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751.
David Israeli David Tanne Dianne Daniels David Last Ran Shneor David Guez Efrat Landau Yiftach Roth Aharon Ocherashvilli Mati Bakon Chen Hoffman Amit Weinberg Talila Volk Yael Mardor 《International journal of biological sciences》2011,7(1):1-8
The development of imaging methodologies for detecting blood-brain-barrier (BBB) disruption may help predict stroke patient''s propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI at relatively long delays (~15 minutes) after contrast injection and subtracting from them images acquired immediately after contrast administration. In addition, the relatively long delays allow for acquisition of high resolution images resulting in high resolution BBB disruption maps. The sensitivity is further increased by image preprocessing with corrections for intensity variations and with whole body (rigid+elastic) registration. Since only two separate time points are required, the time between the two acquisitions can be used for acquiring routine clinical data, keeping the total imaging time to a minimum.A proof of concept study was performed in 34 patients with ischemic stroke and 2 patients with brain metastases undergoing high resolution T1-weighted MRI acquired at 3 time points after contrast injection. The MR images were pre-processed and subtracted to produce BBB disruption maps. BBB maps of patients with brain metastases and ischemic stroke presented different patterns of BBB opening. The significant advantage of the long extravasation time was demonstrated by a dynamic-contrast-enhancement study performed continuously for 18 min. The high sensitivity of our methodology enabled depiction of clear BBB disruption in 27% of the stroke patients who did not have abnormalities on conventional contrast-enhanced MRI. In 36% of the patients, who had abnormalities detectable by conventional MRI, the BBB disruption volumes were significantly larger in the maps than in conventional MRI.These results demonstrate the advantages of delayed contrast extravasation in increasing the sensitivity to subtle BBB disruption in ischemic stroke patients. The calculated disruption maps provide clear depiction of significant volumes of BBB disruption unattainable by conventional contrast-enhanced MRI. 相似文献
752.
This experimental study focused on the effects of a mirid bug herbivore, Capsodes infuscatus on the flower nectar yield of a Mediterranean geophyte, Asphodelus aestivus. The effects of increasing densities of adult C. infuscatus bugs on A. aestivus, on the nectar volume and concentration were examined. Significant decreases were found in the number of flowers and nectar
production as C. infuscatus densities increased. Analysis of covariance (ANCOVA) showed that nectar production was not affected by environmental variables
(air temperature, relative air humidity and day-time) that were treated as covariates for the various bug herbivory intensities.
Sugar concentration did not vary significantly among treatments, indicating that abiotic conditions were not responsible for
differing nectar amounts. In light of A. aestivus’s dependence on pollinator visits to produce seeds, we conclude that C. infuscatus could impair pollination success by reducing the amount of nectar in flowers. To the best of our knowledge, the present study
is the first to show that insect herbivores do not necessarily have to remove segments from the flower in order to decrease
nectar secretion. 相似文献
753.
754.
Noam Koren Khaled Zubeidat Yasmin Saba Yael Horev Or Barel Anneke Wilharm Oded Heyman Sharon Wald Luba Eli-berchoer Hagit Shapiro Chen Nadler Eran Elinav Asaf Wilensky Immo Prinz Hillel Bercovier Avi-Hai Hovav 《Cell host & microbe》2021,29(2):197-209.e5
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755.
756.
Inon Scharf Yael Lubin Ofer Ovadia 《Biological reviews of the Cambridge Philosophical Society》2011,86(3):626-639
Foraging theory was first developed to predict the behaviour of widely‐foraging animals that actively search for prey. Although the behaviour of sit‐and‐wait predators often follows predictions derived from foraging theory, the similarity between these two distinct groups of predators is not always obvious. In this review, we compare foraging activities of trap‐building predators (mainly pit‐building antlions and web‐building spiders), a specific group of sit‐and‐wait predators that construct traps as a foraging device, with those of widely‐foraging predators. We refer to modifications of the trap characteristics as analogous to changes in foraging intensity. Our review illustrates that the responses of trap‐building and widely‐foraging predators to different internal and external factors, such as hunger level, conspecific density and predation threat are quite similar, calling for additional studies of foraging theory using trap‐building predators. In each chapter of this review, we summarize the response of trap‐building predators to a different factor, while contrasting it with the equivalent response characterizing widely‐foraging predators. We provide here evidence that the behaviour of trap‐building predators is not stereotypic or fixed as was once commonly accepted, rather it can vary greatly, depending on the individual's internal state and its interactions with external environmental factors. 相似文献
757.
Annick Pierce-Cretel Morchedai Izhar Yael Nuchamowitz Gérard Strecker Jean Montreuil Geneviève Spik David Mirelman 《FEMS microbiology letters》1983,20(2):237-242
Abstract Guinea pig colonic epithelial cells release a soluble lectin capable of agglutinating numerous strains of Shigella and Escherichia coli as well as other bacteria. Using pure oligosaccharides and glycopeptides with well-defined structures to inhibit the agglutination of Shigella flexneri 1b by the soluble intestinal lectin, we have been able to demonstrate that the latter recognises different structural types. Inhibition by human milk glucoprotein glycopeptides with biantennary glycans of the N -acetyllactosamine type was dependent on the simultaneous presence of unsubstituted terminal non-reducing galactose residues and of a fucose residue α-1,6-linked to the asparagine-conjugated N -acetylglucosamine residue. Unsubstituted terminal non-reducing galactose was also determinant for inhibition by human milk oligosaccharides. Finally oligosaccharides possessing the Man (α1–2) Man structure inhibited more effectively than those with a Man(α1–3)Man sequence. The fact that these different structural motifs were all inhibitory raises the problem of the possible existence of a multispecific lectin or of several different lectins in the guinea pig colonic mucosa mediating bacterial adherence. 相似文献
758.
759.
Alona Kuzmina Yara Khalaila Olga Voloshin Ayelet Keren-Naus Liora Boehm-Cohen Yael Raviv Yonat Shemer-Avni Elli Rosenberg Ran Taube 《Cell host & microbe》2021,29(4):522-528.e2
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760.
Yael Minai-Fleminger Moran Elishmereni Francesca Vita Maria Rosa Soranzo David Mankuta Guliano Zabucchi Francesca Levi-Schaffer 《Cell and tissue research》2010,341(3):405-415
We have hypothesized that mast cells (MC) and eosinophils (Eos), the main effectors of allergy, can form an effector unit.
These cells co-exist in the inflamed tissues during the late and chronic stages of allergy and have been shown to be capable
of influencing each other's survival and activity via soluble mediators. We have recently described couples of receptor-ligands
that are expressed on either/both of these cells and that imply a physical interaction. In this study, we have investigated
the existence of short-term (60 min) in vitro interactions between human peripheral blood Eos and cord-blood-derived MC by
transmission electron microscopy. We have found that MC and Eos adhere to each other; the lipid body content and the granule
morphology of co-cultured MC and Eos, respectively, are altered, and the level of Eos peroxidase (EPO) released by co-cultured
Eos is elevated. Moreover, the transfer of EPO from Eos to MC and tryptase from MC to Eos has been observed. Our results thus
indicate that, when co-cultured, MC and Eos show signs of physical contact and of reciprocal activation. This is the first
in vitro evidence of functional physical interactions between human MC and Eos, interactions that might also occur in vivo
during allergic diseases. 相似文献