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Find video protocols related to scientific articles indexed in Pubmed.
Both endo-siRNAs and tRNA-derived small RNAs are involved in the differentiation of primitive eukaryote Giardia lamblia.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 09-15-2014
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Small RNAs (sRNAs), including microRNAs and endogenous siRNAs (endo-siRNAs), regulate most important biologic processes in eukaryotes, such as cell division and differentiation. Although sRNAs have been extensively studied in various eukaryotes, the role of sRNAs in the early emergence of eukaryotes is unclear. To address these questions, we deep sequenced the sRNA transcriptome of four different stages in the differentiation of Giardia lamblia, one of the most primitive eukaryotes. We identified a large number of endo-siRNAs in this fascinating parasitic protozoan and found that they were produced from live telomeric retrotransposons and three genomic regions (i.e., endo-siRNA generating regions [eSGRs]). eSGR-derived endo-siRNAs were proven to target mRNAs in trans. Gradual up-regulation of endo-siRNAs in the differentiation of Giardia suggested that they might be involved in the regulation of this process. This hypothesis was supported by the impairment of the differentiation ability of Giardia when GLDICER, essential for the biogenesis of endo-siRNAs, was knocked down. Endo-siRNAs are not the only sRNA regulators in Giardia differentiation, because a great number of tRNAs-derived sRNAs showed more dramatic expression changes than endo-siRNAs in this process. We totally identified five novel kinds of tRNAs-derived sRNAs and found that the biogenesis in four of them might be correlated with that of stress-induced tRNA-derived RNA (sitRNA), which was discovered in our previous studies. Our studies reveal an unexpected complex panorama of sRNA in G. lamblia and shed light on the origin and functional evolution of eukaryotic sRNAs.
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Characterizing heat-sensitization responses in suspended moxibustion with high-density EEG.
Pain Med
PUBLISHED: 08-19-2014
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We have reported "heat-sensitization" responses during suspended moxibustion, whose occurrence is associated with significantly better therapeutic effects. The present study aimed to characterize the electrophysiological features of this interesting phenomenon with high-density electroencephalography (EEG).
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Parthenolide-induced apoptosis, autophagy and suppression of proliferation in HepG2 cells.
Asian Pac. J. Cancer Prev.
PUBLISHED: 07-08-2014
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To investigate the anticancer effects and underlying mechanisms of parthenolide on HepG2 human hepatocellular carcinoma cells.
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[The interference effect of lentiviral mediated shRNA on the expression of Pin 1 in A549 cells].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 03-11-2014
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To construct a Pin1shRNA lentiviral vector and transfect stably A549 cells.
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Pollen sensitivity to ultraviolet-B (UV-B) suggests floral structure evolution in alpine plants.
Sci Rep
PUBLISHED: 03-06-2014
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Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Floral forms were categorized as either protecting or exposing pollen grains to UV-B. The floral materials of plants with exposed and protected pollen grains were able to block UV-B at similar levels. Exposure to UV-B radiation in vitro resulted in a significantly greater loss of viability in pollen from plant species with protective floral structures. The pronounced sensitivity of protected pollen to UV-B radiation was associated with the type of flower structure. These findings demonstrate that UV-B plays an important role in the evolution of protective floral forms in alpine plants.
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Depletion of canonical Wnt signaling components has a neuroprotective effect on midbrain dopaminergic neurons in an MPTP-induced mouse model of Parkinson's disease.
Exp Ther Med
PUBLISHED: 03-04-2014
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The canonical Wnt signaling pathway is critical for the development of midbrain dopaminergic (DA) neurons, and recent studies have suggested that disruption of this signaling cascade may underlie the pathogenesis of Parkinson's disease (PD). However, the exact role of the canonical Wnt signaling pathway, including low-density lipoprotein receptor-related protein 5 and 6 (LRP5/6) and ?-catenin components, in a mouse model of PD remains unclear. In the present study, the tyrosine hydroxylase (TH)-Cre transgenic mouse line was used to generate mice with the specific knockout of LRP5, LRP6 or ?-catenin in DA neurons. Following inactivation of LRP5, LRP6 or ?-catenin, TH-immunohistochemical staining was performed. The results indicated that ?-catenin is required for the development or maintenance of these neurons; however, LRP5 and LRP6 were found to be dispensable. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, the depletion of LRP5, LRP6 or ?-catenin was found to be protective for the midbrain DA neurons to a certain extent. These in vivo results provide a novel perspective for the function of the canonical Wnt signaling pathway in a mouse model of PD.
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MiR397b regulates both lignin content and seed number in Arabidopsis via modulating a laccase involved in lignin biosynthesis.
Plant Biotechnol. J.
PUBLISHED: 02-18-2014
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Plant laccase (LAC) enzymes belong to the blue copper oxidase family and polymerize monolignols into lignin. Recent studies have established the involvement of microRNAs in this process; however, physiological functions and regulation of plant laccases remain poorly understood. Here, we show that a laccase gene, LAC4, regulated by a microRNA, miR397b, controls both lignin biosynthesis and seed yield in Arabidopsis. In transgenic plants, overexpression of miR397b (OXmiR397b) reduced lignin deposition. The secondary wall thickness of vessels and the fibres was reduced in the OXmiR397b line, and both syringyl and guaiacyl subunits are decreased, leading to weakening of vascular tissues. In contrast, overexpression of miR397b-resistant laccase mRNA results in an opposite phenotype. Plants overexpressing miR397b develop more than two inflorescence shoots and have an increased silique number and silique length, resulting in higher seed numbers. In addition, enlarged seeds and more seeds are formed in these miR397b overexpression plants. The study suggests that miR397-mediated development via regulating laccase genes might be a common mechanism in flowering plants and that the modulation of laccase by miR397 may be potential for engineering plant biomass production with less lignin.
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Two hydroxypyruvate reductases encoded by OsHPR1 and OsHPR2 are involved in photorespiratory metabolism in rice.
J Integr Plant Biol
PUBLISHED: 01-08-2014
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Mutations in the photorespiration pathway display a lethal phenotype in atmospheric air, which can be fully recovered by elevated CO2 . An exception is that mutants of peroxisomal hydroxypyruvate reductase (HPR1) do not have this phenotype, indicating the presence of cytosolic bypass in the photorespiration pathway. In this study, we constructed overexpression of the OsHPR1 gene and RNA interference plants of OsHPR1 and OsHPR2 genes in rice (Oryza sativa L. cv. Zhonghua 11). Results from reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and enzyme assays showed that HPR1 activity changed significantly in corresponding transgenic lines without any effect on HPR2 activity, which is the same for HPR2. However, metabolite analysis and the serine glyoxylate aminotransferase (SGAT) activity assay showed that the metabolite flux of photorespiration was disturbed in RNAi lines of both HPR genes. Furthermore, HPR1 and HPR2 proteins were located to the peroxisome and cytosol, respectively, by transient expression experiment. Double mutant hpr1?×?hpr2 was generated by crossing individual mutant of hpr1 and hpr2. The phenotypes of all transgenic lines were determined in ambient air and CO2 -elevated air. The phenotype typical of photorespiration mutants was observed only where activity of both HPR1 and HPR2 were downregulated in the same line. These findings demonstrate that two hydroxypyruvate reductases encoded by OsHPR1 and OsHPR2 are involved in photorespiratory metabolism in rice.
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Genome-wide transcriptional analysis of two soybean genotypes under dehydration and rehydration conditions.
BMC Genomics
PUBLISHED: 09-25-2013
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Soybean is an important crop that provides valuable proteins and oils for human use. Because soybean growth and development is extremely sensitive to water deficit, quality and crop yields are severely impacted by drought stress. In the face of limited water resources, drought-responsive genes are therefore of interest. Identification and analysis of dehydration- and rehydration-inducible differentially expressed genes (DEGs) would not only aid elucidation of molecular mechanisms of stress response, but also enable improvement of crop stress tolerance via gene transfer. Using Digital Gene Expression Tag profiling (DGE), a new technique based on Illumina sequencing, we analyzed expression profiles between two soybean genotypes to identify drought-responsive genes.
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Depression status and associated factors in chinese occupational truck drivers.
Cell Biochem. Biophys.
PUBLISHED: 05-29-2013
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The aim of this study was to assess the depression status and associated factors in occupational truck drivers. Four hundred and forty-one male occupational truck drivers were recruited from transport companies. The self-rating depression scale (SDS) and Eysenck Personality Questionnaire-R Short Scale were used to measure the depression status and factors associated with it for occupational truck drivers. The observed SDS of (mean ± SD) 52.91 ± 11.41 was significantly higher than the average national score (41.99 ± 10.57). There were 237 cases of depression, making the incidence of 53.74 %: 116 (26.30 %) patients had mild depression, 104 (23.58 %) moderate depression, and 17 (3.85 %) severe depression. Drivers with <1 year of experience had the highest SDS score; their score was significantly (p < 0.05) different from the one in more experienced drivers. Furthermore, the SDS score in drivers with high school education was significantly higher than in drivers with secondary education (53.41 ± 11.67 vs. 50.62 ± 11.77, respectively; p < 0.05). SDS scores positively correlated with extroversion and neuroticism, and negatively correlated with psychoticism. In conclusion, depression is present in professional drivers, especially those with <1 year of driving experience. The level of depression is associated with driving experience, education status and personality. Based on this study, we propose to establish psychological health profiles for each professional driver, and to provide psychological counseling to them, especially drivers with <1 year of experience.
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Preparation and characterization of novel microparticles based on poly(3-hydroxybutyrate-co-3-hydroxyoctanoate).
J Microencapsul
PUBLISHED: 05-23-2013
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Abstract In this study, a novel poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (P(HB-HO)) microparticle with an encapsulated antibiotic (azithromycin, AZI) was prepared by the electrospinning method. The resulting microparticles were evaluated for surface morphology, particle size, drug loading, encapsulation efficiency, in vitro drug-release and degradation. The in vitro cytotoxicity and in vivo pharmacokinetics were also studied. The sizes of microparticles showed a narrow monodisperse size distribution approximately from 3 to 30?µm. In vitro release experiments exhibited sustained release behavior. The results of in vitro degradation tests demonstrated that the mass loss of the P(HB-HO) microparticles was 9.6% and the morphology varied greatly within 24 weeks. P(HB-HO) showed no cytotoxicity to fibroblast when incubated with blank P(HB-HO) microparticles during the tests. The in vivo pharmacokinetic study demonstrated that the microparticles exhibited longer circulation properties than free AZI. It is suggested that novel AZI-loaded P(HB-HO) microparticles can be utilized as a biodegradable and biocompatible drug delivery system.
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Long noncoding RNAs: new regulators in plant development.
Biochem. Biophys. Res. Commun.
PUBLISHED: 05-16-2013
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Plant long noncoding RNAs (lncRNAs) play important roles in a wide range of biological processes, especially in plant reproductive development and response to stresses. They are transcribed by RNA polymerase II (Pol II), Pol III and Pol V, and exert their functions by a variety of regulation pathways. In this review, we summarized the current knowledge of lncRNAs discoveries in plant, including their identification, functions and regulation pathways as well as production and mediators, with an emphasizing on the novel regulation mechanisms in plant development.
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Comparison of electroacupuncture in restrained and unrestrained rat models.
Evid Based Complement Alternat Med
PUBLISHED: 04-10-2013
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Acupuncture and electroacupuncture (EA) are widely used to treat a variety of diseases including pain. In preclinical research, EA is usually applied by inserting acupuncture needles into the hindlimbs of rats restrained in small tubes or bags. This restrained model of EA not only causes stress-like behaviors but also is limited in stimulating locations and intensities. In 2004, a novel, unrestrained model of EA was introduced. However, these two EA methods have never been directly compared regarding their analgesic effects and other features such as stress. In the present study, we reported similar analgesic effects between restrained and unrestrained EA in rats of acute inflammatory pain induced by intraplantar injection of CFA. In addition, rats receiving unrestrained EA showed less significant stress-like behaviors and tolerated higher current intensity. These advantages suggest that this unrestrained EA method can replace the traditional restrained procedure with similar analgesic effects and allow for more choices of stimulating intensities and locations.
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[Frequencies of 9 bp deletion of mitochondrial DNA in ethnic Miao, Buyi and Dong from Guizhou].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 04-10-2013
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To study the frequency of a 9 bp deletion polymorphism of mitochondrial DNA (mtDNA) in ethnic Miao, Buyi and Dong populations from Guizhou province.
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Overexpression of microRNA OsmiR397 improves rice yield by increasing grain size and promoting panicle branching.
Nat. Biotechnol.
PUBLISHED: 04-04-2013
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Increasing grain yields is a major focus of crop breeders around the world. Here we report that overexpression of the rice microRNA (miRNA) OsmiR397, which is naturally highly expressed in young panicles and grains, enlarges grain size and promotes panicle branching, leading to an increase in overall grain yield of up to 25% in a field trial. To our knowledge, no previous report has shown a positive regulatory role of miRNA in the control of plant seed size and grain yield. We determined that OsmiR397 increases grain yield by downregulating its target, OsLAC, whose product is a laccase-like protein that we found to be involved in the sensitivity of plants to brassinosteroids. As miR397 is highly conserved across different species, our results suggest that manipulating miR397 may be useful for increasing grain yield not only in rice but also in other cereal crops.
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Plasma mercury levels in Hong Kong residents: in relation to fish consumption.
Sci. Total Environ.
PUBLISHED: 03-12-2013
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Mercury exposure is of particular concern since mercury is a neurotoxin and the developing fetus is most sensitive to its adverse effect. Human blood is routinely used as an indicator for the evaluation of human exposure to Hg. To investigate Hg species in human plasma for Hong Kong residents and the relationship between fish consumption and Hg species in plasma, 151 plasma samples were analyzed for Hg species. The mean values of total Hg (THg) and methyl-mercury (MeHg) concentration in plasma were 0.62 and 0.28 ?g/L, respectively. No significant differences were observed between females and males as well as among age groups. Fish consumption rate was significantly positively correlated with MeHg concentrations in plasma, which demonstrated that plasma could be a biomarker for human MeHg exposure. Two methods were used to estimate human MeHg exposure. One was based on fish MeHg content and fish consumption rate (EDI(Fish)), another was employed by converting MeHg concentration in blood to MeHg exposure amount (EDI(Blood)). A significant positive correlation was observed between EDI(Blood) and EDI(Fish), and no significant difference was found between EDI(Blood) and EDI(Fish). These results demonstrated that fish consumption was the major source of MeHg for humans.
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[A study of interleukin-10 gene polymorphisms in Miao, Dong and Buyi ethnics of Guizhou].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 03-02-2013
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To investigate allelic frequencies of interluekin-10 (IL-10) gene promoter in Miao, Dong and Buyi ethnics of Guizhou.
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Identification of three genes encoding for the late acyltransferases of lipid A in Cronobacter sakazakii.
Mar Drugs
PUBLISHED: 01-06-2013
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Lipid A, the hydrophobic anchor of lipopolysaccharide, is an essential component in the outer membrane of most Gram-negative bacteria. Food-borne pathogen Cronobacter sakazakii synthesizes two lipid A species, differing by the length of the secondary acyl chain. In this work, we identified three genes ESA02293, ESA02951 and ESA01386 encoding for the late acyltransferases of lipid A biosynthesis pathway in C. sakazakii. Based on the sequence alignment, proteins YP_001438378.1 encoded by ESA02293, YP_001439016.1 encoded by ESA02951, and YP_001437482.1 encoded by ESA01386 are homologous to E. coli LpxL, LpxP and LpxM, respectively. Functions of the three acyltransferases were confirmed by overexpressing the genes in E. coli, isolating lipid As and analyzing their structures using an ESI/MS. C. sakazakii LpxL and LpxM transfer a C14:0 secondary acyl chain to the 2- and 3-position of lipid A, respectively. C. sakazakii LpxP can transfer either a C16:1 or a C14:0 secondary acyl chains to the 2-position of lipid A.
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Self-repair of rat cortical bone microdamage after fatigue loading in vivo.
Int J Endocrinol
PUBLISHED: 01-03-2013
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Bone microdamage can be repaired through bone remodeling induced by loading. In this study, a loading device was developed for improved efficiency and the self-repair process of bone microdamage was studied in ovariectomized rats. First, four-point bending fixtures capable of holding two live rats simultaneously were designed. Rats were loaded and subjected to a sinusoidal wave for 10,000 cycles. They were then divided into four groups to evaluate time points from 1 to 4 weeks in the microdamage repair process. The loaded right ulna was used for microdamage parameter analysis, and the loaded right radius was tested for mechanical properties. In all groups, microdamage consisted primarily of microcracks, which were observed in bone surrounding the force-bearing point. The values of the microdamage parameters were significantly lower at 3 weeks than at 2 weeks. However, none of the differences in mechanical properties between any four groups were statistically significant. This study shows that the improved application of loading in the form of bending for double-rat simultaneous administration was practical and efficient. These results suggest that microdamage was repaired between 2 weeks to 3 weeks after fatigue damage and microdamage is a more sensitive index of bone quality than mechanical properties.
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Amide- and urea-functionalized dithienylethene: synthesis, photochromism, and binding with halide anions.
Org. Lett.
PUBLISHED: 10-25-2011
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A versatile amide- and urea-functionalized dithienylethene has been successfully synthesized. Upon irradiation with UV or visible light, the compound showed excellent fatigue resistance. As a synthetic receptor, the dithienylethene displayed switchable affinities for Cl(-) and Br(-) anions when the UV/vis light was introduced. The switchable binding ability also had good reversibility.
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Plasma concentrations of interleukin-6, C-reactive protein, tumor necrosis factor-? and matrix metalloproteinase-9 in aortic dissection.
Clin. Chim. Acta
PUBLISHED: 06-09-2011
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The role of inflammation in aortic dissection (AD) has not fully been investigated. We evaluated the potential relationships between interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-? (TNF-?), and matrix metalloproteinase-9 (MMP-9) and AD.
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Selective seed abortion induced by nectar robbing in the selfing plant Comastoma pulmonarium.
New Phytol.
PUBLISHED: 06-08-2011
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• Self-pollination often provides plants with the benefit of reproductive assurance; thus, it is generally assumed that species interactions that alter floral attractiveness or rewards, such as nectar robbing, will have little effect on the seed production of selfing species. We challenge this view with experimental data from Comastoma pulmonarium, a selfing annual experiencing a high ratio of nectar robbing in the Qinghai-Tibet Plateau. • We manipulated robbing (robbed or netted) and pollination mode (hand-selfed or hand-outcrossed) in a factorial design and measured the number of developing ovules and mature seeds, together with seed weight and seed germination, in each treatment. • Robbing decreased the number of mature seeds, but not the number of developing ovules, suggesting a negative influence of robbers through indirect effects via selective seed abortion. We found no evidence for early-acting inbreeding depression, but found later-acting inbreeding depression. Our data also suggested that later-acting inbreeding depression of progeny from robbed flowers could be reduced in comparison with that from unrobbed flowers. • We suggest that nectar robbing can have both negative and positive effects on the quantity and quality, respectively, of progeny produced in selfing plants, and challenge the view that robbing has no effect on selfing species.
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Measurements of ultrasonic phase velocities and attenuation of slow waves in cellular aluminum foams as cancellous bone-mimicking phantoms.
J. Acoust. Soc. Am.
PUBLISHED: 05-17-2011
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The water-saturated aluminum foams with an open network of interconnected ligaments were investigated by ultrasonic transmission technique for the suitability as cancellous bone-mimicking phantoms. The phase velocities and attenuation of nine samples covering three pores per inch (5, 10, and 20 PPI) and three aluminum volume fractions (5, 8, and 12% AVF) were measured over a frequency range of 0.7-1.3 MHz. The ligament thickness and pore sizes of the phantoms and low-density human cancellous bones are similar. A strong slow wave and a weak fast wave are observed for all samples while the latter is not visible without significant amplification (100x). This study reports the characteristics of slow wave, whose speeds are less than the sound speed of the saturating water and decrease mildly with AVF and PPI with an average 1469 m/s. Seven out of nine samples show positive dispersion and the rest show minor negative dispersion. Attenuation increases with AVF, PPI, and frequency except for the 20 PPI samples, which exhibit non-increasing attenuation level with fluctuations due to scattering. The phase velocities agree with Biots porous medium theory. The RMSE is 16.0 m/s (1%) at n = 1.5. Below and above this value, the RMSE decreases mildly and rises sharply, respectively.
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Genome-wide discovery and analysis of microRNAs and other small RNAs from rice embryogenic callus.
RNA Biol
PUBLISHED: 05-01-2011
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Small RNAs constitute a new and unanticipated layer of gene regulation present in the three domains of life. In plants, all organs are ultimately derived from a few pluripotent stem cells localized in specialized structures called apical meristems. The development of meristems involves a coordinated balance between undifferentiated growth and differentiation, a phenomenon requiring a tight regulation of gene expression. We used in vitro cultured embryogenic calli as a model to investigate the roles of meristem-associated small RNAs. Using high throughput sequencing, we sequenced 20 million short reads with size of 18-30 nt from rice undifferentiated and differentiated calli. We confirmed 50 known microRNA families, representing one third of annotated rice microRNAs. Using a specific computational pipeline for plant microRNA identification, we identified 24 novel microRNA families. Among them, 53 microRNA or microRNA* sequences appear to vary in expression between differentiated and undifferentiated calli, suggesting a role in meristem development. Our analysis also revealed a new class of plant small RNAs derived from 5 or 3 ends of mature tRNA analogous to the tRFs in human cancer cell. We independently verified the expression of these small RNAs from 5 end of mature tRNA using qRT-PCR.
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An evaluation of legislative measures on electrical and electronic waste in the Peoples Republic of China.
Waste Manag
PUBLISHED: 03-09-2011
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With the increasing number of recycling mishaps in connection with waste electronic and electrical equipment (WEEE) in the Peoples Republic of China, it is imperative that the handling and recycling of WEEE be sufficiently regulated in China. Regulations covering three major issues, namely, take-back issues, controls on hazardous substances in WEEE and the assurance of good environmental management in WEEE plants, were promulgated between 2006 and 2008. The evaluation in this country report shows that few of these regulatory measures have performed satisfactorily in terms of enforcement, of public acceptance and of environmental concerns. In brief, the take-back requirements and the associated financial responsibilities are only vaguely defined; the control on hazardous substances and the so-called "environmental expiry date" requirements cannot be properly enforced, and the resources needed to ensure the satisfactory enforcement of the environmental abatement and pollution control requirements in WEEE plants are overwhelming. In addition, the use of a "multiple enforcement body" approach to the control of hazardous substances in WEEE is an indication that the Chinese government lacks the determination to properly enforce the relevant legal requirements.
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[Expression and clinical significance of VEGF and apoptosis in frozen-thawed mouse ovaries after transplantation].
Zhongguo Ying Yong Sheng Li Xue Za Zhi
PUBLISHED: 08-06-2010
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To investigate expression and clinical significance of VEGF and apoptosis in frozen-thawed mouse ovaries after transplantation.
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Characterization of lipid A Cronobacter sakazakii.
Eur J Mass Spectrom (Chichester, Eng)
PUBLISHED: 07-14-2010
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We have characterized the structure of lipid A in food-borne pathogen Cronobacter sakazakii BAA-894. Lipid A molecules were purified by mild acid hydrolysis, DEAE-cellulose anion exchange chromatography and preparative thin-layer chromatography. Its structure was analyzed by electrospray ionization/mass spectrometry. Two lipid A species have been found in C. sakazakii BAA-894. The majority has a structure of disaccharide of glucosamine, phosphorylated at 1- and 4-positions, and acylated with primary 3-hydroxymyristoyl chains at 2-, 3-, 2- and 3-positions and secondary myristoyl residues at 2- and 3- positions. The other contains a secondary lauroyl chain at 2-position in place of the myristoyl residue.
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Purification and characterization of lipopolysaccharides.
Subcell. Biochem.
PUBLISHED: 07-02-2010
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Lipopolysaccharides are the major components on the surface of most Gram-negative bacteria, and recognized by immune cells as a pathogen-associated molecule. They can cause severe diseases like sepsis and therefore known as endotoxins. Lipopolysaccharide consists of lipid A, core oligosaccharide and O-antigen repeats. Lipid A is responsible for the major bioactivity of endotoxin. Because of their specific structure and amphipathic property, purification and analysis of lipopolysaccharides are difficult. In this chapter, we summarize the available approaches for extraction, purification and analysis of lipopolysaccharides.
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[Studies on HPCE fingerprint of Folium Apocyni Veneti].
Zhong Yao Cai
PUBLISHED: 06-26-2010
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To establish the analytical method for the fingerprint of Folium Apocyni Veneti by HPCE and estimate the quality of Folium Apocyni Veneti from different habitats.
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Using ultrasound to guide the insertion of pedicle screws during scoliosis surgery.
Stud Health Technol Inform
PUBLISHED: 06-15-2010
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Scoliosis surgery involves the insertion of screws and/or hooks into selected vertebrae to secure a pre-bent rod placed along the concave side of the spine. Usually conventional x-rays will be taken before the surgery to plan the alignment and positioning of the pedicle screws. However, reports state that perforation rate range from 6% to 54%. A misalignment of a pedicle screw can potentially cause permanent neurological spinal cord injury or even a life-threatening vascular injury. Because of the importance of positioning and aligning of pedicle screws, we are working on an ultrasound method to guide the insertion of pedicle screws in real time. A pulse-echo immersion experiment was set up to study how well the edges of cortical bone could be detected using a bovine spinous process in-vitro. Two ultrasound frequencies (3.5 MHz and 5.0 MHz) were considered in this study. This preliminary study shows that ultrasound is able to penetrate cortical bone and reflect back from the outer boundary. All interfaces are clearly identified for both frequencies. Strong reflection signals are obtained when the beam is normal to the interface. Derived thickness values from the reflections are comparable with those from micro-CT image. The 5.0 MHz ultrasound frequency provided better resolution than the 3.0 MHz frequency.
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Isolation and identification of a subgroup A avian leukosis virus from imported meat-type grand-parent chickens.
Virol Sin
PUBLISHED: 04-09-2010
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An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced antibody reactions specific to subgroup A or B. But gp85 amino acid sequence comparisons indicated that SDAU09C1 fell into subgroup A; it had homology of 88.8%-90.3% to 6 reference strains of subgroup A, much higher compared to other subgroups including subgroup B. This is the first report for ALV of subgroup A isolated from imported breeders.
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[Isolation and identification of a subgroup B avian leukosis virus from chickens of Chinese native breed Luhua].
Bing Du Xue Bao
PUBLISHED: 03-25-2010
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By inoculation of blood samples in DF-1 (C/E) cell culture, an exogenous avian leukosis virus (ALV) strain SDAU09C2 was isolated from a breeder farm of Chinese native breed "Luhua" in Shandong province. Comparisons of the amino acid sequence of env gene gp85 from the isolate with those from other ALV reference strains of different subgroups indicated that SDAU09C2 had the highest gp85 identity to two reference strains of subgroup B of 92.5%. Its gp85 identity to other chicken ALV subgroups A, C, D, E was in the range of 73.2%-87.9%. The identity to subgroup J was only 30.3%-32.4%. This is the first report on isolation and identification of ALV-B and its gp85 from Chinese native breed chickens.
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Folate-mediated poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) nanoparticles for targeting drug delivery.
Eur J Pharm Biopharm
PUBLISHED: 03-22-2010
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A novel targeting drug delivery system (TDDS) has been developed. Such a TDDS was prepared by W(1)/O/W(2) solvent extraction/evaporation method, adopting poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) [P(HB-HO)] as the drug carrier, folic acid (FA) as the targeting ligand, and doxorubicin (DOX) as the model anticancer drug. The average size, drug loading capacity and encapsulation efficiency of the prepared DOX-loaded, folate-mediated P(HB-HO) nanoparticles (DOX/FA-PEG-P(HB-HO) NPs) were found to be around 240 nm, 29.6% and 83.5%. The in vitro release profile displayed that nearly 50% DOX was released in the first 5 days. The intracellular uptake tests of the nanoparticles (NPs) in vitro showed that the DOX/FA-PEG-P(HB-HO) NPs were more efficiently taken up by HeLa cells compared to non-folate-mediated P(HB-HO) NPs. In addition, DOX/FA-PEG-P(HB-HO) NPs (IC(50)=0.87 microM) showed greater cytotoxicity to HeLa cells than other treated groups. In vivo anti-tumor activity of the DOX/FA-PEG-P(HB-HO) NPs showed a much better therapeutic efficacy in inhibiting tumor growth, and the final mean tumor volume was 178.91+/-17.43 mm(3), significantly smaller than normal saline control group (542.58+/-45.19 mm(3)). All these results have illustrated that our techniques for the preparing of DOX/FA-PEG-P(HB-HO) NPs developed in present work are feasible and these NPs are effective in selective delivery of anticancer drug to the folate receptor-overexpressed cancer cells. The new TDDS may be a competent candidate in application in targeting treatment of cancers.
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Generation of and control measures for, e-waste in Hong Kong.
Waste Manag
PUBLISHED: 03-03-2010
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While accurately estimating electrical and electronic waste (e-waste) generation is important for building appropriate infrastructure for its collection and recycling, making reliable estimates of this kind is difficult in Hong Kong owing to the fact that neither accurate trade statistics nor sales data of relevant products are available. In view of this, data of e-products consumption at household level was collected by a tailor-made questionnaire survey from the public for obtaining a reasonable e-waste generation estimate. It was estimated that on average no more than 80,443 tones (11.5 kg/capita) of waste is generated from non-plasma and non-liquid crystal display televisions, refrigerators, washing machines, air-conditioners and personal computers each year by Hong Kong households. However, not more than 17% of this is disposed as waste despite a producer responsibility scheme (PRS) not being in place because of the existence of a vibrant e-waste trading sector. The form of PRS control that can possibly win most public support is one that would involve the current e-waste traders as a major party in providing the reverse logistics with a visible recycling charge levied at the point of importation. This reverse logistic service should be convenient, reliable and highly accessible to the consumers.
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Glyoxylate rather than ascorbate is an efficient precursor for oxalate biosynthesis in rice.
J. Exp. Bot.
PUBLISHED: 03-01-2010
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Oxalate is widely distributed in the plant kingdom. While excess oxalate in food crops is detrimental to animal and human health, it may play various functional roles in plants, particularly for coping with environmental stresses. Understanding its biosynthetic mechanism in plants, therefore, becomes increasingly important both theoretically and practically. However, it is still a matter of debate as to what precursor and pathway are ultimately used for oxalate biosynthesis in plants. In this study, both physiological and molecular approaches were applied to address these questions. First, it was observed that when glycolate or glyoxylate was fed into detached leaves, both organic acids were equally effective in stimulating oxalate accumulation. In addition, the stimulation could be completely inhibited by cysteine, a glyoxylate scavenger that forms cysteine-glyoxylate adducts. To verify the role of glyoxylate further, various transgenic plants were generated, in which several genes involved in glyoxylate metabolism [i.e. SGAT (serine-glyoxylate aminotransferase), GGAT (glutamate-glyoxylate aminotransferase), HPR (hydroxypyruvate reductase), ICL (isocitrate lyase)], were transcriptionally regulated through RNAi or over-expression. Analyses on these transgenic plants consistently revealed that glyoxylate acted as an efficient precursor for oxalate biosynthesis in rice. Unexpectedly, it was found that oxalate accumulation was not correlated with photorespiration, even though this pathway is known to be a major source of glyoxylate. Further, when GLDH (L-galactono-1,4-lactone dehydrogenase), a key enzyme gene for ascorbate biosynthesis, was down-regulated, the oxalate abundance remained constant, despite ascorbate having been largely reduced as expected in these transgenic plants. Taken together, our results strongly suggest that glyoxylate rather than ascorbate is an efficient precursor for oxalate biosynthesis, and that oxalate accumulation and regulation do not necessarily depend on photorespiration, possibly due to the occurrence of the anaplerotic reaction that may compensate for glyoxylate formation in rice.
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Deep sequencing of human nuclear and cytoplasmic small RNAs reveals an unexpectedly complex subcellular distribution of miRNAs and tRNA 3 trailers.
PLoS ONE
PUBLISHED: 02-03-2010
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MicroRNAs (miRNAs) are approximately 22-nt small non-coding regulatory RNAs that have generally been considered to regulate gene expression at the post-transcriptional level in the cytoplasm. However, recent studies have reported that some miRNAs localize to and function in the nucleus.
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Measuring bulky waste arisings in Hong Kong.
Waste Manag
PUBLISHED: 01-06-2010
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All too often, waste authorities either assume that they know enough about their bulky waste stream or that it is too insignificant to deserve attention. In this paper, we use Hong Kong as an example to illustrate that official bulky waste figures can actually be very different from the reality and therefore important waste management decisions made based on such statistics may be wrong too. This study is also the first attempt in Hong Kong to outline the composition of bulky waste. It was found that about 342tonnes/day of wood waste were omitted by official statistics owing to incomplete records on actual bulky waste flow. This is more than enough to provide all the feedstock needed for one regular-sized wood waste recycling facility in Hong Kong. In addition, the proportion of bulky waste in the municipal solid waste (MSW) streams in Hong Kong should be about 6.1% instead of the officially stated 1.43%. Admittedly, there are limitations with this study. Yet, present findings are suggestive of significant MSW data distortion in Hong Kong.
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[Study on the dynamic change of essential components in Folium Apocyni Veneti].
Zhong Yao Cai
PUBLISHED: 12-19-2009
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To determine the dynamic change of essential components in Folium Apocyni Veneti, and provide scientific basis for determining the best collecting time.
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Protective effect of chrysoeriol against doxorubicin-induced cardiotoxicity in vitro.
Chin. Med. J.
PUBLISHED: 12-03-2009
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The use of doxorubicin (DOX) is limited by its dose-dependent cardiotoxicity. Reactive oxygen species (ROSs) play an important role in the pathological process of DOX-induced cardiotoxicity. The aim of this study was to evaluate the protective effect of chrysoeriol, a flavone compound, against DOX-induced apoptosis and death in H9c2 cells and to find out its preliminary mechanism.
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[A novel hot-spot mutation S236G in the cardiac myosin binding protein C gene in Chinese patient with hypertrophic cardiomyopathy].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 10-19-2009
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To identify the disease-causing gene mutations and to reveal the relationship between the genotype and the phenotype in Chinese patients with hypertrophic cardiomyopathy (HCM).
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[The genotype-phenotype correlation of the MYH7 gene c.1273G > a mutation in familial hypertrophic cardiomyopathy].
Yi Chuan
PUBLISHED: 07-10-2009
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To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy (HCM), peripheral blood samples were collected from 7 members of a Chinese HCM family, and 120 normal subjects were recruited as control. The full encoding exons and flanking sequences of the cardiac troponin T (TNNT2) gene, beta-myosin heavy chain (MYH7) gene and myosin binding protein C (MYBPC3) gene were amplified and the products were sequenced directly to detect the mutations. A missense mutation, c.1273G>A, was identified in exon 14 of the MYH7 gene in 4 members of the Chinese HCM family, which resulted a glycine (Gly) to arginine (Arg) exchange at amino acid residue 425. The 425th glycine amino acid residue is highly conservative across the different species. The clinical phenotypes among the family members who carried this mutation presented significant individual differences. The c.1273G>A mutation of the MYH7 gene might be the causal mutation of the familial HCM. The heterogeneity of phenotypes suggested that multiple factors may be involved in the pathogenesis of HCM.
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Measurement of tortuosity in aluminum foams using airborne ultrasound.
Ultrasonics
PUBLISHED: 04-18-2009
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The slow compressional wave in air-saturated aluminum foams was studied by means of ultrasonic transverse transmission method over a frequency range from 0.2 MHz to 0.8 MHz. The samples investigated have three different cell sizes or pores per inch (5, 10 and 20 ppi) and each size has three aluminum volume fractions (5%, 8% and 12% AVF). Phase velocities show minor dispersion at low frequencies but remain constant after 0.7 MHz. Pulse broadening and amplitude attenuation are obvious and increase with increasing ppi. Attenuation increases considerably with AVF for 20 ppi foams. Tortuosity ranges from 1.003 to 1.032 and increases with AVF and ppi. However, the increase of tortuosity with AVF is very small for 10 and 20 ppi samples.
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Expression analysis of phytohormone-regulated microRNAs in rice, implying their regulation roles in plant hormone signaling.
FEBS Lett.
PUBLISHED: 01-13-2009
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Twenty-two conserved miRNAs were chosen to investigate the expression pattern in response to phytohormone treatments, in which the effects of five classic plant hormone stresses were surveyed in Oryza sativa. The results showed that 11 miRNAs were found to be dysregulated by one or more phytohormone treatments. The target genes of these miRNAs were validated in vivo and their expression profiling were revealed. We also analyzed the promoter regions of the 22 conserved miRNAs for phytohormone-responsive elements and the existence of the elements provided further evidences supporting our results. These findings enable us to further investigate the role of miRNAs in phytohormone signaling.
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[Study on the association between RANTES-403G/A as well as -28C/G gene polymorphism and their susceptibility to the hepatitis B virus infections in Dong and Han ethnicities in Guizhou, China].
Zhonghua Liu Xing Bing Xue Za Zhi
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To investigate the association between both regulated upon activation normal T cell expressed and secreted (RANTES) -403G/A, -28C/G gene polymorphism and the susceptibilities to hepatitis B virus (HBV) infection, among people with Dong and Han ethnicities, in Guizhou.
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Effects of salinity and humic acid on the sorption of Hg on Fe and Mn hydroxides.
J. Hazard. Mater.
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The objective of this study was to investigate the influence of humic acid (HA) and salinity on adsorption of Hg on the amorphous and crystalline of iron and manganese hydroxides. The results show that the adsorption of Hg(2+) on Fe and Mn hydroxides was inhibited in marine system due to the formation of stable, nonsorbing aqueous HgCl(2) complexes in solution. Moreover, Cl(-) inhibited the Hg(2+) adsorption more severely on amorphous than crystalline hydroxides. The addition of HA inhibited Hg(2+) adsorption on Fe and Mn hydroxides in freshwater system might be attributed to the competition between Hg(2+) and HA on adsorption to Fe and Mn hydroxides. In contrast, the addition of HA promoted Hg(2+) adsorption on Fe and Mn hydroxides in the marine system, which might be due to the addition of humic acid resulted in the reaction between Cl(-) and HA, and therefore the reducing of Cl(-) promoted more Hg(2+) on Fe and Mn hydroxides. In addition, the influence of HA on Hg(2+) adsorption on Fe and Mn hydroxides are more visible for crystalline than amorphous hydroxides.
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Two bifunctional enzymes with ferric reduction ability play complementary roles during magnetosome synthesis in Magnetospirillum gryphiswaldense MSR-1.
J. Bacteriol.
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The bacterial strain Magnetospirillum gryphiswaldense MSR-1 does not produce siderophores, but it absorbs a large amount of ferric iron and synthesizes magnetosomes. We demonstrated previously the presence of six types of ferric reductase isozymes (termed FeR1 through FeR6) in MSR-1. Of these isozymes, FeR5 was the most abundant and FeR6 showed the highest ferric reductase activity. In the present study, we cloned the fer5 and fer6 genes from MSR-1 and expressed them separately in Escherichia coli. FeR5 and FeR6 were shown to be bifunctional enzymes through analysis of amino acid sequence homologies, structural predictions (using data from GenBank), and detection of enzyme activities. FeR5 is a thioredoxin reductase and FeR6 is a flavin reductase, in addition to being ferric reductases. To elucidate the functions of the enzymes, we constructed two single-gene-deletion mutant strains (?fer5 and ?fer6 mutants) and a double-gene-deletion mutant strain (?fer5 ?fer6 [?fer5+6] mutant) along with its complemented strains (C5 and C6). An evaluation of phenotypic and physiological properties did not reveal significant differences between the wild-type and single-gene-deletion strains, whereas the double-gene-deletion strain showed reduced iron absorption and no magnetosome synthesis. Complementation of the double-gene-deletion strain using either fer5 or fer6 resulted in the partial recovery of magnetosome synthesis. Quantitative real-time PCR analysis of fer5 and fer6 transcriptional levels in the wild-type and complemented strains demonstrated consistent transcription of the two genes and confirmed that FeR5 and FeR6 are bifunctional enzymes that play complementary roles during the process of magnetosome synthesis in MSR-1.
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A material flow analysis on current electrical and electronic waste disposal from Hong Kong households.
Waste Manag
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A material flow study on five types of household electrical and electronic equipment, namely television, washing machine, air conditioner, refrigerator and personal computer (TWARC) was conducted to assist the Government of Hong Kong to establish an e-waste take-back system. This study is the first systematic attempt on identifying key TWARC waste disposal outlets and trade practices of key parties involved in Hong Kong. Results from two questionnaire surveys, on local households and private e-waste traders, were used to establish the material flow of household TWARC waste. The study revealed that the majority of obsolete TWARC were sold by households to private e-waste collectors and that the current e-waste collection network is efficient and popular with local households. However, about 65,000 tonnes/yr or 80% of household generated TWARC waste are being exported overseas by private e-waste traders, with some believed to be imported into developing countries where crude recycling methods are practiced. Should Hong Kong establish a formal recycling network with tight regulatory control on imports and exports, the potential risks of current e-waste recycling practices on e-waste recycling workers, local residents and the environment can be greatly reduced.
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Fallopian tube occlusion with a shape memory polymer device: evaluation in a rabbit model.
Contraception
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The present study evaluates the feasibility of a shape memory polymer (SMP) device for fallopian tube occlusion in rabbits.
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FeoB2 Functions in magnetosome formation and oxidative stress protection in Magnetospirillum gryphiswaldense strain MSR-1.
J. Bacteriol.
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Magnetotactic bacteria (MTB) synthesize unique organelles, the magnetosomes, which are intracellular nanometer-sized, membrane-enveloped magnetite. The biomineralization of magnetosomes involves the uptake of large amounts of iron. However, the iron metabolism of MTB is not well understood. The genome of the magnetotactic bacterium Magnetospirillum gryphiswaldense strain MSR-1 contains two ferrous iron transport genes, feoB1 and feoB2. The FeoB1 protein was reported to be responsible mainly for the transport of ferrous iron and to play an accessory role in magnetosome formation. To determine the role of feoB2, we constructed an feoB2 deletion mutant (MSR-1 ?feoB2) and an feoB1 feoB2 double deletion mutant (MSR-1 NfeoB). The single feoB2 mutation did not affect magnetite crystal biomineralization. MSR-1 NfeoB had a significantly lower average magnetosome number per cell (?65%) than MSR-1 ?feoB1, indicating that FeoB2 plays a role in magnetosome formation when the feoB1 gene is deleted. Our findings showed that FeoB1 has a greater ferrous iron transport ability than FeoB2 and revealed the differential roles of FeoB1 and FeoB2 in MSR-1 iron metabolism. Interestingly, compared to the wild type, the feoB mutants showed increased sensitivity to oxidative stress and lower activities of the enzymes superoxide dismutase and catalase, indicating that the FeoB proteins help protect bacterial cells from oxidative stress.
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Comparative peptidome analyses of the profiles of the peptides ranging from 1-10 KD in CSF samples pooled from probable sporadic CJD and non-CJD patients.
Prion
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The shotgun strategy applying tandem mass spectrometry has been widely used to identify the proteins that are differentially distributed among diseases for its high reliability and efficiency. To find out the potential difference of protein profiles in cerebrospinal fluids (CSF) between Creutzfeldt-Jakob disease (CJD) and non-CJD patients, especially in the fraction ranging from 1-10 KD, the CSF samples of 40 probable sporadic CJD (sCJD) patients, 32 non-CJD cases with dementia and 17 non-CJD cases without dementia were separately pooled and enriched by the magnetic beads based weak cation exchange chromatography (MB-WCX). After trypsin digestion, each enriched CSF was separated and identified by RP-HPLC-ESI-QTOF MS/MS. In total, 42, 53 and 47 signals of proteins were identified in the pooled CSF fraction less than 10 KD of probable sCJD, non-CJD with dementia and non-CJD without dementia, respectively. Compared with that of probable sCJD, the similarity of CSF protein profiles of non-CJD with dementia (76.2%) were higher than that of non-CJD without dementia (57.1%). Nine CSF proteins were found to be specially observed in probable sCJD group. Those data may help to select the potential biomarkers for diagnosis of CJD. Additionally, further studies of the small segments of cellular proteins in CSF of CJD patients may also provide scientific clues for understanding the neuropathogenesis of TSEs.
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