupation, but that bacterial interactions with host tissu...

  6. THE EMISSION NEBULA Sh 2-174: A RADIO INVESTIGATION OF THE SURROUNDING REGION

    Energy Technology Data Exchange (ETDEWEB)

    Ransom, R. R. [Department of Physics and Astronomy, Okanagan College, 583 Duncan Avenue West, Penticton, BC V2A 8E1 (Canada); Kothes, R.; Geisbuesch, J.; Landecker, T. L. [National Research Council Herzberg, Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, BC V2A 6J9 (Canada); Reich, W., E-mail: RRansom@okanagan.bc.ca [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)

    2015-02-01

    Sh 2-174 is believed to be either a planetary nebula (PN) or ionized, ambient interstellar medium (ISM). We present in this paper 1420 MHz polarization, 1420 MHz total intensity (Stokes-I), and neutral hydrogen (H I) images of the region around Sh 2-174. The radio images address not only the nature of the object, but also the history of the relationship between Sh 2-174 and its surrounding environment. The H I images show that Sh 2-174 sits presently at the center of a ∼1.°2 × ∼0.°4 cloud (with peak hydrogen density n {sub H} = 4 ± 2 cm{sup –3}). The Stokes-I image shows thermal-emission peaks (with electron densities n{sub e} = 11 ± 3 cm{sup –3}) coincident with the R-band optical nebula, as well as low-surface-brightness emission from an ionized ''halo'' around Sh 2-174 and from an ionized ''plateau'' extending southeast from the cloud. The polarization images reveal Faraday-rotation structures along the projected trajectory of Sh 2-174, including a high-contrast structure with ''arms'' that run precisely along the eastern edge of the H I cloud and a wide central region that merges with the downstream edge of Sh 2-174. The high-contrast structure is consistent with an ionized tail that has both early-epoch (before Sh 2-174 entered the cloud) and present-epoch (after Sh 2-174 entered the cloud) components. Furthermore, our rotation-measure analysis indicates that the ISM magnetic field is deflected at the leading edge of Sh 2-174. The downstream tail and upstream field deflection point to a PN-ISM interaction. Our estimated space velocity for the host white dwarf (GD 561) demonstrates that Sh 2-174 entered the cloud ∼27,000 yr ago, and gives a PN-ISM interaction timescale ≲ 2.0 × 10{sup 5} yr. We estimate an ambient magnetic field in the cloud of 11 ± 3 μG.

  7. Diversity of Sucking Lice on Small Mammals in the Surrounding Areas of Erhai Lake in Yunnan, China%中国云南洱海周边小兽体表吸虱多样性

    Institute of Scientific and Technical Information of China (English)

    董文鸽; 郭宪国; 门兴元; 钱体军; 吴滇

    2009-01-01

    An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004.From investigation sites, 3 303 small mammal hosts were captured and identified into 7families, 15 genera and 21 species in 4 orders (Rodentia, Insectivora, Scandentia and Carnivora), while 14 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura. The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain.The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity,abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking li ce and their corresponding hosts. A certain species of hosts usually have theirfixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mam mal host in different oriented areas of Erhai Lake are homologous. The results stronglysuggest a close relationship of co-evolution between sucking lice and their hosts.

  8. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding.

    Science.gov (United States)

    Kosovicheva, Anna A; Sheremata, Summer L; Rokem, Ariel; Landau, Ayelet N; Silver, Michael A

    2012-01-01

    Acetylcholine (ACh) reduces the spatial spread of excitatory fMRI responses in early visual cortex and receptive field size of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two phenomena that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Experiment 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: (1) surround grating with the same orientation as the center (parallel), (2) surround orthogonal to the center, or (3) no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS). Cholinergic enhancement decreased thresholds only in the parallel condition, thereby reducing OSSS. In Experiment 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the targets and flanking letters that allowed reliable identification. Cholinergic enhancement with donepezil had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early

  9. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

    Directory of Open Access Journals (Sweden)

    Anna A. Kosovicheva

    2012-09-01

    Full Text Available Acetylcholine (ACh reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Exp. 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: 1 surround grating with the same orientation as the center (parallel, 2 surround orthogonal to the center, or 3 no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS. Cholinergic enhancement reduced thresholds only in the parallel condition, thereby reducing OSSS. In Exp. 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the target and flanking letters that allowed reliable identification. Cholinergic enhancement had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical

  10. Neural mechanisms of surround attenuation and distractor competition in visual search.

    Science.gov (United States)

    Boehler, Carsten N; Tsotsos, John K; Schoenfeld, Mircea A; Heinze, Hans-Jochen; Hopf, Jens-Max

    2011-04-06

    Visual attention biases relevant processing in the visual system by amplifying relevant or attenuating irrelevant sensory input. A potential signature of the latter operation, referred to as surround attenuation, has recently been identified in the electromagnetic brain response of human observers performing visual search. It was found that a zone of attenuated cortical excitability surrounds the target when the search required increased spatial resolution for item discrimination. Here we address the obvious hypothesis that surround attenuation serves distractor suppression in the vicinity of the target where interference from irrelevant search items is maximal. To test this hypothesis, surround attenuation was assessed under conditions when the target was presented in isolation versus when it was surrounded by distractors. Surprisingly, substantial and indistinguishable surround attenuation was seen under both conditions, indicating that it reflects an attentional operation independent of the presence of distractors. Adding distractors in the target's surround, however, increased the amplitude of the N2pc--an evoked response known to index distractor competition in visual search. Moreover, adding distractors led to a topographical change of source activity underlying the N2pc toward earlier extrastriate areas. In contrast, the topography of reduced source activity due to surround attenuation remained unaltered with and without distractors in the target's surround. We conclude that surround attenuation is not a direct consequence of the attenuation of distractors in visual search and that it dissociates from attentional operations reflected by the N2pc. A theoretical framework is proposed that links both operations in a common model of top-down attentional selection in visual cortex.

  11. Incubation and application of transgenic green fluorescent nude mice in visualization studies on glioma tissue remodeling

    Institute of Scientific and Technical Information of China (English)

    DONG Jun; LAN Qing; HUANG Qiang; DAI Xing-liang; LU Zhao-hui; FEI Xi-feng; CHEN Hua; ZHANG Quan-bin; ZHAO Yao-dong; WANG Zhi-min; WANG Ai-dong

    2012-01-01

    Background The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells.However,these tumor cells are hard to be visualized directly in histopathological preparations,or in experimental glioma models.Therefore,we developed an experimental human dual-color in vivo glioma model,which made tracking solitary invasive glioma cells possible,for the purpose of visualizing the interactions between red fluorescence labeled human glioma cells and host brain cells.This may offer references for further studying the roles of tumor microenvironment during glioma tissue remodeling.Methods Transgenic female C57BL/6 mice expressing enhanced green fluorescent protein (EGFP) were crossed with male Balb/c nude mice.Then sib mating was allowed to occur continuously in order to establish an inbred nude mice strain with 50% of their offspring that are EGFP positive.Human glioma cell lines U87-MG and SU3 were transfected with red fluorescent protein (RFP) gene,and a rat C6 glioma cell line was stained directly with CM-Dil,to establish three glioma cell lines emitting red fluorescence (SU3-RFP,U87-RFP,and C6-CM-Dil).Red fluorescence tumor cells were inoculated via intra-cerebral injection into caudate nucleus of the EGFP nude mice.Tumor-bearing mice were sacrificed when their clinical symptoms appeared,and the whole brain was harvested and snap frozen for further analysis.Confocal laser scanning microscopy was performed to monitor the mutual interactions between tumor cells and host brain cells.Results Almost all the essential tissues of the established EGFP athymic Balb/c nude mice,except hair and erythrocytes,fluoresced green under excitation using a blue light-emitting flashlight with a central peak of 470 nm,approximately 50% of the offsprings were nu/nu EGFP+.SU3-RFP,U87-RFP,and C6-CM-Dil almost 100% expressed red fluorescence under the fluorescence

  12. Measurement of elastic modulus and Vickers hardness of surround bone implant using dynamic microindentation--parameters definition.

    Science.gov (United States)

    Soares, Priscilla Barbosa Ferreira; Nunes, Sarah Arantes; Franco, Sinésio Domingues; Pires, Raphael Rezende; Zanetta-Barbosa, Darceny; Soares, Carlos José

    2014-01-01

    The clinical performance of dental implants is strongly defined by biomechanical principles. The aim of this study was to quantify the Vicker's hardness (VHN) and elastic modulus (E) surround bone to dental implant in different regions, and to discuss the parameters of dynamic microindantion test. Ten cylindrical implants with morse taper interface (Titamax CM, Neodent; 3.5 mm diameter and 7 mm a height) were inserted in rabbit tibia. The mechanical properties were analyzed using microhardness dynamic indenter with 200 mN load and 15 s penetration time. Seven continuous indentations were made distancing 0.08 mm between each other perpendicularly to the implant-bone interface towards the external surface, at the limit of low (Lp) and high implant profile (Hp). Data were analyzed by Student's t-test (a=0.05) to compare the E and VHN values obtained on both regions. Mean and standard deviation of E (GPa) were: Lp. 16.6 ± 1.7, Hp. 17.0 ± 2.5 and VHN (N/mm2): Lp. 12.6 ± 40.8, Hp. 120.1 ± 43.7. No statistical difference was found between bone mechanical properties of high and low profile of the surround bone to implant, demonstrating that the bone characterization homogeneously is pertinent. Dynamic microindantion method proved to be highly useful in the characterization of the individual peri-implant bone tissue.

  13. Pattern recognition in hyperspectral data acquired during surgical procedures: differentiation between nerve and adipose tissue

    NARCIS (Netherlands)

    Schols, R.M.; Laan, M. ter; Stassen, L.P.S.; Bouvy, N.D.; Wieringa, F.P.; Alic, L.

    2016-01-01

    Intraoperative nerve localization is extremely important during surgery, especially laparoscopy. This is particularly challenging when nerves show visual resemblance to surrounding tissue. An example of such a delicate procedure is thyroid and parathyroid surgery, where iatrogenic injury of the recu

  14. Stem Cell Therapies for the Treatment of Radiation-Induced Normal Tissue Side Effects

    NARCIS (Netherlands)

    Benderitter, Marc; Caviggioli, Fabio; Chapel, Alain; Coppes, Robert P.; Guha, Chandan; Klinger, Marco; Malard, Olivier; Stewart, Fiona; Tamarat, Radia; Van Luijk, Peter; Limoli, Charles L.

    2014-01-01

    Significance: Targeted irradiation is an effective cancer therapy but damage inflicted to normal tissues surrounding the tumor may cause severe complications. While certain pharmacologic strategies can temper the adverse effects of irradiation, stem cell therapies provide unique opportunities for

  15. Stem Cell Therapies for the Treatment of Radiation-Induced Normal Tissue Side Effects

    NARCIS (Netherlands)

    Benderitter, Marc; Caviggioli, Fabio; Chapel, Alain; Coppes, Robert P.; Guha, Chandan; Klinger, Marco; Malard, Olivier; Stewart, Fiona; Tamarat, Radia; Van Luijk, Peter; Limoli, Charles L.

    2014-01-01

    Significance: Targeted irradiation is an effective cancer therapy but damage inflicted to normal tissues surrounding the tumor may cause severe complications. While certain pharmacologic strategies can temper the adverse effects of irradiation, stem cell therapies provide unique opportunities for re

  16. Yersinia virulence factors - a sophisticated arsenal for combating host defences.

    Science.gov (United States)

    Atkinson, Steve; Williams, Paul

    2016-01-01

    The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six 'effector' proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.

  17. Yersinia virulence factors - a sophisticated arsenal for combating host defences

    Science.gov (United States)

    Atkinson, Steve; Williams, Paul

    2016-01-01

    The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen. PMID:27347390

  18. Porous decellularized adipose tissue foams for soft tissue regeneration.

    Science.gov (United States)

    Yu, Claire; Bianco, Juares; Brown, Cody; Fuetterer, Lydia; Watkins, John F; Samani, Abbas; Flynn, Lauren E

    2013-04-01

    To design tissue-specific bioscaffolds with well-defined properties and 3-D architecture, methods were developed for preparing porous foams from enzyme-solubilized human decellularized adipose tissue (DAT). Additionally, a technique was established for fabricating "bead foams" comprised of interconnected networks of porous DAT beads fused through a controlled freeze-thawing and lyophilization procedure. In characterization studies, the foams were stable without the need for chemical crosslinking, with properties that could be tuned by controlling the protein concentration and freezing rate during synthesis. Adipogenic differentiation studies with human adipose-derived stem cells (ASCs) suggested that stiffness influenced ASC adipogenesis on the foams. In support of our previous work with DAT scaffolds and microcarriers, the DAT foams and bead foams strongly supported adipogenesis and were also adipo-inductive, as demonstrated by glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, endpoint RT-PCR analysis of adipogenic gene expression, and intracellular lipid accumulation. Adipogenic differentiation was enhanced on the microporous DAT foams, potentially due to increased cell-cell interactions in this group. In vivo assessment in a subcutaneous Wistar rat model demonstrated that the DAT bioscaffolds were well tolerated and integrated into the host tissues, supporting angiogenesis and adipogenesis. The DAT-based foams induced a strong angiogenic response, promoted inflammatory cell migration and gradually resorbed over the course of 12 weeks, demonstrating potential as scaffolds for wound healing and soft tissue regeneration.

  19. Isolation of a sesquiterpene synthase expressing in specialized epithelial cells surrounding the secretory cavities in rough lemon (Citrus jambhiri).

    Science.gov (United States)

    Uji, Yuya; Ozawa, Rika; Shishido, Hodaka; Taniguchi, Shiduku; Takabayashi, Junji; Akimitsu, Kazuya; Gomi, Kenji

    2015-05-15

    Volatile terpenoids such as monoterpenes and sesquiterpenes play multiple roles in plant responses and are synthesized by terpene synthases (TPSs). We have previously isolated a partial TPS gene, RlemTPS4, that responds to microbial attack in rough lemon. In this study, we isolated a full length RlemTPS4 cDNA from rough lemon. RlemTPS4 localized in the cytosol. The recombinant RlemTPS4 protein was obtained using a prokaryotic expression system and GC-MS analysis of the terpenes produced by the RlemTPS4 enzymatic reaction determined that RlemTPS4 produces some sesquiterpenes such as δ-elemene. The RlemTPS4 gene was specifically expressed in specialized epithelial cells surrounding the oil secretory cavities in rough lemon leaf tissue.

  20. High pressure freezing/freeze substitution fixation improves the ultrastructural assessment of Wolbachia endosymbiont-filarial nematode host interaction.

    Directory of Open Access Journals (Sweden)

    Kerstin Fischer

    Full Text Available BACKGROUND: Wolbachia α-proteobacteria are essential for growth, reproduction and survival for many filarial nematode parasites of medical and veterinary importance. Endobacteria were discovered in filarial parasites by transmission electron microscopy in the 1970's using chemically fixed specimens. Despite improvements of fixation and electron microscopy techniques during the last decades, methods to study the Wolbachia/filaria interaction on the ultrastructural level remained unchanged and the mechanisms for exchange of materials and for motility of endobacteria are not known. METHODOLOGY/PRINCIPAL FINDING: We used high pressure freezing/freeze substitution to improve fixation of Brugia malayi and its endosymbiont, and this led to improved visualization of different morphological forms of Wolbachia. The three concentric, bilayer membranes that surround the endobacterial cytoplasm were well preserved. Vesicles with identical membrane structures were identified close to the endobacteria, and multiple bacteria were sometimes enclosed within a single outer membrane. Immunogold electron microscopy using a monoclonal antibody directed against Wolbachia surface protein-1 labeled the membranes that enclose Wolbachia and Wolbachia-associated vesicles. High densities of Wolbachia were observed in the lateral chords of L4 larvae, immature, and mature adult worms. Extracellular Wolbachia were sometimes present in the pseudocoelomic cavity near the developing female reproductive organs. Wolbachia-associated actin tails were not observed. Wolbachia motility may be explained by their residence within vacuoles, as they may co-opt the host cell's secretory pathway to move within and between cells. CONCLUSIONS/SIGNIFICANCE: High pressure freezing/freeze substitution significantly improved the preservation of filarial tissues for electron microscopy to reveal membranes and sub cellular structures that could be crucial for exchange of materials between Wolbachia

  1. Injectable silk foams for soft tissue regeneration.

    Science.gov (United States)

    Bellas, Evangelia; Lo, Tim J; Fournier, Eric P; Brown, Joseph E; Abbott, Rosalyn D; Gil, Eun S; Marra, Kacey G; Rubin, J Peter; Leisk, Gary G; Kaplan, David L

    2015-02-18

    Soft tissue fillers are needed for restoration of a defect or augmentation of existing tissues. Autografts and lipotransfer have been under study for soft tissue reconstruction but yield inconsistent results, often with considerable resorption of the grafted tissue. A minimally invasive procedure would reduce scarring and recovery time as well as allow the implant and/or grafted tissue to be placed closer to existing vasculature. Here, the feasibility of an injectable silk foam for soft tissue regeneration is demonstrated. Adipose-derived stem cells survive and migrate through the foam over a 10-d period in vitro. The silk foams are also successfully injected into the subcutaneous space in a rat and over a 3-month period integrating with the surrounding native tissue. The injected foams are palpable and soft to the touch through the skin and returning to their original dimensions after pressure is applied and then released. The foams readily absorb lipoaspirate making the foams useful as a scaffold or template for existing soft tissue filler technologies, useful either as a biomaterial alone or in combination with the lipoaspirate.

  2. Leptospira interrogans endostatin-like outer membrane proteins bind host fibronectin, laminin and regulators of complement.

    Directory of Open Access Journals (Sweden)

    Brian Stevenson

    Full Text Available The pathogenic spirochete Leptospira interrogans disseminates throughout its hosts via the bloodstream, then invades and colonizes a variety of host tissues. Infectious leptospires are resistant to killing by their hosts' alternative pathway of complement-mediated killing, and interact with various host extracellular matrix (ECM components. The LenA outer surface protein (formerly called LfhA and Lsa24 was previously shown to bind the host ECM component laminin and the complement regulators factor H and factor H-related protein-1. We now demonstrate that infectious L. interrogans contain five additional paralogs of lenA, which we designated lenB, lenC, lenD, lenE and lenF. All six genes encode domains predicted to bear structural and functional similarities with mammalian endostatins. Sequence analyses of genes from seven infectious L. interrogans serovars indicated development of sequence diversity through recombination and intragenic duplication. LenB was found to bind human factor H, and all of the newly-described Len proteins bound laminin. In addition, LenB, LenC, LenD, LenE and LenF all exhibited affinities for fibronectin, a distinct host extracellular matrix protein. These characteristics suggest that Len proteins together facilitate invasion and colonization of host tissues, and protect against host immune responses during mammalian infection.

  3. Mercury in parasitic nematodes and trematodes and their double-crested cormorant hosts: Bioaccumulation in the face of sequestration by nematodes

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Stacey A., E-mail: srobinsc@connect.carleton.ca [Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6 (Canada); Forbes, Mark R., E-mail: mforbes6@gmail.com [Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6 (Canada); Hebert, Craig E., E-mail: Craig.Hebert@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1A 0H3 (Canada)

    2010-10-15

    Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values ({delta}{sup 15}N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. {delta}{sup 13}C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.

  4. Phylogenetic and host-parasite relationship analysis of Henneguya multiplasmodialis n. sp. infecting Pseudoplatystoma spp. in Brazilian Pantanal wetland.

    Science.gov (United States)

    Adriano, E A; Carriero, M M; Maia, A A M; Silva, M R M; Naldoni, J; Ceccarelli, P S; Arana, S

    2012-04-30

    A new species of the genus Henneguya (Henneguya multiplasmodialis n. sp.) was found infecting the gills of three of 89 specimens (3.3%) of Pseudoplatystoma corruscans and two of 79 specimens (2.6%) of Pseudoplatystoma reticulatum from rivers in the Pantanal wetland, Brazil. Partial sequencing of the 18S rDNA gene of the spores obtained from one plasmodium from the gills of P. corruscans and other one from the gills of P. reticulatum, respectively, resulted in a total of 1560 and 1147 base pairs. As the spores of H. multiplasmodialis n. sp. resemble those of Henneguya corruscans, which is also a parasite of P. corruscans, sequencing of the 18S rDNA gene of the spores of H. corruscans found on P. corruscans caught in the Brazilian Pantanal wetland was also provided to avoid any taxonomic pendency between these two species, resulting in 1913 base pairs. The sequences of H. multiplasmodialis n. sp. parasite of P. corruscans and P. reticulatum and H. corruscans did not match any of the Myxozoa available in the GenBank. The similarity of H. multiplasmodialis n. sp. obtained from P. corruscans to that from P. reticulatum was of 99.7%. Phylogeny revealed a strong tendency among Henneguya species to form clades based on the order and/or family of the host fish. H. multiplasmodialis n. sp. clustered in a clade with Henneguya eirasi and H. corruscans, which are also parasites of siluriforms of the family Pimelodidae and, together with the clade composed of Henneguya spp. parasites of siluriforms of the family Ictaluridae, formed a monophyletic clade of parasites of siluriform hosts. The histological study revealed that the wall of the plasmodia of H. multiplasmodialis n. sp. were covered with a stratified epithelium rich in club cells and supported by a layer of connective tissue. The interior of the plasmodia had a network of septa that divided the plasmodia into numerous compartments. The septa were composed of connective tissue also covered on both sides with a stratified

  5. Location of Host and Host Habitat by Fruit Fly Parasitoids

    Directory of Open Access Journals (Sweden)

    Pascal Rousse

    2012-11-01

    Full Text Available Augmentative releases of parasitoids may be a useful tool for the area-wide management of tephritid pests. The latter are parasitized by many wasp species, though only a few of them are relevant for augmentative biocontrol purposes. To date, nearly all the actual or potential biocontrol agents for such programs are egg or larval Opiinae parasitoids (Hymenoptera: Braconidae. Here, we review the literature published on their habitat and host location behavior, as well as the factors that modulate this behavior, which is assumed to be sequential; parasitoids forage first for the host habitat and then for the host itself. Parasitoids rely on chemical, visual, and mechanical stimuli, often strongly related to their ecology. Behavioral modulation factors include biotic and abiotic factors including learning, climatic conditions and physiological state of the insect. Finally, conclusions and perspectives for future research are briefly highlighted. A detailed knowledge of this behavior may be very useful for selecting the release sites for both inundative/augmentative releases of mass-reared parasitoids and inoculative releases for classical biocontrol.

  6. Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification

    Science.gov (United States)

    Fergason, R. L.; Gaddis, L. R.; Rogers, A. D.

    2014-07-01

    The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates. The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies provide information about past environments that may have supported liquid water and may have been habitable. This work further defines the association and relationship between hematite-bearing materials and low albedo (presumably aeolian) deposits and layered materials, identifies physical characteristics that are strongly correlated with the presence of hematite, and refines hypotheses for the origin and post-emplacement modification (including transport) of these hematite-bearing and associated materials. There are only three regions surrounding Candor Mensa where hematite has been identified, even though morphologic properties are similar throughout the entire mensa. Three possible explanations for why hematite is only exposed in these regions include: (1) the topographic structure of the mensa walls concentrates hematite at the base of the layered deposits, influencing the ability to detect hematite from orbit; (2) the presence of differing amounts of “dark mantling material” and hematite-free erosional sediment; (3) the potential fracturing of the mensa and the influence of these structures on fluid flow and subsequent digenesis. The observations of hematite-bearing materials in this work support the hypothesis that hematite is eroding from a unit in the Candor Mensa interior layered deposits (ILD) and is being concentrated as a lag deposit adjacent to the lower layers of Candor Mensa and at the base in the form of dark aeolian material. Due to the similar geologic context associated with hematite-bearing and ILD materials throughout the Valles Marineris canyon system, the insight gained from studying these

  7. Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification

    Science.gov (United States)

    Fergason, Robin L.; Gaddis, Lisa R.; Rogers, A. D.

    2014-01-01

    The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates. The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies provide information about past environments that may have supported liquid water and may have been habitable. This work further defines the association and relationship between hematite-bearing materials and low albedo (presumably aeolian) deposits and layered materials, identifies physical characteristics that are strongly correlated with the presence of hematite, and refines hypotheses for the origin and post-emplacement modification (including transport) of these hematite-bearing and associated materials. There are only three regions surrounding Candor Mensa where hematite has been identified, even though morphologic properties are similar throughout the entire mensa. Three possible explanations for why hematite is only exposed in these regions include: (1) the topographic structure of the mensa walls concentrates hematite at the base of the layered deposits, influencing the ability to detect hematite from orbit; (2) the presence of differing amounts of “dark mantling material” and hematite-free erosional sediment; (3) the potential fracturing of the mensa and the influence of these structures on fluid flow and subsequent digenesis. The observations of hematite-bearing materials in this work support the hypothesis that hematite is eroding from a unit in the Candor Mensa interior layered deposits (ILD) and is being concentrated as a lag deposit adjacent to the lower layers of Candor Mensa and at the base in the form of dark aeolian material. Due to the similar geologic context associated with hematite-bearing and ILD materials throughout the Valles Marineris canyon system, the insight gained from studying these

  8. Compensation for risks: host community benefits in siting locally unwanted facilities

    Science.gov (United States)

    Himmelberger, Jeffery J.; Ratick, Samuel J.; White, Allen L.

    1991-09-01

    This article analyzes the recent negotiations connected with siting 24 solid-waste landfills in Wisconsin. We examine the association between the type and amount of compensation paid to host communities by facility developers and the size of facilities, certain facility characteristics, the timing of negotiated agreements, the size of the host community, and the socioeconomic status of the host area. Our findings suggest that the level of compensation after adjusting for landfill capacity is positively associated with the percentage of total facility capacity dedicated to host community use, positively associated with the percentage of people of the host area who are in poverty, and larger for public facilities that accept municipal wastes. Other explanatory variables we examined, whose association with levels of compensation proved statistically insignificant, were facility size, facility status (new vs expansion), facility use (countyonly vs multicounty), timing of negotiation, host community size, and the host area education level, population density, and per capita income. We discuss the policy implications of our principal findings and future research questions in light of the persistent opposition surrounding the siting of solid-waste and other waste-management facilities.

  9. Can hemozoin alone cause host anaemia?

    Science.gov (United States)

    Sun, Jun; Wang, Su-Wen; Jin, Chang-Long; Zeng, Xiao-Li; Piao, Xing-Yu; Bai, Ling; Tang, Dan-Li; Ji, Chang-Le

    2016-12-01

    Both schistosomes and malaria parasites produce hemozoin and cause host anaemia. However, the relationship between anaemia and hemozoin is unclear. Although some studies have proposed that hemozoin is related to anaemia in malaria patients, whether hemozoin alone can cause anaemia in patients infected by malaria parasites or schistosomes is uncertain. To investigate the effect of hemozoin on hosts, β-haematin was injected intravenously to normal mice. Then, liver and spleen tissues were observed. Mouse blood was examined. Red blood cells (RBCs), white blood cells (WBCs) and haemoglobin were analysed. Macrophage changes in the spleens and marrow cells were compared using immunofluorescence and H&E or Giemsa stain, respectively. We found that after 15 injections of β-haematin, a large amount of β-haematin was observed to deposit in the livers and spleens. Splenomegaly and bone marrow mild hyperplasia were detected. The average number of RBCs, average number of WBCs and average concentration of haemoglobin decreased significantly from 9.36 × 10(12) cells/L to 8.7 × 10(12) cells/L, 3.8 × 10(9) cells/L to 1.7 × 10(9) cells/L and 142.8 g/L to 131.8 g/L, respectively. In specific, the number of macrophages in the spleens greatly increased after β-haematin infection. The results showed that injections of β-haematin alone can cause anaemia possibly through hypersplenism.

  10. Numerical Analysis of Advanced Displacement in Construction Progress of Tunnel Excavation with Weak Surrounding Rock

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2013-07-01

    Full Text Available Analysis of advanced displacement in construction progress of tunnel excavation with weak surrounding rock is carried out by numerical method and comparison of model test result. In allusion to the problems of regional landslides and extruded large-deformation seriously impacting the stability of rock mass in construction process of large-section tunnel with weak surrounding rock, the elastic-plastic numerical simulation relying on Liangshui tunnel of Lan-Yu railroad is conducted on mechanical behaviors and deformation steric effect of tunnel construction and the calculation results are compared with the modeling data. The research results show that: the steric effect of excavation face is the dominant factor in the incidence of working face and the stress of surrounding rocks gradually releases from excavation face; the range of 0.5~1 times the cave diameter around rock mass in front of working face is the disturbance range and the key area of stabilization and reinforcement for wake surrounding rock. According to the analysis and construction practice, the supporting structure of large-section tunnel with weak surrounding rock should be established as soon as possible to control the displacement change of surrounding rock in the range of load-bearing ring, reduce disturbance and improve the self-bearing capability of surrounding rock. Because of the distinct excavation steric effect of weak surrounding rock, the secondary lining structure must be established in time to bear the later pressure and restrict the large displacement of surrounding rock. The research results can provide reliable basis for engineering stability control of analogous tunnels.

  11. Taenia solium: inhibition of spontaneous evagination of cysticerci by the host inflammatory capsule.

    Science.gov (United States)

    Ostrosky, L; Correa, D; Faradji, R; Garcia, H; Flisser, A

    1991-09-01

    The effect of the host's inflammatory capsule or of physical restraint on the spontaneous evagination capacity of Taenia solium cysticerci was evaluated. Parasites obtained from infected pig muscle, in which the surrounding inflammatory capsule was not eliminated, were unable to evaginate spontaneously after 12 or 60 h of culture. This phenomenon was not abolished when the capsule was eliminated and the parasites were cultured in semi-solid agar or in liquid medium.

  12. Immunological methods for the detection and determination of connective tissue proteoglycans

    DEFF Research Database (Denmark)

    Caterson, B; Baker, J R; Christner, J E

    1982-01-01

    In this paper we report the use of immunological methods for specifically detecting and determining proteoglycan in cartilage and other connective tissues. Antibodies (polyclonal and monoclonal) have been raised against specific components of cartilage proteoglycan aggregates (i.e., proteoglycan...... in skin. Using antibodies specific for chondroitin-4-sulfated proteoglycan, their presence was demonstrated in dermal connective tissue and connective tissue surrounding nerve and muscle sheaths. However, chondroitin-4-sulfated proteoglycan was completely absent in the epidermis of skin and areas...... surrounding invaginating hair follicles. These immunological procedures are currently being used to complement conventional biochemical analyses of proteoglycans found in different connective tissue matrices....

  13. Hepatitis B and hepatitis C viruses: a review of viral genomes, viral induced host immune responses, genotypic distributions and worldwide epidemiology

    Directory of Open Access Journals (Sweden)

    Umar Saeed

    2014-04-01

    Full Text Available Hepatitis B and hepatitis C viruses (HCV are frequently propagating blood borne pathogens in global community. Viral hepatitis is primarily associated with severe health complications, such as liver cirrhosis, hepatocellular carcinoma, hepatic fibrosis and steatosis. A literature review was conducted on hepatitis B virus (HBV, HBV genome, genotypic distribution and global epidemiology of HBV, HCV, HCV genome, HCV and host immune responses, HCV genotypic distribution and global epidemiology. The valued information was subjected for review. HBV has strict tissue tropism to liver. The virus infecting hepatocytes produces large amount of hepatitis B surface antigen particles which lack the DNA. It has capability to integrate into host genome. It has been found that genotype C is most emerging genotype associated with more severe liver diseases (cirrhosis. The approximate prevalence rate of genotype C is 27.7% which represents a major threat to future generations. Approximately 8% of population is chronic carrier of HBV in developing countries. The chronic carrier rate of HBV is 2%-7% in Middle East, Eastern and Southern Europe, South America and Japan. Among HCV infected individuals, 15% usually have natural tendency to overcome acute viral infection, where as 85% of individuals were unable to control HCV infection. The internal ribosomal entry site contains highly conserved structures important for binding and appropriate positioning of viral genome inside the host cell. HCV infects only in 1%-10% of hepatocytes, but production of tumor necrosis factor alpha (from CD8+ cells and interferon-gamma cause destruction of both infected cells and non-infected surrounding cells. Almost 11 genotypes and above 100 subtypes of HCV exists worldwide with different geographical distribution. Many efforts are still needed to minimize global burden of these infections. For the complete eradication of HBV (just like small pox and polio via vaccination strategies

  14. Trypanosoma cruzi infection: a continuous invader-host cell cross talk with participation of extracellular matrix and adhesion and chemoattractant molecules

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    Marino A.P.M.P.

    2003-01-01

    Full Text Available Several lines of evidence have shown that Trypanosoma cruzi interacts with host extracellular matrix (ECM components producing breakdown products that play an important role in parasite mobilization and infectivity. Parasite-released antigens also modulate ECM expression that could participate in cell-cell and/or cell-parasite interactions. Increased expression of ECM components has been described in the cardiac tissue of chronic chagasic patients and diverse target tissues including heart, thymus, central nervous system and skeletal muscle of experimentally T. cruzi-infected mice. ECM components may adsorb parasite antigens and cytokines that could contribute to the establishment and perpetuation of inflammation. Furthermore, T. cruzi-infected mammalian cells produce cytokines and chemokines that not only participate in the control of parasitism but also contribute to the establishment of chronic inflammatory lesions in several target tissues and most frequently lead to severe myocarditis. T. cruzi-driven cytokines and chemokines may also modulate VCAM-1 and ICAM-1 adhesion molecules on endothelial cells of target tissues and play a key role in cell recruitment, especially of activated VLA-4+LFA-1+CD8+ T lymphocytes, resulting in a predominance of this cell population in the inflamed heart, central nervous system and skeletal muscle. The VLA-4+-invading cells are surrounded by a fine network of fibronectin that could contribute to cell anchorage, activation and effector functions. Since persistent "danger signals" triggered by the parasite and its antigens are required for the establishment of inflammation and ECM alterations, therapeutic interventions that control parasitism and selectively modulate cell migration improve ECM abnormalities, paving the way for the development of new therapeutic strategies improving the prognosis of T. cruzi-infected individuals.