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41.
Seidl K Solis NV Bayer AS Hady WA Ellison S Klashman MC Xiong YQ Filler SG 《PloS one》2012,7(6):e39633
Endothelial cells are important in the pathogenesis of bloodstream infections caused by Candida albicans and Staphylococcus aureus. Numerous investigations have used human umbilical vein endothelial cells (HUVECs) to study microbial-endothelial cell interactions in vitro. However, the use of HUVECs requires a constant supply of umbilical cords, and there are significant donor-to-donor variations in these endothelial cells. The use of an immortalized endothelial cell line would obviate such difficulties. One candidate in this regard is HMEC-1, an immortalized human dermal microvascular endothelial cell line. To determine if HMEC-1 cells are suitable for studying the interactions of C. albicans and S. aureus with endothelial cells in vitro, we compared the interactions of these organisms with HMEC-1 cells and HUVECs. We found that wild-type C. albicans had significantly reduced adherence to and invasion of HMEC-1 cells as compared to HUVECs. Although wild-type S. aureus adhered to and invaded HMEC-1 cells similarly to HUVECs, an agr mutant strain had significantly reduced invasion of HMEC-1 cells, but not HUVECs. Furthermore, HMEC-1 cells were less susceptible to damage induced by C. albicans, but more susceptible to damage caused by S. aureus. In addition, HMEC-1 cells secreted very little IL-8 in response to infection with either organism, whereas infection of HUVECs induced substantial IL-8 secretion. This weak IL-8 response was likely due to the anatomic site from which HMEC-1 cells were obtained because infection of primary human dermal microvascular endothelial cells with C. albicans and S. aureus also induced little increase in IL-8 production above basal levels. Thus, C. albicans and S. aureus interact with HMEC-1 cells in a substantially different manner than with HUVECs, and data obtained with one type of endothelial cell cannot necessarily be extrapolated to other types. 相似文献
42.
Adam R. Boyko Pascale Quignon Lin Li Jeffrey J. Schoenebeck Jeremiah D. Degenhardt Kirk E. Lohmueller Keyan Zhao Abra Brisbin Heidi G. Parker Bridgett M. vonHoldt Michele Cargill Adam Auton Andy Reynolds Abdel G. Elkahloun Marta Castelhano Dana S. Mosher Nathan B. Sutter Gary S. Johnson John Novembre Melissa J. Hubisz Adam Siepel Robert K. Wayne Carlos D. Bustamante Elaine A. Ostrander 《PLoS biology》2010,8(8)
Domestic dogs exhibit tremendous phenotypic diversity, including a greater
variation in body size than any other terrestrial mammal. Here, we generate a
high density map of canine genetic variation by genotyping 915 dogs from 80
domestic dog breeds, 83 wild canids, and 10 outbred African shelter dogs across
60,968 single-nucleotide polymorphisms (SNPs). Coupling this genomic resource
with external measurements from breed standards and individuals as well as
skeletal measurements from museum specimens, we identify 51 regions of the dog
genome associated with phenotypic variation among breeds in 57 traits. The
complex traits include average breed body size and external body dimensions and
cranial, dental, and long bone shape and size with and without allometric
scaling. In contrast to the results from association mapping of quantitative
traits in humans and domesticated plants, we find that across dog breeds, a
small number of quantitative trait loci (≤3) explain the majority of
phenotypic variation for most of the traits we studied. In addition, many
genomic regions show signatures of recent selection, with most of the highly
differentiated regions being associated with breed-defining traits such as body
size, coat characteristics, and ear floppiness. Our results demonstrate the
efficacy of mapping multiple traits in the domestic dog using a database of
genotyped individuals and highlight the important role human-directed selection
has played in altering the genetic architecture of key traits in this important
species. 相似文献
43.
Abdel Galil A. Hewaidy Gamal M. El Qot El Sayed M. Moneer 《Annales de Paléontologie》2019,105(1):45-61
The Campanian–lower Eocene sedimentary succession in the Kharga Oasis yields rare cephalopods that have so far received little attention. Eight cephalopod species; six nautiloids and two ammonites, are identified in the study area. The nautiloids are referred to five genera in three families. All nautiloid species are recorded from the Paleocene and Eocene rocks, two of which are described as new, as follows: Cimomia kurkurensis nov. sp. and Deltoidonautilus hassani nov. sp. The two ammonite species are Libycoceras ismaelis (von Zittel, 1884) and Baculites ovatus Say, 1820, representing the families Sphenodiscidae and Baculitidae, respectively. Baculites anceps of Quaas (1902, non Lamarck, 1822) from the Maastrichtian of the Western Desert of Egypt is here assigned to Baculites ovatus. The palaeobiogeography of these species is studied in detail. 相似文献
44.
45.
The aim of this study was to evaluate the efficacy of selected bacterial strains against the wheat soil‐borne pathogen Fusarium graminearum under greenhouse conditions. The most potent isolates were 3 isolates out of 18 isolates, which have numbers 3, 9 and 10 with in vitro inhibition index 42.5%, 41.3% and 46.3% respectively. Isolates 3 and 10 were selected for the following experiments. Isolates 3 and 10 were identified as Bacillus subtilis MAA03 and Pseudomonas fluorescens MAA10, respectively according to International Identification Keys and, confirmed by using Biolog system and 16S rDNA where the strains exhibited more than 99.5% sequence identity. Their close taxonomic relationship was further documented by phenotypic similarities. The using of B. subtilis and P. fluorescens separately or in mixture as biocontrol agent against F. graminearum on wheat significantly increased the final germination percent, the mean daily germination and germination index of wheat cultivar, while the mean germination time was significantly decreased relative to infested control. The final infection percent, the mean daily infection and infection index were decreased significantly, while the mean infection time was significantly increased relative to infested control. The use of P. fluorescens as biocontrol agent was the most efficient than B. subtilis or in mixture and the best treatment was seed coating. The application of B. subtilis and P. fluorescens separately or in combination significantly affected the growth parameters of wheat cultivar Tabuki, the root length was significantly increased in seed coating and seed soaking treatments, while non‐significantly decreased in case of soil drench treatment relative to infested control. Shoot length was significantly decreased in case of seed coating treatment relative to infested control. The shoot fresh and dry weights were significantly increased in seed coating and seed soaking treatments relative to infested control. The root fresh and dry weights were significantly increased in seed coating and seed soaking treatments relative to infested control. The number of leaves was significantly increased in all treatments relative to infested control. 相似文献
46.
Ana Milstein Mohammed Ekram Azim Mohammed Abdul Wahab Marc Charles Jean Verdegem 《Environmental Biology of Fishes》2003,68(3):247-260
The potential of periphyton-based aquaculture in South Asia is under investigation in an extensive research program. This paper is a further analysis of data from four experiments carried out in that framework, to explore periphyton, fish and fertilizer dose effects on water quality. Factor analysis and ANOVA models applied to a data matrix of water quality parameters in ponds with and without artificial substrates (bamboo poles and kanchi sticks), with and without fish (filter feeders catla and rohu, with and without bottom feeder kalbaush), and with a standard or 50% increased fertilizer dose, allowed us to identify the underlying ecological processes governing this novel periphyton-based pond system, and construct conceptual graphic models of the periphyton–environment relationships observed. We clearly established that the phosphorus flow is mainly linked to phytoplankton activity in the water column and decomposition on the pond bottom, while nitrogen flow is mainly linked to autotrophic (photosynthesis) and heterotrophic (decomposition and nitrification) processes that take place in the periphyton in addition to the water column and pond bottom. Consequently, disruption of the pond bottom by bottom feeding fish primarily promoted phosphate cycling and phytoplankton, while periphyton development on the supplied substrates and fertilization mainly improved oxygen balance and nitrogen related processes developing in the water column. The use of bamboo poles led to better results than kanchi sticks, related to the greater autotrophic periphyton development on bamboo and to the larger surface of bamboo poles that facilitate fish grazing and periphyton dislodgment that in turn have a renewal effect on periphyton. Stocking bottom feeding fish produces a fertilizing effect through the food web that benefits the filter-feeding fish and that makes it unnecessary to increase the dose of inorganic and organic fertilizers applied to the ponds. Thus, the output of this analysis will help the fish farmers in resource constrained countries to improve their production in periphyton-based ponds just by choosing bamboo substrates, stocking a bottom feeder fish together with the filter feeders, and saving money on fertilizers. 相似文献
47.
Volatile Oils from the Aerial Parts of Eremophila maculata and Their Antimicrobial Activity 下载免费PDF全文
Fadia S. Youssef Razan Hamoud Mohamed L. Ashour Abdel Nasser Singab Michael Wink 《化学与生物多样性》2014,11(5):831-841
The essential oils isolated from the fresh flowers, fresh leaves, and both fresh and air‐dried stems of Eremophila maculata (Scrophulariaceae) were characterized by GC‐FID and GC/MS analyses. Sabinene was the major component in most of the oils, followed by limonene, α‐pinene, benzaldehyde, (Z)‐β‐ocimene, and spathulenol. The leaf and flower essential oils showed antibacterial and antifungal activity against five Gram‐positive and four Gram‐negative bacterial strains, multi‐resistant clinical isolates from patients, i.e., methicillin‐resistant Staphylococcus aureus (MRSA), as well as two yeasts. Minimum inhibitory concentrations (MICs) and minimum microbicidal concentrations (MMCs) were between 0.25 and 4 mg/ml. 相似文献
48.
T. El‐Sayed Ali A. M. Osman S. H. Abdel‐Aziz F. A. Bawazeer 《Zeitschrift fur angewandte Ichthyologie》2011,27(3):840-846
Growth and longevity were studied for three species of the family scaridae, the longnose parrotfish (Hipposcarus harid), rusty parrotfish (Scarus ferrugineus) and bullethead parrotfish (Chlorurus sordidus), sampled at the eastern coast of the Red Sea, off Saudi Arabia. The three species are protogynous hermaphrodites presenting two distinct phases whereby the initial phase includes females and primary males, and the terminal phase is exclusively secondary males transformed from females. Annual marks in the ctenoid scales from the three species were used to develop size‐at‐age plots. Linear relationships were found between the scale radius and standard length for the three species, and the relationships between body weight (w) and standard length (L) were estimated. Scales of these species increased in size consistently throughout life, even though the somatic growth rate decreased with age. Sex‐specific growth effects in the three species were demonstrated. Growth of initial phase females was the lowest, followed by the initial phase males and terminal phase males, the latter showing the fastest growth rates. Thus, transition to the terminal male identity was associated with enhanced growth, resulting in larger terminal males than females of equivalent size. The von Bertalanffy growth formula (VBGF) was estimated for H. harid, S. ferrugineus and C. sordidus (L∞ = 43.92, 27.4 and 23.3; K = 0.067, 0.27 and 0.56; t0 = ?6.92, ?4.98 and ?4.6, respectively). The relationship between growth and reproduction of these species is also discussed. 相似文献
49.
Zaki A. Abdel‐Fattah Ehab M. Assal 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2016,49(3):398-412
Macroborings provide detailed information on the bioerosion, accretion and palaeoenvironment of both modern and fossil reefs. Dolomitized reefal carbonates in the Um Mahara Formation exhibit an outstanding example of spatially distributed, well‐preserved bioerosion structures in tropical to subtropical syn‐rift Miocene reefs. Ten ichnospecies belonging to five ichnogenera are identified; three belonging to the bivalve‐boring ichnogenus Gastrochaenolites, three attributed to the sponge‐boring ichnogenus Entobia, and four ichnospecies assigned to three worm‐boring ichnogenera Trypanites, Maeandropolydora and Caulostrepsis. The distribution of the reported borings is strongly linked to the palaeo‐reef zones. Two distinctive ichnological boring assemblages are recognized. The Gastrochaenolites‐dominated assemblage reflects shallower‐marine conditions, under water depths of a few metres, mostly in back‐reef to patch‐reef zones of a back‐reef lagoon. The Entobia‐dominated assemblage signifies relatively deeper marine conditions, mostly in reef core of the fringing Miocene reefs. These ichnological assemblages are attributed herein to the Entobia sub‐ichnofacies of the Trypanites ichnofacies. This ichnofacies indicates boring in hard carbonate substrates (such as corals, rhodoliths, carbonate cements and hardgrounds) during periods of non‐sedimentation or reduced sediment input. 相似文献
50.
Brampton C Wahab O Batchelor MR Allen S Williams PM 《European biophysics journal : EBJ》2011,40(3):247-257
Investigations into the energy pathways of biomolecular interactions by use of dynamic force spectroscopy are limited by the
range of loading rates accessible with a single technique. In the work discussed in this paper, this range has been extended
for a previously studied system by using the biomembrane force probe (BFP). This work builds on our previous single-molecule
atomic force microscopy (AFM) study of the dissociation of a bulge-motif-containing RNA complex. The disparity observed, at
high loading rates, between the dissociation of a 12-base pair complex with and without a central three-base pair bulge was
not observed at low rates. This suggests that the two species share a similar outer barrier to dissociation and that inclusion
of the bulge motif creates an additional barrier at a distance closer to the bound state. Experiments performed in different
buffer environments yielded similar results. The results, when combined with those of previous studies, suggest that the shared
outer barrier to dissociation is that due to a rearrangement and fraying of the ends of the helix. 相似文献