JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Intestinal Triacylglycerol Synthesis in Fat Absorption and Systemic Energy Metabolism.
J. Lipid Res.
PUBLISHED: 09-19-2014
Show Abstract
Hide Abstract
The intestine plays a prominent role in the biosynthesis of triacylglycerol (TAG). Digested dietary triacylglycerol is re-packaged in the intestine to form the hydrophobic core of chylomicrons, which deliver metabolic fuels, essential fatty acids, and other lipid-soluble nutrients to the peripheral tissues. By controlling the flux of dietary fat into the circulation, intestinal TAG synthesis can greatly impact systemic metabolism. Genes encoding many of the enzymes involved in TAG synthesis have been identified. Among TAG synthesis enzymes, acyl CoA:monoacylglycerol acyltransferase 2 (MGAT2) and acyl CoA:diacylglycerol acyltransferase 1 (DGAT1) are highly expressed in the intestine. Their physiological functions have been examined in the context of whole organisms using genetically engineered mice and, in the case of DGAT1, specific inhibitors. An emerging theme from recent findings is that limiting the rate of TAG synthesis in the intestine can modulate gut hormone secretion, lipid metabolism, and systemic energy balance. The underlying mechanisms and their implications for humans are yet to be explored. Pharmacological inhibition of TAG hydrolysis in the intestinal lumen has been employed to combat obesity and associated disorders with modest efficacy and unwanted side effects. The therapeutic potential of inhibiting specific enzymes involved in intestinal TAG synthesis warrants further investigation.
Related JoVE Video
Identification, immunolocalization, and characterization analyses of an exopeptidase of papain superfamily, (cathepsin C) from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 08-21-2014
Show Abstract
Hide Abstract
Cathepsin C is an important exopeptidase of papain superfamily and plays a number of great important roles during the parasitic life cycle. The amino acid sequence of cathepsin C from Clonorchis sinensis (C. sinensis) showed 54, 53, and 49% identities to that of Schistosoma japonicum, Schistosoma mansoni, and Homo sapiens, respectively. Phylogenetic analysis utilizing the sequences of papain superfamily of C. sinensis demonstrated that cathepsin C and cathepsin Bs came from a common ancestry. Cathepsin C of C. sinensis (Cscathepsin C) was identified as an excretory/secretory product by Western blot analysis. The results of transcriptional level and translational level of Cscathepsin C at metacercaria stage were higher than that at adult worms. Immunolocalization analysis indicated that Cscathepsin C was specifically distributed in the suckers (oral sucker and ventral sucker), eggs, vitellarium, intestines, and testis of adult worms. In the metacercaria, it was mainly detected on the cyst wall and excretory bladder. Combining with the results mentioned above, it implies that Cscathepsin C may be an essential proteolytic enzyme for proteins digestion of hosts, nutrition assimilation, and immune invasion of C. sinensis. Furthermore, it may be a potential diagnostic antigen and drug target against C. sinensis infection.
Related JoVE Video
Understanding and tuning electronic structure in modified ceria nanocrystals by defect engineering.
Langmuir
PUBLISHED: 08-21-2014
Show Abstract
Hide Abstract
This study investigates the effect of Fe(3+) on the electronic structure of nanocrystalline ceria. Systematic synchrotron X-ray absorption spectroscopy coupled with scanning transmission electron microscopy/electron energy loss spectroscopy was utilized. The oxygen vacancies can be engineered and their number varied with the degree of iron doping. Comparing the local electronic structure around Ce sites with that around Fe sites reveals two stages of defect engineering. The concentration of Ce(3+) and the distribution of defects differ between lower and higher degrees of doping. Charge is transferred between Ce and Fe when the doping level is less than 5%, but this effect is not significant at a doping level of over 5%. This transfer of charge is verified by energy loss spectroscopy. These Fe-modified ceria nanoparticles exhibit core-shell-like structures at low doping levels and this finding is consistent with the results of scanning transmission electron microscopy/electron energy loss spectroscopy. More Fe is distributed at the surface for doping levels less than 5%, whereas the homogeneity of Fe in the system increases for doping levels higher than 5%. X-ray magnetic circular dichroism spectroscopy reveals that Ce, rather than Fe, is responsible for the ferromagnetism. Interestingly, Ce(3+) is not essential for producing the ferromagnetism. The oxygen vacancies and the defect structure are suggested to be the main causes of the ferromagnetism. The charge transfer and defect structure Fe(3+)-Vo-Ce(3+) and Fe(3+)-Vo-Fe(3+) are critical for the magnetism, and the change in saturated magnetization can be understood as being caused by the competition between interactions that originate from magnetic polarons and from paired ions.
Related JoVE Video
Low Carrier Density Epitaxial Graphene Devices On SiC.
Small
PUBLISHED: 08-18-2014
Show Abstract
Hide Abstract
The transport characteristics of graphene devices with low n- or p-type carrier density (?10(10) -10(11) cm(-2) ), fabricated using a new process that results in minimal organic surface residues, are reported. The p-type molecular doping responsible for the low carrier densities is initiated by aqua regia. The resulting devices exhibit highly developed ? = 2 quantized Hall resistance plateaus at magnetic field strengths of less than 4 T.
Related JoVE Video
Hot carriers in epitaxial graphene sheets with and without hydrogen intercalation: role of substrate coupling.
Nanoscale
PUBLISHED: 08-13-2014
Show Abstract
Hide Abstract
The development of graphene electronic devices produced by industry relies on efficient control of heat transfer from the graphene sheet to its environment. In nanoscale devices, heat is one of the major obstacles to the operation of such devices at high frequencies. Here we have studied the transport of hot carriers in epitaxial graphene sheets on 6H-SiC (0001) substrates with and without hydrogen intercalation by driving the device into the non-equilibrium regime. Interestingly, we have demonstrated that the energy relaxation time of the device without hydrogen intercalation is two orders of magnitude shorter than that with hydrogen intercalation, suggesting application of epitaxial graphene in high-frequency devices which require outstanding heat exchange with an outside cooling source.
Related JoVE Video
The effect of alcohol intoxication on mortality of blunt head injury.
Biomed Res Int
PUBLISHED: 08-04-2014
Show Abstract
Hide Abstract
Alcohol is found to have neuroprotection in recent studies in head injuries. We investigated the association of blood alcohol concentration (BAC) with mortality of patients with blunt head injury after traffic accident. All patients sustaining blunt head injury caused by traffic accident brought to our emergency department who had obtained a brain computed tomography scans and BAC were analyzed. Patients with unknown mechanisms, transfers from outside hospitals, and incomplete data were excluded. Logistic regression was used to identify independent predictors of mortality. During the study period, 3,628 patients with brain computed tomography (CT) were included. Of these, BAC was measured in 556 patients. Patients with the lowest BAC (less than 8?mg/dl) had lower mortality; intoxicated patients with BAC between 8 and less than 100?mg/dl were associated with significantly higher mortality than those patients in other intoxicated groups. Adjusted logistic regression demonstrated higher BAC group and Glasgow coma scale (GCS) scores, and lower ISS and age were identified as independent predictors of reduced mortality. In our study, we found that patients who had moderate alcohol intoxication had higher risk of mortality. However, higher GCS scores, lower ISS, and younger age were identified as independent predictors of reduced mortality in the study patients.
Related JoVE Video
Syndecan-1 is required to maintain intradermal fat and prevent cold stress.
PLoS Genet.
PUBLISHED: 08-01-2014
Show Abstract
Hide Abstract
Homeostatic temperature regulation is fundamental to mammalian physiology and is controlled by acute and chronic responses of local, endocrine and nervous regulators. Here, we report that loss of the heparan sulfate proteoglycan, syndecan-1, causes a profoundly depleted intradermal fat layer, which provides crucial thermogenic insulation for mammals. Mice without syndecan-1 enter torpor upon fasting and show multiple indicators of cold stress, including activation of the stress checkpoint p38? in brown adipose tissue, liver and lung. The metabolic phenotype in mutant mice, including reduced liver glycogen, is rescued by housing at thermoneutrality, suggesting that reduced insulation in cool temperatures underlies the observed phenotypes. We find that syndecan-1, which functions as a facultative lipoprotein uptake receptor, is required for adipocyte differentiation in vitro. Intradermal fat shows highly dynamic differentiation, continuously expanding and involuting in response to hair cycle and ambient temperature. This physiology probably confers a unique role for Sdc1 in this adipocyte sub-type. The PPAR? agonist rosiglitazone rescues Sdc1-/- intradermal adipose tissue, placing PPAR? downstream of Sdc1 in triggering adipocyte differentiation. Our study indicates that disruption of intradermal adipose tissue development results in cold stress and complex metabolic pathology.
Related JoVE Video
Patient outcomes following subarachnoid hemorrhage between the medical center and regional hospital: whether all patients should be transferred to medical centers.
Biomed Res Int
PUBLISHED: 07-14-2014
Show Abstract
Hide Abstract
Subarachnoid hemorrhage (SAH) is a critical illness that may result in patient mortality or morbidity. In this study, we investigated the outcomes of patients treated in medical center and nonmedical center hospitals and the relationship between such outcomes and hospital and surgeon volume. Patient data were abstracted from the National Health Insurance Research Database of Taiwan in the Longitudinal Health Insurance Database 2000, which contains all claims data of 1 million beneficiaries randomly selected in 2000. The International Classification of Diseases, Ninth Revision, subarachnoid hemorrhage (430) was used for the inclusion criteria. We identified 355 patients between 11 and 87 years of age who had subarachnoid hemorrhage. Among them, 32.4% (115/355) were men. The median Charlson comorbidity index (CCI) score was 1.3 (SD ± 0.6). Unadjusted logistic regression analysis demonstrated that low mortality was associated with high hospital volume (OR = 3.21; 95% CI: 1.18-8.77). In this study, we found no statistical significances of mortality, LOS, and total charges between medical centers and nonmedical center hospitals. Patient mortality was associated with hospital volume. Nonmedical center hospitals could achieve resource use and outcomes similar to those of medical centers with sufficient volume.
Related JoVE Video
Recombinant viral capsid protein VP1 suppresses lung cancer metastasis by inhibiting COX-2/PGE2 and MIG-7.
Oncotarget
PUBLISHED: 07-09-2014
Show Abstract
Hide Abstract
Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus binds to integrins to modulate Akt/GSK3-? signaling and suppress migration/invasion and metastasis of cancer cells, but the underlying molecular mechanism is unclear. Here, we showed that the rVP1-mediated inhibition of Akt/GSK3-? signaling and cell migration/invasion was accompanied by downregulation in phosphatidylinositol (3,4,5)-triphosphate (PIP3), integrin-linked kinase (ILK) and IKK/NF-?B signaling as well as suppression of COX-2/PGE2 and MIG-7. Addition of PIP3 or overexpression of ILK reversed the rVP1-induced inhibition of IKK/NF-?B signaling, COX-2 and MIG-7. The rVP1-mediated downregulation of COX-2/PGE2 and MIG-7 led to not only attenuation of epithelial-mesenchymal transition, MMP2 activity and invasion of lung cancer cells in vitro but also decreased tumor growth and metastasis of lung cancer in xenograft mice. Moreover, downregulation of COX-2/PGE2 and MIG-7 significantly prolonged the overall and disease-free survival of lung cancer-bearing mice. These results suggest that rVP1 inhibits cancer invasion/metastasis, partly if not mainly, via downregulating integrin/PI3K/Akt, ILK and IKK/NF-?B signaling to suppress expression of COX-2/PGE2 and MIG-7.
Related JoVE Video
Localization and electron-electron interactions in few-layer epitaxial graphene.
Nanotechnology
PUBLISHED: 05-30-2014
Show Abstract
Hide Abstract
This paper presents a study of the quantum corrections caused by electron-electron interactions and localization to the conductivity in few-layer epitaxial graphene, in which the carriers responsible for transport are massive. The results demonstrate that the diffusive model, which can generally provide good insights into the magnetotransport of two-dimensional systems in conventional semiconductor structures, is applicable to few-layer epitaxial graphene when the unique properties of graphene on the substrate, such as intervalley scattering, are taken into account. It is suggested that magnetic-field-dependent electron-electron interactions and Kondo physics are required for obtaining a thorough understanding of magnetotransport in few-layer epitaxial graphene.
Related JoVE Video
Comparison of two serpins of Clonorchis sinensis by bioinformatics, expression, and localization in metacercaria.
Pathog Glob Health
PUBLISHED: 05-16-2014
Show Abstract
Hide Abstract
Clonorchiasis, which has been an important public health problem in China, is caused by ingestion of raw or undercooked fish contaminated by live metacercaria. Therefore, preventing fish from infecting is of great significance for controlling the disease. SERPINs (serine protease inhibitors) are well known as negative regulators of hemostasis, thrombolysis, and innate immune responses. In the present study, two full-length sequences encoding SERPIN were identified from metacercaria cDNA library of Clonorchis sinensis (C. sinensis) and were denominated as CsSERPIN and CsSERPIN3, respectively. Bioinformatics analysis showed that the two sequences shares 35.9% identity to each other. Both of the sequences have SERPIN domain and the greatest difference between the two domains is the reactive centre loop. Transmembrane region was found in CsSERPIN3 while not in CsSERPIN. The expression of the two CsSERPINs was significantly higher at the life stage of metacercaria than that of adult. The transcription levels of CsSERPIN and CsSERPIN3 at metacercaria stage were 3.249- and 11.314-fold of that at adult stage, respectively. Furthermore, the expression of CsSERPIN was 4.32-fold of that of CsSERPIN3 at metacercaria stage. Immunobiochemistry revealed that CsERPIN was dispersed at subtegument and oral sucker of metacercaria, while CsSERPIN3 localized intensely in the tegument of metacercaria of C. sinensis inside of the cyst wall. All these indicated that the CsSERPINs play important roles at metacercaria stage of the parasite. CsSERPIN may take part in regulation of endogenous serine proteinase and CsSERPIN3 may be involved in immune evasion and be a potential candidate for vaccine and drug target for clonorchiasis.
Related JoVE Video
How early should VATS be performed for retained haemothorax in blunt chest trauma?
Injury
PUBLISHED: 05-10-2014
Show Abstract
Hide Abstract
Blunt chest injury is not uncommon in trauma patients. Haemothorax and pneumothorax may occur in these patients, and some of them will develop retained pleural collections. Video-assisted thoracoscopic surgery (VATS) has become an appropriate method for treating these complications, but the optimal timing for performing the surgery and its effects on outcome are not clearly understood.
Related JoVE Video
Intestine-specific deletion of acyl-CoA:monoacylglycerol acyltransferase (MGAT) 2 protects mice from diet-induced obesity and glucose intolerance.
J. Biol. Chem.
PUBLISHED: 05-01-2014
Show Abstract
Hide Abstract
The absorption of dietary fat involves the re-esterification of digested triacylglycerol in the enterocytes, a process catalyzed by acyl-CoA:monoacylglycerol acyltransferase (MGAT) 2. Mice without a functional gene encoding MGAT2 (Mogat2(-/-)) are protected from diet-induced obesity. Surprisingly, these mice absorb normal amounts of dietary fat but increase their energy expenditure. MGAT2 is expressed in tissues besides intestine, including adipose tissue in both mice and humans. To test the hypothesis that intestinal MGAT2 regulates systemic energy balance, we generated and characterized mice deficient in MGAT2 specifically in the small intestine (Mogat2(IKO)). We found that, like Mogat2(-/-) mice, Mogat2(IKO) mice also showed a delay in fat absorption, a decrease in food intake, and a propensity to use fatty acids as fuel when first exposed to a high fat diet. Mogat2(IKO) mice increased energy expenditure although to a lesser degree than Mogat2(-/-) mice and were protected against diet-induced weight gain and associated comorbidities, including hepatic steatosis, hypercholesterolemia, and glucose intolerance. These findings illustrate that intestinal lipid metabolism plays a crucial role in the regulation of systemic energy balance and may be a feasible intervention target. In addition, they suggest that MGAT activity in extraintestinal tissues may also modulate energy metabolism.
Related JoVE Video
Molecular and biochemical characterizations of three fructose-1,6-bisphosphate aldolases from Clonorchis sinensis.
Mol. Biochem. Parasitol.
PUBLISHED: 04-13-2014
Show Abstract
Hide Abstract
Fructose-1,6-bisphosphate aldolase (FbA) is a ubiquitous enzyme in glycolysis. In the present study, we screened out three distinct genes encoding FbA isozymes (CsFbAs, CsFbA-1/2/3) from Clonorchis sinensis (C. sinensis) and characterized their sequences and structures profiles as well as biochemical properties. The amino acid sequences of CsFbAs shared homology with those of Class I FbAs from other species. The putative quaternary structures revealed that CsFbA-2 and CsFbA-3 were tetramers, while CsFbA-1 was dimer. Recombinant CsFbA-2 and CsFbA-3 (rCsFbA-2/3) were confirmed to be Class I FbAs for their stable enzymatic activities in the presence of EDTA or metal ions. However, recombinant CsFbA-1 (rCsFbA-1) did not show the catalytic activity, which might be due to the inappropriate fold and interaction between its subunits. Both rCsFbA-2 and rCsFbA-3 showed similar enzymatic properties such as optimal temperatures and broad pH ranges that similar to human FbA isozymes. They showed relatively higher affinities for fructose-1,6-bisphosphate (FBP) than fructose-1-phosphate (F-1-P). Their kcat ratios of FBP to F-1-P were in accordance with those of human FbA-A or C. In addition, CsFbAs were differentially transcribed in the developmental stages of C. sinensis, suggesting their essential roles throughout the life stages. Extensive distribution of CsFbAs in adult worms indicated that ubiquitous activities of CsFbAs took place in these organs. Collectively, these results suggested that long-term parasitic environment might adapt these isozymes similar to host FbAs for metabolic requirement. Our study will provide new insight into CsFbAs in the glycometabolism of C. sinensis and relationship between the host and the parasite.
Related JoVE Video
Using cognitive modelling to investigate the psychological processes of the Go/NoGo discrimination task in male abstinent heroin misusers.
Addiction
PUBLISHED: 04-11-2014
Show Abstract
Hide Abstract
To use cognitive modelling to investigate psychological processes underlying decision-making in male abstinent heroin misusers (AHMs).
Related JoVE Video
Synthesis of the heparin-based anticoagulant drug fondaparinux.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 04-10-2014
Show Abstract
Hide Abstract
Fondaparinux, a synthetic pentasaccharide based on the heparin antithrombin-binding domain, is an approved clinical anticoagulant. Although it is a better and safer alternative to pharmaceutical heparins in many cases, its high cost, which results from the difficult and tedious synthesis, is a deterrent for its widespread use. The chemical synthesis of fondaparinux was achieved in an efficient and concise manner from commercially available D-glucosamine, diacetone ?-D-glucose, and penta-O-acetyl-D-glucose. The method involves suitably functionalized building blocks that are readily accessible and employs shared intermediates and a series of one-pot reactions that considerably reduce the synthetic effort and improve the yield.
Related JoVE Video
TorsinA hypofunction causes abnormal twisting movements and sensorimotor circuit neurodegeneration.
J. Clin. Invest.
PUBLISHED: 04-10-2014
Show Abstract
Hide Abstract
Lack of a preclinical model of primary dystonia that exhibits dystonic-like twisting movements has stymied identification of the cellular and molecular underpinnings of the disease. The classical familial form of primary dystonia is caused by the DYT1 (?E) mutation in TOR1A, which encodes torsinA, AAA? ATPase resident in the lumen of the endoplasmic reticular/nuclear envelope. Here, we found that conditional deletion of Tor1a in the CNS (nestin-Cre Tor1a(flox/-)) or isolated CNS expression of DYT1 mutant torsinA (nestin-Cre Tor1a(flox/?E)) causes striking abnormal twisting movements. These animals developed perinuclear accumulation of ubiquitin and the E3 ubiquitin ligase HRD1 in discrete sensorimotor regions, followed by neurodegeneration that was substantially milder in nestin-Cre Tor1a(flox/?E) compared with nestin-Cre Tor1a(flox/-) animals. Similar to the neurodevelopmental onset of DYT1 dystonia in humans, the behavioral and histopathological abnormalities emerged and became fixed during CNS maturation in the murine models. Our results establish a genetic model of primary dystonia that is overtly symptomatic, and link torsinA hypofunction to neurodegeneration and abnormal twisting movements. These findings provide a cellular and molecular framework for how impaired torsinA function selectively disrupts neural circuits and raise the possibility that discrete foci of neurodegeneration may contribute to the pathogenesis of DYT1 dystonia.
Related JoVE Video
Systemic and local mucosal immune responses induced by orally delivered Bacillus subtilis spore expressing leucine aminopeptidase 2 of Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 04-07-2014
Show Abstract
Hide Abstract
Human clonorchiasis caused by Clonorchis sinensis (C. sinensis) has been increasingly prevalent in recent years so that an effective measure is essential and urgent to control the infectious disease. Oral delivery of antigens from C. sinensis may be an important approach to effectively induce both systemic and local immune responses to anti-infection of the parasite. In the current study, we used Bacillus subtilis (B. subtilis) spores as a delivery vehicle to introduce leucine aminopeptidase 2 of C. sinensis (CsLAP2), an excretory/secretory antigen with high immunogenicity, expressing on their surface. SDS-PAGE, western blotting, and flow cytometry indicated that CsLAP2 was successfully expressed on the surface of B. subtilis spores (CotC-CsLAP2 spores). BALB/c mice were treated with spores intragastrically. On day 31 after the treatment, we found that mice intragastrically treated with CotC-CsLAP2 spores exhibited higher IgG, IgG1, IgG2a, and IgA level in sera as well as higher sIgA level in bile and intestinal lavage fluid compared to mice orally administrated with spores not expressing CsLAP2 (CotC spores) and naïve mice. The peak titer of IgG/IgA presented on day 31/49 after oral administration. IgG1 level was lower than IgG2a in group administrated with CotC-CsLAP2 spores. sIgA-secreting cells were obviously observed in intestinal epithelium of mice orally treated with CotC-CsLAP2 spores. After incubated with CotC-CsLAP2, the levels of IFN-?, IL-6, IL-10, IL-17A, and TNF significantly increased in the supernatant of splenocytes isolated from mice orally treated with CotC-CsLAP2 spores, while there was no statistically significant difference of IL-4 level representing Th2 response among the groups. Our study demonstrated that oral administration of CsLAP2 delivered by B. subtilis spore elicited obvious systemic and local mucosal immunity. Secretory IgA and Th1-Th17 cellular immunity might involved in mechanisms of the immune response.
Related JoVE Video
A putative novel protein, DEPDC1B, is overexpressed in oral cancer patients, and enhanced anchorage-independent growth in oral cancer cells that is mediated by Rac1 and ERK.
J. Biomed. Sci.
PUBLISHED: 03-26-2014
Show Abstract
Hide Abstract
The DEP domain is a globular domain containing approximately 90 amino acids, which was first discovered in 3 proteins: Drosophila disheveled, Caenorhabditis elegans EGL-10, and mammalian Pleckstrin; hence the term, DEP. DEPDC1B is categorized as a potential Rho GTPase-activating protein. The function of the DEP domain in signal transduction pathways is not fully understood. The DEPDC1B protein exhibits the characteristic features of a signaling protein, and contains 2 conserved domains (DEP and RhoGAP) that are involved in Rho GTPase signaling. Small GTPases, such as Rac, CDC42, and Rho, regulate a multitude of cell events, including cell motility, growth, differentiation, cytoskeletal reorganization and cell cycle progression.
Related JoVE Video
Biochemical and immunological characterization of annexin B30 from Clonorchis sinensis excretory/secretory products.
Parasitol. Res.
PUBLISHED: 03-19-2014
Show Abstract
Hide Abstract
Clonorchis sinensis has been classified as group I biological carcinogen for cholangiocarcinoma by the World Health Organization. Biological studies on excretory/secretory products (ESPs) enabled us to understand the pathogenesis mechanism of C. sinensis and develop new strategies for the prevention of clonorchiasis. In this study, sequence analysis showed that annexin B30 from C. sinensis (CsANXB30) is composed of four annexin repeats which were characterized by type II and III Ca(2+)-binding sites or KGD motif with the capability of Ca(2+)-binding. In addition, immunoblot assay revealed that recombinant CsANXB30 (rCsANXB30) could be recognized by the sera from rats infected with C. sinensis and the sera from rats immunized by CsESPs. Real-time PCR showed that its transcriptional level was the highest at the stage of metacercaria. Immunofluorescence assay was employed to confirm that CsANXB30 was distributed in the tegument, intestine, and egg of adult worms, as well as the tegument and vitellarium of metacercaria. rCsANXB30 was able to bind phospholipid in a Ca(2+)-dependent manner and human plasminogen in a dose-dependent manner. Moreover, cytokine and antibody measurements indicated that rats subcutaneously immunized with rCsANXB30 developed a strong IL-10 production in spleen cells and a high level of IgG1 isotype, indicating that rCsANXB30 could trigger specific humoral and cellular immune response in rats. The present results implied that CsANXB30 might be involved in a host-parasite interaction and affected the immune response of the host during C. sinensis infection.
Related JoVE Video
Incidence, national trend, and outcome of nontraumatic subarachnoid haemorrhage in Taiwan: initial lower mortality, poor long-term outcome.
Biomed Res Int
PUBLISHED: 03-10-2014
Show Abstract
Hide Abstract
To investigate the longitudinal trend of nontraumatic subarachnoid haemorrhage (SAH), we analyzed the annual population-based incidence and mortality rate of nontraumatic subarachnoid hemorrhage in Taiwan. Logistic regression was used to identify independent predictors of mortality. The average incidence rate (IR) of nontraumatic SAH was 6.25 ± 0.88 per 100,000 per year. The prevalence of female patients was higher than in the male population (54.5% versus 45.5%). The average age of these patients was 55.78 ± 17.09 and females were older than males (58.50 ± 15.9 versus 52.45 ± 18.50, P < 0.001). Of these patients, 97.6% (611/626) were treated with surgical intervention with clipping procedure and 2.9% (18/626) with coiling. Total mortality of these patients was 13.4% (84/626). In adjusted analysis, age (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.98-0.98; P < 0.001) and Charlson comorbidity index (OR, 0.709; 95% CI, 0.57-0.88; P = 0.002) remained independent predictors of the mortality. Patients with nontraumatic SAH had a much higher prevalence in older age groups and in females than in the general population. Patients with old age and more comorbidity have higher mortality. Aggressive management of patients might reduce the initial mortality; however, patient outcome still remains poor.
Related JoVE Video
Broadly neutralizing HIV antibodies define a glycan-dependent epitope on the prefusion conformation of gp41 on cleaved envelope trimers.
Immunity
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
Broadly neutralizing HIV antibodies are much sought after (a) to guide vaccine design, both as templates and as indicators of the authenticity of vaccine candidates, (b) to assist in structural studies, and (c) to serve as potential therapeutics. However, the number of targets on the viral envelope spike for such antibodies has been limited. Here, we describe a set of human monoclonal antibodies that define what is, to the best of our knowledge, a previously undefined target on HIV Env. The antibodies recognize a glycan-dependent epitope on the prefusion conformation of gp41 and unambiguously distinguish cleaved from uncleaved Env trimers, an important property given increasing evidence that cleavage is required for vaccine candidates that seek to mimic the functional HIV envelope spike. The availability of this set of antibodies expands the number of vaccine targets on HIV and provides reagents to characterize the native envelope spike.
Related JoVE Video
Molecular characterization of Clonorchis sinensis secretory myoglobin: delineating its role in anti-oxidative survival.
Parasit Vectors
PUBLISHED: 02-22-2014
Show Abstract
Hide Abstract
Clonorchiasis is a globally important, neglected food-borne disease caused by Clonorchis sinensis (C. sinensis), and it is highly related to cholangiocarcinoma and hepatocellular carcinoma. Increased molecular evidence has strongly suggested that the adult worm of C. sinensis continuously releases excretory-secretory proteins (ESPs), which play important roles in the parasite-host interactions, to establish successful infection and ensure its own survival. Myoglobin, a hemoprotein, is present in high concentrations in trematodes and ESPs. To further understand the biological function of CsMb and its putative roles in the interactions of C. sinensis with its host, we explored the molecular characterization of CsMb in this paper.
Related JoVE Video
Identification, immunolocalization, and immunological characterization of nitric oxide synthase-interacting protein from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 02-14-2014
Show Abstract
Hide Abstract
Recently, accumulating evidences indicate that nitric oxide (NO) is a potent mediator with diverse roles in regulating cellular functions, signaling pathways, and variety of pathological processes. In the present study, using data from the published genomic for Clonorchis sinensis (C. sinensis), we investigated a gene encoding nitric oxide synthase-interacting protein (NOSIP) of C. sinensis. Recombinant CsNOSIP (rCsNOSIP) was expressed and purified from Escherichia coli BL21. The open reading frame of CsNOSIP comprises 867 bp which encodes 289 amino acids and shares 72.9, 45.2, 47, 46.4, and 45.8% identity with NOSIP from Schistosoma mansoni, Xenopus laevis, Rattus norvegicus, Mus musculus, and Homo sapiens, respectively. Bioinformatics analysis suggested that the full-length sequence contains an eNOS-interacting domain and numerous B-cell epitopes. Quantitative RT-PCR indicated that CsNOSIP differentially transcribed throughout the adult worms, metacercariae, and egg stages of C. sinensis, and were highly expressed in the adult worms. Moreover, western blot analysis showed that the rCsNOSIP could be detected by the serum from BALB/c mice infected with C. sinensis and the serum from BALB/c mice immunized with excretory/secretory products (ESPs). Furthermore, immunolocalization assay showed that CsNOSIP was specifically localized in the intestine, vitellarium, and eggs of adult worm. Both immunoblot and immunolocalization results demonstrated that CsNOSIP was one component of ESPs of C. sinensis, which could be supported by SignalP analysis. Moreover, analysis of the antibody subclass and cytokine profile demonstrated that subcutaneously immunized BALB/c mice with rCsNOSIP could significantly enhance serum IgG1 level and up-regulate expression of IL-4 and IL-6 in the splenocytes. Our results suggested that CsNOSIP was an important antigen exposed to host immune system and probably involved in immune regulation of host by inducing Th2-polarized immune response.
Related JoVE Video
Local geometric and electronic structures of gasochromic VO(x) films.
Phys Chem Chem Phys
PUBLISHED: 01-29-2014
Show Abstract
Hide Abstract
VOx films were deposited by radio-frequency reactive magnetron sputtering from a vanadium target at room temperature. Local atomic and electronic structures of the films were then modified by thermal annealing. The oxidation state and structural and gasochromic properties of the films were elucidated by X-ray absorption spectroscopy. Analytical results indicate that the as-deposited VOx films were amorphous with mixed V(4+) and V(5+) valences. The amorphous VOx had a disordered and expanded lamellar structure resembling that of polymer-intercalated V2O5 gels. VOx films were crystallized into orthorhombic V2O5 at 300 °C, and the lamellar structure was eliminated at 400 °C. Additionally, the gasochromic reaction reduced the vanadium valence via intervalence transitions between V(5+) and V(3+). Moreover, removing the lamellar structure reduced the gasochromic rate, and the gasochromic reaction transformed the V2O5 crystalline phase irreversibly into an H1.43V2O5 phase. Based on the results of this study, amorphous VOx with a lamellar structure is recommended for use in H2 gas sensors.
Related JoVE Video
Endoscopic diagnosis of cervical esophageal heterotopic gastric mucosa with conventional and narrow-band images.
World J. Gastroenterol.
PUBLISHED: 01-14-2014
Show Abstract
Hide Abstract
To compare the diagnostic yield of heterotopic gastric mucosa (HGM) in the cervical esophagus with conventional imaging (CI) and narrow-band imaging (NBI).
Related JoVE Video
Identification, sequence analysis, and characterization of serine/threonine protein kinase 17A from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-12-2014
Show Abstract
Hide Abstract
This is the first report of a novel protein from Clonorchis sinensis (C. sinensis), serine/threonine protein kinase 17A (CsSTK17A), which belongs to a member of the death-associated protein kinase (DAPK) family known to regulate diverse biological processes. The full-length sequence encoding CsSTK17A was isolated from C. sinensis adult cDNA plasmid library. Two transcribed isoforms of the gene were identified from the genome of C. sinensis. CsSTK17A contains a kinase domain at the N-terminus that shares a degree of conservation with the DAPK families. Besides, the catalytic domain contains 11 subdomains conserved among STKs and shares the highest identity with STK from Schistosoma mansoni (55.9%). Three-dimensional structure of CsSTK17A displays the canonical STK fold, including the helix C, P-loop, and the activation loop. We obtained recombinant CsSTK17A (rCsSTK17A) and anti-rCsSTK17A IgG. The rCsSTK17A could be probed by anti-rCsSTK17A rat serum, C. sinensis-infected rat serum and the sera from rats immunized with C. sinensis excretory-secretory products, indicating that it is a circulating antigen possessing a strong immunocompetence. Moreover, quantitative RT-PCR and western blotting analyses revealed that CsSTK17A exhibited the highest mRNA and protein expression level in eggs, followed by metacercariae and adult worms. Intriguingly, in the immunolocalization assay, CsSTK17A was intensively localized to the operculum region of eggs in uterus, as well as the vitelline gland of both adult worm and metacercaria, implying that the protein was associated with the reproduction and development of C. sinensis. Overall, these fundamental studies might contribute to further researches on signaling systems of the parasite.
Related JoVE Video
Association of head, thoracic and abdominal trauma with delayed diagnosis of co-existing injuries in critical trauma patients.
Injury
PUBLISHED: 01-08-2014
Show Abstract
Hide Abstract
Management of critically injured patients is usually complicated and challenging. A structured team approach with comprehensive survey is warranted. However, delayed diagnosis of co-existing injuries that are less severe or occult might still occur, despite a standard thorough approach coupled with advances in image intervention. Clinicians are easily distracted or occupied by the more obvious or threatening conditions. We hypothesised that the major area of injured body regions might contribute to this unwanted condition.
Related JoVE Video
Ultrahigh-gain photodetectors based on atomically thin graphene-MoS2 heterostructures.
Sci Rep
PUBLISHED: 01-03-2014
Show Abstract
Hide Abstract
Due to its high carrier mobility, broadband absorption, and fast response time, the semi-metallic graphene is attractive for optoelectronics. Another two-dimensional semiconducting material molybdenum disulfide (MoS2) is also known as light- sensitive. Here we show that a large-area and continuous MoS2 monolayer is achievable using a CVD method and graphene is transferable onto MoS2. We demonstrate that a photodetector based on the graphene/MoS2 heterostructure is able to provide a high photogain greater than 10(8). Our experiments show that the electron-hole pairs are produced in the MoS2 layer after light absorption and subsequently separated across the layers. Contradictory to the expectation based on the conventional built-in electric field model for metal-semiconductor contacts, photoelectrons are injected into the graphene layer rather than trapped in MoS2 due to the presence of a perpendicular effective electric field caused by the combination of the built-in electric field, the applied electrostatic field, and charged impurities or adsorbates, resulting in a tuneable photoresponsivity.
Related JoVE Video
Sequence analysis and molecular characterization of Clonorchis sinensis hexokinase, an unusual trimeric 50-kDa glucose-6-phosphate-sensitive allosteric enzyme.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Clonorchiasis, which is induced by the infection of Clonorchis sinensis (C. sinensis), is highly associated with cholangiocarcinoma. Because the available examination, treatment and interrupting transmission provide limited opportunities to prevent infection, it is urgent to develop integrated strategies to prevent and control clonorchiasis. Glycolytic enzymes are crucial molecules for trematode survival and have been targeted for drug development. Hexokinase of C. sinensis (CsHK), the first key regulatory enzyme of the glycolytic pathway, was characterized in this study. The calculated molecular mass (Mr) of CsHK was 50.0 kDa. The obtained recombinant CsHK (rCsHK) was a homotrimer with an Mr of approximately 164 kDa, as determined using native PAGE and gel filtration. The highest activity was obtained with 50 mM glycine-NaOH at pH 10 and 100 mM Tris-HCl at pH 8.5 and 10. The kinetics of rCsHK has a moderate thermal stability. Compared to that of the corresponding negative control, the enzymatic activity was significantly inhibited by praziquantel (PZQ) and anti-rCsHK serum. rCsHK was homotropically and allosterically activated by its substrates, including glucose, mannose, fructose, and ATP. ADP exhibited mixed allosteric effect on rCsHK with respect to ATP, while inorganic pyrophosphate (PPi) displayed net allosteric activation with various allosteric systems. Fructose behaved as a dose-dependent V activator with the substrate glucose. Glucose-6-phosphate (G6P) displayed net allosteric inhibition on rCsHK with respect to ATP or glucose with various allosteric systems in a dose-independent manner. There were differences in both mRNA and protein levels of CsHK among the life stages of adult worm, metacercaria, excysted metacercaria and egg of C. sinensis, suggesting different energy requirements during different development stages. Our study furthers the understanding of the biological functions of CsHK and supports the need to screen for small molecule inhibitors of CsHK to interfere with glycolysis in C. sinensis.
Related JoVE Video
Characterization of the sialic acid binding activity of influenza A viruses using soluble variants of the H7 and H9 hemagglutinins.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Binding of influenza viruses to target cells is mediated by the viral surface protein hemagglutinin. To determine the presence of binding sites for influenza A viruses on cells and tissues, soluble hemagglutinins of the H7 and H9 subtype were generated by connecting the hemagglutinin ectodomain to the Fc portion of human immunoglobulin G (H7Fc and H9Fc). Both chimeric proteins bound to different cells and tissues in a sialic acid-dependent manner. Pronounced differences were observed between H7Fc and H9Fc, in the binding both to different mammalian and avian cultured cells and to cryosections of the respiratory epithelium of different virus host species (turkey, chicken and pig). Binding of the soluble hemagglutinins was similar to the binding of virus particles, but showed differences in the binding pattern when compared to two sialic acid-specific plant lectins. These findings were substantiated by a comparative glycan array analysis revealing a very narrow recognition of sialoglycoconjugates by the plant lectins that does not reflect the glycan structures preferentially recognized by H7Fc and H9Fc. Thus, soluble hemagglutinins may serve as sialic acid-specific lectins and are a more reliable indicator of the presence of binding sites for influenza virus HA than the commonly used plant lectins.
Related JoVE Video
Molecular Characterization of Severin fromClonorchis sinensis Excretory/Secretory Products and Its Potential Anti-apoptotic Role in Hepatocarcinoma PLC Cells.
PLoS Negl Trop Dis
PUBLISHED: 12-01-2013
Show Abstract
Hide Abstract
Clonorchiasis, caused by the infection of Clonorchis sinensis (C. sinensis), is a kind of neglected tropical disease, but it is highly related to cholangiocarcinoma and hepatocellular carcinoma (HCC). It has been well known that the excretory/secretory products of C. sinensis (CsESPs) play key roles in clonorchiasis associated carcinoma. From genome and transcriptome of C. sinensis, we identified one component of CsESPs, severin (Csseverin), which had three putative gelsolin domains. Its homologues are supposed to play a vital role in apoptosis resistance of tumour cell.
Related JoVE Video
The role of repairing lung lacerations during video-assisted thoracoscopic surgery evacuations for retained haemothorax caused by blunt chest trauma.
Eur J Cardiothorac Surg
PUBLISHED: 11-15-2013
Show Abstract
Hide Abstract
Retained haemothorax and pneumothorax are the most common complications after blunt chest traumas. Lung lacerations derived from fractures of the ribs are usually found in these patients. Video-assisted thoracoscopic surgery (VATS) is usually used as a routine procedure in the treatment of retained pleural collections. The objective of this study was to find out if there is any advantage in adding the procedure for repairing lacerated lungs during VATS.
Related JoVE Video
Molecular characterization and immune modulation properties of Clonorchis sinensis-derived RNASET2.
Parasit Vectors
PUBLISHED: 09-04-2013
Show Abstract
Hide Abstract
Clonorchis sinensis (C. sinensis, Cs) is a trematode parasite that often causes chronic cumulative infections in the hepatobiliary ducts of the host and can lead to pathological changes by continuously released excretory/secretory proteins (ESPs). A T2 ribonuclease in trematode ESPs, has been identified as a potent regulator of dendritic cell (DCs) modulation. We wondered whether there was a counterpart present in CsESPs with similar activity. To gain a better understanding of CsESPs associated immune responses, we identified and characterized RNASET2 of C. sinensis (CsRNASET2) in this paper.
Related JoVE Video
Oxidative decomposition of propylene carbonate in lithium ion batteries: a DFT study.
J Phys Chem A
PUBLISHED: 08-05-2013
Show Abstract
Hide Abstract
This paper reports an in-depth mechanistic study on the oxidative decomposition of propylene carbonate in the presence of lithium salts (LiClO4, LiBF4, LiPF6, and LiAsF6) with the aid of density functional theory calculations at the B3LYP/6-311++G(d,p) level of theory. The solvent effect is accounted for by using the implicit solvation model with density method. Moreover, the rate constants for the decompositions of propylene carbonate have been investigated by using transition-state theory. The shortening of the original carbonyl C-O bond and a lengthening of the adjacent ethereal C-O bonds of propylene carbonate, which occurs as a result of oxidation, leads to the formation of acetone radical and CO2 as a primary oxidative decomposition product. The termination of the primary radical generates polycarbonate, acetone, diketone, 2-(ethan-1-ylium-1-yl)-4-methyl-1,3-dioxolan-4-ylium, and CO2. The thermodynamic and kinetic data show that the major oxidative decomposition products of propylene carbonate are independent of the type of lithium salt. However, the decomposition rate constants of propylene carbonate are highly affected by the lithium salt type. On the basis of the rate constant calculations using transition-state theory, the order of gas volume generation is: [PC-ClO4](-) > [PC-BF4](-) > [PC-AsF6](-) > [PC-PF6](-).
Related JoVE Video
Immunization of fucose-containing polysaccharides from Reishi mushroom induces antibodies to tumor-associated Globo H-series epitopes.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 08-01-2013
Show Abstract
Hide Abstract
Carbohydrate-based vaccines have shown therapeutic efficacy for infectious disease and cancer. The mushroom Ganoderma lucidum (Reishi) containing complex polysaccharides has been used as antitumor supplement, but the mechanism of immune response has rarely been studied. Here, we show that the mice immunized with a l-fucose (Fuc)-enriched Reishi polysaccharide fraction (designated as FMS) induce antibodies against murine Lewis lung carcinoma cells, with increased antibody-mediated cytotoxicity and reduced production of tumor-associated inflammatory mediators (in particular, monocyte chemoattractant protein-1). The mice showed a significant increase in the peritoneal B1 B-cell population, suggesting FMS-mediated anti-glycan IgM production. Furthermore, the glycan microarray analysis of FMS-induced antisera displayed a high specificity toward tumor-associated glycans, with the antigenic structure located in the nonreducing termini (i.e., Fuc?1-2Gal?1-3GalNAc-R, where Gal, GalNAc, and R represent, respectively, D-galactose, D-N-acetyl galactosamine, and reducing end), typically found in Globo H and related tumor antigens. The composition of FMS contains mainly the backbone of 1,4-mannan and 1,6-?-galactan and through the Fuc?1-2Gal, Fuc?1-3/4Man, Fuc?1-4Xyl, and Fuc?1-2Fuc linkages (where Man and Xyl represent d-mannose and d-xylose, respectively), underlying the molecular basis of the FMS-induced IgM antibodies against tumor-specific glycans.
Related JoVE Video
Towards understanding the electronic structure of Fe-doped CeO2 nanoparticles with X-ray spectroscopy.
Phys Chem Chem Phys
PUBLISHED: 08-01-2013
Show Abstract
Hide Abstract
This study reports on the electronic structure of Fe-doped CeO2 nanoparticles (NPs), determined by coupled X-ray absorption spectroscopy and X-ray emission spectroscopy. A comparison of the local electronic structure around the Ce site with that around the Fe site indicates that the Fe substitutes for the Ce. The oxygen K-edge spectra that originated from the hybridization between cerium 4f and oxygen 2p states are sensitive to the oxidation state and depend strongly on the concentration of Fe doping. The Ce M(4,5)-edges and the Fe L(2,3)-edges reveal the variations of the charge states of Ce and Fe upon doping, respectively. The band gap is further obtained from the combined absorption-emission spectrum and decreased upon Fe doping, implying Fe doping introduces vacancies. The oxygen vacancies are induced by Fe doping and the spectrum reveals the charge transfer between Fe and Ce. Fe(3+) doping has two major effects on the formation of ferromagnetism in CeO2 nanoparticles. The first, at an Fe content of below 5%, is that the formation of Fe(3+)-Vo-Ce(3+) introduces oxygen deficiencies favoring ferromagnetism. The other, at an Fe content of over 5%, is the formation of Fe(3+)-Vo-Fe(3+), which favors antiferromagnetism, reducing the Ms. The defect structures Fe(3+)-Vo-Ce(3+) and Fe(3+)-Vo-Fe(3+) are crucial to the magnetism in these NPs and the change in Ms can be described as the effect of competitive interactions of magnetic polarons and paired ions.
Related JoVE Video
Nitrogen-doped graphene sheets grown by chemical vapor deposition: synthesis and influence of nitrogen impurities on carrier transport.
ACS Nano
PUBLISHED: 07-30-2013
Show Abstract
Hide Abstract
A significant advance toward achieving practical applications of graphene as a two-dimensional material in nanoelectronics would be provided by successful synthesis of both n-type and p-type doped graphene. However, reliable doping and a thorough understanding of carrier transport in the presence of charged impurities governed by ionized donors or acceptors in the graphene lattice are still lacking. Here we report experimental realization of few-layer nitrogen-doped (N-doped) graphene sheets by chemical vapor deposition of organic molecule 1,3,5-triazine on Cu metal catalyst. When reducing the growth temperature, the atomic percentage of nitrogen doping is raised from 2.1% to 5.6%. With increasing doping concentration, N-doped graphene sheet exhibits a crossover from p-type to n-type behavior accompanied by a strong enhancement of electron-hole transport asymmetry, manifesting the influence of incorporated nitrogen impurities. In addition, by analyzing the data of X-ray photoelectron spectroscopy, Raman spectroscopy, and electrical measurements, we show that pyridinic and pyrrolic N impurities play an important role in determining the transport behavior of carriers in our N-doped graphene sheets.
Related JoVE Video
Fabrication and photoresponse of ZnO nanowires/CuO coaxial heterojunction.
Nanoscale Res Lett
PUBLISHED: 07-25-2013
Show Abstract
Hide Abstract
The fabrication and properties of n-ZnO nanowires/p-CuO coaxial heterojunction (CH) with a photoresist (PR) blocking layer are reported. In our study, c-plane wurtzite ZnO nanowires were grown by aqueous chemical method, and monoclinic CuO (111) was then coated on the ZnO nanowires by electrochemical deposition to form CH. To improve the device performance, a PR layer was inserted between the ZnO buffer layer and the CuO film to serve as a blocking layer to block the leakage current. Structural investigations of the CH indicate that the sample has good crystalline quality. It was found that our refined structure possesses a better rectifying ratio and smaller reverse leakage current. As there is a large on/off ratio between light on and off and the major light response is centered at around 424 nm, the experimental results suggest that the PR-inserted ZnO/CuO CH can be used as a good narrow-band blue light detector.
Related JoVE Video
Dirac fermion heating, current scaling, and direct insulator-quantum Hall transition in multilayer epitaxial graphene.
Nanoscale Res Lett
PUBLISHED: 07-02-2013
Show Abstract
Hide Abstract
We have performed magnetotransport measurements on multilayer epitaxial graphene. By increasing the driving current I through our graphene devices while keeping the bath temperature fixed, we are able to study Dirac fermion heating and current scaling in such devices. Using zero-field resistivity as a self thermometer, we are able to determine the effective Dirac fermion temperature (TDF) at various driving currents. At zero field, it is found that TDF ? I?1/2. Such results are consistent with electron heating in conventional two-dimensional systems in the plateau-plateau transition regime. With increasing magnetic field B, we observe an I-independent point in the measured longitudinal resistivity ?xx which is equivalent to the direct insulator-quantum Hall (I-QH) transition characterized by a temperature-independent point in ?xx. Together with recent experimental evidence for direct I-QH transition, our new data suggest that such a transition is a universal effect in graphene, albeit further studies are required to obtain a thorough understanding of such an effect.
Related JoVE Video
Synthesis of graphene-ZnO-Au nanocomposites for efficient photocatalytic reduction of nitrobenzene.
Environ. Sci. Technol.
PUBLISHED: 06-04-2013
Show Abstract
Hide Abstract
A simple hydrothermal method of preparing highly photocatalytic graphene-ZnO-Au nanocomposites (G-ZnO-Au NCs) has been developed. Zinc acetate and graphene oxide are reduced by catechin to form graphene-zinc oxide nanospheres (G-ZnO NSs; average diameter of (45.3 ± 3.7) nm) in the presence of ethylenediamine (EDA) as a stabilizing agent and gold nanorods (Au NRs) at 300 °C for 2 h. Then Au NRs are deposited onto as-formed G-ZnO NSs to form G-ZnO-Au NCs. Upon ultraviolet light activation, G-ZnO-Au NCs (4 mg mL(-1)) in methanol generates electron-hole pairs. Methanol (hydroxyl group) assists in trapping holes, enabling photogenerated electrons to catalyze reduction of nitrobenzene (NB) to aniline with a yield of 97.8% during a reaction course of 140 min. The efficiency of G-ZnO-Au NCs is 3.5- and 4.5-fold higher than those provided by commercial TiO2 and ZnO NSs, respectively. Surface assisted laser desorption/ionization mass spectrometry has been for the first time applied to detect the intermediates (nitrosobenzene and phenylhydroxylamine) and major product (aniline) of NB through photoelectrocatalytic or photocatalytic reactions. The result reveals that the reduction of NB to aniline is through nitrosobenzene to phenylhydroxylamine in the photoelectrocatalytic reaction, while via nitrosobenzene directly in the photocatalytic reaction. G-ZnO-Au NC photocatalyst holds great potential in removal of organic pollutants like NB and in the production of aniline.
Related JoVE Video
[HPLC characteristic chromatographic profile of Sarcandra glabra].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 05-31-2013
Show Abstract
Hide Abstract
To develop the characteristic chromatographic profile of Sarcandra glabra by HPLC for its quality control.
Related JoVE Video
Tunable insulator-quantum Hall transition in a weakly interacting two-dimensional electron system.
Nanoscale Res Lett
PUBLISHED: 05-07-2013
Show Abstract
Hide Abstract
We have performed low-temperature measurements on a gated two-dimensional electron system in which electron-electron (e-e) interactions are insignificant. At low magnetic fields, disorder-driven movement of the crossing of longitudinal and Hall resistivities (?xx and ?xy) can be observed. Interestingly, by applying different gate voltages, we demonstrate that such a crossing at ?xx ~ ?xy can occur at a magnetic field higher, lower, or equal to the temperature-independent point in ?xx which corresponds to the direct insulator-quantum Hall transition. We explicitly show that ?xx ~ ?xy occurs at the inverse of the classical Drude mobility 1/?D rather than the crossing field corresponding to the insulator-quantum Hall transition. Moreover, we show that the background magnetoresistance can affect the transport properties of our device significantly. Thus, we suggest that great care must be taken when calculating the renormalized mobility caused by e-e interactions.
Related JoVE Video
Room-temperature violet luminescence and ultraviolet photodetection of Sb-doped ZnO/Al-doped ZnO homojunction array.
Nanoscale Res Lett
PUBLISHED: 05-06-2013
Show Abstract
Hide Abstract
A Sb-doped ZnO microrod array was fabricated on an Al-doped ZnO thin film by electrodeposition. Strong violet luminescence, originated from free electron-to-acceptor level transitions, was identified by temperature-dependent photoluminescence measurements. This acceptor-related transition was attributed to substitution of Sb dopants for Zn sites, instead of O sites, to form a complex with two Zn vacancies (VZn), the SbZn-2VZn complex. This SbZn-2VZn complex has a lower formation energy and acts as a shallow acceptor which can induce the observed strong violet luminescence. The photoresponsivity of our ZnO p-n homojunction device under a negative bias demonstrated a nearly 40-fold current gain, illustrating that our device is potentially an excellent candidate for photodetector applications in the ultraviolet wavelength region.
Related JoVE Video
Experimental evidence for direct insulator-quantum Hall transition in multi-layer graphene.
Nanoscale Res Lett
PUBLISHED: 04-05-2013
Show Abstract
Hide Abstract
We have performed magnetotransport measurements on a multi-layer graphene flake. At the crossing magnetic field Bc, an approximately temperature-independent point in the measured longitudinal resistivity ?xx, which is ascribed to the direct insulator-quantum Hall (I-QH) transition, is observed. By analyzing the amplitudes of the magnetoresistivity oscillations, we are able to measure the quantum mobility ?q of our device. It is found that at the direct I-QH transition, ?qBc ? 0.37 which is considerably smaller than 1. In contrast, at Bc, ?xx is close to the Hall resistivity ?xy, i.e., the classical mobility ?Bc is ??1. Therefore, our results suggest that different mobilities need to be introduced for the direct I-QH transition observed in multi-layered graphene. Combined with existing experimental results obtained in various material systems, our data obtained on graphene suggest that the direct I-QH transition is a universal effect in 2D.
Related JoVE Video
Intestine-specific expression of MOGAT2 partially restores metabolic efficiency in Mogat2-deficient mice.
J. Lipid Res.
PUBLISHED: 03-27-2013
Show Abstract
Hide Abstract
Acyl CoA:monoacylglycerol acyltransferase (MGAT) catalyzes the resynthesis of triacylglycerol, a crucial step in the absorption of dietary fat. Mice lacking the gene Mogat2, which codes for an MGAT highly expressed in the small intestine, are resistant to obesity and other metabolic disorders induced by high-fat feeding. Interestingly, these Mogat2?/? mice absorb normal amounts of dietary fat but exhibit a reduced rate of fat absorption, increased energy expenditure, decreased respiratory exchange ratio, and impaired metabolic efficiency. MGAT2 is expressed in tissues besides intestine. To test the hypothesis that intestinal MGAT2 enhances metabolic efficiency and promotes the storage of metabolic fuels, we introduced the human MOGAT2 gene driven by the intestine-specific villin promoter into Mogat2?/? mice. We found that the expression of MOGAT2 in the intestine increased intestinal MGAT activity, restored fat absorption rate, partially corrected energy expenditure, and promoted weight gain upon high-fat feeding. However, the changes in respiratory exchange ratio were not reverted, and the recoveries in metabolic efficiency and weight gain were incomplete. These data indicate that MGAT2 in the intestine plays an indispensable role in enhancing metabolic efficiency but also raise the possibility that MGAT2 in other tissues may contribute to the regulation of energy metabolism.
Related JoVE Video
Early predictors of narcotics-dependent patients in the emergency department.
Kaohsiung J. Med. Sci.
PUBLISHED: 03-22-2013
Show Abstract
Hide Abstract
It is not unusual that narcotics-dependent patients fulfill their medical requirements in the emergency department (ED). The behavior of these patients varies, and their manifestations and predictors are still not fully studied. We performed this retrospective study by prospectively collecting data on patients with suspected drug dependence who were undiagnosed at first and then treated for some kind of reported pain at the ED. Patients who were confirmed to have narcotics dependence were compared with control patients in a ratio of 1:3 matching for age, gender, disease, and clinical diagnoses. From January 2006 to October 2009, 26 of 223 patients treated for pain were found to be drug dependent (12 males and 14 females). The average dose of narcotics used was higher than the control group [3.23 ± 1.14 vs. 1.12 ± 0.36, p < 0.001, confidence interval (CI): 1.648-2.583]. Numbers of patients making unscheduled returns to the ED within 24 hours were significant [24/26 vs. 8/78, p ? 0.001, odds ratio (OR) 105.00, 95% CI 20.834-529.175]. In addition, patients showing aggressive attitudes were significant (17/26 vs. 2/78, p < 0.001, OR 71.78, 95% CI 14.206-362.663). In the case group, six of them told the physician that they were allergic to medicines other than the particular one they wanted, and three of the six presented injuries that were reported to be in the same (or repeated) place for unscheduled returns, which were not found in the control group. In this study, some behaviors were commonly observed in the at-risk group. These patients were prone to manifest some types of symptoms and behaviors, such as uncontrolled pain with three doses of analgesics, aggressive attitude, returning to the ED within 24 hours with the complaint of the same severe pain, repeating the same injury, claiming allergy to other analgesics, and asking for certain analgesics. All these behaviors should alert the physician to suspect a drug-seeking problem.
Related JoVE Video
Impact of extracorporeal membrane oxygenation support on clinical outcome of pediatric patients with acute cardiopulmonary failure: a single-center experience.
Biomed J
PUBLISHED: 03-22-2013
Show Abstract
Hide Abstract
Conventional therapy against acute pediatric cardiopulmonary failure (APCPF) caused by a variety of disease entities remains unsatisfactory with extremely high morbidity and mortality. For refractory APCPF, extracorporeal membrane oxygenation (ECMO) is one of the last resorts.
Related JoVE Video
Clean-lifting transfer of large-area residual-free graphene films.
Adv. Mater. Weinheim
PUBLISHED: 03-13-2013
Show Abstract
Hide Abstract
A unique "clean-lifting transfer" (CLT) technique that applies a controllable electrostatic force to transfer large-area and high-quality CVD-grown graphene onto various rigid or flexible substrates is reported. The CLT technique without using any organic support or adhesives can produce residual-free graphene films with large-area processability, and has great potential for future industrial production of graphene-based electronics or optoelectronics.
Related JoVE Video
Analysis of the bacterial communities associated with different drinking water treatment processes.
World J. Microbiol. Biotechnol.
PUBLISHED: 03-12-2013
Show Abstract
Hide Abstract
A drinking water plant was surveyed to determine the bacterial composition of different drinking water treatment processes (DWTP). Water samples were collected from different processing steps in the plant (i.e., coagulation, sedimentation, sand filtration, and chloramine disinfection) and from distantly piped water. The samples were pyrosequensed using sample-specific oligonucleotide barcodes. The taxonomic composition of the microbial communities of different DWTP and piped water was dominated by the phylum Proteobacteria. Additionally, a large proportion of the sequences were assigned to the phyla Actinobacteria and Bacteroidetes. The piped water exhibited increasing taxonomic diversity, including human pathogens such as the Mycobacterium, which revealed a threat to the safety of drinking water. Surprisingly, we also found that a sister group of SAR11 (LD12) persisted throughout the DWTP, which was always detected in freshwater aquatic systems. Moreover, Polynucleobacter, Rhodoferax, and a group of Actinobacteria, hgcI clade, were relatively consistent throughout the processes. It is concluded that smaller-size microorganisms tended to survive against the present treatment procedure. More improvement should be made to ensure the long-distance transmission drinking water.
Related JoVE Video
Pepsinogen A and C genes in turbot (Scophthalmus maximus): characterization and expression in early development.
Comp. Biochem. Physiol. B, Biochem. Mol. Biol.
PUBLISHED: 02-26-2013
Show Abstract
Hide Abstract
We characterized the expression patterns of pepsinogen A (tPGA) and pepsinogen C (tPGC) in turbot (Scophthalmus maximus). Quantitative expression analysis showed that tPGC was preferentially expressed in early developmental stages, and that the tPGA mRNA expression level was higher in adult fish. Full-length cDNA constructs of tPGA and tPGC were 1307 bp (from which 377 amino acids were deduced); and 1430 bp (from which 385 amino acids were deduced), respectively. The deduced proteins of tPGA and tPGC possessed signal peptides of 17 amino acids and 20 amino acids respectively. The initial transcripts of tPGA and tPGC were detected at 22 days post hatching (dph), well after the formation of gastric glands (16 dph). This suggested that the morphologic development of gastric glands was not synchronous with their functional development. In addition, tPGA and tPGC mRNAs were also expressed in muscle and ovary at much lower levels than in stomach and esophagus. The distribution of tPGA and tPGC in the turbot was investigated using in-situ hybridization, and tPGA and tPGC were first detected in the esophagus and cardiac region of the stomach, and then throughout the stomach.
Related JoVE Video
Building an ethical environment improves patient privacy and satisfaction in the crowded emergency department: a quasi-experimental study.
BMC Med Ethics
PUBLISHED: 02-06-2013
Show Abstract
Hide Abstract
To evaluate the effectiveness of a multifaceted intervention in improving emergency department (ED) patient privacy and satisfaction in the crowded ED setting.
Related JoVE Video
The carcinogenic liver fluke, Clonorchis sinensis: new assembly, reannotation and analysis of the genome and characterization of tissue transcriptomes.
PLoS ONE
PUBLISHED: 01-30-2013
Show Abstract
Hide Abstract
Clonorchis sinensis (C. sinensis), an important food-borne parasite that inhabits the intrahepatic bile duct and causes clonorchiasis, is of interest to both the public health field and the scientific research community. To learn more about the migration, parasitism and pathogenesis of C. sinensis at the molecular level, the present study developed an upgraded genomic assembly and annotation by sequencing paired-end and mate-paired libraries. We also performed transcriptome sequence analyses on multiple C. sinensis tissues (sucker, muscle, ovary and testis). Genes encoding molecules involved in responses to stimuli and muscle-related development were abundantly expressed in the oral sucker. Compared with other species, genes encoding molecules that facilitate the recognition and transport of cholesterol were observed in high copy numbers in the genome and were highly expressed in the oral sucker. Genes encoding transporters for fatty acids, glucose, amino acids and oxygen were also highly expressed, along with other molecules involved in metabolizing these substrates. All genes involved in energy metabolism pathways, including the ?-oxidation of fatty acids, the citrate cycle, oxidative phosphorylation, and fumarate reduction, were expressed in the adults. Finally, we also provide valuable insights into the mechanism underlying the process of pathogenesis by characterizing the secretome of C. sinensis. The characterization and elaborate analysis of the upgraded genome and the tissue transcriptomes not only form a detailed and fundamental C. sinensis resource but also provide novel insights into the physiology and pathogenesis of C. sinensis. We anticipate that this work will aid the development of innovative strategies for the prevention and control of clonorchiasis.
Related JoVE Video
Molecular identification, immunolocalization, and characterization of Clonorchis sinensis calmodulin.
Parasitol. Res.
PUBLISHED: 01-29-2013
Show Abstract
Hide Abstract
One cDNA clone (Cs18h09) encoding Clonorchis sinensis calmodulin (CsCaM) was isolated from our adult cDNA plasmid library. The open reading frame of CsCaM contains 450 bp which encodes 149 amino acids. CsCaM protein comprises four calcium-binding EF-hand motifs. The amino acid sequence of CsCaM shares very high homology with other species. Quantitative RT-polymerase chain reaction (PCR) revealed that CsCaM mRNA was constitutively transcribed in development cycle stages of the parasite, including adult worm, metacercaria, excysted metacercaria, and egg. In addition, recombinant CsCaM (rCsCaM) was expressed as a soluble protein and anti-rCsCaM rat serum could detect CsCaM in the C. sinensis somatic extracts but not in the C. sinensis excretory-secretory products (ESPs). Moreover, immunolocalization assay showed that CsCaM was located in tegument, intestine, pharynx, and eggs. Furthermore, rCsCaM was found to bind calcium ion (Ca2+) and magnesium (Mg2+) in electrophoretic mobility shift assay. Ca2+ binding increased the ability of rCsCaM to bind the hydrophobic fluorescent probe 8-anilinonaphthalene-1-sulphonate, causing a blue shift in the fluorescence emission from 540 to 515 nm with an excitation wavelength of 380 nm and substantial increase in fluorescence intensity but not Mg2+. Collectively, here we showed the basic characterization of CsCaM and inferred that CsCaM could be a Ca2+ sensor protein, and CsCaM may possibly participate in growth and development of adult worm and egg of C. sinensis through binding Ca2+.
Related JoVE Video
Identification and immunological characterization of thioredoxin transmembrane-related protein from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 01-29-2013
Show Abstract
Hide Abstract
Thioredoxin transmembrane related protein (TMX), a member of thioredoxin superfamily, is localized to the endoplasmic reticulum and possesses a thioredoxin-like domain that plays an important role as an oxidoreductase. The functions of TMX in Clonorchis sinensis remain to be elucidated. In this study, we cloned and characterized a novel TMX of C. sinensis (CsTMX). The CsTMX cDNA sequence contained a 414-nucleotide open-reading frame encoding a protein of 137 amino acids. A thioredoxin domain was found in the position of aa21-117 and contained the putative active-site motif Cys-Pro-Ala-Cys. BLASTx analysis showed that CsTMX shared 39-57% amino acid identities with TMX of other organisms. Quantitative RT-PCR analysis demonstrated that CsTMX was differentially transcribed, with the highest level of expression in the adult worm stage and the lowest expression in egg stage. In addition, immunofluorescence assay showed CsTMX was localized in the tegument, vitelline gland, intestine, and intrauterine eggs of adult worm. Besides, immunoblot assay revealed that the recombinant CsTMX (rCsTMX) could be recognized by the sera from rats infected with C. sinensis and the sera from rats immunized by excretory-secretory products. Furthermore, analysis of the antibody isotype profile revealed that rats subcutaneously immunized with rCsTMX developed rCsTMX-specific antibody, which is dominance of IgG2a in sera. Meanwhile, production of IFN-? was elevated strongly in the supernatants of spleen cell. The results collectively indicated that CsTMX might play an important role in the host-parasite interaction, as well as CsTMX probably involved in immunoregulation of host by inducing Th1-type dominated immune response in rats.
Related JoVE Video
FIP200 is required for maintenance and differentiation of postnatal neural stem cells.
Nat. Neurosci.
PUBLISHED: 01-20-2013
Show Abstract
Hide Abstract
Despite recent studies showing that inhibition of autophagy depletes the hematopoietic stem cell pool and increases intracellular reactive oxygen species (ROS), it remains unknown whether autophagy is essential in the maintenance of other stem cells. Moreover, it is unclear whether and how the aberrant ROS increase causes depletion of stem cells. Here we report that ablation of FIP200 (also known as Rb1cc1), a gene essential for autophagy induction in mammalian cells, results in a progressive loss of neural stem cells (NSCs) and impairment in neuronal differentiation specifically in the postnatal brain, but not the embryonic brain, in mice. The defect in maintaining the postnatal NSC pool was caused by p53-dependent apoptotic responses and cell cycle arrest. However, the impaired neuronal differentiation was rescued by treatment with the antioxidant N-acetylcysteine but not by p53 inactivation. These data reveal that FIP200-mediated autophagy contributes to the maintenance and functions of NSCs through regulation of oxidative state.
Related JoVE Video
Biochemical characterization and functional analysis of fructose-1,6-bisphosphatase from Clonorchis sinensis.
Mol. Biol. Rep.
PUBLISHED: 01-12-2013
Show Abstract
Hide Abstract
Fructose-1,6-bisphosphatase (FBPase), a key regulatory enzyme of gluconeogenesis, plays an essential role in metabolism and development of most organisms. To the wealth of available knowledge about FBPase from Clonorchis sinensis (CsFBPase), in this study, the characteristics of CsFBPase and its potential role in pathogenesis of clonorchiasis were investigated. The Km value of CsFBPase was calculated to be 41.9 uM. The optimal temperature and pH of CsFBPase were 37 °C and pH 7.5-8.0, respectively. In addition, Mg(2+) or K(+) played a regulatory role in enzyme activity of CsFBPase. Both transcriptional and translational level of CsFBPase were higher in metacercariae (one of larva stages) than those in adult worm (P < 0.05). CsFBPase were observed to extensively express in the intestine, vitellaria and tegument of adult worms and ubiquitously in metacercariae. Moreover, CsFBPase was confirmed as a component of excretory/secretory products. Consequently, the translocation of CsFBPase could be detected on epithelial cells of bile duct in liver of C. sinensis infected rat. Recombinant CsFBPase can specifically bind to the membrane of human hepatic stellate cell line LX-2 by immunofluorescence analysis and stimulated proliferation and activation of LX-2 which demonstrated by Cell Counting Kit-8 and upregulation of key fibrosis-related factors, such as ?-smooth muscle actin, collagen I and collagen III using qRT-PCR. Thus, we predicated that CsFBPase might be a multifunctional enzyme which played as both regulatory enzyme and virulence factor in pathogenesis of C. sinensis infection.
Related JoVE Video
Direct measurement of the spin gaps in a gated GaAs two-dimensional electron gas.
Nanoscale Res Lett
PUBLISHED: 01-12-2013
Show Abstract
Hide Abstract
We have performed magnetotransport measurements on gated GaAs two-dimensional electron gases in which electrons are confined in a layer of the nanoscale. From the slopes of a pair of spin-split Landau levels (LLs) in the energy-magnetic field plane, we can perform direct measurements of the spin gap for different LLs. The measured g-factor g is greatly enhanced over its bulk value in GaAs (0.44) due to electron-electron (e-e) interactions. Our results suggest that both the spin gap and g determined from conventional activation energy studies can be very different from those obtained by direct measurements.
Related JoVE Video
Low Divergence of Clonorchis sinensis in China Based on Multilocus Analysis.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Clonorchis sinensis, an ancient parasite that infects a number of piscivorous mammals, attracts significant public health interest due to zoonotic exposure risks in Asia. The available studies are insufficient to reflect the prevalence, geographic distribution, and intraspecific genetic diversity of C. sinensis in endemic areas. Here, a multilocus analysis based on eight genes (ITS1, act, tub, ef-1a, cox1, cox3, nad4 and nad5 [4.986 kb]) was employed to explore the intra-species genetic construction of C. sinensis in China. Two hundred and fifty-six C. sinensis isolates were obtained from environmental reservoirs from 17 provinces of China. A total of 254 recognized Multilocus Types (MSTs) showed high diversity among these isolates using multilocus analysis. The comparison analysis of nuclear and mitochondrial phylogeny supports separate clusters in a nuclear dendrogram. Genetic differentiation analysis of three clusters (A, B, and C) showed low divergence within populations. Most isolates from clusters B and C are geographically limited to central China, while cluster A is extraordinarily genetically diverse. Further genetic analyses between different geographic distributions, water bodies and hosts support the low population divergence. The latter haplotype analyses were consistent with the phylogenetic and genetic differentiation results. A recombination network based on concatenated sequences showed a concentrated linkage recombination population in cox1, cox3, nad4 and nad5, with spatial structuring in ITS1. Coupled with the history record and archaeological evidence of C. sinensis infection in mummified desiccated feces, these data point to an ancient origin of C. sinensis in China. In conclusion, we present a likely phylogenetic structure of the C. sinensis population in mainland China, highlighting its possible tendency for biogeographic expansion. Meanwhile, ITS1 was found to be an effective marker for tracking C. sinensis infection worldwide. Thus, the present study improves our understanding of the global epidemiology and evolution of C. sinensis.
Related JoVE Video
Molecular characterization and expression of a cysteine protease from Clonorchis sinensis and its application for serodiagnosis of clonorchiasis.
Parasitol. Res.
PUBLISHED: 11-02-2011
Show Abstract
Hide Abstract
Cysteine proteases play essential roles in parasite physiology as well as in host-parasite interactions through their modulation of various biological and pathobiological events. In the present study, a full-length sequence encoding cysteine protease of Clonorchis sinensis (CsCP) was isolated from our adult cDNA library. The open reading frame contains 984 bp encoding 327 amino acids. The present amino acid sequence shared 68% identity with two known CsCP genes and 29-49% identity with that of other species. Bioinformatics analysis showed that conserved domains and characteristic amino acid residues of cysteine proteases were observed in this sequence. Real-time PCR experiments revealed that CsCP was consecutively transcribed in various developmental stages of the parasite, including adult worm, excysted juvenile, metacercaria and egg. Recombinant CsCP (rCsCP) could be probed by rat anti-CsCP serum, rabbit anti-excretory-secretory products (ESP) serum and serum from human infected with Clonorchis sinensis in Western blot. The result of immunolocalization showed that CsCP was mainly located in the oral sucker, excretory bladder and tegument of cercariae and metacercariae, as well as the intestine of adult worm. The rCsCP-based IgG and its isotypes were all detected in sera from human infected with C. sinensis by enzyme-linked immunosorbent assay, and the level of IgG1 is the highest. The receiver-operating characteristic (ROC) analysis was used to determine the most appropriate cut-off value that yielded the high sensitivity (86.96%) and specificity (70.42%). These results revealed that CsCP may play an important role in the biology of C. sinensis and could be a diagnostic candidate for clonorchiasis.
Related JoVE Video
Genetic predisposition and nongenetic risk factors of thiazolidinedione-related edema in patients with type 2 diabetes.
Pharmacogenet. Genomics
PUBLISHED: 09-22-2011
Show Abstract
Hide Abstract
This study aimed to analyze the association of thiazolidinedione (TZD)-related edema with genetic and clinical variables and develop a simple points system to predict the risk of developing TZD-related edema.
Related JoVE Video
Age-related changes of task-specific brain activity in normal aging.
Neurosci. Lett.
PUBLISHED: 09-15-2011
Show Abstract
Hide Abstract
An important question in healthcare for older patients is whether age-related changes in cortical reorganization can be measured with advancing age. This study investigated the factors behind such age-related changes, using time-frequency analysis of event-related potentials (ERPs). We hypothesized that brain rhythms was affected by age-related changes, which could be reflected in the ERP indices. An oddball task was conducted in two experimental groups, namely young participants (N=15; mean age 23.7±2.8 years) and older participants (N=15; mean age 70.1±7.9 years). Two types of stimuli were used: the target (1 kHz frequency) and standard (2 kHz frequency). We scrutinized three ERP indices: event-related spectral power (ERPSP), inter-trial phase-locking (ITPL), and event-related cross-phase coherence (ERPCOH). Both groups performed equally well for correct response rate. However, the results revealed a statistically significant age difference for inter-trial comparison. Compared with the young, the older participants showed the following age-related changes: (a) power activity decreased; however, an increase was found only in the late (P3, 280-450 ms) theta (4-7 Hz) component over the bilateral frontal and temporo-frontal areas; (b) low phase-locking in the early (N1, 80-140 ms) theta band over the parietal/frontal (right) regions appeared; (c) the functional connections decreased in the alpha (7-13 Hz) and beta (13-30 Hz) bands, but no difference emerged in the theta band between the two groups. These results indicate that age-related changes in task-specific brain activity for a normal aging population can be depicted using the three ERP indices.
Related JoVE Video
Do age-related changes contribute to the flanker effect?
Clin Neurophysiol
PUBLISHED: 09-06-2011
Show Abstract
Hide Abstract
The present study examined age-related changes in the flanker effect and the extent to which age interacts with flanker-induced differences in perceptual processing, which contribute to the flanker effect.
Related JoVE Video
Magnetic bead-based hydrophilic interaction liquid chromatography for glycopeptide enrichments.
J Chromatogr A
PUBLISHED: 09-05-2011
Show Abstract
Hide Abstract
Purification of glycopeptides prior to the analysis by mass spectrometry (MS) is demanded due to ion suppression effect during ionization caused by the co-presence of non-glycosylated peptides. Among various purification methods, hydrophilic interaction liquid chromatography (HILIC) has become a popular method in recent years. In this work, we reported a novel magnetic bead-based zwitterionic HILIC (ZIC-HILIC) material which was fabricated by coating a zwitterionic polymer synthesized by spontaneous acid-catalyzed polymerization of 4-vinyl-pyridinium ethanesulfonate monomer on iron oxide magnetic nanoparticles. The resulting magnetic ZIC-HILIC nanoparticles were shown to provide high specificity and high recovery yield (95-100%) for the enrichment of glycopeptides from a standard glycoprotein, fetuin, using a simple magnetic bar. In addition, we proposed a two-step HILIC enrichment strategy using magnetic ZIC-HILIC nanoparticles for a large scale analysis of glycoproteins in complex biological samples. Using this approach, we identified 85 N-glycosylation sites in 53 glycoproteins from urine samples. Two novel glycosylation sites on N513 of uromodulin and N470 of lysosomal alpha-glucosidase which have not yet been reported were identified by two-step HILIC approach. Furthermore, all these identified sites were confirmed by studies conducted using PNGase F deglycosylation and 18O enzymatic labeling.
Related JoVE Video
Gene/protein expression level, immunolocalization and binding characteristics of fatty acid binding protein from Clonorchis sinensis (CsFABP).
Mol. Cell. Biochem.
PUBLISHED: 08-29-2011
Show Abstract
Hide Abstract
Clonorchis sinensis fatty acid-binding protein (CsFABP) belongs to a multigene family of lipid-binding proteins and is considered to be a promising vaccine candidate for human clonorchiasis. In this study, binding characteristics of CsFABP have been examined for the first time. The recombinant CsFABP (rCsFABP) was found to bind 11-(dansylamino) undecanoic acid (DAUDA), causing a blue shift in the fluorescence emission from 543 to 531 nm with an excitation wavelength of 345 nm and a substantial increase in fluorescence intensity. Fluorimetric titration of rCsFABP with DAUDA exhibited an apparent dissociation constant (K (d)) of 1.58 ± 0.14 ?M. In the competitive experiment, the rCsFABP efficiently bound saturated C(10)-C(18) fatty acids and unsaturated fatty acids (oleic acid and linoleic acid), and the latter presented the higher affinity. Furthermore, quantitative RT-PCR and western blotting analysis revealed that CsFABP mRNA and protein were differentially expressed throughout the developmental cycle stages of the parasite, which occur in the definitive host (metacercariae, adult worms, and eggs). In addition, immunolocalization assay showed that CsFABP was localized on the vitelline gland, tegument, intestine, seminal vesicle, eggs in uterus, ovary, and testicle of C. sinensis adult worm, as well as on the vitelline gland of metacercaria. Intriguingly, the surface tissue of the bile duct where C. sinensis resided in the infected Sprague-Dawley rat was also strongly labeled, implying that CsFABP may possibly mediate direct interactions with host cells as a component of excretory/secretory products.
Related JoVE Video
Lack of association between CLEC5A gene single-nucleotide polymorphisms and Kawasaki disease in Taiwanese children.
J. Biomed. Biotechnol.
PUBLISHED: 08-28-2011
Show Abstract
Hide Abstract
Kawasaki disease is characterized by systemic vasculitis of unknown etiology. Previous genetic studies have identified certain candidate genes associated with susceptibility to KD and coronary artery lesions. Host innate immune response factors are involved in modulating the disease outcome. The aim of this study was to investigate CLEC5A (C-type lectin domain family 5) genetic polymorphisms with regards to the susceptibility and outcome of KD.
Related JoVE Video
Cholesterol and lipoprotein dynamics in a hibernating mammal.
PLoS ONE
PUBLISHED: 08-13-2011
Show Abstract
Hide Abstract
Hibernating mammals cease feeding during the winter and rely primarily on stored lipids to fuel alternating periods of torpor and arousal. How hibernators manage large fluxes of lipids and sterols over the annual hibernation cycle is poorly understood. The aim of this study was to investigate lipid and cholesterol transport and storage in ground squirrels studied in spring, summer, and several hibernation states. Cholesterol levels in total plasma, HDL and LDL particles were elevated in hibernators compared with spring or summer squirrels. Hibernation increased plasma apolipoprotein A-I expression and HDL particle size. Expression of cholesterol 7 alpha-hydroxylase was 13-fold lower in hibernators than in active season squirrels. Plasma triglycerides were reduced by fasting in spring but not summer squirrels. In hibernators plasma ?-hydroxybutyrate was elevated during torpor whereas triglycerides were low relative to normothermic states. We conclude that the switch to a lipid-based metabolism during winter, coupled with reduced capacity to excrete cholesterol creates a closed system in which efficient use of lipoproteins is essential for survival.
Related JoVE Video
Hemagglutinin-neuraminidase balance confers respiratory-droplet transmissibility of the pandemic H1N1 influenza virus in ferrets.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 08-08-2011
Show Abstract
Hide Abstract
A novel reassortant derived from North American triple-reassortant (TRsw) and Eurasian swine (EAsw) influenza viruses acquired sustained human-to-human transmissibility and caused the 2009 influenza pandemic. To identify molecular determinants that allowed efficient transmission of the pandemic H1N1 virus among humans, we evaluated the direct-contact and respiratory-droplet transmissibility in ferrets of representative swine influenza viruses of different lineages obtained through a 13-y surveillance program in southern China. Whereas all viruses studied were transmitted by direct contact with varying efficiency, respiratory-droplet transmissibility (albeit inefficient) was observed only in the TRsw-like A/swine/Hong Kong/915/04 (sw915) (H1N2) virus. The sw915 virus had acquired the M gene derived from EAsw and differed from the gene constellation of the pandemic H1N1 virus by the neuraminidase (NA) gene alone. Glycan array analysis showed that pandemic H1N1 virus A/HK/415742/09 (HK415742) and sw915 possess similar receptor-binding specificity and affinity for ?2,6-linked sialosides. Sw915 titers in differentiated normal human bronchial epithelial cells and in ferret nasal washes were lower than those of HK415742. Introducing the NA from pandemic HK415742 into sw915 did not increase viral replication efficiency but increased respiratory-droplet transmissibility, despite a substantial amino acid difference between the two viruses. The NA of the pandemic HK415742 virus possessed significantly higher enzyme activity than that of sw915 or other swine influenza viruses. Our results suggest that a unique gene constellation and hemagglutinin-neuraminidase balance play a critical role in acquisition of efficient and sustained human-to-human transmissibility.
Related JoVE Video
Molecular expression and characterization of a novel protein phosphatase 2A gene from Clonorchis sinensis.
Parasitol. Res.
PUBLISHED: 08-01-2011
Show Abstract
Hide Abstract
Reversible phosphorylation of proteins is a critical mechanism involved in physiological function of organisms, including Clonorchis sinensis. In the present study, One cDNA clone encoding protein phosphatase 2A (CsPP2A) was isolated from a C. sinensis adult cDNA plasmid library. The open reading frame of the novel gene contains 924 bp and encoded a putative protein of 307 amino acids. A similarity analysis showed high homology with Schistosoma japonicum (76.3%) and Homo sapiens (84.4%), respectively. Recombinant CsPP2A (rCsPP2A) was expressed and purified from Escherichia coli BL21 using pET28a (+) as an expression vector. CsPP2A showed higher transcript level in adult worm but excysted metacercaria (P > 0.05), metacercaria (P < 0.05), and egg (P < 0.05) using real-time RT-PCR. Western blotting analysis showed that rCsPP2A could be identified by anti-rCsPP2A rat serum, C. sinensis-infected rat serum, and the serum from the rats immunized with excretory-secretory products of C. sinensis. Immunohistochemical assay showed that CsPP2A was deposited at the egg, the vitellarium of adult worm, and the excretory bladder of metacercaria. Collectively, the results of this study suggested that CsPP2A may be involved in the development of adult and metacercaria of C. sinensis.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.