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Find video protocols related to scientific articles indexed in Pubmed.
Molecular cloning and functional characterization of the lycopene ?-cyclase gene via virus-induced gene silencing and its expression pattern in Nicotiana tabacum.
Int J Mol Sci
PUBLISHED: 08-22-2014
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Lycopene ?-cyclase (?-LCY) is a key enzyme that catalyzes the synthesis of ?-branch carotenoids through the cyclization of lycopene. Two cDNA molecules encoding ?-LCY (designated Nt?-LCY1 and Nt?-LCY2) were cloned from Nicotiana tabacum. Nt?-LCY1 and Nt?-LCY2 are encoded by two distinct genes with different evolutionary origins, one originating from the tobacco progenitor, Nicotiana sylvestris, and the other originating from Nicotiana tomentosiformis. The two coding regions are 97% identical at the nucleotide level and 95% identical at the amino acid level. Transcripts of Nt?-LCY were detectable in both vegetative and reproductive organs, with a relatively higher level of expression in leaves than in other tissues. Subcellular localization experiments using an Nt?-LCY1-GFP fusion protein demonstrated that mature Nt?-LCY1 protein is localized within the chloroplast in Bright Yellow 2 suspension cells. Under low-temperature and low-irradiation stress, Nt?-LCY transcript levels substantially increased relative to control plants. Tobacco rattle virus (TRV)-mediated silencing of ?-LCY in Nicotiana benthamiana resulted in an increase of ?-branch carotenoids and a reduction in the levels of ?-branch carotenoids. Meanwhile, transcripts of related genes in the carotenoid biosynthetic pathway observably increased, with the exception of ?-OHase in the TRV-?-lcy line. Suppression of ?-LCY expression was also found to alleviate photoinhibition of Potosystem II in virus-induced gene silencing (VIGS) plants under low-temperature and low-irradiation stress. Our results provide insight into the regulatory role of ?-LCY in plant carotenoid biosynthesis and suggest a role for ?-LCY in positively modulating low temperature stress responses.
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Novel LRRK2 GTP-binding inhibitors reduced degeneration in Parkinson's disease cell and mouse models.
Hum. Mol. Genet.
PUBLISHED: 07-03-2014
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Mutations in the leucine-rich repeat kinase-2 (LRRK2) gene cause autosomal-dominant Parkinson's disease (PD) and contribute to sporadic PD. LRRK2 contains Guanosine-5'-triphosphate (GTP) binding, GTPase and kinase activities that have been implicated in the neuronal degeneration of PD pathogenesis, making LRRK2, a potential drug target. To date, there is no disease-modifying drug to slow the neuronal degeneration of PD and no published LRRK2 GTP domain inhibitor. Here, the biological functions of two novel GTP-binding inhibitors of LRRK2 were examined in PD cell and mouse models. Through a combination of computer-aided drug design (CADD) and LRRK2 bio-functional screens, two novel compounds, 68: and 70: , were shown to reduce LRRK2 GTP binding and to inhibit LRRK2 kinase activity in vitro and in cultured cell assays. Moreover, these two compounds attenuated neuronal degeneration in human SH-SY5Y neuroblastoma cells and mouse primary neurons expressing mutant LRRK2 variants. Although both compounds inhibited LRRK2 kinase activity and reduced neuronal degeneration, solubility problems with 70: prevented further testing in mice. Thus, only 68: was tested in a LRRK2-based lipopolysaccharide (LPS)-induced pre-inflammatory mouse model. 68: reduced LRRK2 GTP-binding activity and kinase activity in brains of LRRK2 transgenic mice after intraperitoneal injection. Moreover, LPS induced LRRK2 upregulation and microglia activation in mouse brains. These findings suggest that disruption of GTP binding to LRRK2 represents a potential novel therapeutic approach for PD intervention and that these novel GTP-binding inhibitors provide both tools and lead compounds for future drug development.
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Sensitization of Er3+ ions in silicon rich oxynitride films: effect of thermal treatments.
Opt Express
PUBLISHED: 06-13-2014
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The optical properties of reactive co-sputtered erbium doped silicon rich oxynitride (Er:SRON) films are studied as a function of annealing temperatures (Ta). The sensitization mechanism of Er3+ is found to evolve with Ta: excess Si related localized states play the essential role in samples when Ta is below 700 °C, while silicon nanoclusters (Si-NCs) become the dominate sensitizers when Ta exceeds 800 °C. Our results show that higher density of sensitized Er3+ could be acquired via energy transfer from localized states, and thus provide an alternative way for the engineering of light sources based on Er:SRON.
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A rapidly modulated multifocal detection scheme for parallel acquisition of Raman spectra from a 2-D focal array.
Anal. Chem.
PUBLISHED: 06-13-2014
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We report the development of a rapidly modulated multifocal detection scheme that enables full Raman spectra (~500-2000 cm(-1)) from a 2-D focal array to be acquired simultaneously. A spatial light modulator splits a laser beam to generate an m × n multifocal array. Raman signals generated within each focus are projected simultaneously into a spectrometer and imaged onto a TE-cooled CCD camera. A shuttering system using different masks is constructed to collect the superimposed Raman spectra of different multifocal patterns. The individual Raman spectrum from each focus is then retrieved from the superimposed spectra with no crosstalk using a postacquisition data processing algorithm. This system is expected to significantly improve the speed of current Raman-based instruments such as laser tweezers Raman spectroscopy and hyperspectral Raman imaging.
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Characterization of 40 single nucleotide polymorphism (SNP) via Tm-shift assay in the mud crab (Scylla paramamosain).
Mol. Biol. Rep.
PUBLISHED: 05-16-2014
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In this study, single nucleotide polymorphism (SNP) were identified, confirmed and genotyped in the mud crab (Scylla paramamosain) using Tm-shift assay. High quality sequences (13, 311 bp long) were obtained by re-sequencing that contained 91 SNPs, with a density of one SNP every 146 bp. Of all 91 SNPs, 40 were successfully genotyped and characterized using 30 wild specimens by Tm-shift assay. The minor allele frequency per locus ranged from 0.017 to 0.500. The observed and expected heterozygosity, and polymorphism information content (PIC) ranged from 0.000 to 0.600, from 0.033 to 0.509, and from 0.033 to 0.375, respectively, with an average of 0.142, 0.239 and 0.198 per locus. Seventeen SNPs were significantly deviated from Hardy-Weinberg equilibrium. No significant linkage disequilibrium between pairs of loci was detected after sequential Bonferroni correction (P > 0.00125). Seventeen SNPs were related with known function genes. This study provided new molecular markers for investigation of population genetic diversity, construction of genetic linkage maps and molecular marker-assisted selection in this important crustacean species.
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A highly selective and simple fluorescent sensor for mercury (II) ion detection based on cysteamine-capped CdTe quantum dots synthesized by the reflux method.
Luminescence
PUBLISHED: 05-12-2014
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Cysteamine (CA)-capped CdTe quantum dots (QDs) (CA-CdTe QDs) were prepared by the reflux method and utilized as an efficient nano-sized fluorescent sensor to detect mercury (II) ions (Hg(2+) ). Under optimum conditions, the fluorescence quenching effect of CA-CdTe QDs was linear at Hg(2+) concentrations in the range of 6.0-450?nmol/L. The detection limit was calculated to be 4.0?nmol/L according to the 3? IUPAC criteria. The influence of 10-fold Pb(2+) , Cu(2+) and Ag(+) on the determination of Hg(2+) was?
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2-[2-(2-Nitro-phen-yl)-4,5-diphenyl-1H-imidazol-1-yl]-3-phenyl-propan-1-ol.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 05-01-2014
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In the title compound, C30H25N3O3, the central imidazole ring forms dihedral angles of 77.34?(6), 12.56?(6) and 87.04?(6)°, respectively, with the o-nitro-benzene ring and the phenyl substituents in the 5- and 4-positions. The mol-ecular conformation is stabilized by weak intra-molecular C-H?? inter-actions. In the crystal, mol-ecules are linked by O-H?N hydrogen bonds, forming chains running parallel to the b-axis direction.
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Sensitive voltammetric sensor based on isopropanol-Nafion-PSS-GR nanocomposite modified glassy carbon electrode for determination of clenbuterol in pork.
Food Chem
PUBLISHED: 04-12-2014
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In the present study, poly(sodium 4-styrenesulfonate) (PSS) functionalized graphene (GR) was synthesised via a simple one-step chemical reduction of exfoliated graphite oxides in the presence of PSS. Characterisation of as-made nanocomposite using Fourier transform infrared spectroscopy (FT-IR) and ultraviolet and visible spectroscopy (UV-vis) clearly demonstrate the successful attachment of PSS to graphene sheets. A novel clenbuterol (CLB) electrochemical sensor was fabricated based on isopropanol-Nafion-PSS-GR composite film modified glassy carbon electrode. In the Britton-Robinson buffer (pH 1.2), the sensor exhibited superior electrocatalytic activity towards the oxidation of CLB. Applying linear sweep voltammetry, a good linear relationship of the oxidation peak current with respect to concentrations of CLB cross the range of 7.5 × 10(-8)-2.5 × 10(-5)mol L(-1) and a detection limit of 2.2 × 10(-8) mol L(-1) were achieved. The proposed method was successfully applied for the determination of CLB in pork.
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Photocurrent response of carbon nanotube-metal heterojunctions in the terahertz range.
Opt Express
PUBLISHED: 03-26-2014
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We investigate the optoelectronic properties of a carbon nanotube (CNT)-metal heterostructure in the terahertz range. On the basis of terahertz time-domain spectroscopy characterization of a double-walled CNT (DWNT) film, we present and analyze the photocurrent measurement for a DWNT-nickel heterojunction illuminated by continuous-wave terahertz radiation. A significant current across the junction directly induced by terahertz excitation is observed and a negative photoconductivity behavior is found to occur in the device. The photocurrent shows a linear response to the bias voltage and the illumination power within the examined range. These phenomena support the feasibility of using CNT-metal heterojunctions as novel terahertz detectors.
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Expression of microRNA-454 in TGF-?1-stimulated hepatic stellate cells and in mouse livers infected with Schistosoma japonicum.
Parasit Vectors
PUBLISHED: 03-17-2014
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In the process of hepatic fibrosis, hepatic stellate cells (HSCs) can be activated by many inflammatory cytokines. The transforming growth factor-?1 (TGF-?1) is one of the main profibrogenic mediators. Recently, some studies have also shown that microRNAs (miRNAs) play essential roles in the progress of liver fibrosis by being involved in the differentiation, fat metabolism and ECM production of HSCs.
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Total body irradiation causes long-term mouse BM injury via induction of HSC premature senescence in an Ink4a- and Arf-independent manner.
Blood
PUBLISHED: 03-12-2014
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Exposure to total body irradiation (TBI) induces not only acute hematopoietic radiation syndrome but also long-term or residual bone marrow (BM) injury. This residual BM injury is mainly attributed to permanent damage to hematopoietic stem cells (HSCs), including impaired self-renewal, decreased long-term repopulating capacity, and myeloid skewing. These HSC defects were associated with significant increases in production of reactive oxygen species (ROS), expression of p16(Ink4a) (p16) and Arf mRNA, and senescence-associated ?-galacotosidase (SA-?-gal) activity, but not with telomere shortening or increased apoptosis, suggesting that TBI induces residual BM injury via induction of HSC premature senescence. This suggestion is supported by the finding that SA-?-gal(+) HSC-enriched LSK cells showed more pronounced defects in clonogenic activity in vitro and long-term engraftment after transplantation than SA-?-gal(-) LSK cells isolated from irradiated mice. However, genetic deletion of p16 and/or Arf had no effect on TBI-induced residual BM suppression and HSC senescence, because HSCs from irradiated p16 and/or Arf knockout (KO) mice exhibited changes similar to those seen in HSCs from wild-type mice after exposure to TBI. These findings provide important new insights into the mechanism by which TBI causes long-term BM suppression (eg, via induction of premature senescence of HSCs in a p16-Arf-independent manner).
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Rapamycin enhances long-term hematopoietic reconstitution of ex vivo expanded mouse hematopoietic stem cells by inhibiting senescence.
Transplantation
PUBLISHED: 02-22-2014
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The mammalian target of rapamycin (mTOR) is an important regulator of hematopoietic stem cell (HSC) self-renewal and its overactivation contributes to HSC premature exhaustion in part via induction of HSC senescence. Inhibition of mTOR with rapamycin has the potential to promote long-term hematopoiesis of ex vivo expanded HSCs to facilitate the clinical application of HSC transplantation for various hematologic diseases.
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Optimization of condition for conjugation of enrofloxacin to enzymes in chemiluminescence enzyme immunoassay.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 02-09-2014
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In this study, in order to find out a proper method for conjugation of enrofloxacin to label enzymes, two methods were compared and carbodiimide condensation was proved to be better. The results showed that the binding ratio of enrofloxacin and alkaline phosphatase (ALP) was 8:1 and that of enrofloxacin and horseradish peroxidase (HRP) was 5:1. This indicated that conjugate synthesized by carbodiimide condensation was fit for chemiluminescence enzyme immunoassay (CLEIA). Furthermore, data revealed that dialysis time was an important parameter for conjugation and 6days was best. Buffer to dilute conjugate had little effect on CLEIA. The storage condition for conjugates was also studied and it was shown that the conjugate was stable at 4°C with no additive up to 30days. These data were valuable for establishing CLEIA to quantify enrofloxacin.
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Expression of AEG-1 and microvessel density correlates with metastasis and prognosis of oral squamous cell carcinoma.
Hum. Pathol.
PUBLISHED: 01-08-2014
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Astrocyte elevated gene 1 (AEG-1) expression is up-regulated in various human cancers and plays an important role in tumorigenesis and progression. The aim of this study was to explore AEG-1 expression in oral squamous cell carcinoma (OSCC) and to assess whether it is associated with microvessel density (MVD), metastasis, and survival. Specimens from 87 patients with OSCC were investigated by immunohistochemistry staining for AEG-1 and MVD. By statistical analysis, we studied the correlations between the expression of AEG-1 and MVD and various clinicopathological factors, including overall survival (OS). We found that AEG-1 was highly expressed in 51.72% of OSCC. Expression was closely correlated with differentiation, clinical stage, T classification, and lymph node metastasis. The MVD had similar results. Expression of AEG-1 correlated positively with MVD. The lymph node metastatic rate in patients with high AEG-1/high MVD was significantly higher than in patients with high AEG-1/low MVD, low AEG-1/high MVD, or low AEG-1/low MVD. Patients with high AEG-1 expression showed far lower OS rates than those with low expression. For MVD, there were similar results. Only AEG-1 and MVD expression were independent prognostic factors for OS by multivariate analysis. Expression of AEG-1 may be correlated with tumor angiogenesis and metastasis and is a valuable prognostic factor in patients with OSCC.
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Role of EZH2 in oral squamous cell carcinoma carcinogenesis.
Gene
PUBLISHED: 01-04-2014
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Oral squamous cell carcinoma (OSCC) is a common human malignancy with high incidence rate and poor prognosis. Although the polycomb group protein enhancer of zeste homolog 2 (EZH2) plays a crucial role in cell proliferation and differentiation during the occurrence and development progress of several kinds of malignant tumors, the impact of EZH2 on the development and progression of OSCC is unclear. In this study, we demonstrate that EZH2 is overexpressed in OSCC cells and clinical tissue. With in vitro RNAi analysis, we generated stable EZH2 knocking down cell lines from two OSCC cell lines, with two sh-RNAs targeting to EZH2, respectively. We found that knocking down of EZH2 could decrease the proliferation ability and induce apoptosis of OSCC cells. Moreover, we demonstrated that of EZH2 inhibition decreased the migration and metastasis of OSCC cells. In conclusion, the results of the current study demonstrated an association between EZH2 expression and OSCC cell development. We recommend that EZH2 acts as an oncogene and plays an important role in OSCC carcinogenesis.
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Varying High Levels of Faecal Carriage of Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae in Rural Villages in Shandong, China: Implications for Global Health.
PLoS ONE
PUBLISHED: 01-01-2014
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Antibiotic resistance is considered a major threat to global health and is affected by many factors, of which antibiotic use is probably one of the more important. Other factors include hygiene, crowding and travel. The rapid resistance spread in Gram-negative bacteria, in particular extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E), is a global challenge, leading to increased mortality, morbidity and health systems costs worldwide. Knowledge about resistance in commensal flora is limited, including in China. Our aim was to establish the faecal carriage rates of ESBL-E and find its association with known and suspected risk factors in rural residents of all ages in three socio-economically different counties in the Shandong Province, China. Faecal samples and risk-factor information (questionnaire) were collected in 2012. ESBL-E carriage was screened using ChromID ESBL agar. Risk factors were analysed using standard statistical methods. Data from 1000 individuals from three counties and in total 18 villages showed a high and varying level of ESBL-E carriage. Overall, 42% were ESBL-E carriers. At county level the carriage rates were 49%, 45% and 31%, respectively, and when comparing individual villages (n?=?18) the rate varied from 22% to 64%. The high level of ESBL-E carriage among rural residents in China is an indication of an exploding global challenge in the years to come as resistance spreads among bacteria and travels around the world with the movement of people and freight. A high carriage rate of ESBL-E increases the risk of infection with multi-resistant bacteria, and thus the need for usage of last resort antibiotics, such as carbapenems and colistin, in the treatment of common infections.
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Pyrroloquinoline Quinone (PQQ) Inhibits Lipopolysaccharide Induced Inflammation in Part via Downregulated NF-?B and p38/JNK Activation in Microglial and Attenuates Microglia Activation in Lipopolysaccharide Treatment Mice.
PLoS ONE
PUBLISHED: 01-01-2014
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Therapeutic strategies designed to inhibit the activation of microglia may lead to significant advancement in the treatment of most neurodegenerative diseases. Pyrroloquinoline quinone (PQQ) is a naturally occurring redox cofactor that acts as an essential nutrient, antioxidant, and has been reported to exert potent immunosuppressive effects. In the present study, the anti-inflammatory effects of PQQ was investigated in LPS treated primary microglia cells. Our observations showed that pretreatment with PQQ significantly inhibited the production of NO and PGE2 and suppressed the expression of pro-inflammatory mediators such as iNOS, COX-2, TNF-a, IL-1b, IL-6, MCP-1 and MIP-1a in LPS treated primary microglia cells. The nuclear translocation of NF-?B and the phosphorylation level of p65, p38 and JNK MAP kinase pathways were also inhibited by PQQ in LPS stimulated primary microglia cells. Further a systemic LPS treatment acute inflammation murine brain model was used to study the suppressive effects of PQQ against neuroinflammation in vivo. Mice treated with PQQ demonstrated marked attenuation of neuroinflammation based on Western blotting and immunohistochemistry analysis of Iba1-against antibody in the brain tissue. Indicated that PQQ protected primary cortical neurons against microglia-mediated neurotoxicity. These results collectively suggested that PQQ might be a promising therapeutic agent for alleviating the progress of neurodegenerative diseases associated with microglia activation.
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Temperature dependence of sensitized Er(3+) luminescence in silicon-rich oxynitride films.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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The temperature dependence of sensitized Er(3+) emission via localized states and silicon nanoclusters has been studied to get an insight into the excitation and de-excitation processes in silicon-rich oxynitride films. The thermal quenching of Er(3+) luminescence is elucidated by terms of decay time and effective excitation cross section. The temperature quenching of Er(3+) decay time demonstrates the presence of non-radiative trap states, whose density and energy gap between Er(3+) (4) I 13/2 excited levels are reduced by high-temperature annealing. The effective excitation cross section initially increases and eventually decreases with temperature, indicating that the energy transfer process is phonon assisted in both samples.
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Evolution of the sensitized Er(3+) emission by silicon nanoclusters and luminescence centers in silicon-rich silica.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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The structural and optical properties of erbium-doped silicon-rich silica samples containing different Si concentrations are studied. Intense photoluminescence (PL) from luminescence centers (LCs) and silicon nanoclusters (Si NCs), which evolves with annealing temperatures, is obtained. By modulating the silicon concentrations in samples, the main sensitizers of Er(3+) ions can be tuned from Si NCs to LCs. Optimum Er(3+) PL, with an enhancement of more than two, is obtained in the samples with a medium Si concentration, where the sensitization from Si NCs and LCs coexists.
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Transcriptome analysis of the mud crab (Scylla paramamosain) by 454 deep sequencing: assembly, annotation, and marker discovery.
PLoS ONE
PUBLISHED: 01-01-2014
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In this study, we reported the characterization of the first transcriptome of the mud crab (Scylla paramamosain). Pooled cDNAs of four tissue types from twelve wild individuals were sequenced using the Roche 454 FLX platform. Analysis performed included de novo assembly of transcriptome sequences, functional annotation, and molecular marker discovery. A total of 1,314,101 high quality reads with an average length of 411 bp were generated by 454 sequencing on a mixed cDNA library. De novo assembly of these 1,314,101 reads produced 76,778 contigs (consisting of 818,154 reads) with 5.4-fold average sequencing coverage. The remaining 495,947 reads were singletons. A total of 78,268 unigenes were identified based on sequence similarity with known proteins (E?0.00001) in UniProt and non-redundant protein databases. Meanwhile, 44,433 sequences were identified (E?0.00001) using a BLASTN search against the NCBI nucleotide database. Gene Ontology (GO) analysis indicated that biosynthetic process, cell part, and ion binding were the most abundant terms in biological process, cellular component, and molecular function categories, respectively. Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis revealed that 4,878 unigenes distributed in 281 different pathways. In addition, 19,011 microsatellites and 37,063 potential single nucleotide polymorphisms were detected from the transcriptome of S. paramamosain. Finally, thirty polymorphic microsatellite markers were developed and used to assess genetic diversity of a wild population of S. paramamosain. So far, existing sequence resources for S. paramamosain are extremely limited. The present study provides a characterization of transcriptome from multiple tissues and individuals, as well as an assessment of genetic diversity of a wild population. These sequence resources will facilitate the investigation of population genetic diversity, the development of genetic maps, and the conduct of molecular marker-assisted breeding in S. paramamosain and related crab species.
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Identification of transcriptome-derived microsatellite markers and their association with the growth performance of the mud crab (Scylla paramamosain).
PLoS ONE
PUBLISHED: 01-01-2014
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Microsatellite markers from a transcriptome sequence library were initially isolated, and their genetic variation was characterized in a wild population of the mud crab (Scylla paramamosain). We then tested the association between these microsatellite markers and the growth performance of S. paramamosain. A total of 129 polymorphic microsatellite markers were identified, with an observed heterozygosity ranging from 0.19 to 1.00 per locus, an expected heterozygosity ranging from 0.23 to 0.96 per locus, and a polymorphism information content (PIC) ranging from 0.21 to 0.95 per locus. Of these microsatellite markers, 30 showed polymorphism in 96 full-sib individuals of a first generation family. Statistical analysis indicated that three microsatellite markers were significantly associated with 12 growth traits of S. paramamosain. Of these three markers, locus Scpa36 was significantly associated with eight growth traits, namely, carapace length, abdomen width (AW), body height (BH), fixed finger length of the claw, fixed finger width of the claw, fixed finger height of the claw, meropodite length of pereiopod 2, and meropodite length of pereiopod 3 (MLP3) (P<0.05). Locus Scpa75 was significantly associated with five growth traits, namely, internal carapace width, AW, carapace width at spine 8, distance between lateral spine 2 (DLS2), and MLP3 (P<0.05). Locus Spm30 was significantly associated with BH, DLS2, and body weight (P<0.05). Further analysis suggested a set of genotypes (BC at Scpa36, BC and BD at Scpa75, and AC at Spm30) that have great potential in the selection of S. paramamosain for growth traits. These findings will facilitate the development of population conservation genetics and molecular marker-assisted selective breeding of S. paramamosain and other closely related species.
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Monitoring rates and heterogeneity of high-pressure germination of bacillus spores by phase-contrast microscopy of individual spores.
Appl. Environ. Microbiol.
PUBLISHED: 10-25-2013
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Germination of Bacillus spores with a high pressure (HP) of ?150 MPa is via activation of spores germinant receptors (GRs). The HP germination of multiple individual Bacillus subtilis spores in a diamond anvil cell (DAC) was monitored with phase-contrast microscopy. Major conclusions were that (i) >95% of wild-type spores germinated in 40 min in a DAC at ?150 MPa and 37°C but individual spores germination kinetics were heterogeneous; (ii) individual spores HP germination kinetic parameters were similar to those of nutrient-triggered germination with a variable lag time (Tlag) prior to a period of the rapid release (?Trelease) of the spores dipicolinic acid in a 1:1 chelate with Ca(2+) (CaDPA); (iii) spore germination at 50 MPa had longer average Tlag values than that at ?150 MPa, but the ?Trelease values at the two pressures were identical and HPs of <10 MPa did not induce germination; (iv) B. subtilis spores that lacked the cortex-lytic enzyme CwlJ and that were germinated with an HP of 150 MPa exhibited average ?Trelease values ?15-fold longer than those for wild-type spores, but the two types of spores exhibited similar average Tlag values; and (v) the germination of wild-type spores given a ?30-s 140-MPa HP pulse followed by a constant pressure of 1 MPa was the same as that of spores exposed to a constant pressure of 140 MPa that was continued for ?35 min; (vi) however, after short 150-MPa HP pulses and incubation at 0.1 MPa (ambient pressure), spore germination stopped 5 to 10 min after the HP was released. These results suggest that an HP of ?150 MPa for ?30 s is sufficient to fully activate spores GRs, which remain activated at 1 MPa but can deactivate at ambient pressure.
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Spectrophotometric and ultrasensitive DNA bioassay by circular-strand displacement polymerization reaction.
Analyst
PUBLISHED: 10-15-2013
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We demonstrated a new spectrophotometric DNA detection approach based on a circular strand-displacement polymerization reaction for the quantitative detection of sequence specific DNA. In this assay, the hybridization of an immobilized hairpin probe on the microtiter plate, to target DNA, results in a conformational change and leads to a stem separation. A short primer thus anneals with the open stem and triggers a polymerization reaction, allowing a cyclic reaction comprising the release of target DNA and hybridization of the target with the remaining immobilized hairpin probe. Through this cyclical process, a large number of duplex DNA complexes are produced. Finally, the biotin modified duplex DNA products can be detected via the HRP catalyzed substrate 3,3,5,5-tetramethylbenzidine using a spectrophotometer. As a proof of concept, a short DNA sequence (20-nt) related to the South East Asia (SEA) type deletion of ?-thalassemia was chosen as the model target. This proposed assay has a very high sensitivity and selectivity with a dynamic response ranging from 0.1 fM to 10 nM and the detection limit was 8 aM. It can be performed within 2 hours, and it can differentiate target SEA DNA from wild-type DNA. By substituting the hairpin probes used in the present work, this assay can be used to detect other subtypes of genetic disorders.
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Determination of residual enrofloxacin in food samples by a sensitive method of chemiluminescence enzyme immunoassay.
Food Chem
PUBLISHED: 09-11-2013
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A chemiluminescence enzyme immunoassay (CLEIA) based on the HRP-luminol-H2O2 chemiluminescence system for highly sensitive detection of enrofloxacin (ENR) was proposed in this study. Key factors that affect the precision and accuracy for the determination of ENR residues were optimised. Under the optimal conditions, the proposed method showed an excellent performance. The linearity range for method developed for determination of ENR was 0.35-1.0ng/mL with a correlation coefficient greater than 0.994. The limit of detection was 0.03ng/mL and the relative standard deviations (RSDs) were less than 9.4% and 13.0% for intra-day and inter-day assays. The proposed method was satisfactorily applied to determine ENR in milk, eggs, and honey samples at three spiked levels (0.4, 0.7, and 1.0ng/mL) and the recoveries ranged from 92.4% to 104.2% for milk, 93.8% to 103.2% for eggs and 94.1% to 105.0% for honey, respectively. Compared the results of CLEIA with those of ELISA and HPLC, the advantages of the CLEIA were further confirmed. Moreover, one 96-well microtiter plate coated with anti-ENR can be used to detect multiple samples at the same time, which indicated that the CLEIA using HRP-luminol-H2O2 system was a sensitive, high throughput and real-time method for ENR residues analysis.
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A sensitive electrochemical chlorophenols sensor based on nanocomposite of ZnSe quantum dots and cetyltrimethylammonium bromide.
Anal. Chim. Acta
PUBLISHED: 07-26-2013
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In this work, a very sensitive and simple electrochemical sensor for chlorophenols (CPs) based on a nanocomposite of cetyltrimethylammonium bromide (CTAB) and ZnSe quantum dots (ZnSe-CTAB) through electrostatic self-assembly technology was built for the first time. The composite of ZnSe-CTAB introduced a favorable access for the electron transfer and gave superior electrocatalytic activity for the oxidation of CPs than ZnSe QDs and CTAB alone. Differential pulse voltammetry (DPV) was used for the quantitative determination of the CPs including 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP). Under the optimum conditions, the peak currents of the CPs were proportional to their concentrations in the range from 0.02 to 10.0?M for 2-CP, 0.006 to 9.0?M for 2,4-DCP, and 0.06 to 8.0 for PCP. The detection limits were 0.008?M for 2-CP, 0.002?M for 2,4-DCP, and 0.01?M for PCP, respectively. The method was successfully applied for the determination of CPs in waste water with satisfactory recoveries. This ZnSe-CTAB electrode system provides operational access to design environment-friendly CPs sensors.
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Direct analysis of water content and movement in single dormant bacterial spores using confocal Raman microspectroscopy and Raman imaging.
Anal. Chem.
PUBLISHED: 07-15-2013
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Heavy water (D2O) has a distinct molecular vibration spectrum, and this has been used to analyze the water content, distribution, and movement in single dormant Bacillus cereus spores using confocal Raman microspectroscopy and Raman imaging. These methods have been used to measure the kinetics of D2O release from spores suspended in H2O, the spatial distribution of D2O in spores, and the kinetics of D2O release from spores during dehydration in air at room temperature. The results obtained were as follows. (1) The Raman spectrum of single D2O-loaded dormant spores suggests that D2O in spores is in a relatively weak hydrogen-bonded mode, compared to the strong hydrogen-bonded mode in pure D2O. (2) The D2O content of individual spores in a population was somewhat heterogeneous. (3) The spatial distribution of D2O in single dormant spores is uneven, and is less dense in the central core region. Raman images of different molecular components indicate that the water distribution is somewhat different from those of proteins and Ca-dipicolinic acid. (4) Exchange of spore D2O with external H2O took place in less than 1 s. (5) However, release of spore D2O during air dehydration at room temperature was slow and heterogeneous and took 2-3 h for complete D2O release.
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An enzyme-free and label-free assay for copper(II) ion detection based on self-assembled DNA concatamers and Sybr Green I.
Analyst
PUBLISHED: 07-01-2013
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An enzyme-free and label-free fluorescence turn on biosensor for amplified copper(II) ion (Cu(2+)) detection has been constructed based on self-assembled DNA concatamers and Sybr Green I. This assay is simple, inexpensive and sensitive, enabling quantitative detection of as low as 12.8 pM Cu(2+).
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[Determination of volatile N-nitrosamine compounds in salted aquatic products by gas chromatography-mass spectrometry].
Se Pu
PUBLISHED: 06-22-2013
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An analytical method was developed for the determination of the extraction of volatile N-nitrosamine compounds including N-nitrosodimethylamine ( NDMA) , N-nitrosodiethylamine (NDEA), N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosopiperidine (NPIP), and N-nitrosopyrrolidine (NPYR) from salted aquatic products by gas chromatography-mass spectrometry (GC-MS). In this experiment, the separation and detection conditions were optimized for different extraction methods, solid-phase extraction columns, and chromatographic columns. The results showed that the linear correlation coefficients (R2) were higher than 0. 999 8 within 10 - 1 000 micro g/L, and the reproducibilities were good with the - relative standard deviations (RSD) less than 8%. The recoveries were 79% - 105%. It is noted that this method for the determination of volatile N-nitrosamine compounds in salted aquatic products was much more sensitivity and with a lower detection limits (0. 05 micro g/kg except NDPA) than the previously reported methods. This proposed method is rapid and convenient for the determination, and easy for the operation. It is appropriate for the determination of volatile N-nitrosamine compounds in various salted aquatic products.
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Genetic programs in human and mouse early embryos revealed by single-cell RNA sequencing.
Nature
PUBLISHED: 06-10-2013
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Mammalian pre-implantation development is a complex process involving dramatic changes in the transcriptional architecture. We report here a comprehensive analysis of transcriptome dynamics from oocyte to morula in both human and mouse embryos, using single-cell RNA sequencing. Based on single-nucleotide variants in human blastomere messenger RNAs and paternal-specific single-nucleotide polymorphisms, we identify novel stage-specific monoallelic expression patterns for a significant portion of polymorphic gene transcripts (25?to 53%). By weighted gene co-expression network analysis, we find that each developmental stage can be delineated concisely by a small number of functional modules of co-expressed genes. This result indicates a sequential order of transcriptional changes in pathways of cell cycle, gene regulation, translation and metabolism, acting in a step-wise fashion from cleavage to morula. Cross-species comparisons with mouse pre-implantation embryos reveal that the majority of human stage-specific modules (7?out of?9) are notably preserved, but developmental specificity and timing differ between human and mouse. Furthermore, we identify conserved key members (or hub genes) of the human and mouse networks. These genes represent novel candidates that are likely to be key in driving mammalian pre-implantation development. Together, the results provide a valuable resource to dissect gene regulatory mechanisms underlying progressive development of early mammalian embryos.
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A universal biosensor for multiplex DNA detection based on hairpin probe assisted cascade signal amplification.
Chem. Commun. (Camb.)
PUBLISHED: 05-01-2013
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A hairpin DNA probe mediated cascade signal amplification method was developed for visual and rapid DNA analysis with a detection limit of 100 aM. The implementation of tag/anti-tag DNA and gold nanoparticle reporters permits a universal platform for multiplex genotyping without instrumentation.
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ZFP36L2 is required for self-renewal of early burst-forming unit erythroid progenitors.
Nature
PUBLISHED: 04-23-2013
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Stem cells and progenitors in many lineages undergo self-renewing divisions, but the extracellular and intracellular proteins that regulate this process are largely unknown. Glucocorticoids stimulate red blood cell formation by promoting self-renewal of early burst-forming unit-erythroid (BFU-E) progenitors. Here we show that the RNA-binding protein ZFP36L2 is a transcriptional target of the glucocorticoid receptor (GR) in BFU-Es and is required for BFU-E self-renewal. ZFP36L2 is normally downregulated during erythroid differentiation from the BFU-E stage, but its expression is maintained by all tested GR agonists that stimulate BFU-E self-renewal, and the GR binds to several potential enhancer regions of ZFP36L2. Knockdown of ZFP36L2 in cultured BFU-E cells did not affect the rate of cell division but disrupted glucocorticoid-induced BFU-E self-renewal, and knockdown of ZFP36L2 in transplanted erythroid progenitors prevented expansion of erythroid lineage progenitors normally seen following induction of anaemia by phenylhydrazine treatment. ZFP36L2 preferentially binds to messenger RNAs that are induced or maintained at high expression levels during terminal erythroid differentiation and negatively regulates their expression levels. ZFP36L2 therefore functions as part of a molecular switch promoting BFU-E self-renewal and a subsequent increase in the total numbers of colony-forming unit-erythroid (CFU-E) progenitors and erythroid cells that are generated.
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Successful PGD for late infantile neuronal ceroid lipofuscinosis achieved by combined chromosome and TPP1 gene analysis.
Reprod. Biomed. Online
PUBLISHED: 02-16-2013
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Late infantile neuronal ceroid lipofuscinosis (NCL-2) is a severe debilitating autosomal recessive disease caused by mutations in TPP1. There are no effective treatments, resulting in early childhood death. A couple with two affected children presented for reproductive genetic counselling and chose to undertake IVF and preimplantation genetic diagnosis (PGD) to avoid the possibility of another affected child. However, DNA testing revealed only one mutation in the proband inherited from mother. Linkage analysis identified five informative linked short tandem repeat markers to aid the genetic diagnosis. Following IVF, five cleavage-stage embryos were biopsied and blastomeres were first subjected to whole-genome amplification, then a series of down-stream molecular genetic analyses to diagnose TPP1 genotype and finally array comparative genomic hybridization (CGH) to assess the chromosomal ploidy of each embryo. Two unaffected euploid embryos were identified for transfer. One was transferred on day 5 resulting in an ongoing pregnancy. Confirmatory prenatal diagnosis by amniocentesis showed concordance of the embryo and fetal diagnosis. As far as is known, this is the first successful report of PGD for NCL-2 using double-factor PGD with simultaneous single-gene testing and array CGH to identify an unaffected and chromosomally normal embryo for transfer.
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Study on the reaction mechanism and the static injection chemiluminescence method for detection of acetaminophen.
Luminescence
PUBLISHED: 02-14-2013
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Acetaminophen, also called paracetamol, is found in Tylenol, Excedrin and other products as over-the-counter medicines. In this study, acetaminophen as a luminol signal enhancer was used in the chemiluminescence (CL) substrate solution of horseradish peroxidase (HRP) for the first time. The use of acetaminophen in the luminol-HRP-H2 O2 system affected not only the intensity of the obtained signal, but also its kinetics. It was shown that acetaminophen was to be a potent enhancer of the luminol-HRP-H2 O2 system. A putative enhancement mechanism for the luminol-H2 O2 -HRP-acetaminophen system is presented. The resonance of the nucleophilic amide group and the benzene ring of acetaminophen structure have a great effect on O-H bond dissociation energy of the phenol group and therefore on phenoxyl radical stabilization. These radicals act as mediators between HRP and luminol in an electron transfer reaction that generates luminol radicals and subsequently light emission, in which the intensity of CL is enhanced in the presence of acetaminophen. In addition, a simple method was developed to detect acetaminophen by static injection CL based on the enhanced CL system of luminol-H2 O2 -HRP by acetaminophen. Experimental conditions, such as pH and concentrations of substrates, have been examined and optimized. The proposed method exhibited good performance, the linear range was from 0.30 to 7.5 mM, the relative standard deviation was 1.86% (n?=?10), limit of detection was 0.16 mM and recovery was 99?±?4%. Copyright © 2013 John Wiley & Sons, Ltd.
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Genome sequencing of the important oilseed crop Sesamum indicum L.
Genome Biol.
PUBLISHED: 01-31-2013
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ABSTRACT: The Sesame Genome Working Group (SGWG) has been formed to sequence and assemble the sesame (Sesamum indicum L.) genome. The status of this project and our planned analyses are described.
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Optical coherence tomographic observations of polytetrafluoroethylene-covered sirolimus-eluting coronary arterial stent.
Am. J. Cardiol.
PUBLISHED: 01-23-2013
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The aim of this study was to evaluate neointimal coverage obtained using a new method of polytetrafluoroethylene-covered stent (PCS) implantation combined with underlying longer sirolimus-eluting stent (SES) implantation using optical coherence tomography. Nine patients were enrolled in this study, including patients with coronary artery perforations, original coronary aneurysms, and acquired coronary aneurysms after drug-eluting stent implantation. All patients were first treated with long SES implantation and then with focal PCS implantation. Postprocedural and follow-up angiographic and optical coherence tomographic examinations were performed in all patients, and intravascular ultrasound was performed in 5 patients. All patients were asymptomatic during follow-up, without recurrent angina. There was no stent-edge or stent-segment binary restenosis. Values of late loss for proximal SES segments, PCS segments, and distal SES segments were similar (0.09, 0.07, and 0.04 mm, respectively, p = 0.8113). The mean neointimal thickness of PCS was less than that of proximal and distal SES. However, no malapposed cross sections or uncovered cross sections were found in PCS segments compared with SES segments (p = 0.0011). In conclusion, the combination of PCS and underlying longer SES implantation can offer better angiographic follow-up results. High-resolution optical coherence tomography provided convincing proof of full neointimal coverage of PCS. This new method of combined PCS and SES implantation may be a better choice compared with direct PCS implantation in certain clinical settings.
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Projection-based volume alignment.
J. Struct. Biol.
PUBLISHED: 01-18-2013
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When heterogeneous samples of macromolecular assemblies are being examined by 3D electron microscopy (3DEM), often multiple reconstructions are obtained. For example, subtomograms of individual particles can be acquired from tomography, or volumes of multiple 2D classes can be obtained by random conical tilt reconstruction. Of these, similar volumes can be averaged to achieve higher resolution. Volume alignment is an essential step before 3D classification and averaging. Here we present a projection-based volume alignment (PBVA) algorithm. We select a set of projections to represent the reference volume and align them to a second volume. Projection alignment is achieved by maximizing the cross-correlation function with respect to rotation and translation parameters. If data are missing, the cross-correlation functions are normalized accordingly. Accurate alignments are obtained by averaging and quadratic interpolation of the cross-correlation maximum. Comparisons of the computation time between PBVA and traditional 3D cross-correlation methods demonstrate that PBVA outperforms the traditional methods. Performance tests were carried out with different signal-to-noise ratios using modeled noise and with different percentages of missing data using a cryo-EM dataset. All tests show that the algorithm is robust and highly accurate. PBVA was applied to align the reconstructions of a subcomplex of the NADH: ubiquinone oxidoreductase (Complex I) from the yeast Yarrowia lipolytica, followed by classification and averaging.
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The complete mitochondrial genome sequence and gene organization of the mud crab (Scylla paramamosain) with phylogenetic consideration.
Gene
PUBLISHED: 01-14-2013
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The complete mitochondrial genome is of great importance for better understanding the genome-level characteristics and phylogenetic relationships among related species. In the present study, we determined the complete mitochondrial genome DNA sequence of the mud crab (Scylla paramamosain) by 454 deep sequencing and Sanger sequencing approaches. The complete genome DNA was 15,824 bp in length and contained a typical set of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and a putative control region (CR). Of 37 genes, twenty-three were encoded by the heavy strand (H-strand), while the other ones were encoded by light strand (L-strand). The gene order in the mitochondrial genome was largely identical to those obtained in most arthropods, although the relative position of gene tRNA(His) differed from other arthropods. Among 13 protein-coding genes, three (ATPase subunit 6 (ATP6), NADH dehydrogenase subunits 1 (ND1) and ND3) started with a rare start codon ATT, whereas, one gene cytochrome c oxidase subunit I (COI) ended with the incomplete stop codon TA. All 22 tRNAs could fold into a typical clover-leaf secondary structure, with the gene sizes ranging from 63 to 73 bp. The phylogenetic analysis based on 12 concatenated protein-coding genes showed that the molecular genetic relationship of 19 species of 11 genera was identical to the traditional taxonomy.
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Effect of Hsp27 on early embryonic development in the mouse.
Reprod. Biomed. Online
PUBLISHED: 01-06-2013
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Previous studies by this study group have showed that heat shock protein 27 (Hsp27), expressed in the oocyte of growing follicles, is down-regulated in polycystic ovary syndrome ovaries and that down-regulation of Hsp27 improves the maturation of mouse oocytes and increases early apoptosis of oocytes. In this study, the effect of Hsp27 on early embryo development in the mouse was observed. Following microinjection of AdCMV-Hsp27 or AdsiRNA-Hsp27 into the cytoplasm of mouse zygotes, blastocyst morphology was observed and cell apoptosis of blastocysts was detected by TUNEL. After culture in vitro for 96h, blastocysts were analysed for Hsp27 expression by real-time PCR and immunofluorescence. The blastocyst formation rate and embryo quality were evaluated. The expression of Hsp27 was significantly increased in embryos with Hsp27 overexpression (AdCMV-Hsp27), while it was significantly suppressed by 75% in embryos with the gene silenced (AdsiRNA-Hsp27; both P<0.05). Cell apoptosis in blastocysts, blastocyst formation rate and embryo quality were unaffected by Hsp27 overexpression or gene silencing. In conclusion, overexpression or down-regulation of Hsp27 in zygotes, as a single factor, does not significantly affect the subsequent embryonic development.
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Normal human embryonic stem cell lines were derived from microsurgical enucleated tripronuclear zygotes.
J. Cell. Biochem.
PUBLISHED: 01-03-2013
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A normal fertilized human zygote contains two pronuclei, but zygotes may also display one, three, or even more pronuclei resulting from irregular insemination or meiotic division. Today diploid and triploid human embryonic stem cell (hESC) lines have been derived from tripronuclear (3PN) triploid zygotes, and an in-vitro fertilization (IVF) baby was born from a rescued diploid zygote by removing the extra male pronucleus of the 3PN zygote. However, whether hESCs can be derived from a rescued 3PN zygote is still unknown. Here, by microsurgical pronuclear removal, we restored 61 diploid zygotes from 3PN zygotes donated by 35 couples, and 11 blastocysts developed with a blastocyst rate of 18.0%, which seems higher than that of nonrescued 3PN zygotes according to previous reports. After the whole zona pellucida free embryos were plated onto feeder cells to grow and passage, 2 hESC lines (CCRM-hESC-22 and CCRM-hESC-23) were generated and both carried normal karyotype (46, XY). The hESC lines were then characterized by morphology, expansion in vitro, and expression of specific markers of alkaline phosphatase, OCT4, SSEA4, TRA-1-60 and TRA-1-81. Furthermore, the pluripotency of these 2 hESC lines was confirmed by in vitro embryoid body formation and in vivo teratoma production. Our study indicates that depronucleared 3PN zygotes can improve the blastocysts formation rate, and normal hESC lines can be derived from those corrected 2PN embryos. Based on their multi-directional differentiation potential in vitro, the established hESC lines could be applied to the developmental risk assessment for IVF babies born from restored zygotes.
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Pyrroloquinoline quinine inhibits RANKL-mediated expression of NFATc1 in part via suppression of c-Fos in mouse bone marrow cells and inhibits wear particle-induced osteolysis in mice.
PLoS ONE
PUBLISHED: 01-01-2013
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The effects of pyrroloquinoline quinine (PQQ) on RANKL-induced osteoclast differentiation and on wear particle-induced osteolysis were examined in this study. PQQ inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages (BMMs) in a dose-dependent manner without any evidence of cytotoxicity. The mRNA expression of c-Fos, NFATc1, and TRAP in RANKL-treated BMMs was inhibited by PQQ treatment. Moreover, RANKL-induced c-Fos and NFATc1 protein expression was suppressed by PQQ. PQQ additionally inhibited the bone resorptive activity of differentiated osteoclasts. Further a UHMWPE-induced murine calvaria erosion model study was performed to assess the effects of PQQ on wear particle-induced osteolysis in vivo. Mice treated with PQQ demonstrated marked attenuation of bone erosion based on Micro-CT and histologic analysis of calvaria. These results collectively suggested that PQQ demonstrated inhibitory effects on osteoclast differentiation in vitro and may suppress wear particle-induced osteolysis in vivo, indicating that PQQ may therefore serve as a useful drug in the prevention of bone loss.
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Multifocus confocal Raman microspectroscopy for rapid single-particle analysis.
J Biomed Opt
PUBLISHED: 12-24-2011
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We have developed a multifocus confocal Raman microspectroscopy system that allows simultaneous analyses of ? 80 individual biological or airborne microparticles based on a precise image-guided technique. Multiple individual particles adhered in random positions on a coverslip were illuminated by a multifocus excitation pattern formed by rapidly steering a single laser beam with a pair of galvo-mirrors, and their Raman scatterings were synchronously projected with another galvo-mirror to different rows of a CCD chip for parallel spectroscopic analyses. We show that this technique can be used to rapidly identify single airborne particles or bacteria collected on a slide and to monitor germination dynamics of multiple bacterial spores in real-time.
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Activation of peroxisome proliferator activated receptor alpha ameliorates ethanol induced steatohepatitis in mice.
Lipids Health Dis
PUBLISHED: 11-19-2011
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Peroxisome proliferator activated receptor alpha (PPAR?) regulates lipids metabolism and inhibits inflammatory response. However, the role of PPAR? in alcoholic liver disease is largely unknown. We aim to elucidate the effect and the molecular basis of PPAR? in ethanol induced hepatic injury in mice.
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Inhibition of p38 MAPK attenuates ionizing radiation-induced hematopoietic cell senescence and residual bone marrow injury.
Radiat. Res.
PUBLISHED: 10-20-2011
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Exposure to a moderate or high total-body dose of radiation induces not only acute bone marrow suppression but also residual (or long-term) bone marrow injury. The induction of residual bone marrow injury is primarily attributed to the induction of hematopoietic cell senescence by ionizing radiation. However, the mechanisms underlying radiation-induced hematopoietic cell senescence are not known and thus were investigated in the present study. Using a well-established long-term bone marrow cell culture system, we found that radiation induced hematopoietic cell senescence at least in part via activation of p38 mitogen-activated protein kinase (p38). This suggestion is supported by the finding that exposure to radiation selectively activated p38 in bone marrow hematopoietic cells. The activation was associated with a significant reduction in hematopoietic cell clonogenic function, an increased expression of p16(INK4a) (p16), and an elevated senescence-associated ?-galactosidase (SA-?-gal) activity. All these changes were attenuated by p38 inhibition with a specific p38 inhibitor, SB203580 (SB). Selective activation of p38 was also observed in bone marrow hematopoietic stem cells (HSCs) after mice were exposed to a sublethal total-body dose (6.5 Gy) of radiation. Treatment of the irradiated mice with SB after total-body irradiation (TBI) increased the frequencies of HSCs and hematopoietic progenitor cells (HPCs) in their bone marrow and the clonogenic functions of the irradiated HSCs and HPCs. These findings suggest that activation of p38 plays a role in mediating radiation-induced hematopoietic cell senescence and residual bone marrow suppression.
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From stem cell to red cell: regulation of erythropoiesis at multiple levels by multiple proteins, RNAs, and chromatin modifications.
Blood
PUBLISHED: 10-12-2011
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This article reviews the regulation of production of RBCs at several levels. We focus on the regulated expansion of burst-forming unit-erythroid erythroid progenitors by glucocorticoids and other factors that occur during chronic anemia, inflammation, and other conditions of stress. We also highlight the rapid production of RBCs by the coordinated regulation of terminal proliferation and differentiation of committed erythroid colony-forming unit-erythroid progenitors by external signals, such as erythropoietin and adhesion to a fibronectin matrix. We discuss the complex intracellular networks of coordinated gene regulation by transcription factors, chromatin modifiers, and miRNAs that regulate the different stages of erythropoiesis.
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Geriatric education for surgical residents: identifying a major need.
Am Surg
PUBLISHED: 09-28-2011
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This study evaluated a program designed to test and enhance residents knowledge of geriatrics. A 2-year prospective interventional trial was conducted. Surgical residents underwent pretesting (pre) in three areas: polypharmacy, delirium, and end of life. They then received educational materials and completed a posttest within 1 month and a patient simulation examination graded by a physician observer and the patient on his or her satisfaction. Forty-nine residents (51% interns, 55% general surgery residents) participated. Seventy per cent had no prior geriatrics education. Test scores significantly improved from pretest to posttest (12.9 ± 3.1 vs 13.78 ± 3.12, P = 0.01). The scores were consistently better on poly topics and consistently worse on end-of-life topics: pretest per cent correct: polypharmacy 60, end of life 46, P = 0.007; posttest percent correct: polypharmacy 63, end of life 49, P = 0.0014. By Pearson correlation, the pretest and posttest scores did not correlate with either the observer (R = -0.16, P = 0.27 pre, R = -0.08, P = 0.59 post) or subscores (R = -0.27, P = 0.11 pre, R = -0.13, P = 0.45 post), although the observer and subscore correlated with each other (R = 0.35, P = 0.036). Performance was poor and did not correlate with better patient care by simulation. Other options for geriatric education need to be considered and evaluated.
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A new 14-membered tetraazamacrocycle-bonded silica stationary phase for reversed-phase high-performance liquid chromatography.
Talanta
PUBLISHED: 09-11-2011
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A new high-performance liquid chromatography stationary phase has been prepared by covalently bonding 14-membered tetraazamacrocycle to silica gel using ?-chloropropyltrimethoxylsilane as coupling agent. The structure of the new material was characterized by infrared spectroscopy and elemental analysis. With 32 solutes including aromatic and aliphatic compounds, the linear solvation energy relationship method was successfully used to chromatographically evaluate the new phase in reversed phase mode. The retention property of the new phase shows evident similarity with that of ODS stationary phase, as well as distinctive, unique retention characteristics. The separations of n-alkylbenzene, carbamate and organophosphorus pesticides with diversified functional groups as well as phenolic compounds demonstrate that in addition to hydrophobic interaction, dipole-dipole interaction and hydrogen bonding interaction plus acid-base equilibrium could also be simultaneously offered by this new stationary phase, as a result excellent chromatographic performances are guaranteed.
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Inclusion complexes of phosphorylated daidzein derivatives with ?-cyclodextrin: Preparation and inclusion behavior study.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 08-11-2011
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In the present work the feasibility of ?-cyclodextrin in complexation was explored, as a tool for improving the solubility and biological ability of daidzein derivatives. A series of phosphorylated daidzein derivatives featuring different chain lengths were synthesized through a modified Atherton-Todd reaction and their inclusion complexes with ?CD were prepared by coprecipitation method. The inclusion complexation behavior was studied by fluorescence, UV, FT-IR, MS and (1)H NMR. The results showed that only phosphorylated daidzein derivative carrying small substituent group ((C(2)H(5)O)(2)PO) entered the cavity of ?CD and formed 1:1 inclusion complex. The formation constant was 175(mol/L)(-1).
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Nonparametric Bayesian dictionary learning for analysis of noisy and incomplete images.
IEEE Trans Image Process
PUBLISHED: 06-20-2011
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Nonparametric Bayesian methods are considered for recovery of imagery based upon compressive, incomplete, and/or noisy measurements. A truncated beta-Bernoulli process is employed to infer an appropriate dictionary for the data under test and also for image recovery. In the context of compressive sensing, significant improvements in image recovery are manifested using learned dictionaries, relative to using standard orthonormal image expansions. The compressive-measurement projections are also optimized for the learned dictionary. Additionally, we consider simpler (incomplete) measurements, defined by measuring a subset of image pixels, uniformly selected at random. Spatial interrelationships within imagery are exploited through use of the Dirichlet and probit stick-breaking processes. Several example results are presented, with comparisons to other methods in the literature.
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Monitoring the wet-heat inactivation dynamics of single spores of Bacillus species by using Raman tweezers, differential interference contrast microscopy, and nucleic acid dye fluorescence microscopy.
Appl. Environ. Microbiol.
PUBLISHED: 05-20-2011
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Dynamic processes during wet-heat treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis at 80 to 90°C were investigated using dual-trap Raman spectroscopy, differential interference contrast (DIC) microscopy, and nucleic acid stain (SYTO 16) fluorescence microscopy. During spore wet-heat treatment, while the spores 1:1 chelate of Ca(2+) with dipicolinic acid (CaDPA) was released rapidly at a highly variable time T(lag), the levels of spore nucleic acids remained nearly unchanged, and the T(lag) times for individual spores from the same preparation were increased somewhat as spore levels of CaDPA increased. The brightness of the spores DIC image decreased by ~50% in parallel with CaDPA release, and there was no spore cortex hydrolysis observed. The lateral diameters of the spores DIC image and SYTO 16 fluorescence image also decreased in parallel with CaDPA release. The SYTO 16 fluorescence intensity began to increase during wet-heat treatment at a time before T(lag) and reached maximum at a time slightly later than T(release). However, the fluorescence intensities of wet-heat-inactivated spores were ~15-fold lower than those of nutrient-germinated spores, and this low SYTO 16 fluorescence intensity may be due in part to the low permeability of the dormant spores inner membranes to SYTO 16 and in part to nucleic acid denaturation during the wet-heat treatment.
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Chemiluminescence enzyme immunoassay for the determination of sulfamethoxydiazine.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 05-02-2011
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Sulfamethoxydiazine (SMD), which is often used for animal disease treatment, is harmful to human health. No SMD residue should be detected in food in some countries, such as USA and Japan. Therefore, it is significant to develop a high-throughput, high-sensitivity and accurate method for the determination of the content of SMD in food. In this paper, chemiluminescence enzyme immunoassay (CLEIA) was developed for quantification of SMD. For this method, the limit of detection was 3.2 pg/ml, the linear range was from 10 to 2000 pg/ml, the within-day and inter-day precision were below 13% and below 18%, respectively, and the recovery was from 85% to 105%. Milk and egg were selected as samples to be examined with this method, and the result indicated that this CLEIA method was suitable for screening and quality control of food.
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Autophagy regulates ROS-induced cellular senescence via p21 in a p38 MAPK? dependent manner.
Exp. Gerontol.
PUBLISHED: 04-25-2011
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Oxidative stress induces not only senescence but also autophagy in a variety of mammalian cells. However, the relationship between these two has not been well established and thus, was investigated in the present study using WI38 human diploid fibroblasts (WI38 cells) as a model system. Our results showed that exposure of WI38 cells to H2O2 induced both senescence and autophagy. Downregulation of autophagy protein 5 (Atg5) with Atg5 siRNA inhibited not only autophagy but also senescence induced by H2O2. Further studies showed that Atg5 regulates H2O2-induced senescence primarily by up-regulating the expression of p21 at the level of post-transcription. In addition, we examined the mechanisms by which H2O2 induces autophagy in WI38 cells. Our results revealed that H2O2 increases autophagy independent of the mammalian target of rapamycin (mTOR) negative feedback pathway. Instead, the induction of autophagy by H2O2 depends on the induction of intracellular production of reactive oxygen species (ROS) and activation of the p38 mitogen-activated protein kinase ? (p38 MAPK?) pathway.
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The cross-talk between ROS and p38MAPK? in the Ex Vivo expanded human umbilical cord blood CD133(+) cells.
J. Huazhong Univ. Sci. Technol. Med. Sci.
PUBLISHED: 04-21-2011
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This study investigated the correlation between and compared the effects of reactive oxygen species (ROS) and p38 mitogen-activated protein kinase ? (p38MAPK?) in the ex vivo expanded umbilical cord blood (hUCB) CD133(+) cells. hUCB CD133(+) cells were cultured in the hematopoietic stem cells (HSCs) culture medium with N-acetylcysteine (NAC, an anti-oxidant), p38MAPK?-specific inhibitor (SB203580) or their combination. The levels of ROS and expression of phosphorylated p38MAPK? (p-p38) in CD133(+) cells were flow cytometrically detected. The efficacy of ex vivo expansion was evaluated by the density of CD133(+) cell sub-group colony-forming cells (CFC) and cobblestone area-forming cells (CAFC) assay. Our results showed decreased ROS levels in NAC, SB203580, and their combination treatment groups were almost 37%, 48%, and 85%, respectively. Furthermore, SB203580 abrogated the activation of p38MAPK? more obviously than NAC. Moreover, the CD133(+) cells in SB203580 treatment group had a 21.93±1.36-fold increase, and 14.50±1.19-fold increase in NAC treatment group, but only 10.13±0.57-fold increase in control group. In addition, SB203580 treatment led a higher level increase in the number of CFU and CAFC than NAC did. These findings suggested that, in expanded CD133(+) cells, ROS activates p38MAPK?, which, in turn, induces ROS production, and p38MAPK? might be the most suitable regulator in ROS-p38MAPK? pathway for the promotion of HSCs ex vivo expansion.
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Characterization of bacterial spore germination using phase-contrast and fluorescence microscopy, Raman spectroscopy and optical tweezers.
Nat Protoc
PUBLISHED: 04-21-2011
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This protocol describes a method combining phase-contrast and fluorescence microscopy, Raman spectroscopy and optical tweezers to characterize the germination of single bacterial spores. The characterization consists of the following steps: (i) loading heat-activated dormant spores into a temperature-controlled microscope sample holder containing a germinant solution plus a nucleic acid stain; (ii) capturing a single spore with optical tweezers; (iii) simultaneously measuring phase-contrast images, Raman spectra and fluorescence images of the optically captured spore at 2- to 10-s intervals; and (iv) analyzing the acquired data for the loss of spore refractility, changes in spore-specific molecules (in particular, dipicolinic acid) and uptake of the nucleic acid stain. This information leads to precise correlations between various germination events, and takes 1-2 h to complete. The method can also be adapted to use multi-trap Raman spectroscopy or phase-contrast microscopy of spores adhered on a cover slip to simultaneously obtain germination parameters for multiple individual spores.
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Molecular tilting and its impact on frictional properties of n-alkane self-assembled monolayers.
Langmuir
PUBLISHED: 04-13-2011
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Hydrophobic, methyl-terminated self-assembled monolayer (SAM) surfaces can be used to reduce friction. Among methyl-terminated SAMs, the frictional properties of alkanethiol SAMs and silane SAMs have been well-studied. In this research, we investigated friction of methyl-terminated n-hexatriacontane (C36) SAM and compared its friction properties with the alkanethiol and silane SAMs. Alkane SAM does not have an anchoring group. The alkane molecules stand on the surface by physical adsorption, which leads to a higher surface mobility of alkane molecules. We found that C36 SAM has a higher coefficient of friction than that of octadecyltrichlorosilane (OTS) silane. When an atomic force microscope (AFM) tip was swiped across the alkane SAM with a loading force, we found that the alkane SAM can withstand the tip loading pressure up to 0.48 GPa. Between 0.48 and 0.49Ga, the AFM tip partially penetrated the SAM. When the tip moved away, the deformed SAM healed and maintained the structural integrity. When the loading pressure was higher than 0.49 GPa, the alkane SAM was shaved into small pieces by the tip. In addition, we found that the molecular tilting of C36 molecules interacted with the tribological properties of the alkane SAM surface. On one hand, a higher loading force can push the rod-like alkane molecules to a higher tilting angle; on the other hand, a higher molecular tilting leads to a lower friction surface.
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Gender-related difference of sevoflurane postconditioning in isolated rat hearts: focus on phosphatidylinositol-3-kinase/Akt signaling.
J. Surg. Res.
PUBLISHED: 03-13-2011
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Previous studies have reported that female gender confers cardioprotection against ischemia/reperfusion (I/R) injury, partly because estrogen activates phosphatidylinositol-3-kinase/Akt (PI3K/Akt) pathway. We have previously proven that cardioprotection of sevoflurane postconditioning is mediated by PI3K/Akt pathway in male rats. The purpose of the present study was to determine whether the cardioprotection of sevoflurane postconditioning is influenced by gender, and the role of PI3K/Akt pathway in such gender difference.
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Inhibition of p38 mitogen-activated protein kinase promotes ex vivo hematopoietic stem cell expansion.
Stem Cells Dev.
PUBLISHED: 02-24-2011
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Hematopoietic stem cell (HSC) self-renewal is tightly regulated by a complex crosstalk between many cell-intrinsic regulators and a variety of extrinsic signals from the stem cell niche. In this study, we examined whether the p38 mitogen-activated protein kinase (p38) is one of the intrinsic regulators that can negatively regulate HSC self-renewal in vitro and whether inhibition of p38 activity with a small molecule inhibitor can promote HSC expansion ex vivo. The results from this study showed that sorted mouse bone marrow Lin(-)Sca1(+)c-kit(+) cells (LSK(+) cells) exhibited selective activation of p38 after culture in a serum-free medium supplemented with 100 ng/mL stem cell factor, thrombopoietin, and Flt3 ligand. The activation of p38 was associated with a significant reduction in HSCs and induction of apoptosis and cellular senescence in LSK(+) cells and their progeny. Addition of the specific p38 inhibitor SB203580 (SB, 5 ?M) to the culture inhibited the activation of p38 in LSK(+) cells, which led to increase in HSC self-renewal and ex vivo expansion as shown by the cobblestone area forming cell assay, competitive repopulation, and serial transplantation. The increase in HSC expansion is likely attributable to SB-mediated inhibition of HSC apoptosis and senescence and upregulation of HoxB4 and CXCR4. These findings suggest that p38 plays an important role in the regulation of HSC self-renewal in vitro and inhibition of p38 activation with a small molecule inhibitor may represent a novel approach to promote ex vivo expansion of HSCs.
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cDNA cloning and expression analysis of gustavus gene in the oriental river prawn Macrobrachium nipponense.
PLoS ONE
PUBLISHED: 01-22-2011
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The gustavus gene is required for localizing pole plasm and specifying germ cells. Research on gustavus gene expression will advance our understanding of the biological function of gustavus in animals. A cDNA encoding gustavus protein was identified and termed MnGus in the oriental river prawn Macrobrachium nipponense. Bioinformatic analyses showed that this gene encoded a protein of 262 amino acids and the protein belongs to the Spsb1 family. Real-time quantitative PCR analyses revealed that the expression level of MnGus in prawn embryos was slightly higher at the cleavage stage than at the blastula stage, and reached the maximum level during the zoea stage of embryos. The minimum level of MnGus expression occurred during the perinucleolus stage in the ovary, while the maximum was at the oil globule stage, and then the level of MnGus expression gradually decreased with the advancement of ovarian development. The expression level of MnGus in muscle was much higher than that in other tissues in mature prawn. The gustavus cDNA sequence was firstly cloned from the oriental river prawn and the pattern of gene expression was described during oocyte maturation, embryonic development, and in other tissues. The differential expression patterns of MnGus in the embryo, ovary and other somatic tissues suggest that the gustavus gene performs multiple physiological functions in the oriental river prawn.
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Determination of puerarin in biological samples and its application to a pharmacokinetic study by flow-injection chemiluminescence.
Luminescence
PUBLISHED: 01-09-2011
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A simple and sensitive flow injection-chemiluminescence (FI-CL) method has been developed for the determination of puerarin, based on the fact that puerarin can greatly inhibit CL of the luminol-H?O?-haemoglobin system. The inhibition of CL intensity was linear to the logarithm of the concentration of puerarin in the range 0.08-10.0??g/mL (r² ?=?0.9912). The limit of detection was 0.05??g/mL (3?) and the relative standard deviation (RSD) for 1.0??g/mL (n?=?11) of puerarin solution was 1.4%. Coupled with solid-phase extraction (SPE) as the sample pretreatment, the determination of puerarin in biological samples and a preliminary pharmocokinetic study of puerarin in rats were performed. The recoveries for plasma and urine at three different concentrations were 89.2-110.0% and 91.4-104.8%, respectively. The pharmacokinetics of puerarin in plasma of rat coincides with the two-compartment open model. The T(½?) , T(½?) , CL/F, V(Z/F), AUC(??t), MRT???, T(max) and C(max) were 0.77?±?0.21?h, 7.55?±?2.64?h, 2.43?±?1.02?L/kg/h, 11.40?±?3.45?L/kg, 56.67?±?10.65?mg/h/L, 5.04?±?2.78?h, 1.00?±?0.35?h and 19.70?±?4.67??g/mL, respectively.
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miR-191 regulates mouse erythroblast enucleation by down-regulating Riok3 and Mxi1.
Genes Dev.
PUBLISHED: 01-04-2011
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Using RNA-seq technology, we found that the majority of microRNAs (miRNAs) present in CFU-E erythroid progenitors are down-regulated during terminal erythroid differentiation. Of the developmentally down-regulated miRNAs, ectopic overexpression of miR-191 blocks erythroid enucleation but has minor effects on proliferation and differentiation. We identified two erythroid-enriched and developmentally up-regulated genes, Riok3 and Mxi1, as direct targets of miR-191. Knockdown of either Riok3 or Mxi1 blocks enucleation, and either physiological overexpression of miR-191 or knockdown of Riok3 or Mxi1 blocks chromatin condensation. Thus, down-regulation of miR-191 is essential for erythroid chromatin condensation and enucleation by allowing up-regulation of Riok3 and Mxi1.
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Combination of Raman tweezers and quantitative differential interference contrast microscopy for measurement of dynamics and heterogeneity during the germination of individual bacterial spores.
J Biomed Opt
PUBLISHED: 11-09-2010
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Raman tweezers and quantitative differential interference contrast (DIC) microscopy are combined to monitor the dynamic germination of individual bacterial spores of Bacillus species, as well as the heterogeneity in this process. The DIC bias phase is set properly such that the brightness of DIC images of individual spores is proportional to the dipicolinic acid (DPA) level of the spores, and an algorithm is developed to retrieve the phase image of an individual spore from its DIC image. We find that during germination, the rapid drop in both the intensity of the original DIC image and the intensity of the reconstructed phase image precisely corresponds to the release of all DPA from that spore. The summed pixel intensity of the DIC image of individual spores adhered on a microscope coverslip is not sensitive to the drift of the slide in both horizontal and vertical directions, which facilitates observation of the germination of thousands of individual spores for long periods of time. A motorized stage and synchronized image acquisition system is further developed to effectively expand the field of view of the DIC imaging. This quantitative DIC technique is used to track the germination of hundreds or thousands of individual spores simultaneously.
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Multiple-trap laser tweezers Raman spectroscopy for simultaneous monitoring of the biological dynamics of multiple individual cells.
Opt Lett
PUBLISHED: 10-23-2010
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We report the development of a multiple-trap laser tweezers Raman spectroscopy (LTRS) array for simultaneously acquiring Raman spectra of individual cells in physiological environments. This LTRS-array technique was also combined with phase contrast and fluorescence microscopy, allowing measurement of Raman spectra, refractility, and fluorescence images of individual cells with a temporal resolution of ~5 s. As a demonstration, we used this technique to monitor multiple Bacillus cereus spores germinating in a nutrient medium for up to 90min and observed the kinetics of dipicolinic acid release and uptake of nucleic acid-binding stain molecules during spore germination.
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Heme oxygenase-1 prevents non-alcoholic steatohepatitis through suppressing hepatocyte apoptosis in mice.
Lipids Health Dis
PUBLISHED: 10-03-2010
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Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant properties. However, the role of HO-1 on hepatocyte apoptosis remains unclear. We aim to elucidate the effects of HO-1 on oxidative stress related hepatocellular apoptosis in nutritional steatohepatitis in mice.
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Monitoring the kinetics of uptake of a nucleic acid dye during the germination of single spores of Bacillus species.
Anal. Chem.
PUBLISHED: 09-30-2010
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Dormant bacterial spores do not take up and bind nucleic acid dyes in the spore core but readily take up such dyes when they are fully germinated. We present a methodology that combines fluorescence microscopy, phase contrast microscopy, and laser tweezers Raman spectroscopy to monitor the kinetics of uptake of the nucleic acid dye SYTO 16 during germination of individual Bacillus cereus and Bacillus subtilis spores. The level of dye bound to nucleic acids of individual spores was measured by fluorescence emission, while changes in spore refractility and the level of the 1:1 chelate of dipicolinic acid and Ca(2+) (CaDPA) were monitored by phase contrast microscopy and Raman spectroscopy, respectively. The results obtained include (1) during nutrient germination, SYTO 16 began to enter the spore core and bind to nucleic acids just when spores had released all CaDPA and continued until hydrolysis of spores peptidoglycan cortex was complete; (2) during germination with exogenous CaDPA, rapid SYTO 16 uptake began only 2-7 min after complete release of endogenous CaDPA for both B. cereus and B. subtilis spores; (3) the rate but not the timing of dye uptake and the maximum level of dye bound to nucleic acid were increased during nutrient germination of B. subtilis spores lacking ~75% of the DNA binding proteins that normally saturate dormant spore DNA; (4) SYTO 16-DNA binding was not observed during nutrient germination of B. subtilis spores lacking the protease that degrades spores DNA binding proteins, even after cortex hydrolysis; (5) SYTO 16 uptake by germinating B. subtilis spores lacking the cortex-lytic enzyme (CLE) CwlJ was low, again even after cortex hydrolysis, although SYTO 16 uptake by germinating spores lacking the other redundant CLE SleB was even higher than in germinating wild-type spores; and (6) there was no SYTO 16 uptake by germinating spores that lacked both CwlJ and SleB, even after CaDPA release. These results suggest that during spore germination SYTO 16 uptake is minimal until CaDPA has been released and DNA binding proteins have been degraded and further that CLEs degradation of the spore cortex plays a crucial role in uptake of this dye.
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Operational energy performance assessment system of municipal wastewater treatment plants.
Water Sci. Technol.
PUBLISHED: 09-24-2010
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Based on the statistical analysis of operational energy consumption and its influential factors from data of 599 Chinese WWTPs in 2006, it is noticed that the most influential factors include treatment technology adopted, treated sewage amount, removed pollutants amount, etc. Using the conclusion above, this paper sets up an integrated system of operational energy performance assessment for municipal wastewater treatment plants. Combining with result from on-spot research and model simulation, the calculating method of benchmark value and score of 7 energy efficiency indicators grouped into 3 levels is stated. Applying the assessment system to three plants, its applicability and objectivity are proved and suggestions to improve energy performance are provided.
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Detection of phenolic metabolites of styrene in mouse liver and lung microsomal incubations.
Drug Metab. Dispos.
PUBLISHED: 08-19-2010
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Metabolic activation is considered to be a critical step for styrene-induced pulmonary toxicity. Styrene-7,8-oxide is a primary oxidative metabolite generated by vinyl epoxidation of styrene. In addition, urinary 4-vinylphenol (4-VP), a phenolic metabolite formed by aromatic hydroxylation, has been detected in workers and experimental animals after exposure to styrene. In the present study, new oxidative metabolites of styrene, including 2-vinylphenol (2-VP), 3-vinylphenol (3-VP), vinyl-1,4-hydroquinone, and 2-hydroxystyrene glycol were detected in mouse liver microsomal incubations. The production rates of 2-VP, 3-VP, 4-VP, and styrene glycol were 0.0527 ± 0.0045, 0.0019 ± 0.0006, 0.0053 ± 0.0002, and 4.42 ± 0.33 nmol/(min · mg protein) in mouse liver microsomes, respectively. Both disulfiram (100 ?M) and 5-phenyl-1-pentyne (5 ?M) significantly inhibited the formation of the VPs and styrene glycol. 2-VP, 3-VP, and 4-VP were metabolized in mouse liver microsomes at rates of 2.50 ± 0.30, 2.63 ± 0.13, and 3.45 ± 0.11 nmol/(min · mg protein), respectively. The three VPs were further metabolized to vinylcatechols and/or vinyl-1,4-hydroquinone and the corresponding glycols. Pulmonary toxicity of 2-VP, 3-VP, and 4-VP was evaluated in CD-1 mice, and 4-VP was found to be more toxic than 2-VP and 3-VP.
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Development of lipid-rich plaque inside bare metal stent: possible mechanism of late stent thrombosis? An optical coherence tomography study.
Heart
PUBLISHED: 07-20-2010
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To study in-stent tissue characteristics by optical coherence tomography (OCT) at long-term follow-up in patients with previous bare metal stent implantation.
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Development of eighteen polymorphic microsatellite markers in Scylla paramamosain by 5 anchored PCR technique.
Mol. Biol. Rep.
PUBLISHED: 07-16-2010
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The mud crab Scylla paramamosain plays a significant role in fishery resources in China. In this study, we developed 18 polymorphic microsatellite markers in this important crab by 5 anchored PCR technique. A total of 125 alleles were detected in a single population of 32 individuals of S. paramamosain. The number of alleles per locus ranged from five to nine, with the allele size ranging from 166 to 316 bp. The polymorphism information content (PIC), observed and expected heterozygosity ranged from 0.39 to 0.88, from 0.33 to 0.92 and from 0.42 to 0.86, respectively. Three loci (Scypa13, Scypa14 and Scypa15) deviated significantly from Hardy-Weinberg equilibrium (HWE) after Bonferroni correction (P < 0.0028), and no linkage disequilibrium was found between loci pairs. These polymorphic microsatellite markers will be useful for the study of population genetic structure, construction of genetic linkage maps and mapping of economically quantitative trait loci (QTL) in S. paramamosain.
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[The effect of uvulopalatopharyngoplasty by radio frequency plasma].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 05-01-2010
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To study the effect of uvulopalatopharyngoplasty(UPPP) by using radio frequency plasma on obstructive sleep apnea-hypopnea syndrome(OSAHS) with velopharyngeal obstruction.
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Ultrasonic-assisted synthesis of chrysin derivatives linked with 1,2,3-triazoles by 1,3-dipolar cycloaddition reaction.
Ultrason Sonochem
PUBLISHED: 04-10-2010
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The 1,3-dipolar cycloaddition reaction between 7-(3-azidopropoxy)-5-hydroxyflavone and phenylacetylene was carried out to investigate the synthesis of 7-(3-(4-phenyl-1,2,3-triazol-1-yl)propoxy)- 5-hydroxyflavone in presence of ultrasound (sono-synthesis) and absence of ultrasound (conventional method) under relatively optimized solvent and catalyst conditions. The reaction rate was notably accelerated with the help of ultrasound irradiation. An experiment was especially carried out for investigating the acceleration mechanism of ultrasound on the cycloaddition. A novel series of chrysin derivatives linked with 1,2,3-triazoles were obtained by the copper(I)-catalyzed 1,3-dipolar Huisgen cycloaddition reaction using t-BuOH/H(2)O (1:1 v/v) as reaction solvents and CuSO(4)·5H(2)O/sodium ascorbate as the catalyst at room temperature in the presence of ultrasound irradiation. Their structures are elucidated by NMR, ESI MS, IR and Elemental analysis.
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