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31.
Netrin is a key axon guidance cue that orients axon growth during neural circuit formation. However, the mechanisms regulating netrin and its receptors in the extracellular milieu are largely unknown. Here we demonstrate that in Caenorhabditis elegans, LON-2/glypican, a heparan sulfate proteoglycan, modulates UNC-6/netrin signaling and may do this through interactions with the UNC-40/DCC receptor. We show that developing axons misorient in the absence of LON-2/glypican when the SLT-1/slit guidance pathway is compromised and that LON-2/glypican functions in both the attractive and repulsive UNC-6/netrin pathways. We find that the core LON-2/glypican protein, lacking its heparan sulfate chains, and secreted forms of LON-2/glypican are functional in axon guidance. We also find that LON-2/glypican functions from the epidermal substrate cells to guide axons, and we provide evidence that LON-2/glypican associates with UNC-40/DCC receptor–expressing cells. We propose that LON-2/glypican acts as a modulator of UNC-40/DCC-mediated guidance to fine-tune axonal responses to UNC-6/netrin signals during migration. 相似文献
32.
Kimberly M. Koporc Eric Strunz Cassandra Holloway David G. Addiss William Lin 《PLoS neglected tropical diseases》2015,9(12)
Background
Between 2007 and 2012, Children Without Worms (CWW) oversaw the Johnson & Johnson (J&J) donation of Vermox (mebendazole) for treatment of school-age children to control soil-transmitted helminthiasis (STH). To identify factors associated with on-time, delayed, or missed mass drug administration (MDA) interventions, and explore possible indicators for supply chain performance for drug donation programs, we reviewed program data for the 14 STH-endemic countries CWW supported during 2007–2012.Methodology
Data from drug applications, shipping records, and annual treatment reports were tracked using Microsoft Excel. Qualitative data from interviews with key personnel were used to provide additional context on the causes of delayed or missed MDAs. Four possible contributory factors to delayed or missed MDAs were considered: production, shipping, customs clearance, and miscellaneous in-country issues. Coverage rates were calculated by dividing the number of treatments administered by the number of children targeted during the MDA.Principal Findings
Of the approved requests for 78 MDAs, 54 MDAs (69%) were successfully implemented during or before the scheduled month. Ten MDAs (13%) were classified as delayed; seven of these were delayed by one month or less. An additional 14 MDAs (18%) were classified as missed. For the 64 on-time or delayed MDAs, the mean coverage was approximately 88%.Conclusions and Significance
To continue to assess the supply chain processes and identify areas for improvement, we identified four indicators or metrics for supply chain performance that can be applied across all neglected tropical disease (NTD) drug donation programs: (1) donor having available inventory to satisfy the country request for donation; (2) donor shipping the approved number of doses; (3) shipment arriving at the Central Medical Stores one month in advance of the scheduled MDA date; and (4) country programs implementing the MDA as scheduled. 相似文献33.
34.
Magali M. Wright Rob Cross Roger D. Cousens Tom W. May Cassandra B. McLean 《Mycorrhiza》2010,20(6):375-390
The terrestrial orchid genus Caladenia contains many species which are threatened with extinction. They have highly specific associations with Sebacina vermifera and closely related fungi, and conservation of these terrestrial orchids, in part, relies on symbiotic propagation to produce
plants for reintroduction and ex situ conservation collections. However, little is known of the diversity of mycorrhizal fungi
associating with natural populations. Here, restriction fragment polymorphism analysis, internal transcribed spacer and nuclear
large subunit sequencing and symbiotic seed germination were used to investigate the taxonomic and functional diversity of
fungal isolates from single populations of six endangered Caladenia species and one common species across the same biogeographic range. Fifty-nine fungal isolates were collected for investigation
including ten isolates from the six endangered species Caladenia audasii, Caladenia amoena, Caladenia sp. aff. fragrantissima (Central Victoria), Caladenia sp. aff. patersonii, Caladenia rosella and Caladenia orientalis and 49 isolates from six populations of the common species Caladenia tentaculata. While the common species associated with three distinct S. vermifera-like taxa, the six endangered species were restricted to one of these fungal taxa. No direct relationship between the taxonomic
identity of the fungi and their ability to stimulate seed germination was observed; however, the majority of the fungi isolated
from the Caladenia species were capable of germinating seed in vitro, indicating their mycorrhizal status and potential for symbiotic propagation
in conservation programmes. 相似文献
35.
Hannan NJ Stephens AN Rainczuk A Hincks C Rombauts LJ Salamonsen LA 《Journal of proteome research》2010,9(12):6256-6264
Endometrial secretions in the uterine cavity contain mediators important for endometrial receptivity and embryo implantation. Unbiased analysis of uterine fluid from a receptive versus nonreceptive time of the menstrual cycle and in fertile and infertile women will provide new insights into uterine receptivity. We hypothesized that proteomic analysis of human uterine lavages would identify proteins important for the establishment of pregnancy in humans. Lavages collected from fertile (n = 7) and infertile (n = 8) women during the midsecretory (MS) phase, and from fertile women during the midproliferative (MP) (n = 7) phase, were assessed using 2D-differential in gel electrophoresis (2D-DiGE) over a pI 4-7 range. Statistical analysis revealed 7 spots that were significantly decreased in the MP compared to the MS phase, while 18 spots showed differential expression between fertile and infertile women. A number of proteins were identified by mass spectrometry, including antithrombin III and alpha-2-macroglobulin, whose production was confirmed in endometrial epithelium. Their staining pattern suggests roles during embryo implantation. Assessment of the human endometrial secretome has identified differences in the protein content of uterine fluid with respect to receptivity and fertility. 相似文献
36.
Jeffrey A. Anderson Li-Hua Ping Oliver Dibben Cassandra B. Jabara Leslie Arney Laura Kincer Yuyang Tang Marcia Hobbs Irving Hoffman Peter Kazembe Corbin D. Jones Persephone Borrow Susan Fiscus Myron S. Cohen Ronald Swanstrom and the Center for HIV/AIDS Vaccine Immunology 《PLoS pathogens》2010,6(8)
HIV-1 is present in anatomical compartments and bodily fluids. Most transmissions occur through sexual acts, making virus in semen the proximal source in male donors. We find three distinct relationships in comparing viral RNA populations between blood and semen in men with chronic HIV-1 infection, and we propose that the viral populations in semen arise by multiple mechanisms including: direct import of virus, oligoclonal amplification within the seminal tract, or compartmentalization. In addition, we find significant enrichment of six out of nineteen cytokines and chemokines in semen of both HIV-infected and uninfected men, and another seven further enriched in infected individuals. The enrichment of cytokines involved in innate immunity in the seminal tract, complemented with chemokines in infected men, creates an environment conducive to T cell activation and viral replication. These studies define different relationships between virus in blood and semen that can significantly alter the composition of the viral population at the source that is most proximal to the transmitted virus. 相似文献
37.
Cassandra Rowe 《Palaeogeography, Palaeoclimatology, Palaeoecology》2007,251(1):83-103
The islands of Torres Strait occupy a shallow area of submerged continental shelf narrowly separating Cape York Peninsula, Australia, from New Guinea. The human history of Torres Strait is unique with respect to mainland northern Australia. Island vegetation, however, exhibits a strong affinity with the environments of the western lowlands regions of Cape York Peninsula and with the vegetation of seasonal tropical Australia in general. Cape York Peninsula is both climatically and biologically diverse, yet few pollen studies have been carried out in its seasonally tropical environments. A summary presentation of palynological results, tracing the nature of vegetation change in Torres Strait, offers a possible framework for vegetation changes in similar environments on mainland Australia and also provides an opportunity to explore the relationship between Quaternary change in humid-tropical Australian environments and their seasonal-tropical counterparts.Six pollen records from Torres Strait provide evidence of vegetation change and fire history over approximately the last 8000 years. Near-shore sediments reveal a Holocene succession in vegetation incorporating lower-tidal mangrove, upper-tidal mangrove, saltmarsh and freshwater swamp communities. Extensive stable mangrove communities dominated coastal Torres Strait between approximately 6000 and 3000 radiocarbon years before present (yr BP). Inland, the strongest Myrtaceae-forest and rainforest representation occurs around the mid-Holocene only to be replaced by open sclerophyll woodlands, as tree density and diversity decline in the last 3000 years. The development of continuous island freshwater swamp conditions, at the coast and inland, is similarly restricted to the late Holocene (c. 2600 yr BP) and fire, as a prominent feature in the Torres Strait environment, is also a relatively recent phenomenon. Comparisons with regional mainland Australian palynological records reveal a degree of consistency in results from Torres Strait suggesting a similarity in late Quaternary trends through Australian humid and seasonally tropical environments. A number of differences, however, are also apparent, highlighting a degree of diversity which warrants further attention. 相似文献
38.
Van Bogaert IN Saerens K De Muynck C Develter D Soetaert W Vandamme EJ 《Applied microbiology and biotechnology》2007,76(1):23-34
Sophorolipids are surface-active compounds synthesized by a selected number of yeast species. They have been known for over
40 years, but because of growing environmental awareness, they recently regained attention as biosurfactants due to their
biodegradability, low ecotoxicity, and production based on renewable resources. In this paper, an overview is given of the
producing yeast strains and various aspects of fermentative sophorolipid production. Also, the biochemical pathways and regulatory
mechanisms involved in sophorolipid biosynthesis are outlined. To conclude, a summary is given on possible applications of
sophorolipids, either as native or modified molecules. 相似文献
39.
Isolation of avian paramyxovirus 1 from a patient with a lethal case of pneumonia 总被引:4,自引:0,他引:4 下载免费PDF全文
Goebel SJ Taylor J Barr BC Kiehn TE Castro-Malaspina HR Hedvat CV Rush-Wilson KA Kelly CD Davis SW Samsonoff WA Hurst KR Behr MJ Masters PS 《Journal of virology》2007,81(22):12709-12714
An unknown virus was isolated from a lung biopsy sample and multiple other samples from a patient who developed a lethal case of pneumonia following a peripheral blood stem cell transplant. A random PCR-based molecular screening method was used to identify the infectious agent as avian paramyxovirus 1 (APMV-1; a group encompassing Newcastle disease virus), which is a highly contagious poultry pathogen that has only rarely been found in human infections. Immunohistochemical analysis confirmed the presence of APMV-1 antigen in sloughed alveolar cells in lung tissue from autopsy. Sequence from the human isolate showed that it was most closely related to virulent pigeon strains of APMV-1. This is the most completely documented case of a systemic human infection caused by APMV-1 and is the first report of an association between this virus and a fatal disease in a human. 相似文献
40.
Hu CA Donald SP Yu J Lin WW Liu Z Steel G Obie C Valle D Phang JM 《Molecular and cellular biochemistry》2007,299(1-2):85-92
The neuropathogenesis of influenza-associated encephalopathy in children and Reye's syndrome remains unclear. A surveillance
effort conducted during 2000-2003 in South-West Japan reveals that almost all fatal and handicapped influenza-associated encephalopathy
patients exhibit a disorder of mitochondrial β-oxidation with elevated serum acylcarnitine ratios (C16:0+C18:1)/C2. Here we show invasion by a non-neurotropic epidemic influenza A H3N2 virus in cerebral capillaries with progressive brain
edema after intranasal infection of mice having impaired mitochondrial β-oxidation congenitally or posteriorly in the newborn/
suckling periods. Mice genetically lacking of carnitine transporter OCTN2, resulting in carnitine deficiency and impaired
β-oxidation, exhibited significant higher virus-genome numbers in the brain, accumulation of virus antigen exclusively in
the cerebral capillaries and increased brain vascular permeability compared to in wild type mice. Mini-plasmin, which proteolytically
potentiates influenza virus multiplication in vivo and destroys the blood-brain barrier, accumulated with virus antigen in the brain capillaries of OCTN2-deficient mice but
only a little in wild-type mice. These results suggest that the impaired mitochondrial β-oxidation changes the susceptibility
to a non-neurotropic influenza A virus as to multiplication in the brain capillaries and to cause brain edema. These pathological
findings in the brain of mice having impaired mitochondrial β-oxidation after influenza virus infection may have implications
for human influenza-associated encephalopathy. 相似文献