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.
Extra-adrenal Paraganglioma Presenting as Acute Chest Pain Mimicking Acute Myocardial Infarction in a 10-Year-Old Boy.
Pediatr Emerg Care
PUBLISHED: 11-07-2014
Show Abstract
Hide Abstract
Extraadrenal paragangliomas are rare pediatric tumors with variable symptoms that cause difficultly in diagnosis and delayed treatment. We report the case of a 10-year-old boy who presented to the pediatric emergency department with acute chest pain and dyspnea mimicking a non-ST-segment elevation acute myocardial infarction. He was subsequently found to have an extraadrenal paraganglioma after a series of imaging and laboratory examinations. The mass was subsequently removed, and the diagnosis of extraadrenal paraganglioma was confirmed histologically. Acute coronary syndrome as the presenting feature of extraadrenal paragangliomas in pediatric population is an even rarer clinical entity.
Related JoVE Video
Ursolic acid triggers nonprogrammed death (necrosis) in human glioblastoma multiforme DBTRG-05MG cells through MPT pore opening and ATP decline.
Mol Nutr Food Res
PUBLISHED: 09-16-2014
Show Abstract
Hide Abstract
Ursolic acid, a natural pentacyclic triterpenic acid, possesses anticancer potential and diverse biological effects, but its correlation with glioblastoma multiforme cells and different modes of cell death is unclear. We studied the cellular actions of human glioblastoma multiforme DBTRG-05MG cells after ursolic acid treatment and explored cell-selective killing effect of necrotic death as a cell fate.
Related JoVE Video
Tracing evolutionary relicts of positive selection on eight malaria-related immune genes in mammals.
Innate Immun
PUBLISHED: 09-10-2014
Show Abstract
Hide Abstract
Plasmodium-induced malaria widely infects primates and other mammals. Multiple past studies have revealed that positive selection could be the main evolutionary force triggering the genetic diversity of anti-malaria resistance-associated genes in human or primates. However, researchers focused most of their attention on the infra-generic and intra-specific genome evolution rather than analyzing the complete evolutionary history of mammals. Here we extend previous research by testing the evolutionary link of natural selection on eight candidate genes associated with malaria resistance in mammals. Three of the eight genes were detected to be affected by recombination, including TNF-?, iNOS and DARC. Positive selection was detected in the rest five immunogenes multiple times in different ancestral lineages of extant species throughout the mammalian evolution. Signals of positive selection were exposed in four malaria-related immunogenes in primates: CCL2, IL-10, HO1 and CD36. However, selection signals of G6PD have only been detected in non-primate eutherians. Significantly higher evolutionary rates and more radical amino acid replacement were also detected in primate CD36, suggesting its functional divergence from other eutherians. Prevalent positive selection throughout the evolutionary trajectory of mammalian malaria-related genes supports the arms race evolutionary hypothesis of host genetic response of mammalian immunogenes to infectious pathogens.
Related JoVE Video
Exploration and forecasting of behaviours and factors relating to fruit and vegetable intake among seniors in the community.
Public Health Nutr
PUBLISHED: 07-31-2014
Show Abstract
Hide Abstract
The present study investigated the current status of fruit and vegetable intake among seniors and assessed the relationship between personal background factors, social psychological factors and environmental factors of the study participants and their fruit and vegetable consumption behaviour.
Related JoVE Video
Examining the Relationship between Cardiorespiratory Fitness and Body Weight Status: Empirical Evidence from a Population-Based Survey of Adults in Taiwan.
ScientificWorldJournal
PUBLISHED: 07-08-2014
Show Abstract
Hide Abstract
Background. Cardiovascular disease is the number one cause of death worldwide. Meanwhile, obesity has been recognized as a global epidemic. This study aims to examine the extent to which cardiorespiratory fitness is associated with body mass among adult males and females in Taiwan. Materials and Methods. A nationally representative dataset consisting of 68,175 adults aged 18-60, including 31,743 males and 36,432 females, was used. Several multivariate regression models were used to investigate the relationship between cardiorespiratory fitness and body weight status, after controlling for adults' sociodemographic status. Results. A one-unit increase in the BMI lowered the cardiorespiratory fitness score by 0.316 and 0.368 points for adult males and females, respectively. Among adult males, compared to those of normal weight, adult males who were underweight, overweight, or obese had a lower cardiorespiratory fitness score by 1.287, 0.845, and 3.353 points, respectively. Similar results could be found in female samples. Conclusion. The overweight and obese adults had much lower levels of cardiorespiratory fitness as compared to their normal weight counterparts. Given the upward trend in the prevalence of overweight and obesity, it is important to help overweight and obese people to become more fit and reach their healthy weight.
Related JoVE Video
Formation of oligonucleotide-gated silica shell-coated Fe?O?-Au core-shell nanotrisoctahedra for magnetically targeted and near-infrared light-responsive theranostic platform.
J. Am. Chem. Soc.
PUBLISHED: 06-30-2014
Show Abstract
Hide Abstract
A new multifunctional nanoparticle to perform a near-infrared (NIR)-responsive remote control drug release behavior was designed for applications in the biomedical field. Different from the previous studies in formation of Fe3O4-Au core-shell nanoparticles resulting in a spherical morphology, the heterostructure with polyhedral core and shell was presented with the truncated octahedral Fe3O4 nanoparticle as the core over a layer of trisoctahedral Au shell. The strategy of Fe3O4@polymer@Au was adopted using poly-l-lysine as the mediate layer, followed by the subsequent seeded growth of Au nanoparticles to form a Au trisoctahedral shell. Fe3O4@Au trisoctahedra possess high-index facets of {441}. To combine photothermal and chemotherapy in a remote-control manner, the trisoctahedral core-shell Fe3O4@Au nanoparticles were further covered with a mesoporous silica shell, yielding Fe3O4@Au@mSiO2. The bondable oligonucleotides (referred as dsDNA) were used as pore blockers of the mesoporous silica shell that allowed the controlled release, resulting in a NIR-responsive DNA-gated Fe3O4@Au@mSiO2 nanocarrier. Taking advantage of the magnetism, remotely triggered drug release was facilitated by magnetic attraction accompanied by the introduction of NIR radiation. DNA-gated Fe3O4@Au@mSiO2 serves as a drug control and release carrier that features functions of magnetic target, MRI diagnosis, and combination therapy through the manipulation of a magnet and a NIR laser. The results verified the significant therapeutic effects on tumors with the assistance of combination therapy consisting of magnetic guidance and remote NIR control.
Related JoVE Video
Single-crystal X-ray diffraction studies on structural transformations of porous coordination polymers.
Chem Soc Rev
PUBLISHED: 06-28-2014
Show Abstract
Hide Abstract
X-Ray single-crystal diffraction has been the most straightforward and important technique in structural determination of crystalline materials for understanding their structure-property relationships. This powerful tool can be used to directly visualize the precise and detailed structural information of porous coordination polymers or metal-organic frameworks at different states, which are unique for their flexible host frameworks compared with conventional adsorbents. With a series of selected recent examples, this review gives a brief overview of single-crystal X-ray diffraction studies and single-crystal to single-crystal transformations of porous coordination polymers under various chemical and physical stimuli such as solvent and gas sorption/desorption/exchange, chemical reaction and temperature change.
Related JoVE Video
Ghrelin therapy improves survival after whole-body ionizing irradiation or combined with burn or wound: amelioration of leukocytopenia, thrombocytopenia, splenomegaly, and bone marrow injury.
Oxid Med Cell Longev
PUBLISHED: 05-20-2014
Show Abstract
Hide Abstract
Exposure to ionizing radiation alone (RI) or combined with traumatic tissue injury (CI) is a crucial life-threatening factor in nuclear and radiological events. In our laboratory, mice exposed to (60)Co-?-photon radiation (9.5?Gy, 0.4?Gy/min, bilateral) followed by 15% total-body-surface-area skin wounds (R-W CI) or burns (R-B CI) experienced an increment of ?18% higher mortality over a 30-day observation period compared to RI alone. CI was accompanied by severe leukocytopenia, thrombocytopenia, erythropenia, and anemia. At the 30th day after injury, numbers of WBC and platelets still remained very low in surviving RI and CI mice. In contrast, their RBC, hemoglobin, and hematocrit were recovered towards preirradiation levels. Only RI induced splenomegaly. RI and CI resulted in bone-marrow cell depletion. In R-W CI mice, ghrelin (a hunger-stimulating peptide) therapy increased survival, mitigated body-weight loss, accelerated wound healing, and increased hematocrit. In R-B CI mice, ghrelin therapy increased survival and numbers of neutrophils, lymphocytes, and platelets and ameliorated bone-marrow cell depletion. In RI mice, this treatment increased survival, hemoglobin, and hematocrit and inhibited splenomegaly. Our novel results are the first to suggest that ghrelin therapy effectively improved survival by mitigating CI-induced leukocytopenia, thrombocytopenia, and bone-marrow injury or the RI-induced decreased hemoglobin and hematocrit.
Related JoVE Video
Drastic enhancement of catalytic activity via post-oxidation of a porous MnII triazolate framework.
Chemistry
PUBLISHED: 04-16-2014
Show Abstract
Hide Abstract
Mn(III) is a powerful active site for catalytic oxidation of alkyl aromatics, but it can be only stabilized by macrocyclic chelating ligands such porphyrinates. Herein, by using benzobistriazolate as a rigid bridging ligand, a porous Mn(II) azolate framework with a nitrogen-rich coordinated environment similar to that of metalloporphyrins was synthesized, in which the Mn(II) ions can be post-oxidized to Mn(III) to achieve drastic increase of catalytic (aerobic) oxidation performance.
Related JoVE Video
Aspect ratio plays a role in the hazard potential of CeO2 nanoparticles in mouse lung and zebrafish gastrointestinal tract.
ACS Nano
PUBLISHED: 04-16-2014
Show Abstract
Hide Abstract
We have previously demonstrated that there is a relationship between the aspect ratio (AR) of CeO2 nanoparticles and in vitro hazard potential. CeO2 nanorods with AR ? 22 induced lysosomal damage and progressive effects on IL-1? production and cytotoxicity in the human myeloid cell line, THP-1. In order to determine whether this toxicological paradigm for long aspect ratio (LAR) CeO2 is also relevant in vivo, we performed comparative studies in the mouse lung and gastrointestinal tract (GIT) of zebrafish larvae. Although oropharyngeal aspiration could induce acute lung inflammation for CeO2 nanospheres and nanorods, only the nanorods with the highest AR (C5) induced significant IL-1? and TGF-?1 production in the bronchoalveolar lavage fluid at 21 days but did not induce pulmonary fibrosis. However, after a longer duration (44 days) exposure to 4 mg/kg of the C5 nanorods, more collagen production was seen with CeO2 nanorods vs nanospheres after correcting for Ce lung burden. Using an oral-exposure model in zebrafish larvae, we demonstrated that C5 nanorods also induced significant growth inhibition, a decrease in body weight, and delayed vertebral calcification. In contrast, CeO2 nanospheres and shorter nanorods had no effect. Histological and transmission electron microscopy analyses showed that the key injury mechanism of C5 was in the epithelial lining of the GIT, which demonstrated blunted microvilli and compromised digestive function. All considered, these data demonstrate that, similar to cellular studies, LAR CeO2 nanorods exhibit more toxicity in the lung and GIT, which could be relevant to inhalation and environmental hazard potential.
Related JoVE Video
PdO doping tunes band-gap energy levels as well as oxidative stress responses to a Co?O? p-type semiconductor in cells and the lung.
J. Am. Chem. Soc.
PUBLISHED: 04-15-2014
Show Abstract
Hide Abstract
We demonstrate through PdO doping that creation of heterojunctions on Co3O4 nanoparticles can quantitatively adjust band-gap and Fermi energy levels to study the impact of metal oxide nanoparticle semiconductor properties on cellular redox homeostasis and hazard potential. Flame spray pyrolysis (FSP) was used to synthesize a nanoparticle library in which the gradual increase in the PdO content (0-8.9%) allowed electron transfer from Co3O4 to PdO to align Fermi energy levels across the heterojunctions. This alignment was accompanied by free hole accumulation at the Co3O4 interface and production of hydroxyl radicals. Interestingly, there was no concomitant superoxide generation, which could reflect the hole dominance of a p-type semiconductor. Although the electron flux across the heterojunctions induced upward band bending, the E(c) levels of the doped particles showed energy overlap with the biological redox potential (BRP). This allows electron capture from the redox couples that maintain the BRP from -4.12 to -4.84 eV, causing disruption of cellular redox homeostasis and induction of oxidative stress. PdO/Co3O4 nanoparticles showed significant increases in cytotoxicity at 25, 50, 100, and 200 ?g/mL, which was enhanced incrementally by PdO doping in BEAS-2B and RAW 264.7 cells. Oxidative stress presented as a tiered cellular response involving superoxide generation, glutathione depletion, cytokine production, and cytotoxicity in epithelial and macrophage cell lines. A progressive series of acute pro-inflammatory effects could also be seen in the lungs of animals exposed to incremental PdO-doped particles. All considered, generation of a combinatorial PdO/Co3O4 nanoparticle library with incremental heterojunction density allowed us to demonstrate the integrated role of E(v), E(c), and E(f) levels in the generation of oxidant injury and inflammation by the p-type semiconductor, Co3O4.
Related JoVE Video
Phyllanthus urinaria induces mitochondrial dysfunction in human osteosarcoma 143B cells associated with modulation of mitochondrial fission/fusion proteins.
Mitochondrion
PUBLISHED: 04-14-2014
Show Abstract
Hide Abstract
Phyllanthus urinaria (P. urinaria), a widely used herbal medicine, has been reported to possess various biological characteristics including anti-inflammation, anti-virus, anti-bacteria, anti-hepatotoxicity and anti-cancer. This study provides molecular evidence associated with the dynamics and organization of mitochondria in osteosarcoma 143B cells resulted from P urinaria. Herein, P. urinaria-induced cytotoxicity and ROS associated with the inhibition of mitochondrial membrane potential were reversed by N-acetylcysteine (NAC). The endogenous antioxidant enzymes such as manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPX1) were activated by P. urinaria, but not correlated to catalase. P. urinaria decreased mitochondrial respiration activity as well as respiratory chain enzymes and HIF-1? in osteosarcoma 143B cells. Additionally, both adenosine triphosphate (ATP) synthase activation and ATP production were suppressed by P. urinaria. We further investigated changes of mitochondrial dynamic in osteosarcoma 143B cells. P. urinaria indeed fragmented the mitochondrial network of osteosarcoma 143B cells. We found a significant decrease in optic atrophy type 1 (Opa1) and mitofusin 1 (Mfn1) related to fusion proteins as well as increase mitochondrial fission 1 protein (Fis1) related to fission protein. It indicated that P. urinaria modulated the mitochondrial dynamics via fusion and fission machinery. Altogether, this study offers the evidence that mitochondrial dysfunction with dynamic change is essential components for the anti-cancer mechanism elicited by P. urinaria.
Related JoVE Video
Evaluation of the mining techniques in constructing a traditional chinese-language nursing recording system.
Comput Inform Nurs
PUBLISHED: 04-04-2014
Show Abstract
Hide Abstract
In 2009, the Department of Health, part of Taiwan's Executive Yuan, announced the advent of electronic medical records to reduce medical expenses and facilitate the international exchange of medical record information. An information technology platform for nursing records in medical institutions was then quickly established, which improved nursing information systems and electronic databases. The purpose of the present study was to explore the usability of the data mining techniques to enhance completeness and ensure consistency of nursing records in the database system.First, the study used a Chinese word-segmenting system on common and special terms often used by the nursing staff. We also used text-mining techniques to collect keywords and create a keyword lexicon. We then used an association rule and artificial neural network to measure the correlation and forecasting capability for keywords. Finally, nursing staff members were provided with an on-screen pop-up menu to use when establishing nursing records. Our study found that by using mining techniques we were able to create a powerful keyword lexicon and establish a forecasting model for nursing diagnoses, ensuring the consistency of nursing terminology and improving the nursing staff's work efficiency and productivity.
Related JoVE Video
Comparison of procalcitonin and different guidelines for first febrile urinary tract infection in children by imaging.
Pediatr. Nephrol.
PUBLISHED: 02-26-2014
Show Abstract
Hide Abstract
We examined the ability of a procalcitonin (PCT) protocol to detect vesicoureteral reflux (VUR) and renal scarring (RS), evaluated procedural costs and radiation burden, and compared four representative guidelines for children with their first febrile urinary tract infection (UTI).
Related JoVE Video
Androgen receptor enhances cell adhesion and decreases cell migration via modulating ?1-integrin-AKT signaling in hepatocellular carcinoma cells.
Cancer Lett.
PUBLISHED: 02-07-2014
Show Abstract
Hide Abstract
The androgen receptor (AR) has been shown to promote the initiation and development of hepatocellular carcinoma (HCC) during the early stage of the disease process and to suppress HCC cell invasion during the later stages of the disease. The mechanisms governing these dual yet opposite roles have yet to be elucidated. Using carcinogen-induced HCC in vivo mouse models and the in vitro human HCC cell line SKhep1, we found that knockout of AR in primary HCC cells led to a decrease in HCC cell focal adhesion capacity compared to cells from wildtype mice. Similar results were obtained after adding functional AR into human HCC SKhep1 cells. Further analysis revealed that the role AR plays in adhesion of HCC cells is governed, at least in part, by its ability to up-regulate ?1-integrin and activate the PI3K/AKT pathway. We also found that AR-?1-integrin-mediated cell adhesion suppresses cell migration. Those findings indicate that the AR-?1-integrin-PI3K/AKT signaling pathway might play a role in the bimodal function of AR on cell adhesion and migration at the cellular level.
Related JoVE Video
Decreased postoperative C-reactive protein production in dogs with pyometra through the use of low-dose ketamine.
J Vet Emerg Crit Care (San Antonio)
PUBLISHED: 02-06-2014
Show Abstract
Hide Abstract
To determine the effects of subanesthetic ketamine in dogs with pyometra on C-reactive protein (CRP) concentrations following surgery.
Related JoVE Video
Persistent endocrine disruption effects in medaka fish with early life-stage exposure to a triazole-containing aromatase inhibitor (letrozole).
J. Hazard. Mater.
PUBLISHED: 01-28-2014
Show Abstract
Hide Abstract
Letrozole (LET) is a triazole-containing drug that can inhibit the activity of cytochrome P450 aromatase. It is an environmentally emerging pollutant because of its broad use in medicine and frequent occurrence in aquifers receiving the effluent of municipal or hospital wastewater. However, the toxic impact of LET on fish populations remains unclear. We exposed medaka fish (Oryzias latipes) at an early stage of sexual development to a continuous chronic LET at environmentally relevant concentrations and assessed the endocrine disruption effects in adulthood and the next generation. LET exposure at an early life stage persistently altered phenotypic sex development and reproduction in adults and skewed the sex ratio in progeny. As well, LET exposure led to a gender-different endocrine disruption as seen by the interruption in gene expression responsible for estrogen synthesis and metabolism and fish reproduction. LET interfering with the aromatase system in early life stages of medaka can disrupt hormone homeostasis and reproduction. This potent aromatase inhibitor has potential ecotoxicological impact on fish populations in aquatic environments.
Related JoVE Video
Surface interactions with compartmentalized cellular phosphates explain rare earth oxide nanoparticle hazard and provide opportunities for safer design.
ACS Nano
PUBLISHED: 01-26-2014
Show Abstract
Hide Abstract
Growing international exploitation of rare earth oxides (REOs) for commercial and biological use has increased the possibility of human exposure and adverse health effects. Occupational exposure to rare earth materials in miners and polishers leads to a severe form of pneumoconiosis, while gadolinium-containing MRI contrast agents cause nephrogenic systemic fibrosis in patients with renal impairment. The mechanisms for inducing these adverse pro-fibrogenic effects are of considerable importance for the safety assessment of REO particles as well as presenting opportunities for safer design. In this study, using a well-prepared REO library, we obtained a mechanistic understanding of how REOs induce cellular and pulmonary damage by a compartmentalized intracellular biotransformation process in lysosomes that results in pro-fibrogenic growth factor production and lung fibrosis. We demonstrate that rare earth oxide ion shedding in acidifying macrophage lysosomes leads to biotic phosphate complexation that results in organelle damage due to stripping of phosphates from the surrounding lipid bilayer. This results in nanoparticle biotransformation into urchin shaped structures and setting in motion a series of events that trigger NLRP3 inflammasome activation, IL-1? release, TGF-?1 and PDGF-AA production. However, pretreatment of REO nanoparticles with phosphate in a neutral pH environment prevents biological transformation and pro-fibrogenic effects. This can be used as a safer design principle for producing rare earth nanoparticles for biological use.
Related JoVE Video
Pegylated G-CSF inhibits blood cell depletion, increases platelets, blocks splenomegaly, and improves survival after whole-body ionizing irradiation but not after irradiation combined with burn.
Oxid Med Cell Longev
PUBLISHED: 01-22-2014
Show Abstract
Hide Abstract
Exposure to ionizing radiation alone (radiation injury, RI) or combined with traumatic tissue injury (radiation combined injury, CI) is a crucial life-threatening factor in nuclear and radiological accidents. As demonstrated in animal models, CI results in greater mortality than RI. In our laboratory, we found that B6D2F1/J female mice exposed to (60)Co-?-photon radiation followed by 15% total-body-surface-area skin burns experienced an increment of 18% higher mortality over a 30-day observation period compared to irradiation alone; that was accompanied by severe cytopenia, thrombopenia, erythropenia, and anemia. At the 30th day after injury, neutrophils, lymphocytes, and platelets still remained very low in surviving RI and CI mice. In contrast, their RBC, hemoglobin, and hematocrit were similar to basal levels. Comparing CI and RI mice, only RI induced splenomegaly. Both RI and CI resulted in bone marrow cell depletion. It was observed that only the RI mice treated with pegylated G-CSF after RI resulted in 100% survival over the 30-day period, and pegylated G-CSF mitigated RI-induced body-weight loss and depletion of WBC and platelets. Peg-G-CSF treatment sustained RBC balance, hemoglobin levels, and hematocrits and inhibited splenomegaly after RI. The results suggest that pegylated G-CSF effectively sustained animal survival by mitigating radiation-induced cytopenia, thrombopenia, erythropenia, and anemia.
Related JoVE Video
Diabetes with pyogenic liver abscess--A perspective on tongue assessment in traditional Chinese medicine.
Complement Ther Med
PUBLISHED: 01-02-2014
Show Abstract
Hide Abstract
This novel study provides a time series analysis of tongue features extracted from a diabetic patient with pyogenic liver abscess (PLA), treated with the integration of western medicine and traditional Chinese medicine (TCM). The features, namely, tongue color, tongue fur thickness and fur color, identified from a series of tongue images taken every two days, exhibit significant transitions matching closely with the progression of disease. These tongue features could serve as effective, non-intrusive indices for different progression stages of diabetes with PLA.
Related JoVE Video
Lens Subluxation after Plasmin and SF6 Injections in Rabbit Eyes.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To investigate the rate of lens subluxation following plasmin and/or SF6 injections in eyes, and whether a subsequent elevated level of vascular endothelial growth factor (VEGF) and vitreous tap would aggravate subluxation.
Related JoVE Video
Comparison of the effects of air pollution on outpatient and inpatient visits for asthma: a population-based study in Taiwan.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
A nationwide asthma survey on the effects of air pollution is lacking in Taiwan. The purpose of this study was to evaluate the time trend and the relationship between air pollution and health care services for asthma in Taiwan.
Related JoVE Video
Engineering an effective immune adjuvant by designed control of shape and crystallinity of aluminum oxyhydroxide nanoparticles.
ACS Nano
PUBLISHED: 12-02-2013
Show Abstract
Hide Abstract
Adjuvants based on aluminum salts (Alum) are commonly used in vaccines to boost the immune response against infectious agents. However, the detailed mechanism of how Alum enhances adaptive immunity and exerts its adjuvant immune effect remains unclear. Other than being comprised of micrometer-sized aggregates that include nanoscale particulates, Alum lacks specific physicochemical properties to explain activation of the innate immune system, including the mechanism by which aluminum-based adjuvants engage the NLRP3 inflammasome and IL-1? production. This is putatively one of the major mechanisms required for an adjuvant effect. Because we know that long aspect ratio nanomaterials trigger the NLRP3 inflammasome, we synthesized a library of aluminum oxyhydroxide (AlOOH) nanorods to determine whether control of the material shape and crystalline properties could be used to quantitatively assess NLRP3 inflammasome activation and linkage of the cellular response to the materials adjuvant activities in vivo. Using comparison to commercial Alum, we demonstrate that the crystallinity and surface hydroxyl group display of AlOOH nanoparticles quantitatively impact the activation of the NLRP3 inflammasome in human THP-1 myeloid cells or murine bone marrow-derived dendritic cells (BMDCs). Moreover, these in vitro effects were correlated with the immunopotentiation capabilities of the AlOOH nanorods in a murine OVA immunization model. These results demonstrate that shape, crystallinity, and hydroxyl content play an important role in NLRP3 inflammasome activation and are therefore useful for quantitative boosting of antigen-specific immune responses. These results show that the engineered design of aluminum-based adjuvants in combination with dendritic cell property-activity analysis can be used to design more potent aluminum-based adjuvants.
Related JoVE Video
Development and Initial Validation of the Multicultural Personality Inventory (MPI).
J Pers Assess
PUBLISHED: 11-09-2013
Show Abstract
Hide Abstract
Two studies summarize the development and initial validation of the Multicultural Personality Inventory (MPI). In Study 1, the 115-item prototype MPI was administered to 415 university students where exploratory factor analysis resulted in a 70-item, 7-factor model. In Study 2, the 70-item MPI and theoretically related companion instruments were administered to a multisite sample of 576 university students. Confirmatory factory analysis found the 7-factor structure to be a relatively good fit to the data (Comparative Fit Index = .954; root mean square error of approximation = .057), and MPI factors predicted variance in criterion variables above and beyond the variance accounted for by broad personality traits (i.e., Big Five). Study limitations and directions for further validation research are specified.
Related JoVE Video
A flexible porous Cu(ii) bis-imidazolate framework with ultrahigh concentration of active sites for efficient and recyclable CO2 capture.
Chem. Commun. (Camb.)
PUBLISHED: 10-18-2013
Show Abstract
Hide Abstract
By virtue of planar Cu2(?-OH)2(2+) cluster units, a flexible porous metal azolate framework not only adsorbs large amounts of CO2 (19.6 wt% or 266 g L(-1) at 298 K and 1 atm) with a high zero-coverage adsorption enthalpy (-47 kJ mol(-1)), but also desorbs quickly at very low temperatures.
Related JoVE Video
A filter-like AuNPs@MS SERS substrate for Staphylococcus aureus detection.
Biosens Bioelectron
PUBLISHED: 07-24-2013
Show Abstract
Hide Abstract
An accurate, highly sensitive and rapid identification assay of cells is extremely important in areas such as medical diagnosis, biological research, and environmental monitoring. Laboratory examinations of clinical isolates require time-consuming and complex processes to identify the colony count, with approximately 10(6)-10(8) cells needed for the characterization of strains. In the present study, a highly sensitive SERS filter-like substrate is prepared with AuNPs embedded in mesoporous silica (denoted as AuNPs@MS) synthesized by a simple one-spot method, and an example of its use for the filtration and concentration of analytes from aqueous samples is reported. In an application for Staphylococcus aureus SERS discrimination, the results show that the target cells can be concentrated on the filter-like AuNPs@MS substrates within a few seconds, with much better reproducibility with regard to the SERS spectra that are obtained. The experimental findings suggest that the AuNPs@MS substrate supports much higher intensity with more distinguishable peaks compared to Au/Cr-coated substrate, and the reproducibility is also significantly improved. The substrates investigated in this study generated 900 times more SERS signals at a concentration of 10(6)CFU/mL in the detection of S. aureus on mesoporous silica (Au wt%=0) when using AuNPs@MS with 16wt% AuNPs. The limitation of this filter-like SERS substrate can be applicable for small volume samples (few to hundred microliter).
Related JoVE Video
Phosphorescence doping in a flexible ultramicroporous framework for high and tunable oxygen sensing efficiency.
Chem. Commun. (Camb.)
PUBLISHED: 06-21-2013
Show Abstract
Hide Abstract
Doping very small amounts of Ru(II) into a flexible, ultramicroporous, fluorescent Zn(II) coordination polymer produced phosphorescent materials with very high and tunable oxygen quenching efficiency; and a simple color-changing ratiometric oxygen sensor has been constructed.
Related JoVE Video
Use of Coated Silver Nanoparticles to Understand the Relationship of Particle Dissolution and Bioavailability to Cell and Lung Toxicological Potential.
Small
PUBLISHED: 05-24-2013
Show Abstract
Hide Abstract
Since more than 30% of consumer products that include engineered nanomaterials contain nano-Ag, the safety of this material is of considerable public concern. In this study, Ag nanoparticles (NPs) are used to demonstrate that 20 nm polyvinylpyrrolidone (PVP or P) and citrate (C)-coated Ag NPs induce more cellular toxicity and oxidative stress than larger (110 nm) particles due to a higher rate of dissolution and Ag bioavailability. Moreover, there is also a higher propensity for citrate 20 nm (C20) nanoparticles to generate acute neutrophilic inflammation in the lung and to produce chemokines compared to C110. P110 has less cytotoxic effects than C110, likely due to the ability of PVP to complex released Ag(+) . In contrast to the more intense acute pulmonary effects of C20, C110 induces mild pulmonary fibrosis at day 21, likely as a result of slow but persistent Ag(+) release leading to a sub-chronic injury response. Interestingly, the released metallic Ag is incorporated into the collagen fibers depositing around airways and the lung interstitium. Taken together, these results demonstrate that size and surface coating affect the cellular toxicity of Ag NPs as well as their acute versus sub-chronic lung injury potential.
Related JoVE Video
SENP1 deSUMOylates and regulates Pin1 protein activity and cellular function.
Cancer Res.
PUBLISHED: 04-30-2013
Show Abstract
Hide Abstract
The Pin1 prolyl isomerase regulates phosphorylation signaling by controlling protein conformation after phosphorylation, and its upregulation promotes oncogenesis via acting on numerous oncogenic molecules. SUMOylation and deSUMOylation are dynamic mechanisms regulating a spectrum of protein activities. The SUMO proteases (SENP) remove SUMO conjugate from proteins, and their expression is deregulated in cancers. However, nothing is known about the role of SUMOylation in regulating Pin1 function. Here, we show that Pin1 is SUMOylated on Lys6 in the WW domain and on Lys63 in the PPIase domain. Pin1 SUMOylation inhibits its protein activity and oncogenic function. We further identify that SENP1 binds to and deSUMOylates Pin1. Importantly, either overexpression of SENP1 or disruption of Pin1 SUMOylation promotes the ability of Pin1 to induce centrosome amplification and cell transformation. Moreover, SENP1 also increases Pin1 protein stability in cell cultures, and Pin1 levels are positively correlated with SENP1 levels in human breast cancer specimens. These results not only uncover Pin1 SUMOylation on Lys6/63 as a novel mechanism to inhibit its activity and function but also identify a critical role for SENP1-mediated deSUMOylation in promoting Pin1 function during tumorigenesis.
Related JoVE Video
The Effectiveness and Mechanism of Toona sinensis Extract Inhibit Attachment of Pandemic Influenza A (H1N1) Virus.
Evid Based Complement Alternat Med
PUBLISHED: 04-23-2013
Show Abstract
Hide Abstract
TSL-1 is a fraction of the aqueous extract from the tender leaf of Toona sinensis Roem, a nutritious vegetable. The pandemic influenza A (H1N1) virus is a recently described, rapidly contagious respiratory pathogen which can cause acute respiratory distress syndrome (ARDS) and poses a major public health threat. In this study, we found that TSL-1 inhibited viral yields on MDCK plaque formation by pandemic influenza A (H1N1) virus on infected A549 cells with high selectivity index. Meanwhile, TSL-1 also suppressed viral genome loads in infected A549 cells, quantified by qRT-PCR. This study further demonstrated that TSL-1 inhibited pandemic influenza A (H1N1) virus activity through preventing attachment of A549 cells but not penetration. TSL-1 inhibited viral attachment through significant downregulation of adhesion molecules and chemokines (VCAM-1, ICAM-1, E-selectin, IL-8, and fractalkine) compared to Amantadine. Our results suggest that TSL-1 may be used as an alternative treatment and prophylaxis against pandemic influenza A (H1N1) virus.
Related JoVE Video
Development and evaluation of a loop-mediated isothermal amplification method for rapid detection and differentiation of two genotypes of porcine circovirus type 2.
J Microbiol Immunol Infect
PUBLISHED: 04-19-2013
Show Abstract
Hide Abstract
Porcine circovirus type 2 (PCV2) is one of the major swine viral diseases and has caused significant economic loss to pig producers. PCV2 has been divided into two major genotypes: PCV2a, PCV2b. A loop-mediated isothermal amplification (LAMP) method was developed for the detection and differentiation of PCV2a and PCV2b in clinical samples.
Related JoVE Video
Parental stress in raising Mandarin-speaking children with cochlear implants.
Laryngoscope
PUBLISHED: 04-02-2013
Show Abstract
Hide Abstract
To investigate the characteristics of parental stress in the child, parent, and total domains in families of Mandarin-speaking children with cochlear implants at four different time periods in the implantation process. Previous studies have shown that parental stress lessens after cochlear implantation surgery.
Related JoVE Video
Spatial pattern assessment of river water quality: implications of reducing the number of monitoring stations and chemical parameters.
Environ Monit Assess
PUBLISHED: 03-29-2013
Show Abstract
Hide Abstract
The Tamsui River basin is located in Northern Taiwan and encompasses the most metropolitan city in Taiwan, Taipei City. The Taiwan Environmental Protection Administration (EPA) has established 38 water quality monitoring stations in the Tamsui River basin and performed regular river water quality monitoring for the past two decades. Because of the limited budget of the Taiwan EPA, adjusting the monitoring program while maintaining water quality data is critical. Multivariate analysis methods, such as cluster analysis (CA), factor analysis (FA), and discriminate analysis (DA), are useful tools for the statistically spatial assessment of surface water quality. This study integrated CA, FA, and DA to evaluate the spatial variance of water quality in the metropolitan city of Taipei. Performing CA involved categorizing monitoring stations into three groups: high-, moderate-, and low-pollution areas. In addition, this categorization of monitoring stations was in agreement with that of the assessment that involved using the simple river pollution index. Four latent factors that predominantly influence the river water quality of the Tamsui River basin are assessed using FA: anthropogenic pollution, the nitrification process, seawater intrusion, and geological and weathering processes. We plotted a spatial pattern using the four latent factor scores and identified ten redundant monitoring stations near each upstream station with the same score pattern. We extracted five significant parameters by using DA: total organic carbon, total phosphorus, As, Cu, and nitrate, with spatial variance to differentiate them from the polluted condition of the group obtained by using CA. Finally, this study suggests that the Taiwan EPA can adjust the surface water-monitoring program of the Tamsui River by reducing the monitoring stations to 28 and the measured chemical parameters to five to lower monitoring costs.
Related JoVE Video
Asymmetric introgression in the horticultural living fossil cycas sect. Asiorientales using a genome-wide scanning approach.
Int J Mol Sci
PUBLISHED: 03-25-2013
Show Abstract
Hide Abstract
The Asian cycads are mostly allopatric, distributed in small population sizes. Hybridization between allopatric species provides clues in determining the mechanism of species divergence. Horticultural introduction provides the chance of interspecific gene flow between allopatric species. Two allopatrically eastern Asian Cycas sect. Asiorientales species, C. revoluta and C. taitungensis, which are widely distributed in Ryukyus and Fujian Province and endemic to Taiwan, respectively, were planted in eastern Taiwan for horticultural reason. Higher degrees of genetic admixture in cultivated samples than wild populations in both cycad species were detected based on multilocus scans by neutral AFLP markers. Furthermore, bidirectional but asymmetric introgression by horticultural introduction of C. revoluta is evidenced by the reanalyses of species associated loci, which are assumed to be diverged after species divergence. Partial loci introgressed from native cycad to the invaders were also detected at the loci of strong species association. Consistent results tested by all neutral loci, and the species-associated loci, specify the recent introgression from the paradox of sharing of ancestral polymorphisms. Phenomenon of introgression of cultivated cycads implies niche conservation among two geographic-isolated cycads, even though the habitats of the extant wild populations of two species are distinct.
Related JoVE Video
Waist-to-thigh ratio is a predictor of internal organ cancers in humans: findings from a cohort study.
Ann Epidemiol
PUBLISHED: 03-22-2013
Show Abstract
Hide Abstract
Studies have shown that some specific body measures are associated with the occurrence of cancers. Few studies have demonstrated the relationship with more comprehensive approaches. This study aims to explore body measures and the combinations associated with internal organ cancers.
Related JoVE Video
Physical fitness and academic performance: empirical evidence from the National Administrative Senior High School Student Data in Taiwan.
Health Educ Res
PUBLISHED: 03-13-2013
Show Abstract
Hide Abstract
This study examined the relationship between the changes of physical fitness across the 3-year spectrum of senior high school study and academic performance measured by standardized tests in Taiwan. A unique dataset of 149 240 university-bound senior high school students from 2009 to 2011 was constructed by merging two nationwide administrative datasets of physical fitness test performance and the university entrance exam scores. Hierarchical linear regression models were used. All regressions included controls for students baseline physical fitness status, changes of physical fitness performance over time, age and family economic status. Some notable findings were revealed. An increase of 1 SD on students overall physical fitness from the first to third school year is associated with an increase in the university entrance exam scores by 0.007 and 0.010 SD for male and female students, respectively. An increase of 1 SD on anaerobic power (flexibility) from the first to third school year is positively associated with an increase in the university entrance exam scores by 0.018 (0.010) SD among female students. We suggest that education and school health policymakers should consider and design policies to improve physical fitness as part of their overall strategy of improving academic performance.
Related JoVE Video
Adaptive redox response of mesenchymal stromal cells to stimulation with lipopolysaccharide inflammagen: mechanisms of remodeling of tissue barriers in sepsis.
Oxid Med Cell Longev
PUBLISHED: 03-08-2013
Show Abstract
Hide Abstract
Acute bacterial inflammation is accompanied by excessive release of bacterial toxins and production of reactive oxygen and nitrogen species (ROS and RNS), which ultimately results in redox stress. These factors can induce damage to components of tissue barriers, including damage to ubiquitous mesenchymal stromal cells (MSCs), and thus can exacerbate the septic multiple organ dysfunctions. The mechanisms employed by MSCs in order to survive these stress conditions are still poorly understood and require clarification. In this report, we demonstrated that in vitro treatment of MSCs with lipopolysaccharide (LPS) induced inflammatory responses, which included, but not limited to, upregulation of iNOS and release of RNS and ROS. These events triggered in MSCs a cascade of responses driving adaptive remodeling and resistance to a "self-inflicted" oxidative stress. Thus, while MSCs displayed high levels of constitutively present adaptogens, for example, HSP70 and mitochondrial Sirt3, treatment with LPS induced a number of adaptive responses that included induction and nuclear translocation of redox response elements such as NFkB, TRX1, Ref1, Nrf2, FoxO3a, HO1, and activation of autophagy and mitochondrial remodeling. We propose that the above prosurvival pathways activated in MSCs in vitro could be a part of adaptive responses employed by stromal cells under septic conditions.
Related JoVE Video
Surface charge and cellular processing of covalently functionalized multiwall carbon nanotubes determine pulmonary toxicity.
ACS Nano
PUBLISHED: 02-28-2013
Show Abstract
Hide Abstract
Functionalized carbon nanotubes (f-CNTs) are being produced in increased volume because of the ease of dispersion and maintenance of the pristine material physicochemical properties when used in composite materials as well as for other commercial applications. However, the potential adverse effects of f-CNTs have not been quantitatively or systematically explored. In this study, we used a library of covalently functionalized multiwall carbon nanotubes (f-MWCNTs), established from the same starting material, to assess the impact of surface charge in a predictive toxicological model that relates the tubes pro-inflammatory and pro-fibrogenic effects at cellular level to the development of pulmonary fibrosis. Carboxylate (COOH), polyethylene glycol (PEG), amine (NH2), sidewall amine (sw-NH2), and polyetherimide (PEI)-modified MWCNTs were successfully established from raw or as-prepared (AP-) MWCNTs and comprehensively characterized by TEM, XPS, FTIR, and DLS to obtain information about morphology, length, degree of functionalization, hydrodynamic size, and surface charge. Cellular screening in BEAS-2B and THP-1 cells showed that, compared to AP-MWCNTs, anionic functionalization (COOH and PEG) decreased the production of pro-fibrogenic cytokines and growth factors (including IL-1?, TGF-?1, and PDGF-AA), while neutral and weak cationic functionalization (NH2 and sw-NH2) showed intermediary effects. In contrast, the strongly cationic PEI-functionalized tubes induced robust biological effects. These differences could be attributed to differences in cellular uptake and NLRP3 inflammasome activation, which depends on the propensity toward lysosomal damage and cathepsin B release in macrophages. Moreover, the in vitro hazard ranking was validated by the pro-fibrogenic potential of the tubes in vivo. Compared to pristine MWCNTs, strong cationic PEI-MWCNTs induced significant lung fibrosis, while carboxylation significantly decreased the extent of pulmonary fibrosis. These results demonstrate that surface charge plays an important role in the structure-activity relationships that determine the pro-fibrogenic potential of f-CNTs in the lung.
Related JoVE Video
Academic achievements and classroom performance in Mandarin-speaking prelingually deafened school children with cochlear implants.
Int. J. Pediatr. Otorhinolaryngol.
PUBLISHED: 02-27-2013
Show Abstract
Hide Abstract
To document academic achievements and classroom performance in 35 Mandarin-speaking, congenital/pre-lingual, deafened children who used cochlear implants (CIs) for 5-11 years. The possible associated factors were also analyzed.
Related JoVE Video
Ubc9 acetylation modulates distinct SUMO target modification and hypoxia response.
EMBO J.
PUBLISHED: 01-09-2013
Show Abstract
Hide Abstract
While numerous small ubiquitin-like modifier (SUMO) conjugated substrates have been identified, very little is known about the cellular signalling mechanisms that differentially regulate substrate sumoylation. Here, we show that acetylation of SUMO E2 conjugase Ubc9 selectively downregulates the sumoylation of substrates with negatively charged amino acid-dependent sumoylation motif (NDSM) consisting of clustered acidic residues located downstream from the core ?-K-X-E/D consensus motif, such as CBP and Elk-1, but not substrates with core ?-K-X-E/D motif alone or SUMO-interacting motif. Ubc9 is acetylated at residue K65 and K65 acetylation attenuates Ubc9 binding to NDSM substrates, causing a reduction in NDSM substrate sumoylation. Furthermore, Ubc9 K65 acetylation can be downregulated by hypoxia via SIRT1, and is correlated with hypoxia-elicited modulation of sumoylation and target gene expression of CBP and Elk-1 and cell survival. Our data suggest that Ubc9 acetylation/deacetylation serves as a dynamic switch for NDSM substrate sumoylation and we report a previously undescribed SIRT1/Ubc9 regulatory axis in the modulation of protein sumoylation and the hypoxia response.
Related JoVE Video
A RING-type E3 ligase controls anther dehiscence by activating the jasmonate biosynthetic pathway gene DEFECTIVE IN ANTHER DEHISCENCE1 in Arabidopsis.
Plant J.
PUBLISHED: 01-02-2013
Show Abstract
Hide Abstract
Suppression of expression of DAF [DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1)-Activating Factor], a gene that encodes a putative RING-finger E3 ligase protein, causes non-dehiscence of the anthers, alters pollen development and causes sterility in 35S:DAF RNAi/antisense Arabidopsis plants. This mutant phenotype correlates with the suppression of DAF but not with expression of the two most closely related genes, DAFL1/2. The expression of DAD1 was significantly reduced in 35S:DAF RNAi/antisense plants, and complementation with 35S:DAF did not rescue the dad1 mutant, indicating that DAF acts upstream of DAD1 in jasmonic acid biosynthesis. This assumption is supported by the finding that 35S:DAF RNAi/antisense plants showed a similar cellular basis for anther dehiscence to that found in dad1 mutants, and that external application of jasmonic acid rescued the anther non-dehiscence and pollen defects in 35S:DAF antisense flowers. We further demonstrate that DAF is an E3 ubiquitin ligase and that its activity is abolished by C132S and H137Y mutations in its RING motif. Furthermore, ectopic expression of the dominant-negative C132S or H137Y mutations causes similar indehiscence of anthers and reduction in DAD1 expression in transgenic Arabidopsis. This result not only confirms that DAF controls anther dehiscence by positively regulating the expression of DAD1 in the jasmonic acid biosynthesis pathway, but also supports the notion that DAF functions as an E3 ubiquitin ligase, and that the conserved RING-finger region is required for its activity.
Related JoVE Video
Generation of reactive oxygen species by polyenylpyrroles derivatives causes DNA damage leading to G2/M arrest and apoptosis in human oral squamous cell carcinoma cells.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Oral squamous cell carcinoma (OSCC) accounts for 5.8% of all malignancies in Taiwan and the incidence of OSCC is on the rise. OSCC is also a common malignancy worldwide and the five-year survival rate remains poor. Therefore, new and effective treatments are needed to control OSCC. In the present study we have investigated the efficacy and associated mechanisms of polyenylpyrroles and their analogs in both in vitro cell culture and in vivo nude mice xenografts. Auxarconjugatin B (compound 1a) resulted in cell cycle arrest in the G2/M phase and caspase-dependent apoptosis in OEC-M1 and HSC-3 cells by activating DNA damage and mitochondria dysfunction through the loss of mitochondrial membrane potential, release of cytochrome c, increase in B-cell lymphoma-2-associated X protein level, and decrease in B-cell lymphoma-2 level. Compound 1a-induced generation of intracellular reactive oxygen species through cytochrome P450 1A1 was identified as a major mechanism of its effect for DNA damage, mitochondria dysfunction and apoptosis, which was reversed by antioxidant N-acetylcysteine as well as cytochrome P450 1A1 inhibitor and specific siRNA. Furthermore, compound 1a-treated nude mice showed a reduction in the OEC-M1 xenograft tumor growth and an increase in the caspase-3 activation in xenograft tissue. These results provide promising insights as to how compound 1a mediates cytotoxicity and may prove to be a molecular rationale for its translation into a potential therapeutic against OSCC.
Related JoVE Video
Characterization of 24 transferable microsatellite loci in four skullcaps (Scutellaria, Labiatae).
Am. J. Bot.
PUBLISHED: 12-27-2011
Show Abstract
Hide Abstract
Transferable polymorphic microsatellite loci for four skullcaps, Scutellaria indica, S. taiwanensis, S. austrotaiwanensis, and S. playfairii, were developed for future studies of the mating system and population structure of these species. Interspecific amplification was also tested in various Scutellaria species.
Related JoVE Video
Related JoVE Video
Composition and antimicrobial activity of the leaf and twig oils of Litsea acutivena from Taiwan.
Nat Prod Commun
PUBLISHED: 12-23-2011
Show Abstract
Hide Abstract
The chemical composition, and antimicrobial and anti-wood-decay fungal activities of the essential oils isolated from the leaves and twigs of Litsea acutivena of Taiwan were investigated. The essential oils from the fresh leaves and twigs were isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. Ninety-five and fifty-two compounds were identified in the leaf and twig oils, respectively. The main components of the leaf oil were gamma-patchoulene (11.0%), delta-cadinene (6.3%), trans-muurola-3,5-diene (5.9%), and beta-selinene (5.3%), whereas the main components of the twig oil were tau-cadinol (13.1%), beta-selinene (9.6%), trans-beta-ocimene (6.2%) and alpha-cadinol (7.7%). Bioactivity studies demonstrated that twig oil had excellent antimicrobial and anti-wood-decay fungal activities, superior to those of the leaf oil. For the antimicrobial and anti-wood-decay fungal activities of the twig oil, the active compounds were determined to be tau-cadinol and alpha-cadinol.
Related JoVE Video
Composition and antifungal activities of the leaf essential oil of Neolitsea parvigemma from Taiwan.
Nat Prod Commun
PUBLISHED: 09-28-2011
Show Abstract
Hide Abstract
The hydrodistillated leaf essential oil of Neolitsea parvigemma was analyzed to determine its composition and yield. Sixty-two compounds were identified, the main components being beta-caryophyllene (14.2%), beta-eudesmol (12.9%), alpha-cadinol (10.2%) and tau-cadinol (8.8%). Oxygenated sesquiterpenes (48.9%) and sesquiterpene hydrocarbons (48.8%) were the predominant groups of compounds. The antifungal indexes of the leaf oil against the 7 fungi, Aspergillus clavatus, A. niger, Chaetomium globosum, Cladosporium cladosporioides, Myrothecium verrucaria, Penicillium citrinum and Trichoderma viride, were 100.0, 72.3, 100.0, 100.0, 100.0, 75.8 and 88.6% at a 1 mg/mL concentration, respectively. The oil also exhibited anti-wood-decay-fungi activity against Trametes versicolor, Phaneochaete chrysosporium, Phaeolus schweintizii, and Lenzites sulphureu with MIC values of 50, 50, 25 and 25 microg/mL, respectively. For the antifungal and anti-wood-decay fungal activities of the oil, the active source compounds were determined to be alpha-cadinol, beta-eudesmol and tau-cadinol.
Related JoVE Video
[Narrative research on the meaning of professional development in the psychiatric nurse profession].
Hu Li Za Zhi
PUBLISHED: 08-03-2011
Show Abstract
Hide Abstract
The extensive clinical experience of senior nurses is a valuable resource to assist new nurses to prepare for their professional future in the clinical environment.
Related JoVE Video
Evaluation of differential representative values between Chinese hamster cells and human lymphocytes in mitomycin C-induced cytogenetic assays and caspase-3 activity.
Toxicol Ind Health
PUBLISHED: 07-18-2011
Show Abstract
Hide Abstract
Chinese hamster ovary (CHO) cells, its lung fibroblasts (V79), and human lymphocytes are routinely used in in vitro cytogenetic assays, which include micronuclei (MN), sister chromatid exchange (SCE), and chromosome aberration (CA) assays. Mitomycin C (MMC), a DNA cross-link alkylating agent, is both an anticancer medicine and a carcinogen. To study the differential representative values of cell types in MMC-treated cytogenetic assays and its upstream factor, cysteine aspartic acid-specific protease (caspase)-3. Among the chosen cell types, lymphocytes expressed the highest sensitivity in all three MMC-induced assays, whereas CHO and V79 showed varied sensitivity in different assays. In MN assay, the sensitivity of CHO is higher than or equal to V79; in SCE assay, the sensitivity of CHO is the same as V79; and in CA assay, the sensitivity of CHO is higher than V79. In-depth analysis of CA revealed that in chromatid breaks and dicentrics formation, lymphocyte was the most sensitive of all and CHO was more sensitive than V79; and in acentrics and interchanges formation, lymphocyte was much more sensitive than the others. Furthermore, we found caspase-3 activity plays an important role in MMC-induced cytogenetic assays, with MMC-induced caspase-3 activity resulting in more sensitivity in lymphocytes than in CHO and V79. Based on these findings, lymphocyte will make a suitable predictive or representative control reference in cytogenetic assays and caspase-3 activity with its high specificity, positive predictive value, and sensitivity.
Related JoVE Video
Molecular evolution of a family of resistance gene analogs of nucleotide-binding site sequences in Solanum lycopersicum.
Genetica
PUBLISHED: 07-07-2011
Show Abstract
Hide Abstract
Nucleotide-binding site-leucine-rich repeats (NBS-LRR) gene families are one of the major plant resistance genes. Genomic NBS evolution was studied in many plant species for diverse arrays of NBS gene families. In this study, we focused on one family of NBS sequences in an attempt to understand how closely related NBS sequences evolved in the light of selection in domesticated plant species. A phylogenetic analysis revealed five major clades (A-E) and five subclades (A1-A5) within clade A of cloned NBS sequences. Positive selection was only detected in newly evolved NBS lineages in subclades of clade A. Positively selected codon sites were found among NBS sequences of clade A. A sliding-window analysis revealed that regions with Ka/Ks ratios of >1 were in the inter-motifs when paired clades were compared, but regions with Ka/Ks ratios of >1 were found across NBS sequences when subclades of clade A were compared. Our results based on a family of closely related NBS sequences showed that positive selection was first exerted on specific lineages across all NBS sequences after selective constraints. Subsequently, sequences with mutations in commonly conserved motifs were scrutinized by purifying selection. In the long term, conserved high frequency alleles in commonly conserved motifs and changes in inter-motifs were maintained in the investigated family of NBS sequences. Moreover, codons identified to be under positive selection in the inter-motifs were mainly located in regions involved in functions of ATP binding or hydrolysis.
Related JoVE Video
Poor decision making in male patients with anorexia nervosa.
Eur Eat Disord Rev
PUBLISHED: 06-14-2011
Show Abstract
Hide Abstract
Decision making is impaired in female patients with anorexia nervosa (AN), but it is unclear if the same impairment is present in male patients with AN.
Related JoVE Video
Honokiol inhibits LPS-induced maturation and inflammatory response of human monocyte-derived dendritic cells.
J. Cell. Physiol.
PUBLISHED: 06-11-2011
Show Abstract
Hide Abstract
Honokiol (HNK) is a phenolic compound isolated from the bark of houpu (Magnolia officinalis), a plant widely used in traditional Chinese and Japanese medicine. While substantial evidence indicates that HNK possesses anti-inflammatory activity, its effect on dendritic cells (DCs) during the inflammatory reaction remains unclear. The present study investigates how HNK affects lipopolysaccharide (LPS)-stimulated human monocyte-derived DCs. Our experimental results show that HNK inhibits the inflammatory response of LPS-induced DCs by (1) suppressing the expression of CD11c, CD40, CD80, CD83, CD86, and MHC-II on LPS-activated DCs, (2) reducing the production of TNF-?, IL-1?, IL-6, and IL-12p70 but increasing the production of IL-10 and TGF-?1 by LPS-activated DCs, (3) inhibiting the LPS-induced DC-elicited allogeneic T-cell proliferation, and (4) shifting the LPS-induced DC-driven Th1 response toward a Th2 response. Further, our results show that HNK inhibits the phosphorylation levels of ERK1/2, p38, JNK1/2, IKK?, and I?B? in LPS-activated DCs. Collectively, the findings show that the anti-inflammatory actions of HNK on LPS-induced DCs are associated with the NF-?B and mitogen-activated protein kinase (MAPK) signaling pathways.
Related JoVE Video
The molecular determinants of NEDD8 specific recognition by human SENP8.
PLoS ONE
PUBLISHED: 06-07-2011
Show Abstract
Hide Abstract
Although neuronal-precursor-cell-expressed developmentally downregulated protein-8 (NEDD8) and ubiquitin share the highest level of sequence identity and structural similarity among several known ubiquitin-like proteins, their conjugation to a protein leads to distinct biological consequences. In the study, we first identified the NEDD8 protein of Chlamydomonas reinhardtii (CrNEDD8) and discovered that CrNEDD8 is fused at the C-terminus of a ubiquitin moiety (CrUb) in a head-to-tail arrangement. This CrUb-CrNEDD8 protein was termed CrRUB1 (related to ubiquitin 1) by analogy with a similar protein in Arabidopsis thaliana (AtRUB1). Since there is high sequence identity in comparison to the corresponding human proteins (97% for ubiquitin and 84% for NEDD8), a His-CrRUB1-glutathione S-transferase (GST) fusion construct was adopted as the alternative substrate to characterize the specificity of NEDD8-specific peptidase SENP8 for CrNEDD8. The data showed that SENP8 only cleaved the peptide bond beyond the di-glycine motif of CrNEDD8 and His-RUB1 was subsequently generated, confirming that SENP8 has exquisite specificity for CrNEDD8 but not CrUb. To further determine the basis of this specificity, site-directed mutagenesis at earlier reported putative molecular determinants of NEDD8 specific recognition by SENP8 was performed. We found that a single N51E mutation of CrNEDD8 completely inhibited its hydrolysis by SENP8. Conversely, a single E51N mutation of CrUb enabled this ubiquitin mutant to undergo hydrolysis by SENP8, revealing that a single residue difference at the position 51 contributes substantially to the substrate selectivity of SENP8. Moreover, the E51N/R72A double mutant of the CrUb subdomain can further increase the efficiency of cleavage by SENP8, indicating that the residue at position 72 is also important in substrate recognition. The E51N or R72A mutation of CrUb also inhibited the hydrolysis of CrUb by ubiquitin-specific peptidase USP2. However, USP2 cannot cleave the N51E/A72R double mutant of the CrNEDD8 subdomain, suggesting that USP2 requires additional recognition sites.
Related JoVE Video
A rapid, inexpensive yeast-based dual-fluorescence assay of programmed--1 ribosomal frameshifting for high-throughput screening.
Nucleic Acids Res.
PUBLISHED: 05-20-2011
Show Abstract
Hide Abstract
Programmed -1 ribosomal frameshifting (-1 PRF) is a mechanism that directs elongating ribosomes to shift-reading frame by 1 base in the 5 direction that is utilized by many RNA viruses. Importantly, rates of -1 PRF are fine-tuned by viruses, including Retroviruses, Coronaviruses, Flavivriuses and in two endogenous viruses of the yeast Saccharomyces cerevisiae, to deliver the correct ratios of different viral proteins for efficient replication. Thus, -1 PRF presents a novel target for antiviral therapeutics. The underlying molecular mechanism of -1 PRF is conserved from yeast to mammals, enabling yeast to be used as a logical platform for high-throughput screens. Our understanding of the strengths and pitfalls of assays to monitor -1 PRF have evolved since the initial discovery of -1 PRF. These include controlling for the effects of drugs on protein expression and mRNA stability, as well as minimizing costs and the requirement for multiple processing steps. Here we describe the development of an automated yeast-based dual fluorescence assay of -1 PRF that provides a rapid, inexpensive automated pipeline to screen for compounds that alter rates of -1 PRF which will help to pave the way toward the discovery and development of novel antiviral therapeutics.
Related JoVE Video
Structure and immunological characterization of the capsular polysaccharide of a pyrogenic liver abscess caused by Klebsiella pneumoniae: activation of macrophages through Toll-like receptor 4.
J. Biol. Chem.
PUBLISHED: 04-08-2011
Show Abstract
Hide Abstract
The active components of a primary pyrogenic liver abscess (PLA) Klebsiella pneumoniae in stimulating cytokine expression in macrophages are still unclear. The capsular polysaccharide (CPS) of PLA K. pneumoniae is important in determining clinical manifestations, and we have shown that it consists of repeating units of the trisaccharide (?3)-?-D-Glc-(1?4)-[2,3-(S)-pyruvate]-?-D-GlcA-(1?4)-?-L-Fuc-(1?) and has the unusual feature of extensive pyruvation of glucuronic acid and acetylation of C(2)-OH or C(3)-OH of fucose. We demonstrated that PLA K. pneumoniae CPS induces secretion of tumor necrosis factor-? (TNF-?) and interleukin-6 (IL-6) by macrophages through Toll-like receptor 4 (TLR4) and that this effect was lost when pyruvation and O-acetylation were chemically destroyed. Furthermore, expression of TNF-? and IL-6 in PLA K. pneumoniae CPS-stimulated macrophages was shown to be regulated by the TLR4/ROS/PKC-?/NF-?B, TLR4/PI3-kinase/AKT/NF-?B, and TLR4/MAPK signaling pathways.
Related JoVE Video
Composition and antimicrobial activities of the leaf essential oil of Machilus kusanoi from Taiwan.
Nat Prod Commun
PUBLISHED: 03-24-2011
Show Abstract
Hide Abstract
The hydrodistillated leaf essential oil of Machilus kusanoi was analyzed to determine its composition and yield. Twenty-three compounds were identified, the main components being beta-caryophyllene (23.3%), beta-eudesmol (17.1%), alpha-terpineol (16.0%), n-dodecanal (14.2%), and n-decanal (10.4%). Sesquiterpene hydrocarbons (28.1%) and non-terpenoids (25.0%) were the predominant groups of compounds. The leaf oil exhibited excellent antimicrobial and anti-wood-decay fungal activities.
Related JoVE Video
Composition, antioxidant and antimicrobial activities of the seed essential oil of Calocedrus formosana from Taiwan.
Nat Prod Commun
PUBLISHED: 03-04-2011
Show Abstract
Hide Abstract
The hydrodistillated seed essential oil of Calocedrus formosana was analyzed to determine its composition and yield. Twenty-seven compounds were identified, the main ones being alpha-pinene (63.8%), totarol (9.9%) and ferruginol (8.9%). Monoterpene hydrocarbons (73.5%) and oxygenated diterpenes (18.8%) were the predominant groups of compounds. The seed essential oil exhibited excellent antioxidant, antimicrobial and anti-wood-decay fungal activities.
Related JoVE Video
Testosterone improves the transition of primary oocytes in artificial maturation eels (Anguilla japonica) by altering ovarian PTEN expression.
Fish Physiol. Biochem.
PUBLISHED: 02-24-2011
Show Abstract
Hide Abstract
In mammals, androgens appear to enhance the development of primary ovarian follicles, but PI3K (phosphoinositide 3-kinases) pathway is well recognized as one of the critical pathways in early follicular development. Roles of the PI3K were revealed by deletion of PTEN (phosphatase and tensin homolog on chromosome 10). PTEN is demonstrated to play an important role in the early stage of follicle development. In the Japanese eel, two forms of PTEN have been cloned, but what their functions on the development of early ovarian follicles are still not clear. The natural blockage and inducible of ovarian development was a benefit to address this question in the eel. Testosterone (T) shows to ameliorate the early ovarian development in the eel. The aims of this study were to elucidate the two forms of PTEN by cellular and physiological criteria and to study the effects of T on the ovarian PTEN production in the exogenous pituitary extracts-stimulated eel. Our results suggested that two forms of PTEN are existing in the Japanese eel, and eel ovarian development corresponded to the decrease in ovarian PTEN expression, vice versa. In addition, the supplement of T on eel early ovarian development can be attributed to its PTEN inhibitor role.
Related JoVE Video
mGluR5 positive modulators both potentiate activation and restore inhibition in NMDA receptors by PKC dependent pathway.
J. Biomed. Sci.
PUBLISHED: 02-22-2011
Show Abstract
Hide Abstract
In order to understand the interaction between the metabotropic glutamate subtype 5 (mGluR5) and N-methyl-D-aspartate (NMDA) receptors, the influence of mGluR5 positive modulators in the inhibition of NMDA receptors by the noncompetitive antagonist ketamine, the competitive antagonist D-APV and the selective NR2B inhibitor ifenprodil was investigated.
Related JoVE Video
Does the universal health insurance program affect urban-rural differences in health service utilization among the elderly? Evidence from a longitudinal study in taiwan.
J Rural Health
PUBLISHED: 02-08-2011
Show Abstract
Hide Abstract
To assess the impact of the introduction of Taiwans National Health Insurance (NHI) on urban-rural inequality in health service utilization among the elderly.
Related JoVE Video
C-terminal region of plant ferredoxin-like protein is required to enhance resistance to bacterial disease in Arabidopsis thaliana.
Phytopathology
PUBLISHED: 01-26-2011
Show Abstract
Hide Abstract
Protein phosphorylation is an important biological process associated with elicitor-induced defense responses in plants. In a previous report, we described how plant ferredoxin-like protein (PFLP) in transgenic plants enhances resistance to bacterial pathogens associated with the hypersensitive response (HR). PFLP possesses a putative casein kinase II phosphorylation (CK2P) site at the C-terminal in which phosphorylation occurs rapidly during defense response. However, the contribution of this site to the enhancement of disease resistance and the intensity of HR has not been clearly demonstrated. In this study, we generated two versions of truncated PFLP, PEC (extant CK2P site) and PDC (deleted CK2P site), and assessed their ability to trigger HR through harpin (HrpZ) derived from Pseudomonas syringae as well as their resistance to Ralstonia solanacearum. In an infiltration assay of HrpZ, PEC intensified harpin-mediated HR; however, PDC negated this effect. Transgenic plants expressing these versions indicate that nonphosphorylated PFLP loses its ability to induce HR or enhance disease resistance against R. solanacearum. Interestingly, the CK2P site of PFLP is required to induce the expression of the NADPH oxidase gene, AtrbohD, which is a reactive oxygen species producing enzyme. This was further confirmed by evaluating the HR on NADPH oxidase in mutants of Arabidopsis. As a result, we have concluded that the CK2P site is required for the phosphorylation of PFLP to enhance disease resistance.
Related JoVE Video
Structural and functional roles of Daxx SIM phosphorylation in SUMO paralog-selective binding and apoptosis modulation.
Mol. Cell
PUBLISHED: 01-24-2011
Show Abstract
Hide Abstract
Small ubiquitin-like modifier (SUMO) conjugation and interaction are increasingly associated with various cellular processes. However, little is known about the cellular signaling mechanisms that regulate proteins for distinct SUMO paralog conjugation and interactions. Using the transcriptional coregulator Daxx as a model, we show that SUMO paralog-selective binding and conjugation are regulated by phosphorylation of the Daxx SUMO-interacting motif (SIM). NMR structural studies show that Daxx (732)E-I-I-V-L-S-D-S-D(740) is a bona fide SIM that binds to SUMO-1 in a parallel orientation. Daxx-SIM is phosphorylated by CK2 kinase at residues S737 and S739. Phosphorylation promotes Daxx-SIM binding affinity toward SUMO-1 over SUMO-2/3, causing Daxx preference for SUMO-1 conjugation and interaction with SUMO-1-modified factors. Furthermore, Daxx-SIM phosphorylation enhances Daxx to sensitize stress-induced cell apoptosis via antiapoptotic gene repression. Our findings provide structural insights into the Daxx-SIM:SUMO-1 complex, a model of SIM phosphorylation-enhanced SUMO paralog-selective modification and interaction, and phosphorylation-regulated Daxx function in apoptosis.
Related JoVE Video
Heterogeneous impact of Taiwans national health insurance on labor force participation of married women by income and family structures.
Health Care Women Int
PUBLISHED: 01-14-2011
Show Abstract
Hide Abstract
In this study, I investigate how the impact of the National Health Insurance (NHI) introduction in Taiwan in 1995 on the labor force participation (LFP) decisions of married women varies with income and family structures. Employing the difference-in-differences (DID) approach, I find that the NHI introduction reduced LFP of married women in the twenty-fifth to fiftieth percentiles of the income distribution between 17.8 and 21.7 percentage points (33%-40%). The difference-in-differences-in-differences (DIDID) results suggest that married women in different family structures (the presence of children under 3 or less healthy elderly household members) did not respond differently to the NHI introduction.
Related JoVE Video
Cardioprotective effects of luteolin during ischemia-reperfusion injury in rats.
Circ. J.
PUBLISHED: 12-18-2010
Show Abstract
Hide Abstract
Antioxidants effectively reduce ischemia-reperfusion (IR) injury. The cardioprotective effects of luteolin, a flavonoid that exhibits antioxidant properties and is widely available in many fruits and vegetables, were examined in rats subjected to myocardial IR injury.
Related JoVE Video
Composition and antifungal activities of the leaf essential oil of Litsea coreana from Taiwan.
Nat Prod Commun
PUBLISHED: 12-03-2010
Show Abstract
Hide Abstract
The hydrodistilled leaf essential oil of Litsea coreana was analyzed by GC/FID and GC/MS. Fifty-two compounds were identified, the main components being n-decanal (27.5%), 2E,6E-farnesol (25.8%), beta-eudesmol (10.3%), ethyl n-dodecanoate (8.0%) and tau-cadinol (6.6%). Oxygenated sesquiterpenes (56.8%) and non-terpenoids (37.0%) were the predominant groups of compounds. The leaf oil exhibited excellent antifungal and anti-wood-decay fungal activities.
Related JoVE Video
Survival impact of initial surgical approach in stage I ovarian cancer.
Chang Gung Med J
PUBLISHED: 10-29-2010
Show Abstract
Hide Abstract
The aim of this study was to evaluate the impact on survival of initial laparoscopic surgery compared with conventional laparotomy in stage I epithelial ovarian cancer.
Related JoVE Video
Synthesis and biological evaluation of polyenylpyrrole derivatives as anticancer agents acting through caspases-dependent apoptosis.
J. Med. Chem.
PUBLISHED: 10-22-2010
Show Abstract
Hide Abstract
A class of polyenylpyrroles and their analogues were designed from a hit compound identified in a fungus. The compounds synthesized were evaluated for their cell cytotoxicity against human non-small-cell lung carcinoma cell lines A549. Two compounds were found to exhibit high cytotoxicity against A549 cells with IC(50) of 0.6 and 0.01 ?M, respectively. The underlying mechanisms for the anticancer activity were demonstrated as caspases activation dependent apoptosis induction through loss of mitochondrial membrane potential, release of cytochrome c, increase in B-cell lymphoma-2-associated X protein (Bax) level, and decrease in B-cell lymphoma-2 (Bcl-2) level. The two compounds were nontoxic to normal human lung Beas-2b cells (IC(50) > 80 ?M), indicating that they are highly selective in their cytotoxicity activities. Furthermore, one compound showed in vivo anticancer activity in human-lung-cancer-cell-bearing mice. These results open promising insights on how these conjugated polyenes mediate cytotoxicity and may provide a molecular rationale for future therapeutic interventions in carcinogenesis.
Related JoVE Video
Resveratrol arrests cell cycle and induces apoptosis in human hepatocellular carcinoma Huh-7 cells.
J Med Food
PUBLISHED: 10-14-2010
Show Abstract
Hide Abstract
Resveratrol has been shown to possess anticancer, anti-aging, anti-inflammatory, antimicrobial, and neuroprotective activities. In this study, we examined the antiproliferative properties of resveratrol and its molecular mechanism(s) of action in Huh-7 cells, a new human hepatoma cell line system for hepatitis C virus. Results showed that resveratrol significantly inhibited Huh-7 cell proliferation (50% inhibitory concentration = 22.4 ?g/mL) and effectively induced cell cycle arrest and apoptosis. It up-regulated p21/WAF1 expression in a p53-independent manner, but the expressions of cyclin E, cyclin A, and cyclin-dependent kinase 2 were down-regulated. It also caused an increase in the ratio of pro-apoptotic/anti-apoptotic protein, which was associated with the mitochondrial membrane depolarization and the increase in caspase activity. Resveratrol showed no effect on Fas, Fas ligand, extracellular signal regulated kinase (ERK) 1/2, and p38 expression but down-regulated phospho-ERK and phospho-p38 expression. In addition, resveratrol was noted to trigger autophagic cell death through the increased expression of autophagy-related Atg5, Atg7, Atg9, and Atg12 proteins. These results suggest that resveratrol could be an important chemoprevention agent for hepatoma of hepatitis C virus infection.
Related JoVE Video
Osthole regulates inflammatory mediator expression through modulating NF-?B, mitogen-activated protein kinases, protein kinase C, and reactive oxygen species.
J. Agric. Food Chem.
PUBLISHED: 09-16-2010
Show Abstract
Hide Abstract
Osthole, a coumarin compound, has been reported to exhibit various biological activities; however the cellular mechanism of its immune modulating activity has not yet been fully addressed. In this study we isolated osthole from the seeds of Cnidium monnieri and demonstrated that osthole inhibited TNF-?, NO and COX-2 expression in LPS-stimulated macrophages, without reducing the expression of IL-6. Furthermore, the phosphorylation of p38, JNK1/2, PKC-? and PKC-? induced by LPS was inhibited by osthole; however, the phosphorylation of ERK1/2 and PKC-? was not reduced by osthole. Osthole also inhibited NF-?B activation and ROS release in LPS-stimulated macrophages. Our current results indicated that osthole is the major anti-inflammatory ingredient of Cnidium monnieri seed ethanol extract.
Related JoVE Video
The many paths to frameshifting: kinetic modelling and analysis of the effects of different elongation steps on programmed -1 ribosomal frameshifting.
Nucleic Acids Res.
PUBLISHED: 09-07-2010
Show Abstract
Hide Abstract
Several important viruses including the human immunodeficiency virus type 1 (HIV-1) and the SARS-associated Coronavirus (SARS-CoV) employ programmed -1 ribosomal frameshifting (PRF) for their protein expression. Here, a kinetic framework is developed to describe -1 PRF. The model reveals three kinetic pathways to -1 PRF that yield two possible frameshift products: those incorporating zero frame encoded A-site tRNAs in the recoding site, and products incorporating -1 frame encoded A-site tRNAs. Using known kinetic rate constants, the individual contributions of different steps of the translation elongation cycle to -1 PRF and the ratio between two types of frameshift products were evaluated. A dual fluorescence reporter was employed in Escherichia coli to empirically test the model. Additionally, the study applied a novel mass spectrometry approach to quantify the ratios of the two frameshift products. A more detailed understanding of the mechanisms underlying -1 PRF may provide insight into developing antiviral therapeutics.
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.