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891.
Nathan E Monovich A Tirosh-Finkel L Harrelson Z Rousso T Rinon A Harel I Evans SM Tzahor E 《Development (Cambridge, England)》2008,135(4):647-657
During embryogenesis, paraxial mesoderm cells contribute skeletal muscle progenitors, whereas cardiac progenitors originate in the lateral splanchnic mesoderm (SpM). Here we focus on a subset of the SpM that contributes to the anterior or secondary heart field (AHF/SHF), and lies adjacent to the cranial paraxial mesoderm (CPM), the precursors for the head musculature. Molecular analyses in chick embryos delineated the boundaries between the CPM, undifferentiated SpM progenitors of the AHF/SHF, and differentiating cardiac cells. We then revealed the regionalization of branchial arch mesoderm: CPM cells contribute to the proximal region of the myogenic core, which gives rise to the mandibular adductor muscle. SpM cells contribute to the myogenic cells in the distal region of the branchial arch that later form the intermandibular muscle. Gene expression analyses of these branchiomeric muscles in chick uncovered a distinct molecular signature for both CPM- and SpM-derived muscles. Islet1 (Isl1) is expressed in the SpM/AHF and branchial arch in both chick and mouse embryos. Lineage studies using Isl1-Cre mice revealed the significant contribution of Isl1(+) cells to ventral/distal branchiomeric (stylohyoid, mylohyoid and digastric) and laryngeal muscles. By contrast, the Isl1 lineage contributes to mastication muscles (masseter, pterygoid and temporalis) to a lesser extent, with virtually no contribution to intrinsic and extrinsic tongue muscles or extraocular muscles. In addition, in vivo activation of the Wnt/beta-catenin pathway in chick embryos resulted in marked inhibition of Isl1, whereas inhibition of this pathway increased Isl1 expression. Our findings demonstrate, for the first time, the contribution of Isl1(+) SpM cells to a subset of branchiomeric skeletal muscles. 相似文献
892.
Host responses influence on the induction of lambda prophage 总被引:1,自引:0,他引:1
Rokney A Kobiler O Amir A Court DL Stavans J Adhya S Oppenheim AB 《Molecular microbiology》2008,68(1):29-36
893.
Amir Neori 《Journal of applied phycology》2008,20(5):567-570
Ecologically friendly aquaculture crops, such as seaweeds, herbivores, omnivores, and detritivores can be cultured using relatively
less of our limited natural resources and produce relatively less pollution. They also top FAO’s estimates of aquaculture
crops for the 21st century. These crops already comprise nearly 90% of global aquaculture tonnage, >90% of all aquaculture
production in China and >60% of production even in North America. Consumers prefer them, most likely due to their low prices.
Production costs of organisms low on the food chain are low due to the ability of these organisms to efficiently utilize low-cost,
mostly plant-based diets and to recycle their own waste. Thus, ecologically friendly aquaculture is not a dream but a dominant
global reality. The less ecologically-friendly aquaculture of salmon, sea bream, fed shrimp, among others, has attracted public
opposition to aquaculture, but these crops totaled approximately only 10% of global production in 2004. The profitability
of industrialized monocultures of these crops is threatened further by rising costs of energy and feed, environmental regulation
compliance, disease, and public opposition. Current monoculture practices and perceptions intrinsic to the aquaculture industry
can be turned around into a vision of sustained profitable expansion of carnivores production with trophically lower organisms
in ecologically-balanced aquaculture farms. This category of aquaculture, which is the modern intensive form of polyculture
practiced in Asia, feeds the waste of carnivore culture to lower trophic level organisms, primarily algae and mollusks. Species
are selected based on their ecological functions in addition to their economic potential. Ecologically-balanced farms turn
the costly treatment of carnivore waste outside the farm to a revenue-generating process of biofiltration, conversion, and
resource recovery into plant and mollusk crops inside the farm. In doing so, they solve several of the major problems faced
by modern aquaculture. The aquaculture industry can protect its own interests – and reap major benefits – by understanding
the importance of ecological balance, the potential of seaweeds as components in feeds, and the importance of the culture
and R&D of low trophic level organisms. The industry should also accept the relevance of environmental, social, and image
aspects of aquaculture to its success. Governments have the tools to reward multi-trophic farms with seaweeds by means of
tax credits and nutrient credits and to penalize unbalanced monoculture approaches by means of ‘polluter pays’ fines, thereby
providing the multi-trophic farms with a significant economic advantage. Such measures have been discussed, but their implementation
has been slow. 相似文献
894.
Prasanth Rayorath Mundaya N. Jithesh Amir Farid Wajahatullah Khan Ravishankar Palanisamy Simon D Hankins Alan T Critchley Balakrishnan Prithiviraj 《Journal of applied phycology》2008,20(4):423-429
Ascophyllum nodosum extract products are used commercially in the form of liquid concentrate and soluble powder. These formulations are manufactured
from seaweeds that are harvested from natural habitats with inherent environmental variability. The seaweeds by themselves
are at different stages of their development life-cycle. Owing to these differences, there could be variability in chemical
composition that could in turn affect product consistency and performance. Here, we have tested the applicability of using
Arabidopsis thaliana as a model to study the activity of two different extracts from A. nodosum. Three different bioassays: Arabidopsis root-tip elongation bioassay, Arabidopsis liquid growth bioassay and greenhouse growth bioassay were evaluated as growth assays. Our results indicate that both extracts
promoted root and shoot growth in comparison to controls. Further, using Arabidopsis plants with a DR5:GUS reporter gene construct, we provide evidence that components of the commercial A. nodosum extracts modulates the concentration and localisation of auxins which could account, at least in part, for the enhanced plant
growth. The results suggest that A. thaliana could be used effectively as a rapid means to test the bioactivity of seaweed extracts and fractions. 相似文献
895.
The influence of Ni on arbuscular mycorrhizal fungi (AMF) has not been studied yet. We tested the tolerance to Ni of five
AMF isolates from New Caledonian ultramafic soils. Spore germination indicated that these isolates were clearly more tolerant
to Ni than three other isolates from non-ultramafic soils. They were able to germinate at 30 μg g−1 Ni, whereas spores of the non-ultramafic isolates were totally inhibited at 15 μg g−1 Ni. Among the ultramafic isolates, two were obtained from roots of Ni-hyperaccumulating plants. Their tolerance to Ni was
clearly higher than all the other isolates. The proportion of germinated spores of the different isolates in contact with
ultramafic soils showed the same tendencies as those observed with Ni solutions. Tolerance to Ni increased when spores were
produced from mycorrhiza on plants grown on sand containing 20 μg g−1 Ni, in comparison with those produced on sand without Ni. These results indicate that the tolerance to Ni of AMF spores can
be induced by the presence of this metal in the substrate.
相似文献
Hamid AmirEmail: |
896.
A two‐channel flow‐injection (FI) method is reported for the determination of iodide and iodine by its enhancement effect on the Ru(bpy)33+–NADH chemiluminescence (CL) system. The limit of detection (3 s of blank) was 1.0 × 10–9 mol/L iodide/iodine, with a sample throughput of 60/h. The calibration graphs over the range 1.0–50 × 10–8 mol/L gave correlation coefficients of 0.9994 and 0.999 (n = 5) with relative standard deviations (RSD; n = 4) of 1.0–2.5%, respectively. The effects of interfering cations, anions and some organic compounds were also studied. The method was applied to iodized salts and pharmaceutical samples and the results obtained were in good agreement with the value quoted. The CL method developed was compared with spectrophotometric method. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
897.
Membrane fusion is a fundamental requirement in numerous developmental, physiological, and pathological processes in eukaryotes. So far, only a limited number of viral and cellular fusogens, proteins that fuse membranes, have been isolated and characterized. Despite the diversity in structures and functions of known fusogens, some common principles of action apply to all fusion reactions. These can serve as guidelines in the search for new fusogens, and may allow the formulation of a cross-species, unified theory to explain divergent and convergent evolutionary principles of membrane fusion. 相似文献
898.
Pooria Gill Mostafa Ghalami Amir Ghaemi Nader Mosavari Hossein Abdul-Tehrani Majid Sadeghizadeh 《NanoBioTechnology》2008,4(1-4):28-35
A nanodiagnostic method using nucleic acid sequence-based amplification (NASBA) and gold nanoparticle probes (AuNP probes) was developed for colorimetric detection of Mycobacterium tuberculosis. The primers targeting 16S rRNA were used for the amplification of mycobacterial RNA by the isothermal NASBA process. The amplicons were hybridized with specific gold nanoparticle probes. The RNA–DNA hybrids were colorimetrically detected by the accumulation of gold nanoparticles. Using this method, 10 CFU ml?1 of M. tuberculosis was detected within less than 1 h. Results obtained from the clinical specimens showed 94.7% and 96% sensitivity and specificity, respectively. No interference was encountered in the amplification and detection of M. tuberculosis in the presence of non-target bacteria, confirming the specificity of the method. 相似文献
899.
Nabil A. Yassin Samar A. Muwakkit Ahmad O. Ibrahim Imad M. Kayim Mohammad-Zohair M. Habbal Nabil M. Chamseddine Khaled M. Musallam Ali I. Shamseddine 《Journal of applied genetics》2008,49(4):421-424
Gaucher disease (GD) is an autosomal recessive inborn error of metabolism, resulting from a deficiency of the enzyme glucocerebrosidase,
causing an accumulation of the glycolipid glucocerebroside within lysosomes of macrophages in the reticuloendothelial system.
Three major clinical forms have been assigned and more than 200 gene mutations have been identified. We herein report a Lebanese
boy born with a novel combined mutation L371V/Rec-NciI, who presented with moderate-severe type 1 GD. An overview of the clinical
and biomarker improvement following enzyme replacement therapy with imiglucerase is described in a follow-up of 30 months.
Imiglucerase seems to be efficacious in decreasing the severity of the disease associated with this mutation. However, a high
dose may be required to achieve optimal growth, platelet count, and hemoglobin level. 相似文献
900.
Adrenocorticotropic hormone and cortisol plasma levels directly correlate with childhood neglect and depression measures in addicted patients. 总被引:1,自引:0,他引:1
Gilberto Gerra Claudio Leonardi Elena Cortese Amir Zaimovic Grazia Dell'Agnello Matteo Manfredini Lorenzo Somaini Francesca Petracca Vincenzo Caretti Cristina Baroni Claudio Donnini 《Addiction biology》2008,13(1):95-104
Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has been reported to be involved in vulnerability to alcohol and drug dependence in humans, possibly underlying both addictive behaviour and depression susceptibility. The aim of the present study was to investigate the possible interactions between childhood adverse experiences, depressive symptoms and HPA axis function in addicted patients, in comparison with healthy control. Eighty-two abstinent heroin or cocaine dependent patients and 44 normal controls, matched for age and sex, completed the symptoms Check List-90 (SCL-90), measuring depressive symptoms, and the Childhood Experience of Care and Abuse Questionnaire. Blood samples were collected to determine adrenocorticotropic hormone (ACTH) and cortisol basal plasma levels at 8:00 and 8:30 a.m. Addicted individuals showed significantly higher neglect and depression scores and ACTH-cortisol plasma levels respect to control subjects. Depression scores at SCL-90 in addicted patients positively correlated with plasma ACTH and cortisol values. In turn, plasma ACTH levels were directly associated with childhood neglect measures, reaching statistical significance with 'mother-neglect' scores. Plasma cortisol levels were related to 'father antipathy' among cocaine addicts. These findings suggest the possibility that childhood experience of neglect and poor parent-child attachment may have a persistent effect on HPA axis function as an adult, partially contributing, together with genetic factors and other environmental conditions, to both depressive traits and substance abuse neurobiological vulnerability. 相似文献