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961.
Ahmed S Abdel-Moneim Ahmad E Abdel-Ghany Salama AS Shany 《Journal of biomedical science》2010,17(1):25
Background
The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. 相似文献962.
Michel Besserve Bernhard Schölkopf Nikos K. Logothetis Stefano Panzeri 《Journal of computational neuroscience》2010,29(3):547-566
Characterizing how different cortical rhythms interact and how their interaction changes with sensory stimulation is important
to gather insights into how these rhythms are generated and what sensory function they may play. Concepts from information
theory, such as Transfer Entropy (TE), offer principled ways to quantify the amount of causation between different frequency
bands of the signal recorded from extracellular electrodes; yet these techniques are hard to apply to real data. To address
the above issues, in this study we develop a method to compute fast and reliably the amount of TE from experimental time series
of extracellular potentials. The method consisted in adapting efficiently the calculation of TE to analog signals and in providing
appropriate sampling bias corrections. We then used this method to quantify the strength and significance of causal interaction
between frequency bands of field potentials and spikes recorded from primary visual cortex of anaesthetized macaques, both
during spontaneous activity and during binocular presentation of naturalistic color movies. Causal interactions between different
frequency bands were prominent when considering the signals at a fine (ms) temporal resolution, and happened with a very short
(ms-scale) delay. The interactions were much less prominent and significant at coarser temporal resolutions. At high temporal
resolution, we found strong bidirectional causal interactions between gamma-band (40–100 Hz) and slower field potentials when
considering signals recorded within a distance of 2 mm. The interactions involving gamma bands signals were stronger during
movie presentation than in absence of stimuli, suggesting a strong role of the gamma cycle in processing naturalistic stimuli.
Moreover, the phase of gamma oscillations was playing a stronger role than their amplitude in increasing causations with slower
field potentials and spikes during stimulation. The dominant direction of causality was mainly found in the direction from
MUA or gamma frequency band signals to lower frequency signals, suggesting that hierarchical correlations between lower and
higher frequency cortical rhythms are originated by the faster rhythms. 相似文献
963.
964.
Ana Carolina Cuzzuol Fracalossi Sandra Regina Miranda Celina Tijuko Fujiyama Oshima Marcello Franco Daniel Araki Ribeiro 《Journal of molecular histology》2010,41(1):19-25
Matrix metalloproteinases (MMPs) are implicated in a wide range of physiological and pathological processes, including morphogenesis,
wound healing, angiogenesis, inflammation, and cancer. The purpose of this study was to characterize the role of MMPs as depicted
by the expression of MMP-2 and MMP-9 during 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis. Male Wistar rats were
distributed into three groups of 10 animals each and treated with 4-nitroquinoline 1-oxide solution at 50 ppm through their
drinking water for 4, 12, and 20 weeks. Ten animals were used as control group. No histopathological abnormalities were induced
in the epithelium after 4 weeks of carcinogen exposure; however, immunoexpression of MMP-2 was noticed. The same picture occurred
to MMP-9, in which positive expression was detected for this immunomarker. MMP-2 and MMP-9 showed positive expression either
in pre-neoplastic lesions at 12 weeks following carcinogen exposure or in well-differentiated squamous cell carcinoma induced
after 20 weeks of treatment with 4NQO. Taken together, our results support the belief that MMP-2 and MMP-9 play important
role during malignant transformation and conversion of oral mucosa as assessed by immunohistochemistry. 相似文献
965.
Background
NOL7 is a candidate tumor suppressor that localizes to a chromosomal region 6p23. This locus is frequently lost in a number of malignancies, and consistent loss of NOL7 through loss of heterozygosity and decreased mRNA and protein expression has been observed in tumors and cell lines. Reintroduction of NOL7 into cells resulted in significant suppression of in vivo tumor growth and modulation of the angiogenic phenotype. Further, NOL7 was observed to localize to the nucleus and nucleolus of cells. However, the mechanisms regulating its subcellular localization have not been elucidated. 相似文献966.
Jean-Charles Gabillard Cécile Rallière Nathalie Sabin Pierre-Yves Rescan 《BMC biotechnology》2010,10(1):39
Background
Fish skeletal muscle growth involves the activation of a resident myogenic stem cell population, referred to as satellite cells, that can fuse with pre-existing muscle fibers or among themselves to generate a new fiber. In order to monitor the regulation of myogenic cell differentiation and fusion by various extrinsic factors, we generated transgenic trout (Oncorhynchus mykiss) carrying a construct containing the green fluorescent protein reporter gene driven by a fast myosin light chain 2 (MlC2f) promoter, and cultivated genetically modified myogenic cells derived from these fish. 相似文献967.
Raffaele Lombardi Maria Elena Villani Mariasole Di Carli Patrizia Brunetti Eugenio Benvenuto Marcello Donini 《Transgenic research》2010,19(6):1083-1097
It was previously demonstrated that the tumour-targeting antibody mAb H10 can be transiently expressed and purified at high
levels in Nicotiana benthamiana by using a vacuum-agroinfiltration system boosted by the use of a virus silencing suppressor protein. Scope of this work
was to analyse different steps of protein extraction from agroinfiltrated leaves to optimise the purification process of the
secretory mAb H10 providing new insights in the field of large-scale plant production. Two different extraction procedures
(mechanical shearing/homogenisation and recovery of intercellular fluids -IFs-) were evaluated and compared in terms of purified
antibody yields, antibody degradation and total phenolic compounds content. Mechanical grinding from fresh leaf tissues gave
the highest purification yield (75 mg/kg Fresh Weight -75% intact tetrameric IgG-) and total phenolics concentration in the
range of 420 μg/g FW. The second extraction procedure, based on the recovery of IFs, gave purification yields of 15–20 mg/kg
FW (corresponding to 27% of total soluble protein) in which about 40% of purified protein is constituted by fully assembled
IgG with a total phenolic compounds content reduced by one order of magnitude (21 μg/g FW). Despite a higher antibody degradation,
purification from intercellular fluids demonstrated to be very promising since extraction procedures resulted extremely fast
and amenable to scaling-up. Overall data highlight that different extraction procedures can dramatically affect the proteolytic
degradation and quality of antibody purified from agroinfiltrated N. benthamiana leaves. Based on these results, we optimised a pilot-scale purification protocol using a two-step purification procedure
from batches of fresh agroinfiltrated leaves (250 g) allowing purification of milligram quantities (average yield 40 mg/kg
FW) of fully assembled and functional IgG with a 99.4% purity, free of phenolic and alkaloid compounds with low endotoxin
levels (<1 EU/ml). 相似文献
968.
Ju-Hong Zhang Li-Wen Sun Lin-Lin Liu Jie Lian Shao-Li An Xu Wang Jing Zhang Jun-Ling Jin Shan-Yu Li Jing-Hui Xi 《Plant Molecular Biology Reporter》2010,28(2):324-333
In this study, comparative proteomics was used to investigate the interaction of Spodoptera exigua and Arabidopsis thaliana. By using 2-D electrophoresis of differentially expressed proteins, combined with high-throughput matrix-assisted laser desorption/ionization
time of flight mass spectrometry (MALDI-TOF MS) and MALDI-TOF/TOF MS, the changes in the abundance of proteins induced by
insect feeding were studied in A. thaliana. More than 1,100 protein spots were reproducibly detected on each gel. The intensities of 30 protein spots in particular
changed significantly, showing differences in volume of at least twofold. Among these, 17 protein spots were upregulated,
and 13 were downregulated following an 8-h insect feeding period. Nineteen insect-feeding-responsive proteins were identified,
all of which were involved in metabolic regulation, binding functions or cofactor requirement of protein, cell rescue, and
defense and virulence, as assessed by Munich Information Center for Protein Sequences function category. About 50% of these
were involved in metabolism, including transketolase, S-adenosylmethionine synthase 3, 2,3-biphosphoglycerate-independent phosphoglycerate mutase, beta-ureidopropionase, GDP-d-mannose 3′,5′-epimerase, and fatty acid synthase. The identification of insect-feeding-responsive proteins on Arabidopsis provides not only new insights into insect stress but also a good start for further investigation of their functions. Understanding
how the plant responses to insects in the proteomic level will provide tools for a better management of insect pest in the
field. 相似文献
969.
Wei Fan Stefan A. W. Bouwense Ross Crawford Yin Xiao 《Journal of molecular histology》2010,41(1):51-60
Despite the important physiological role of periosteum in the pathogenesis and treatment of osteoporosis, little is known
about the structural and cellular characteristics of periosteum in osteoporosis. To study the structural and cellular differences
in both diaphyseal and metaphyseal periosteum of osteoporotic rats, samples from the right femur of osteoporotic and normal
female Lewis rats were collected and tissue sections were stained with hematoxylin and eosin, antibodies or staining kit against
tartrate resistant acid phosphatase (TRAP), alkaline phosphatase (ALP), vascular endothelial growth factor (VEGF), von Willebrand
(vWF), tyrosine hydroxylase (TH) and calcitonin gene-related peptide (CGRP). The results showed that the osteoporotic rats
had much thicker and more cellular cambial layer of metaphyseal periosteum compared with other periosteal areas and normal
rats (P < 0.001). The number of TRAP+ osteoclasts in bone resorption pits, VEGF+ cells and the degree of vascularization were found to be greater in the cambial layer of metaphyseal periosteum of osteoporotic
rats (P < 0.05), while no significant difference was detected in the number of ALP+ cells between the two groups. Sympathetic nerve fibers identified by TH staining were predominantly located in the cambial
layer of metaphyseal periosteum of osteoporotic rats. No obvious difference in the expression of CGRP between the two groups
was found. In conclusion, periosteum may play an important role in the cortical bone resorption in osteoporotic rats and this
pathological process may be regulated by the sympathetic nervous system. 相似文献
970.
Annexins belong to a multigene family of Ca2+ dependent, phospholipid and cytoskeleton binding proteins. They have been shown to be upregulated under various stress conditions.
We generated transgenic cotton plants expressing mustard annexin (AnnBj1), which showed enhanced tolerance towards different abiotic stress treatments like sodium chloride, mannitol, polyethylene
glycol and hydrogen peroxide. The tolerance to these treatments was associated with decreased hydrogen peroxide levels and
enhanced total peroxidase activity, enhanced content of osmoprotectants- proline and sucrose in transgenic plants. They showed
higher retention of total chlorophyll and reduced TBARS in leaf disc assays with stress treatments, and decreased hydrogen
peroxide accumulation in the stomatal guard cells when compared to their wild type counterparts. They also showed significantly
enhanced fresh weight, relative water content, dry weight under stress. Treatment with sodium chloride resulted in enhanced
expression of genes for ∆-pyrroline-5-carboxylase synthetase in leaves, and sucrose phosphate synthase, sucrose synthase and
cellulose synthase A in the leaves and fibers of transgenic plants. The transgenic plants maintained normal seed development,
fiber quality and cellulose content under stress. 相似文献