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.
[Promotion effects of vitamin B12 on the degradation of 2, 4, 4'-trichlorobiphenyl by Nostoc PD-2].
Huan Jing Ke Xue
PUBLISHED: 10-24-2014
Show Abstract
Hide Abstract
Polychlorinated biphenyls are typical persistent chlorinated organic compounds in the environment. Bioremediation of PCB-contaminated environment has become one of the hot issues. In this study, vitamin B12 (VB12) and chlorine-free culture medium were applied to study the effects of VB12 on the degradation of 2,4,4'-trichlorobiphenyl (PCB28) by Nostoc PD-2 and the gene expression during the PCB-degradation process. Results showed that addition of different concentrations of vitamin B12 could improve the PCB-biodegradation rates by Nostoc PD-2. Compared with the control group, the 7-day degradation rate in 10 microg x L(-1), 100 microg x L(-1), and 1 000 microg x L(-1) VB12-treated groups increased by 11.0%, 19.7%, and 21.9% , respectively. The degradation half-time decreased from 5.53 days (treated with 10 microg x L(-1) VB12) to 3.08 days (treated with 100 microg x L(-1) VB12). The expression of cytochrome b6f complex iron-sulfur protein gene and dioxygenase gene showed significant correlation with PCB28-degradation by Nostoc PD-2. While the expression of iron-sulfur protein gene showed more significant correlation with PCB28-degradation. Results in this study indicated that adding VB12 could promote PCB28-degradation by Nostoc PD-2. Moreover, VB12 addition improved the PCB-degradation activity of Nostoc PD-2 at the gene level. The above conclusions could provide a new choice for developing efficient bioremediation technology for PCB-contaminated environment and a new insight into the PCB-biodegradation mechanism by Nostoc PD-2.
Related JoVE Video
[Preparation and up-conversion luminescence properties of Yb3+/Tm3+ co-doped Sb2O4 powder].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 09-12-2014
Show Abstract
Hide Abstract
The Sb2O4:Yb3+, Tm3+ up-conversion luminescence powder with excellent physical, chemical stability and relative low phonon energy was synthesized by the high temperature solid-state reaction and its up-conversion luminescence property was investigated. Under the 980 nm excitation, infrared and blue up-conversion emissions centered at 800 and 480 nm were observed, which were assigned to the 1G4-->3H6 and 3H4-->3 He transitions of Tm2+, respectively. The influence of Yb3+ and Tm3+ concentration on the up-conversion emission property was also obtained. The up-conversion luminescence increases with increasing of Yb3+ and Tm3+ concentration. Additionally, the up-conversion luminescence mechanism was discussed based on the dependence of Tm3+ up-conversion luminescence on pump power. It is interesting that two photon excitation processes for blue and infrared emission were observed in the Sb2O04: Yb3+, Tm3+ powder under a 980 nm excitation. Based on the energy level diagram of Tma3 and Yb2+ ions, we think that two photons blue emission is contributed to the cooperation energy transfer between Tm"+ and Yb3+ ions. We believe that the Sbz04 : Yb3 , Tm2+ up-conversion luminescence powder will have potential application for new optical devices in up-conversion color displays, sensors, detection of infrared radiation, and lasers.
Related JoVE Video
Luteolin from Flos Chrysanthemi and its derivatives: New small molecule Bcl-2 protein inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 08-20-2014
Show Abstract
Hide Abstract
Over-expression of the Bcl-2 anti-apoptotic proteins is closely related to tumorigenesis and associated with drug resistance. Here we report that luteolin, a main substance found in Flos Chrysanthemi, directly binds to and shows inhibitory activity against the Bcl-2 protein. We studied the binding mode of luteolin and its derivatives with target proteins, their structure-activity relationship, and their effect on the human leukemia cell line HL-60. The results suggest that luteolin and its derivatives with a benzyl group introduced to the B ring, are new small molecule Bcl-2 protein inhibitors, and their anti-tumor activity is likely related to their effect on the Bcl-2 protein.
Related JoVE Video
[Joint effects of apoptosis induced by microcystins and bacterial lipopolysaccharides on grass carp (Ctenopharyngodon idellus) lymphocytes].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 05-17-2014
Show Abstract
Hide Abstract
In this study, grass carp (Ctenopharyngodon idellus) lymphocytes were used as the vitro test object to demonstrate the joint effects of microcystins (MC-LR) and bacterial lipopolysaccharides (LPS) on fish immune system. The results showed that MC-LR and LPS in the single and combined exposure groups could both induce grass carp lymphocytes apoptosis with typical ladder-like DNA electrophoresis characteristics. However, comparing the apoptosis rate of the combined and single exposure groups, it was suggested that bacterial LPS could cooperate with MC-LR causing a higher rate of fish lymphocytes apoptosis (2.1 and 3.3-fold of that for the single exposure group I (MC-LR) and II (LPS), respectively), and there existed a significant dose-response relationship. The MC-LR cooperating with bacterial LPS decreased the activity of glutathione S-transferase (GST), increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), resulted in DNA damage and cell arrest in G0 phase, which inhibited cell proliferation and accelerated apoptosis. It was proved that MC-LR exacerbated fish immunotoxicity by collaborating with LPS, which had a serious adverse effect on aquaculture industry.
Related JoVE Video
[Discrimination of alleles in HLA-C*04:01:01G groups].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 04-26-2014
Show Abstract
Hide Abstract
The aim of this study was to investigate the relatively frequencies of alleles in the HLA-C*04:01:01G group and to analyze their relations with HLA-A and -B loci. DNA samples previously typed as HLA-C*04:01:01G were sequentially selected. The sequences for exon 2 to 7 of the HLA-C locus were analyzed by polymerase chain reaction sequence-based typing(PCR-SBT). The HLA-A, -B, -DRB1 and -DQB1 loci were genotyped using PCR-SBT method. The results showed that 178 samples (94.2%) and 11 samples (5.8%) were assigned as HLA-C*04:01:01 and HLA-C*04:82 respectively among 189 samples previously typed as HLA-C*04:01:01G. 72 haplotypes associated with HLA-C*04:01:01 and C*04:82 were found, in which the frequencies of 26 haplotypes were over 0.0050. HLA-C*04:01:01 was strongly related with A*02:03, A*02:07, A*11:01, A*33:03, B*13:01, B*15:01, B*15:05, B*15:27, B*40:01, B*54:01 alleles, while HLA-C*04:82 was related with B*40:01. It is concluded that HLA-C*04:01:01 and HLA-C*04:82 alleles were confirmed in the HLA-C*04:01:01G group, which should be discriminated by the routine HLA genotyping.
Related JoVE Video
Analysis of microglial migration by a micropipette assay.
Nat Protoc
PUBLISHED: 01-30-2014
Show Abstract
Hide Abstract
Microglial cells have important roles in maintaining brain homeostasis, and they are implicated in multiple brain diseases. There is currently interest in investigating microglial migration that results in cell accumulation at focal sites of injury. Here we describe a protocol for rapidly triggering and monitoring microglial migration by using a micropipette assay. This protocol is an adaptation of the axon turning assay using microglial cells. Chemoattractants released from the micropipette tip produce a chemotactic gradient that induces robust microglial migration. In combination with microscopic imaging, this assay allows simultaneous recording of cell movement and subcellular compartment trafficking, along with quantitative analysis. The actual handling time for the assay takes ?2-3 h in total. The protocol is simple, inexpensive and convenient to set up, and it can be adopted to examine cell migration in multiple cell types, including cancer cells with a wide range of chemical signals.
Related JoVE Video
Identification and characterization of the process-related impurities in fasudil hydrochloride by hyphenated techniques using a quality by design approach.
J Sep Sci
PUBLISHED: 01-17-2014
Show Abstract
Hide Abstract
Following the underlying principles of quality by design mentioned in the ICH Q8 guidance, systematic approaches for the control of process-related impurities have been taken in the manufacturing process of fasudil hydrochloride, a potent Rho-kinase inhibitor and vasodilator. Three related impurities were found in fasudil hydrochloride lab samples by a newly developed RP-HPLC with volatile mobile phase gradient elution and UV detection method. The elemental compositions of the impurities were determined by positive ESI high-resolution TOF-MS analysis of their [M + H](+) ions and their structures were identified through the elucidation of the product mass spectra obtained by a triple quadrupole mass spectrometer. The key impurity was further verified through synthesis and organic spectroscopy including NMR and IR spectroscopy. The origins of these impurities were located and the effective approaches to eliminate them were proposed based on the redesign of the synthetic conditions. The results obtained are important for quality control in the manufacture of fasudil hydrochloride bulk drug substance and injection.
Related JoVE Video
Comparative whole genome analysis of six diagnostic brucellaphages.
Gene
PUBLISHED: 01-07-2014
Show Abstract
Hide Abstract
Whole genome sequencing of six diagnostic brucellaphages, Tbilisi (Tb), Firenze (Fz), Weybridge (Wb), S708, Berkeley (Bk) and R/C, was followed with genomic comparisons including recently described genomes of the Tb phage from Mexico (TbM) and Pr phage to elucidate genomic diversity and candidate host range determinants. Comparative whole genome analysis revealed high sequence homogeneity among these brucellaphage genomes and resolved three genetic groups consistent with defined host range phenotypes. Group I was composed of Tb and Fz phages that are predominantly lytic for Brucella abortus and Brucella neotomae; Group II included Bk, R/C, and Pr phages that are lytic mainly for B. abortus, Brucella melitensis and Brucella suis; Group III was composed of Wb and S708 phages that are lytic for B. suis, B. abortus and B. neotomae. We found that the putative phage collar protein is a variable locus with features that may be contributing to the host specificities exhibited by different brucellaphage groups. The presence of several candidate host range determinants is illustrated herein for future dissection of the differential host specificity observed among these phages.
Related JoVE Video
16S rRNA gene pyrosequencing of reference and clinical samples and investigation of the temperature stability of microbiome profiles.
Microbiome
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Sample storage conditions, extraction methods, PCR primers, and parameters are major factors that affect metagenomics analysis based on microbial 16S rRNA gene sequencing. Most published studies were limited to the comparison of only one or two types of these factors. Systematic multi-factor explorations are needed to evaluate the conditions that may impact validity of a microbiome analysis. This study was aimed to improve methodological options to facilitate the best technical approaches in the design of a microbiome study. Three readily available mock bacterial community materials and two commercial extraction techniques, Qiagen DNeasy and MO BIO PowerSoil DNA purification methods, were used to assess procedures for 16S ribosomal DNA amplification and pyrosequencing-based analysis. Primers were chosen for 16S rDNA quantitative PCR and amplification of region V3 to V1. Swabs spiked with mock bacterial community cells and clinical oropharyngeal swabs were incubated at respective temperatures of -80°C, -20°C, 4°C, and 37°C for 4 weeks, then extracted with the two methods, and subjected to pyrosequencing and taxonomic and statistical analyses to investigate microbiome profile stability.
Related JoVE Video
Shear stress induced by an interstitial level of slow flow increases the osteogenic differentiation of mesenchymal stem cells through TAZ activation.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Shear stress activates cellular signaling involved in cellular proliferation, differentiation, and migration. However, the mechanisms of mesenchymal stem cell (MSC) differentiation under interstitial flow are not fully understood. Here, we show the increased osteogenic differentiation of MSCs under exposure to constant, extremely low shear stress created by osmotic pressure-induced flow in a microfluidic chip. The interstitial level of shear stress in the proposed microfluidic system stimulated nuclear localization of TAZ (transcriptional coactivator with PDZ-binding motif), a transcriptional modulator of MSCs, activated TAZ target genes such as CTGF and Cyr61, and induced osteogenic differentiation. TAZ-depleted cells showed defects in shear stress-induced osteogenic differentiation. In shear stress induced cellular signaling, Rho signaling pathway was important forthe nuclear localization of TAZ. Taken together, these results suggest that TAZ is an important mediator of interstitial flow-driven shear stress signaling in osteoblast differentiation of MSCs.
Related JoVE Video
Genomic characterization of group C Orthobunyavirus reference strains and recent South American clinical isolates.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Group C orthobunyaviruses (family Bunyaviridae, genus Orthobunyavirus), discovered in the 1950s, are vector-borne human pathogens in the Americas. Currently there is a gap in genomic information for group C viruses. In this study, we obtained complete coding region sequences of reference strains of Caraparu (CARV), Oriboca (ORIV), Marituba (MTBV) and Madrid (MADV) viruses, and five clinical isolates from Peru and Bolivia, using an unbiased de novo approach consisting of random reverse transcription, random anchored PCR amplification, and high throughput pyrosequencing. The small, medium, and large segments encode for a 235 amino acid nucleocapsid protein, an approximately 1430 amino acid surface glycoprotein polyprotein precursor, and a 2248 amino acid RNA-dependent RNA polymerase, respectively. Additionally, the S segment encodes for an 83 amino acid non-structural protein, although this protein is truncated or silenced in some isolates. Phylogenetically, three clinical isolates clustered with CARV, one clustered with MTBV, and one isolate appeared to be a reassortant or a genetic drift resulted from the high variability of the medium segment which was also seen in a few other orthobunyaviruses. These data represent the first complete coding region sequences for this serocomplex of pathogenic orthobunyaviruses. The genome-wide phylogeny of reference strains is consistent with the antigenic properties of the viruses reported in the original serological studies conducted in the 1960s. Comparative analysis of conserved protein regions across group C virus strains and the other orthobunyavirus groups revealed that these group C viruses contain characteristic domains of potential structural and functional significance. Our results provide the basis for the developments of diagnostics, further genetic analyses, and future epidemiologic studies of group C viruses.
Related JoVE Video
Prognostic and predictive value of a microRNA signature in stage II colon cancer: a microRNA expression analysis.
Lancet Oncol.
PUBLISHED: 11-13-2013
Show Abstract
Hide Abstract
Current staging methods do not accurately predict the risk of disease recurrence and benefit of adjuvant chemotherapy for patients who have had surgery for stage II colon cancer. We postulated that expression patterns of multiple microRNAs (miRNAs) could, if combined into a single model, improve postoperative risk stratification and prediction of chemotherapy benefit for these patients.
Related JoVE Video
[Establishment of method detecting CD36 expression on human platelet and its application].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 09-04-2013
Show Abstract
Hide Abstract
The individual with the deficiency of CD36 antigen on platelet displayed the risk of anti-CD36 immune reaction induced by transfusion, which is one of the reasons for platelet transfusion refractoriness(PTR). This study was purposed to detect the expression level of CD36 antigen on platelet by flow cytometry among aphoresis platelet donors of Hangzhou area, and the frequency of CD36 deficiency was analyzed. Platelet-rich plasma(PRP) was separated from fresh anticoagulant whole blood by centrifugation, then the platelets were washed and adjusted to 1×10(6). The platelets were incubated with FITC-labeled CD36 and PE-labeled CD41 monoclonal antibodies, then the expression level of CD36 was detected by flow cytometry. The CD36 expression on monocytes for the samples of CD36-deficiency on the platelets was further analyzed. The results showed that 7 samples with CD36 antigen deficiency were found in 192 aphoresis platelet donors. The frequency of CD36 deficiency was 3.6% and all of them were typeII deficiency. The significant difference of CD36 antigen expression was observed in the platelet donors of Hangzhou population, among them 59 individuals with low expressed CD36 antigen and 126 individuals with highly expressed CD36 antigen were found according to the geometric mean fluorescence intensity. It is concluded that the CD36 antigen deficient phenotype existed in the population, these data will provide the information for research of the CD36 antigen distribution and help to solve the platelet transfusion refractoriness.
Related JoVE Video
P2Y4 receptor-mediated pinocytosis contributes to amyloid beta-induced self-uptake by microglia.
Mol. Cell. Biol.
PUBLISHED: 09-03-2013
Show Abstract
Hide Abstract
Brain disturbances, like injuries or aberrant protein deposits, evoke nucleotide release or leakage from cells, leading to microglial chemotaxis and ingestion. Recent studies have identified P2Y12 purinergic receptors as triggers for microglial chemotaxis and P2Y6 receptors as mediators for phagocytosis. However, pinocytosis, known as the internalization of fluid-phase materials, has received much less attention. We found that ATP efficiently triggered pinocytosis in microglia. Pharmacological analysis and knockdown experiments demonstrated the involvement of P2Y4 receptors and the phosphatidylinositol 3-kinase/Akt cascade in the nucleotide-induced pinocytosis. Further evidence indicated that soluble amyloid beta peptide 1-42 induced self-uptake in microglia through pinocytosis, a process involving activation of P2Y4 receptors by autocrine ATP signaling. Our results demonstrate a previously unknown function of ATP as a "drink me" signal for microglia and P2Y4 receptors as a potential therapeutic target for the treatment of Alzheimers disease.
Related JoVE Video
Molecular typing of "Candidatus Bartonella ancashi," a new human pathogen causing verruga peruana.
J. Clin. Microbiol.
PUBLISHED: 08-28-2013
Show Abstract
Hide Abstract
A recently described clinical isolate, "Candidatus Bartonella ancashi," was obtained from a blood sample of a patient presenting with verruga peruana in the Ancash region of Peru. This sample and a second isolate obtained 60 days later from the same patient were molecularly typed using multilocus sequence typing (MLST) and multispacer sequence typing (MST). The isolates were 100% indistinguishable from each other but phylogenetically distant from Bartonella bacilliformis and considerably divergent from other known Bartonella species, confirming their novelty.
Related JoVE Video
The performance of thiol-terminated PEG-paclitaxel-conjugated gold nanoparticles.
Biomaterials
PUBLISHED: 08-11-2013
Show Abstract
Hide Abstract
A series of thiol-terminated polyethylene glycol (PEG)-paclitaxel (PTX) derivatives are designed and synthesized to fabricate PTX-conjugated gold nanoparticles (PTX@GNPs) and improve their overall performance. By extending the molecular weight of PEG from 400 to 1000 Da, the optimized water solubility of the conjugate reaches 184 mg/mL, equal to 4.6 × 10(5) times that of PTX alone (0.4 ?g/mL). High drug loading is obtained by eliminating the steric hindrance between PTX molecules on the surface of GNPs. The gold conjugate shows double simultaneous stimulation-induced drug release behavior in the presence of both esterase and high concentrations of glutathione. The synergic release characteristics of this conjugate results in significant performance improvements, including prolonged circulation due to high stability in vivo, targeted release of PTX inside tumor cells, and increased tumor cell killing efficiency. Improving the in vitro properties of the conjugate not only significantly enhances its therapeutic efficacy in a murine liver cancer model, but also allows drug-conjugated gold nanoparticles to be used as a promising nanoprodrug system in the cancer therapeutics.
Related JoVE Video
Use of qPCR and genomic sequencing to diagnose Plasmodium ovale wallikeri malaria in a returned soldier in the setting of a negative rapid diagnostic assay.
Am. J. Trop. Med. Hyg.
PUBLISHED: 07-08-2013
Show Abstract
Hide Abstract
Plasmodium ovale is one of several clinically relevant malaria species known to cause disease in humans. However, in contrast to Plasmodium falciparum and Plasmodium vivax, which are responsible for most cases of human malaria, P. ovale has a wide distribution but low prevalence in tropical regions. Here, we report the case of a soldier returning from Liberia with P. ovale wallikeri malaria. This case highlights the limitations of both microscopy and the malaria rapid diagnostic test for diagnosing infection with P. ovale and for distinguishing P. ovale wallikeri from P. ovale curtisi. To our knowledge, this is the first case report in which quantitative real-time polymerase chain reaction amplification using the Cytochrome B gene, coupled with genomic sequencing of the potra locus, was used for definitive diagnosis of P. ovale wallikeri malaria.
Related JoVE Video
Fragmentation of genomic DNA using microwave irradiation.
J Biomol Tech
PUBLISHED: 07-02-2013
Show Abstract
Hide Abstract
An unconventional approach for DNA fragmentation was investigated to explore its feasibility as an alternative to the existing DNA fragmentation techniques for next-generation DNA sequencing application. Current methods are based on strong-force liquid shearing or specialized enzymatic treatments. There are shortcomings for these platforms yet to be addressed, including aerosolization of genomic materials, which may result in the cross-contamination and biohazards; the difficulty in multiplexing; and the potential sequence biases. In this proof-of-concept study, we investigated the microwave irradiation as a simple, unbiased, and easy-to-multiplex way to fragment genomic DNA randomly. In addition, heating DNA at high temperature was attempted for the same purpose and for comparison. Adaptive focused acoustic sonication was used as the control. The yield and functionality for the DNA fragments and DNA fragment libraries were analyzed to assess the feasibility and use of the proposed approach. Both microwave irradiation and thermal heating can fragment genomic DNA to the size ranges suitable for next-generation sequencing (NGS) shotgun library preparation. However, both treatments caused severe reduction in PCR amplification efficiency, which led to low production in emulsion PCR (emPCR). The result was improved by amplification prior to emPCR. Further improvements, such as DNA strand repairing, are needed for the method to be applied practically in NGS.
Related JoVE Video
[Identification of the related substances in fasudil hydrochloride with hyphenated techniques].
Yao Xue Xue Bao
PUBLISHED: 06-04-2013
Show Abstract
Hide Abstract
The study aims to identify the related substances in fasudil hydrochloride by hyphenated techniques. A WondaSil C18 (250 mm x 4.6 mm, 5 microm) column was used for the separation of the related substances with a mixture of methanol and ammonium acetate buffer solution as the mobile phase by gradient elution. The structures of the related substances were speculated by electrospray positive ionization LC-TOF/MS accurate ion mass and MS/MS determination and elucidation, and verified further through synthesis and spectroscopic analysis. Fasudil hydrochloride and the related substances were separated under the established HPLC condition. Three related substances in fasudil hydrochloride were characterized by hyphenated techniques. The hyphenated LC-MS method is useful for the identification of related substances in fasudil hydrochloride and the results obtained are valuable for its manufacturing process and quality control.
Related JoVE Video
Impact on L-carnitine Homeostasis of Short-term Treatment with the Pivalate Prodrug Tenofovir Dipivoxil.
Basic Clin. Pharmacol. Toxicol.
PUBLISHED: 04-24-2013
Show Abstract
Hide Abstract
Pivalate-generating prodrugs have been suggested to cause clinically significant hypocarnitinaemia. Tenofovir dipivoxil, a novel ester prodrug of tenofovir, can be used for treatment for hepatitis B and HIV infection and it was necessary to evaluate the effect of its treatment on carnitine homeostasis. We sought to investigate the effect of Class 1 drug tenofovir dipivoxil on endogenous L-carnitine level during a 72-hr test in healthy Chinese volunteers and to establish a suitable dose of L-carnitine nutritional supplement for patients who were administered short-term tenofovir dipivoxil tablets for treatment for hepatitis B and herpes simplex virus infection. Tenofovir dipivoxil was administered in one of eight dosing regimens (single dose 150, 300 and 600 mg, multiple dose 300, 450, and 600 mg, multiple dose 450 (600) mg tenofovir dipivoxil and 0.5 g L-carnitine) to gender-balanced groups of 84 healthy Chinese volunteers. Plasma concentrations of L-carnitine were quantified before, during and after treatment. Plasma L-carnitine concentrations fell during tenofovir dipivoxil dosing. The nadir in L-carnitine concentration was dependent on the dose of tenofovir dipivoxil and it decreased from 6.1 ± 0.6 to 4.4 ± 0.8 ?g/ml, 6.1 ± 1.8 to 3.3 ± 1.2 ?g/ml, 6.2 ± 0.6 to 2.5 ± 0.5 ?g/ml for single doses of 150, 300, 600 mg tenofovir dipivoxil tablets and from 6.0 ± 1.4 to 2.1 ± 1.5 ?g/ml, 6.2 ± 0.4 to 0.9 ± 0.5 ?g/ml for multiple doses of 450, 600 mg tenofovir dipivoxil tablets, respectively. Short-term administration of tenofovir dipivoxil results in hypocarnitinaemia and increased losses of carnitine in resulting of minor adverse events of decreased food appetite, nausea, abdominal distention and muscle weakness.
Related JoVE Video
Complications of radical nephrectomy for renal cell carcinoma: a retrospective study comparing transperitoneal and retroperitoneal approaches using a standardized reporting methodology in two Chinese centers.
Chin J Cancer
PUBLISHED: 01-09-2013
Show Abstract
Hide Abstract
The reporting of complications following transperitoneal and retroperitoneal open radical nephrectomy (RN) is nonstandardized. This study aimed to compare early complications between the two approaches using a standardized reporting methodology in a large contemporary cohort. Between 1996 and 2009, 558 patients underwent open RN for renal cell carcinoma (RCC) in our two centers (424 from Sun Yat-sen University Cancer Center and 134 from the First Affiliated Hospital of Sun Yat-sen University). Records were reviewed for clinicopathologic features and complications. Complications were graded using the Clavien system based on the severity of impact. One hundred and five patients (18.8%) had one or more early complications (168 complications overall). The overall rates of grades I to V complications were 5.6%, 10.8%, 2.2%, 0.4%, and 0.2%, respectively. Patients who underwent transperitoneal RN did not experience more overall or procedure-related complications than those who underwent retroperitoneal RN (P = 0.911 and P = 0.851, respectively). On subgroup analysis, neither grade I/II nor grades III-V complications were significantly different between the transperitonal RN and retroperitoneal RN groups. Multivariate analysis showed that for any grade of complication, age (P = 0.016) and estimated blood loss (P = 0.001) were significant predictors. We concluded that open RN is a safe procedure associated with low rates of serious morbidity and mortality. Compared with retroperitoneal RN, transperitoneal RN was not associated with more complications. Older patient and more blood loss at surgery were independent predictors for higher early postoperative complication rates.
Related JoVE Video
Wood recognition using image texture features.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Inspired by theories of higher local order autocorrelation (HLAC), this paper presents a simple, novel, yet very powerful approach for wood recognition. The method is suitable for wood database applications, which are of great importance in wood related industries and administrations. At the feature extraction stage, a set of features is extracted from Mask Matching Image (MMI). The MMI features preserve the mask matching information gathered from the HLAC methods. The texture information in the image can then be accurately extracted from the statistical and geometrical features. In particular, richer information and enhanced discriminative power is achieved through the length histogram, a new histogram that embodies the width and height histograms. The performance of the proposed approach is compared to the state-of-the-art HLAC approaches using the wood stereogram dataset ZAFU WS 24. By conducting extensive experiments on ZAFU WS 24, we show that our approach significantly improves the classification accuracy.
Related JoVE Video
RAF1-MEK1-ERK/AKT axis may confer NSCLC cell lines resistance to erlotinib.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
The fact that advanced NSCLC patients with wild type (wt) EGFR can benefit from erlotinib therapy makes it critical to find out biomarkers for effective selection of patients and improving the therapy effects. In present study, 3 NSCLC cell lines (U1752, Calu-6 and NCI-H292) with wt EGFR and different sensitivities to erlotinib were used for microarray analysis. The differential basal gene expression between 2 NSCLC cell lines was analyzed, about 353 genes were expression-altered with higher than 2-fold changes between Calu-6 and U1752. And Ingenuity Pathway Analysis (IPA) showed that these genes were mainly enriched in regulation of epithelial-mesenchymal transition (EMT) pathway, Wnt-? catenin signaling, Tec kinase signaling and some types of cancer-related signaling. More interestingly, RAF1 (c-raf), MAP2K1 (MEK1), SNAI and downstream signaling molecules ERK and AKT were predicted to be activated in erlotinib-resistant cell line by IPA. Subsequent immunoblotting experiments showed that the phosphorylation of ERK and AKT were exactly increased stepwise from erlotinib sensitive cell line to erlotinib resistant cell lines. Collectively, activation of RAF1-MEK1-ERK/AKT axis may determine the resistance of NSCLC cell lines bearing wt EGFR to erlotinib. Our work provides potential biomarkers and therapeutic targets for NSCLC patients harboring wt EGFR.
Related JoVE Video
Enhanced de novo assembly of high throughput pyrosequencing data using whole genome mapping.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Despite major advances in next-generation sequencing, assembly of sequencing data, especially data from novel microorganisms or re-emerging pathogens, remains constrained by the lack of suitable reference sequences. De novo assembly is the best approach to achieve an accurate finished sequence, but multiple sequencing platforms or paired-end libraries are often required to achieve full genome coverage. In this study, we demonstrated a method to assemble complete bacterial genome sequences by integrating shotgun Roche 454 pyrosequencing with optical whole genome mapping (WGM). The whole genome restriction map (WGRM) was used as the reference to scaffold de novo assembled sequence contigs through a stepwise process. Large de novo contigs were placed in the correct order and orientation through alignment to the WGRM. De novo contigs that were not aligned to WGRM were merged into scaffolds using contig branching structure information. These extended scaffolds were then aligned to the WGRM to identify the overlaps to be eliminated and the gaps and mismatches to be resolved with unused contigs. The process was repeated until a sequence with full coverage and alignment with the whole genome map was achieved. Using this method we were able to achieved 100% WGRM coverage without a paired-end library. We assembled complete sequences for three distinct genetic components of a clinical isolate of Providencia stuartii: a bacterial chromosome, a novel bla NDM-1 plasmid, and a novel bacteriophage, without separately purifying them to homogeneity.
Related JoVE Video
Stage T1N0M0 renal cell carcinoma: the prognosis in Asian patients.
Chin J Cancer
PUBLISHED: 11-01-2011
Show Abstract
Hide Abstract
The prognostic features of T1N0M0 renal cell carcinoma (RCC) in Asian patients have not been well explored in large sample studies. In this study, we retrospectively analyzed the records of 713 patients undergoing nephrectomy for T1N0M0 RCC between 1991 and 2009 in three Asian hospitals. Univariate and multivariate analysis were performed to identify the independent predictive factors for T1N0M0 RCC prognosis among a series of clinicopathological parameters, including age, gender, tumor size, Fuhrman grade, and histological classification. Our results showed that 388 of 713 patients had tumors 4.0 cm or smaller (stage T1a) and 325 of 713 patients had tumors 4.0-7.0 cm in size (stage T1b). Five-year cancer-specific survival (CSS) and recurrence-free survival (RFS) rates for this group of patients were 96.0% and 93.5%, respectively. The patients with T1b RCC had a significantly lower 5-year CSS and RFS rates than did those with T1a RCC (CSS, 93.1% vs. 98.6%, P = 0.026; RFS, 90.0% vs. 96.5%, P < 0.001). Patients with low grade (grades I-II) tumors had a higher 5-year CSS (97.8% vs. 91.2%, P = 0.001) and RFS (95.5% vs. 85.5%, P < 0.001) rate than did those with high grade (grades I-II) tumors. More interestingly, when stratifying patients to T1a and T1b groups, the role of grade in distinguishing prognosis could be only observed in patients with T1b disease. Cox regression showed tumor size and Fuhrman grade were significant in predicting CSS and RFS. Our study suggests that the prognosis of patients with T1N0M0 RCC is excellent, and these results are comparable to previously reported studies in Western patients. Furthermore, our data indicates that patients with T1b disease and high Fuhrman grade have high risk of tumor recurrence and death, thus requiring more frequent follow-up.
Related JoVE Video
Development and characterization of 20 microsatellite mrkers for Chinese back sleeper, Bostrychus sinensis.
Int J Mol Sci
PUBLISHED: 10-12-2011
Show Abstract
Hide Abstract
Twenty microsatellite markers were isolated and characterized from the Chinese black sleeper, Bostrychus sinensis. Loci were screened in 30 individuals from Taiwan. For each locus, the number of alleles varied from 4 to 22 with mean expected and observed heterozygosity of 0.79 and 0.66, respectively. One locus significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction and no significant linkage disequilibrium was detected. This set of microsatellites will provide a suitable tool for population genetic studies of Chinese black sleeper.
Related JoVE Video
[Identification of an ABx09 phenotype of ABO subtype].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 10-11-2011
Show Abstract
Hide Abstract
To analyze the molecular basis for an individual with ABx09 phenotype of ABO subtype.
Related JoVE Video
[Study on the expression stability of mutant alpha-1,2 fucosyltransferase gene 293C to T and 658C to T in eukaryotic cells].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 10-11-2011
Show Abstract
Hide Abstract
To establish the eukaryotic cell expression system for the alpha-1,2 fucosyltransferase gene FUT1 293C to T and 658C to T mutations and explore the mechanism of FUT1 mutations resulting in the reduced expression of H antigen.
Related JoVE Video
[Molecular properties of grass carp reovirus in southern China and establishment of a duplex PCR detection method].
Bing Du Xue Bao
PUBLISHED: 08-31-2011
Show Abstract
Hide Abstract
A strain of grass carp reovirus was isolated from sick grass carp with symptoms of haemorrhage in Guangdong province in 2009. The strain was tentatively named as GCRV-GD108 because it was isolated from grass carp and possessed 11 segments of dsRNA. Complete genome sequence analysis showed that significant differences existed between GCRV-GD108 and GCRV, as well as other known species of aquareovirus. In this study, molecular characteristics of diseased grass carp collected from different farms in Guangdong, Fujian and Hunan provinces were assayed. Based on the sequences of the 11 segments of GCRV-GD108, PCR primers corresponding to each of the segments were designed and synthesized. Total RNA of the diseased fish was extracted and used as templates of RT-PCR reaction. Specific amplification bands were obtained from all of the samples whereas no band was produced from GCRV standard strain. While using the primers specific to GCRV produced specific band in GCRV standard strain rather than in these collected samples. Sequencing of the amplification products showed that these samples displayed high similarities with each other (95.2%-99.4%), and they also shared high sequence similarities with that of GCRV-GD108 (95.0%-99.8%), suggesting that these samples shared similar molecular characteristics with those of GCRV-GD108, and were quite different from GCRV as well as the known species of genus aquareovirus. The results indicated that there are different molecular types of reovirus existed in the pond-cultured grass carp in China, and GCRV-GD108 is a representative strain in southern China, therefore great attention should be paid in order to control the disease efficiently, especially in vaccine preparation. Two pairs of primers were chosen to establish a duplex PCR assay method by combining each pair of the primers specific to GCRV-GD108 with the GCRV primer pair respectively. The duplex PCR assay method will enable the identification of GCRV-GD108 or GCRV by only a single PCR reaction.
Related JoVE Video
[Recombination between human leukocyte antigen -A and -C loci within two Chinese Han families].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 08-04-2011
Show Abstract
Hide Abstract
To investigate the recombination events between human leukocyte antigen (HLA) loci within two families.
Related JoVE Video
[Molecular mechanism of an individual with weaken B phenotype in ABO blood group].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 08-04-2011
Show Abstract
Hide Abstract
To elucidate the serological characteristics and molecular mechanism of a blood donor with weaken B antigen.
Related JoVE Video
[Transrectal ultrasonography in the etiological diagnosis of male obstructive azoospermia: analysis of 695 cases].
Zhonghua Nan Ke Xue
PUBLISHED: 07-09-2011
Show Abstract
Hide Abstract
To assess the role of transrectal ultrasonography (TRUS) in the etiological diagnosis of male obstructive azoospermia.
Related JoVE Video
[C742T mutation of ?1, 3 N-acetyl-D-galactosaminyltransferase gene is responsible for A2 subgroup].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 07-07-2011
Show Abstract
Hide Abstract
The objective of this study was to analyze the molecular genetic basis for 2 individuals with A2B phenotype of ABO subtype. The ABO group antigens on red blood cells were identified by monoclonal antibodies and the ABO antibodies in serum were detected by the standard A, B, O cells. The exon 5 to exon 7 coding region of ABO gene was amplified by polymerase chain reaction (PCR) and the PCR product was sequenced directly after the enzymes digested. The amplified product was also cloned by TOPO TA cloning sequencing kit to split the 2 alleles apart and chosen colonies were sequencing bidirectionally for exon 6 to 7 of ABO gene. The results showed that both A and B antigen were identified on red blood cells of the individuals and there was anti-A1 antibody in their serum. There was no 261G deletion and showed 297A/G, 467C/T, 526C/G, 657C/T, 703G/A, 742C/T, 796C/A, 803G/C, 930G/A heterozygotes by direct DNA sequencing. After cloning and sequencing, it was obtained the B101 and one novel A allele. The novel allele has one nucleotide change at 742 position C to T compared with A102, which results in an amino acid Arg to Cys at 248 position and was nominated as A213. It is concluded that C742T mutation of the ?1, 3 N-acetyl-D-galactosaminyl-transferase gene can lead to A2 phenotype and with anti-A1 antibody in serum.
Related JoVE Video
[Identification of a novel allele HLA-B*15:129 by polymerase chain reaction with allele group-specific primers].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 06-07-2011
Show Abstract
Hide Abstract
To analyze the sequence of the exons 2-4 of human leukocyte antigen (HLA) novel allele HLA-B*15:129.
Related JoVE Video
Pharmacokinetic differences between the epimers of cefotetan disodium after single intravenous injection in healthy Chinese volunteers.
Eur J Drug Metab Pharmacokinet
PUBLISHED: 05-09-2011
Show Abstract
Hide Abstract
The pharmacokinetic behaviors of the epimers of cefotetan disodium (R-CTT, S-CTT) after a single intravenous injection dose in healthy Chinese volunteers were explored in this study. In an open-label, randomized, three-way, cross-over study, 12 volunteers (6 females and 6 males) received a cross-over fashion doses of 0.5, 1.0, and 2.0 g of cefotetan disodium, separated by washout periods of 7 days. The plasma concentrations of both epimers were measured by validated high-performance liquid chromatography assays. Pharmacokinetic parameters of R-CTT, S-CTT, and total-CTT (R + S mixture) were calculated using a noncompartmental analysis. Generally, the R and S epimers showed different pharmacokinetic behaviors. Following 0.5, 1.0, and 2.0 g doses of cefotetan disodium, values of the total area under the plasma concentration-time curve (AUC(0-?)) were 124.23 ± 19.54, 231.34 ± 39.34, and 459.09 ± 80.65 for R-CTT; 100.95 ± 14.19, 193.80 ± 30.42, and 372.66 ± 67.32 for S-CTT, respectively. Total body clearance values were 4.13, 4.43, and 4.46 L/h for R-CTT and 5.05, 5.28, and 5.50 L/h for S-CTT, respectively. Mean plasma elimination half-life (t (1/2)) values of R-CTT were 4.16, 4.13, and 4.01 h for 0.5, 1.0, and 2.0 g doses, respectively, and those of S-CTT were 3.15, 3.25, and 3.21 h. There were significant differences in t (1/2) between the two epimers (P < 0.05). The t (1/2) of R-CTT was 28% longer than that of S-CTT, which indicated that the elimination of the S-CTT was greater than that of the R-CTT. All treatments were well tolerated.
Related JoVE Video
Detection of hepatitis C virus by an improved loop-mediated isothermal amplification assay.
Arch. Virol.
PUBLISHED: 04-09-2011
Show Abstract
Hide Abstract
An improved, sensitive, specific, and rapid one-step reverse transcription loop-mediated isothermal amplification (LAMP) assay targeting the 5 untranslated region (UTR) was developed to detect hepatitis C virus (HCV) infection. Based on an accelerating primer (AP), the present assay, named AP-LAMP, has the advantages of rapidity and sensitivity over the routine LAMP method. The possible AP-based amplification pathway during the reaction was revealed by restriction enzyme digestion and eletrophoresis. The detection limit of the AP-LAMP assay was approximately 84 IU/ml, and no cross-detection was observed. The assay was evaluated further with 126 clinical specimens, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for detection of HCV RNA.
Related JoVE Video
The value of contrast-enhanced transrectal ultrasound in predicting the nature of prostate diseases and the Gleason score of prostate cancer by a subjective blood flow grading scale.
Urol. Int.
PUBLISHED: 04-01-2011
Show Abstract
Hide Abstract
To investigate the value of contrast-enhanced transrectal ultrasound (CETRUS) in predicting the nature of prostate diseases and prostate cancer Gleason score.
Related JoVE Video
[Para-Bombay phenotype caused by combined heterozygote of two bases deletion on fut1 alleles].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 03-03-2011
Show Abstract
Hide Abstract
This study was purposed to investigate the molecular basis of a para-Bombay phenotype for screening and identification of rare blood group. ABO and H phenotypes of the proband were identified by serological techniques. The exon 6 to exon 7 of ABO gene and full coding region of ?-1,2-fucosyltransferase (fut1) gene of the proband were analyzed by polymerase chain reaction and direct sequencing of the amplified fragments. The haplotype of compound heterozygote of fut1 was also identified by cloning sequencing. The results indicated that a rare para-Bombay phenotype was confirmed by serological techniques. Two deletion or insertion variant sites near nucleotide 547 and 880 were detected in fut1 gene. The results of cloning sequence showed that one haplotype of fut1 gene was two bases deletion at 547-552 (AGAGAG?AGAG), and another one was two bases deletion at position 880-882 (TTT?T). Both two variants caused a reading frame shift and a premature stop codon. It is concluded that a rare para-Bombay phenotype is found and confirmed in blood donor population. The molecular basis of this individual is compound heterozygote of two bases deletion on fut1 gene which weaken the activity of ?-1, 2-fucosyltransferase.
Related JoVE Video
[Cloning and sequence analysis of 5untranslated region of human ABO gene].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 02-03-2011
Show Abstract
Hide Abstract
To clone and investigate the polymorphism of the 5-untranslated region (5-UTR) of the human ABO gene, in order to provide the basis for exploring the transcriptional regulation of the human ABO histo-blood group genes.
Related JoVE Video
[Study on polymorphism of membrane glycoprotein genes related to human platelet alloantigens].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 02-03-2011
Show Abstract
Hide Abstract
To investigate the polymorphisms of platelet membrane glycoprotein genes related to human platelet alloantigen (HPA)-1 to 17w.
Related JoVE Video
[Effects of Chinese herbal medicine Huanglian Jiedu Decoction on urine metabonomics of healthy people].
Zhong Xi Yi Jie He Xue Bao
PUBLISHED: 01-14-2011
Show Abstract
Hide Abstract
To study biomarkers and their diversification in healthy peoples urine before and after oral administration of Huanglian Jiedu Decoction, a compound Chinese herbal medicine, and to investigate the influence of Huanglian Jiedu Decoction on urine metabonomics of healthy people.
Related JoVE Video
Simultaneous determination of ciclesonide and its active metabolite desisobutyryl-ciclesonide in human plasma by LC-APCI-MS/MS: application to pharmacokinetic study in healthy Chinese volunteers.
J Pharm Biomed Anal
PUBLISHED: 01-09-2011
Show Abstract
Hide Abstract
A sensitive and highly selective liquid chromatography tandem mass spectrometric (LC/MS/MS) method was developed and validated for the determination of ciclesonide (CIC) and its active metabolite, desisobutyryl-ciclesonide (des-CIC), in human plasma. Plasma samples were extracted using methyl tert-butyl ether with mifepristone as an internal standard (IS). Separation was carried out on a C(18) column using a mixture of 0.1% formic acid solution and methanol as the mobile phase with linear gradient elution. The detection was operated with positive atmospheric pressure chemical ionization (APCI) by selective multiple reaction monitoring (SRM). The chief benefit of the present method was the high sensitivity, with the lower limit of quantification (LLOQ) as low as 10pg/mL and the linearity ranging from 10 to 10,000pg/mL for both CIC and des-CIC. The method was fully validated and successfully applied to determine CIC and des-CIC simultaneously in human plasma and proved to be suitable for phase I clinical pharmacokinetic study of inhaled ciclesonide in healthy Chinese volunteers.
Related JoVE Video
[Nucleotide sequence analysis of A novel HLA-B*15:124 allele confirmed].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-24-2010
Show Abstract
Hide Abstract
This study was purposed to investigate the nucleotide sequences of a novel HLA-B*15:124 allele and its molecular mechanism. The genomic DNA from whole blood was extracted by using commercial DNA extraction kit. The sequences of exon 2, 3 and 4 of HLA-B locus in the proband were amplified by PCR with group-specific primers, the PCR products were purified by enzymes digestion, then exon 2 to 4 of HLA-B locus for both orientations was sequenced. The results showed that 2 HLA-B alleles of proband were gained after amplification and sequencing of group-specific primers, among them one was a B*40:03, another was a novel allele. After BLAST analysis, the novel allele showed nucleotides different from HLA-B*15:52 in exon 3 at nucleotide position 427 A > T and 440 G > T which resulted in amino acid change from Thr to Ser at codon 143 and Trp to Leu at conon 147. It is concluded that a novel HLA-B allele has two different nucleotides. This HLA-B allele is identified and has been officially named B*15:124 by the WHO Nomenclature Committee.
Related JoVE Video
[Probability of high resolution full match for human leukocyte antigen loci in unrelated donors and recipients with low resolution match].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-24-2010
Show Abstract
Hide Abstract
This study was aimed to analyze the possibility of high resolution matching for human leukocyte antigen (HLA) loci in unrelated donor-recipient pair with low resolution match in HLA-A, -B, -DRB1 loci. Samples were genotyped for HLA-A, -B, -C, -DRB1 and -DQB1 by polymerase chain reaction sequence based typing (PCR-SBT). The results showed that the total number of patients and the donors were 166 and 274. 97 (58.43%) patients were matched for 1 donor and 47 (28.31%) patients were matched for 2 donors at low resolution level; among 274 donor-recipient pairs, HLA-A, -B, -C, -DRB1 and -DQB1 loci matching for 6/10, 7/10, 8/10, 9/10 and 10/10 were 32 (11.68%), 54 (19.71%), 62 (22.63%), 49 (17.88%) and 48 (17.52%) respectively; there were mismatch in HLA-A, -B, -C, -DRB1 and -DQB1 loci, and the most mismatch was in HLA-C locus. The number of alleles of HLA-A, -B, -C, -DRB1 and -DQB1 loci were 23, 46, 21, 30 and 17 respectively in the donors. The alleles number HLA-A, -B, -C, -DRB1 and -DQB1 loci were 20, 40, 22, 29 and 16 respectively in the patients; the haplotype number of HLA loci were 311 in the donors and 224 in the patients. The high frequency of haplotype was A*02:07-B*46:01-C*01:02-DRB1*09:01:02-DQB1*03:03 (5.63% and 6.88%). It is concluded that the probability of high resolution mismatch of HLA loci is high in unrelated donor-recipient pairs with low resolution match in HLA-A, -B, -DRB1 loci.
Related JoVE Video
[In vitro expression activity of ?-(1,2) fucosyltransferase with 35C > T and 682A > G mutations].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-24-2010
Show Abstract
Hide Abstract
In order to explore the effects of 35C > T and 682A > G mutations on the activity of alpha-(1,2) fucosyltransferase, the coding region of fut1 gene was amplified by polymerase chain reaction (PCR) from genomic DNA. PCR product was ligated into expression vector using TOPO TA cloning kit to obtain the recombinant plasmids. The recombinant plasmids were transfected into COS-7 cells by liposome method. After screening by using G418, H antigen expression on the COS-7 was tested by flow cytometry and fut1 mRNA was detected by real-time PCR. The results indicated that three kinds of recombinant plasmids pcDNA3.1/V5-His-wild (35C + 682A), pcDNA3.1/V5-His-35T and pcDNA3.1/V5-His-35T-682G were successfully constructed. After transfection, the H antigen expressed on membrane of COS-7 cells at the second day, with the maximum level of expression at the fourth day. When compared with pcDNA3.1/V5-His-wild transfected cells, the H antigen expression level of the 35T and 682G + 35T recombinant plasmids in the transfected cells was 52.7% and 13.3% on the fourth day, respectively. Although the level of fut1 mRNA decreased with prolonging of time, the mRNA expressed on the pcDNA3.1/V5-His-35T-682G transfected cells reached to 14% of the wild plasmids on the first day. It is concluded that 682A > G mutation obviously reduces the activity of alpha-(1,2) fucosyltransferase, while 35C > T mutation leads to partial reduction of H antigen in vitro expression.
Related JoVE Video
[Quantitative chimerism analysis of regulatory T cell subsets based on immunomagnetic sorting].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-24-2010
Show Abstract
Hide Abstract
The aim of study was to explore the feasibility of quantitative chimerism analysis of regulatory T (Treg) cells using immune sorting coupling short tandem repeat (STR) method. 14 sets of artificial chimera samples were prepared by mixed lymphocytes according to different proportion. The CD4(+)CD25(+) Treg cells were harvested by negative and positive selection of immunomagnetic beads, then the STR polymorphisms of 16 loci in sorted Treg cells was analyzed. The results showed that the DNA amount extracted from sorted Treg cells was fit for STR detection. All STR alleles specific for recipient or donor could be detected and the quantitative results were consistent with theoretic values in over 10% recipient chimeras. But only partial recipient alleles could be detected and the quantitative results were different from theoretic values in less then 1% recipient chimeras. It is concluded that a quantitative chimerism analysis of Treg cell based on immune sorting is established. The sensitivity and accuracy for chimera detection are 1% to 10%, and this method can be used to monitoring hematopoietic chimerism following allogeneic hematopoietic stem cell transplantation.
Related JoVE Video
[Establishment of allele specific primer polymerase chain reaction sequence-based typing and investigation of the polymorphism in exon 3 of HLA-DRB1].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 12-15-2010
Show Abstract
Hide Abstract
To establish the allele specific primer polymerase chain reaction sequence-based typing (PCR-SBT) and investigate the polymorphism of exon 3 of human leukocyte antigen( HLA)-DRB1.
Related JoVE Video
[Immobilization of lignin peroxidase on spherical mesoporous material].
Huan Jing Ke Xue
PUBLISHED: 12-07-2010
Show Abstract
Hide Abstract
The spherical mesoporous particles with two-dimensional (2D) hexagonal mesopores in diameter up to 11.6 nm was fabricated in acetic acid/sodium buffer solution (pH = 3.5) by using tetramethoxysilane (TMOS) as silica source, Pluronic P123 as template and 1,3,5-triisopropylbenzene (TIPB) as swelling agent. Then the mesoporous particles were employed as carriers for the immobilization of lignin peroxidase (LiP). The effect of immobilization time, the amount of added enzyme on the immobilized enzyme amount and activities were investigated. The characteristic and stability of immobilized LiP were also studied. The results showed that, as the mass ratio of enzyme (E) and mesoporous material (MS) was 76.8 mg/g,immobilizing time was 12 h, the largest immobilized enzyme amount (8.87 mg/g) and highest apparent activity (41.45 U/mg) of immobilization LiP were achieved. Comparing with free LiP, the optimum pH and temperature of the immobilized LiP were almost the same, while whose pH stability and thermal stability were significantly improved. No obvious activity loss was observed for the immobilized LiP after 7 weeks storage at 4 degrees C. After 6 times of usage, almost 30% of the initial activity could still remain.
Related JoVE Video
[Molecular basis of a new O61 allele in ABO blood group].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-07-2010
Show Abstract
Hide Abstract
Objective of this study was to explore the molecular basis of a new O61 allele in ABO blood group. The ABO group antigens on red cells of the blood samples were identified by monoclonal antibodies and the ABO antibody in serum was detected by the standard A, B, O red cells. The coding region sequences of exon 5 to exon 7 in ABO gene were amplified by polymerase chain reaction (PCR) and the amplification products were purified with double enzyme digestion and directly sequenced for exon 6 and 7. The diploid of the individual with B phenotype was separated into its haploid components with a haplotype specific extraction method. The exons 6 to 7 of the two single ABO haplotypes were then amplified and sequenced separately. The results indicated that 3 samples had mutation at 743 site in total 417 individuals, in which 2 individuals were with O phenotype and 1 individual was with B phenotype. The DNA sequencing of exon 6 and 7 in 2 samples with O phenotype showed 261G deletion and 743G/C heterozygotes. The DNA sequencing of exon 6 and 7 in the sample with B phenotype showed 261G/deletion and 297A/G, 526C/G, 743G/C, 657C/T, 703G/A, 796C/A, 803G/C, 930G/A heterozygotes. After separating of the 2 single strands in the B sample with haplotype specific extraction, an O and B101 allele were identified after sequencing. The novel allele was submitted to the Blood Group Antigen Gene Mutation database and is named as O61. It is concluded that 743G>C is a novel mutation in exon 7 of ABO and a novel O61 allele with 743G>C has been identified.
Related JoVE Video
[Cloning and expression of MHC class I chain-related gene A in E. coli].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-07-2010
Show Abstract
Hide Abstract
In order to construct prokaryotic expression system of MHC classI chain-related gene A (mica) and purify MICA protein, RNAs were extracted from the peripheral blood samples and mica cDNA fragments were obtained by RT-PCR method. The cDNA for mica was ligated with cloning vector by TOPO method. The recombinant cloning vector and prokaryotic expression vector pET-28a were digested by two restriction enzymes and ligated to construct pET-28a-MICA recombinant expression vector, then the pET-28a-MICA vector was transformed and expressed in E. coli BL21 DE3. The recombinant protein was purified by Ni-NTA Spin method. The results showed that the recombinant MICA protein expressed with soluble form in host with pET-28a-MICA vector after IPTG induction. The recombinant target protein was obtained by Ni-NTA spin purification. In conclusion, this study has constructed prokaryotic expression system of mica gene and has purified MICA protein which would help to explore the interaction between MICA and transplantation immunology.
Related JoVE Video
[Effects of combination of Salvia miltiorrhiza and Panax notoginseng on the pharmacokinetics of their major bioactive components in Beagle dog].
Yao Xue Xue Bao
PUBLISHED: 11-10-2010
Show Abstract
Hide Abstract
After oral administration of Salvia miltiorrhiza (Danshen in Chinese), Panax notoginseng (Sanqi in Chinese) and Danshen Sanqi combination suspensions to Beagle dogs, the plasma concentration-time profiles of danshensu, tanshinone II(A), cryptotanshinone, notoginsenoside R1, ginsenoside Rg1 and Rb1 were analyzed by LC-MS/MS. Pharmacokinetic parameters were calculated and analyzed with BAPP 2.0 software. The results showed that the Cmax and AUC of danshensu, notoginsenoside R1, ginsenoside Rg1 and Rb1 in Danshen Sanqi combination group all decreased in comparison with those of Danshen or Sanqi given alone, while the CLz/F and Vz/F increased to some extent. No significant differences of the pharmacokinetics of tanshinone II(A) and cryptotanshinone were observed between groups.
Related JoVE Video
[Analysis of alpha-1,2-fucosyltransferase gene mutations in a Chinese family with para-Bombay phenotype].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 06-10-2010
Show Abstract
Hide Abstract
To investigate the molecular genetic basis of para-Bombay phenotype in a Chinese family.
Related JoVE Video
Intensive expression of Bmi-1 is a new independent predictor of poor outcome in patients with ovarian carcinoma.
BMC Cancer
PUBLISHED: 04-08-2010
Show Abstract
Hide Abstract
It has been suggested that the B-cell specific moloney leukemia virus insertion site 1 (Bmi-1) gene plays an oncogenic role in several types of human cancer, but the status of Bmi-1 amplification and expression in ovarian cancer and its clinical/prognostic significance are unclear.
Related JoVE Video
Enhanced density control of Al:ZnO nanowires via one-by-one coupling of nanowires and pyramids.
J Nanosci Nanotechnol
PUBLISHED: 04-01-2010
Show Abstract
Hide Abstract
Al doped ZnO nanowire arrays with controlled growth densities were fabricated on silicon without using catalysts via sputtering followed by thermal chemical vapor deposition (CVD). Scanning electron microscopy and high-resolution transmission electron microscopy results show that the Al:ZnO single-crystalline nanowires synthesized by CVD prefer growing epitaxially on the tips of the ZnO pyramids pre-synthesized by sputtering with the c-axis perpendicular to the substrate. Consequently, the densities of the as-grown Al:ZnO nanowires were controllable by changing the particle densities of the pre-grown ZnO seed layers. The Al concentration of the Al:ZnO nanowires were measured to be around 2.63 at.% by electron energy loss spectrum. Field-emission measurements show the turn-on fields of the Al:ZnO nanowire arrays with controllable area densities are tunable. Room-temperature cathodoluminescence spectra of the Al:ZnO nanowires show relatively strong and sharp ultraviolet emissions centered at 383 nm and broad green emissions at around 497 nm. This work provides a simple method to control the field emission and luminescence densities of Al doped ZnO nanowire arrays, which also shows good potential for developing nano-pixel optical devices.
Related JoVE Video
Purification of genomic DNA with minimal contamination of proteins.
J Biomol Tech
PUBLISHED: 12-02-2009
Show Abstract
Hide Abstract
The purification is based on a set of solutions and a simple centrifugation procedure. Protocols are designed for an easy extraction and purification of genomic DNA from a wide range of samples, including whole blood, buffy coat, bone marrow, body fluids, buccal cells, tissues, mouse tails, etc. RBCs are lysed by dilution into a hypotonic solution. Tissues are broken down and digested by proteinase K in the presence of an anion detergent to release genomic DNA. After precipitation of the detergent and proteins, unique beads that bind proteins, lipids, and RNAs are added to achieve the supreme purity. Genomic DNA is then separated by alcohol precipitation. A proprietary nucleic acid precipitation reagent is used to enhance DNA recovery from low concentration samples. No DNA-binding beads or columns are used in the method, eliminating the problem of low yield and the risk of shearing of genomic DNA. The purified samples are free of proteins, lipids, salts, and RNA contamination. Purified samples are also stable for storage and suitable for all downstream applications.
Related JoVE Video
[Study on HPLC fingerprint of flavonoids from Houttuynia cordata by comparing with fingerprint reference].
Zhong Yao Cai
PUBLISHED: 09-24-2009
Show Abstract
Hide Abstract
To establish a stable and repeatable HPLC fingerprint standard and evaluate the flavonoids from Houttuynia cordata qualitatively and quantitatively.
Related JoVE Video
A method for preparing DNA sequencing templates using a DNA-binding microplate.
J Biomol Tech
PUBLISHED: 07-02-2009
Show Abstract
Hide Abstract
A DNA-binding matrix was immobilized on the surface of a 96-well microplate and used for plasmid DNA preparation for DNA sequencing. The same DNA-binding plate was used for bacterial growth, cell lysis, DNA purification, and storage. In a single step using one buffer, bacterial cells were lysed by enzymes, and released DNA was captured on the plate simultaneously. After two wash steps, DNA was eluted and stored in the same plate. Inclusion of phosphates in the culture medium was found to enhance the yield of plasmid significantly. Purified DNA samples were used successfully in DNA sequencing with high consistency and reproducibility. Eleven vectors and nine libraries were tested using this method. In 10 microl sequencing reactions using 3 microl sample and 0.25 microl BigDye Terminator v3.1, the results from a 3730xl sequencer gave a success rate of 90-95% and read-lengths of 700 bases or more. The method is fully automatable and convenient for manual operation as well. It enables reproducible, high-throughput, rapid production of DNA with purity and yields sufficient for high-quality DNA sequencing at a substantially reduced cost.
Related JoVE Video
[A novel M142T mutation in the B glycosyltransferase gene associated with B3 variant in Chinese].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 06-09-2009
Show Abstract
Hide Abstract
To investigate the molecular genetic basis of the B3 variant of ABO blood group system with mixed-field hemagglutination in Chinese.
Related JoVE Video
[Apoptosis of grass carp (Ctenopharngodon idellus) lymphocytes induced by the combination of microcystins and disinfection by-products in drinking water].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 05-20-2009
Show Abstract
Hide Abstract
Aiming at the combined pollution of low dose microcystins (MCs) and disinfection byproducts (DBPs) in drinking water, the individual and combined cytotoxic effects of two MCs (MCLR and MCRR) and two DBP compounds (CHClBr1 and CHCl2Br) on the apoptosis of isolated grass carp (Ctenopharngodon idellus) lymphocytes were examined by using in vitro bioassays. The results showed that after 2 hours exposure to the four pollutants within the range of test concentrations, the apoptosis of isolated lymphocyte occurred, and there existed significant dose-effect relationship. The combined cytotoxic effects of 1 nmol x L(-1) MCLR or MCRR and 1-100 nmol x L(-1) CHClr2 or CHCl2Br were all of additive, and the apoptosis percent was highly correlated with the exposure dose. It was suggested that the apoptosis percent of grass carp lymphocytes could be used as an effective indicator to evaluate the cytotoxicity caused by the combined pollution of MCs and DBPs.
Related JoVE Video
[HPLC tandem-mass spectrometric analysis of the chemical components and decomposition products of allicin extract of garlic].
Yao Xue Xue Bao
PUBLISHED: 04-09-2009
Show Abstract
Hide Abstract
To analyze the chemical components and decomposition products in allicin extract of garlic, the chemical components screening and identification were made with HPLC-MS/MS method by full scan TIC MS, HPLC retention time, product MS spectra and chemical reference standards. The stability of the extract in water and alcoholic solutions was also investigated. There were five major components in allicin extract which were all identified as thiosulfinates. The extract was stable for at least 3 months when stored at -20 degrees C as water solution, but obvious decomposition was observed with the increase of alcoholic concentration. The decomposition products were also identified by HPLC-MS/MS.
Related JoVE Video
Large müllerian duct remnant in an adult.
Urology
PUBLISHED: 04-03-2009
Show Abstract
Hide Abstract
A 20-year-old man presented with a 1-month history of frequently terminal hematuria. Ultrasonography revealed 9 x 5 cm cystic lesion behind bladder and above the prostate. Magnetic resonance imaging showed the midline drop-shaped cyst originating within the prostate gland and separating from the seminal vesicles, in keeping with a müllerian duct remnant. The patient underwent surgical resection of the cyst. The histopathologic staining pattern displayed features consistent with a müllerian duct remnant.
Related JoVE Video
Analysis of long-term survival in patients with localized renal cell carcinoma: laparoscopic versus open radical nephrectomy.
World J Urol
PUBLISHED: 04-02-2009
Show Abstract
Hide Abstract
To assess the impact of surgical approaches and clinico-pathological parameters on the prognosis of localized renal cell carcinoma (RCC) after laparoscopic radical nephrectomy (LRN) or open radical nephrectomy (ORN).
Related JoVE Video
Overexpression of EIF-5A2 predicts tumor recurrence and progression in pTa/pT1 urothelial carcinoma of the bladder.
Cancer Sci.
PUBLISHED: 02-26-2009
Show Abstract
Hide Abstract
The authors investigated the status of abnormalities of eIF-5A2 gene in superficial (pTa/pT1) urothelial carcinoma of the bladder (UC), as well as its correlation with clinicopathologic variables and patient outcome. The methods of immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were utilized to examine protein/mRNA(messenger RNA) expression and amplification of eIF-5A2 in a cohort of pTa/pT1 UCs. Overexpression of EIF-5A2 was examined by IHC in 38/112 (33.9%) pTa/pT1 UCs. A significant association of overexpression of EIF-5A2 with shortened UC patient recurrence-free survival (P = 0.002), as well as with shortened progression-free survival (P = 0.004), was demonstrated. Importantly, multivariate Cox regression analysis revealed that EIF-5A2 expression provided a significant independent prognostic parameter either in tumor recurrence (P = 0.002) or in tumor progression (P = 0.007). FISH results demonstrated that eIF-5A2 amplification was detected in 5/59 of the informative UCs; in each of the five cases with eIF-5A2 amplification, overexpression of EIF-5A2 was observed. In the remaining 54 UCs without eIF-5A2 amplification, 16 cases were also observed to have overexpression of EIF-5A2. In 13 pairs of UC and adjacent normal tissues, eight UCs were examined and showed up-regulated eIF-5A2 mRNA by RT-PCR, while increased expression of EIF-5A2 protein was only detected in 4/8 UCs by Western blotting. These findings suggest that overexpression of EIF-5A2, as detected by IHC, may predict tumor recurrence and progression in pTa/pT1 UC patients, and the protein expression of eIF-5A2 might be regulated not only by gene amplification, but also by other molecular mechanisms.
Related JoVE Video
[Metabonomic study on the effects of allicin on rats].
Yao Xue Xue Bao
PUBLISHED: 02-17-2009
Show Abstract
Hide Abstract
To investigate the effects of allicin on rats by NMR-based metabonomic method, the changes of endogenous metabolites in normal rat urine and the influences on metabolism were analyzed with bio-nuclear magnetic resonance (NMR) method and partial least-squares discriminant analysis (PLS-DA) after intraperitoneal administration of allicin solution. The identified biochemical effects associated with allicin dosing included elevated then gradually recovered urinary levels of Krebs cycle intermediates, such as citrate, alpha-ketoglutarate and succinate and increased concentrations of ketones. Meanwhile, decreased urinary concentrations of glucose, lactate, alanine, hippurate and trimethylamine oxide were observed. The PLS-DA revealed that the metabonomic profiles of allicin treated groups were obviously different from those of the control group. Allicin may change metabolism significantly in normal rats. The study of the pharmacologic mechanism of allicin by metabonomic method is practicable and it could be explored further.
Related JoVE Video
The stability of biapenem and structural identification of impurities in aqueous solution.
J Pharm Biomed Anal
PUBLISHED: 02-04-2009
Show Abstract
Hide Abstract
The stability of biapenem in aqueous solution was investigated. Forced degradation of biapenem was carried out under different concentrations, pH values and temperatures. The degradation products were determined by reverse-phase HPLC and identified by LC-MS/MS. One dimeric impurity was obtained by reverse-phase preparative HPLC and characterized by LC-MS/MS and NMR. A possible degradation mechanism has been presented.
Related JoVE Video
Pharmacokinetic properties of lansoprazole (30-mg enteric-coated capsules) and its metabolites: A single-dose, open-label study in healthy Chinese male subjects.
Curr Ther Res Clin Exp
PUBLISHED: 01-30-2009
Show Abstract
Hide Abstract
Background: Lansoprazole, a benzimidazole derivative, is indicated for the treatment of various peptic diseases. It is metabolized mainly in the liver, and its primary active metabolites present in plasma are 5-hydroxy lansoprazole and lansoprazole sulfone. Few data are available on the pharmacokinetic properties of lansoprazole, 5-hydroxy lansoprazole, and lansoprazole sulfone, which can be used to measure cytochrome P450 (CYP) 2C19 activity. Objectives: The aims of this study were to investigate the clinical plasma pharmacokinetic properties of lansoprazole and its metabolites in healthy Chinese male volunteers, and to assess the influences of CYP2C19 on the pharmacokinetics of lansoprazole. Methods: Healthy adult Chinese male volunteers were enrolled in this single-dose, open-label study. All patients received a single oral enteric capsule containing 30 mg of lansoprazole after a 12-hour overnight fast. Serial blood samples were collected immediately before (0 hour) and at 20, 40, 60, 90, 120, and 150 minutes and 3, 4, 6, 8, 10, 12, 15, and 24 hours after study drug administration. The plasma concentrations of lansoprazole, 5-hydroxy lansoprazole, and lansoprazole sulfone were determined using a validated internal standard high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. Pharmacokinetic properties (including Cmax, Tmax, elimination t½ [t½z], mean residence time [MRT], AUC0-24, AUC0-?, apparent oral clearance [CLz/F], and apparent volume of distribution [Vz/F]) were determined using the noncompartmental method. Results: Twenty volunteers (mean [SD] age, 34.9 [2.9] years; weight, 64.6 [2.2] kg; height, 171.3 [3.3] cm) were enrolled in and completed the study. The mean (SD) pharmacokinetic properties of lansoprazole were as follows: Cmax, 1047 (344) ng/mL; Tmax, 2.0 (0.7) hours; t½z, 2.24 (1.43) hours; MRT, 3.62 (0.87) hours; AUC0-24, 3388 (1484) ng/mL/h; AUC0-?, 3496 (1693) ng/mL/h; CLz/F, 9.96 (3.74) L/h; and Vz/F, 32.83 (11.74) L. The findings with 5-hydroxy lansoprazole and lansoprazole sulfone, respectively, were as follows: Cmax, 111.2 (41.8) and 66.6 (52.9) ng/mL; Tmax, 2.1 (0.8) and 1.9 (0.8) hours; t½z, 2.31 (1.18) and 2.52 (1.54) hours; and AUC0-24, 317.0 (81.2) and 231.9 (241.7) ng/mL/h. No adverse events were reported throughout the study. Conclusions: In these healthy Chinese male volunteers administered a single oral dose of lansoprazole 30 mg, absorption of lansoprazole was rapid (mean Cmax, 1047 ng/mL; Tmax, ~2.0 hours). Its 2 primary active metabolites, 5-hydroxy lansoprazole and lansoprazole sulfone, were identified in measurable quantities in plasma (Cmax, 111.2 and 66.6 ng/mL, respectively; and Tmax, 2.1 and 1.9 hours). The plasma t½z did not appear to reflect the duration of suppression of gastric acid secretion: the t½z values of lansoprazole and the 2 metabolites were ~2 to 2.5 hours, while the acid-inhibitory effect lasted >24 hours. Cmax, AUC, and t½z of lansoprazole, and especially lansoprazole sulfone, varied. Differences in metabolism types and/or genotype of CYP2C19 should be taken into account when planning a lansoprazole dosing regimen.
Related JoVE Video
Expression and amplification of eIF-5A2 in human epithelial ovarian tumors and overexpression of EIF-5A2 is a new independent predictor of outcome in patients with ovarian carcinoma.
Gynecol. Oncol.
PUBLISHED: 01-27-2009
Show Abstract
Hide Abstract
Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in ovarian carcinoma are unclear.
Related JoVE Video
Overexpression of EIF-5A2 is an independent predictor of outcome in patients of urothelial carcinoma of the bladder treated with radical cystectomy.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 01-20-2009
Show Abstract
Hide Abstract
Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in urothelial carcinoma of the bladder (UC) are unclear.
Related JoVE Video
Integrating waveguide biosensor.
Methods Mol. Biol.
PUBLISHED: 01-20-2009
Show Abstract
Hide Abstract
The Integrating Waveguide Biosensor was developed for rapid and sensitive detection of bacterial cells, spores, and toxins. A sandwich format of immunoassay was employed using Salmonella as model. The analyte was immunocaptured on the inner surface of the waveguide and then detected by the antibody conjugated with fluorescent dye. The waveguide was illuminated by an excitation light at a 90 degrees angle. The emitted light from fluorescent labels on the surface of the waveguide was efficiently collected and channeled to a detector at the end of the waveguide, while minimizing interference from the excitation light. Utilizing fluorescent dye Cy5, a 635-nm diode laser for excitation, and a photomultiplier tube detector, the Integrating Waveguide Sensor System was able to detect approximately ten captured cells of Salmonella.
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.