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Find video protocols related to scientific articles indexed in Pubmed.
Application of sub-Doppler DAVLL to laser frequency stabilization in atomic cesium.
Appl Opt
PUBLISHED: 11-18-2014
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We achieve laser frequency stabilization by a simple technique based on sub-Doppler dichroic atomic vapor laser lock (DAVLL) in atomic cesium. The technique that combines saturated-absorption spectroscopy and Zeeman splitting of hyperfine structures allows us to obtain a modulation-free dispersion-like error signal for frequency stabilization. For the error signal, the dependence of peak-to-peak amplitude and the slope at the zero-crossing point on the magnetic field is studied by simulation and experiment. Based on the result, we obtain an available sub-Doppler DAVLL error signal with high sensitivity to the frequency drift by selecting an appropriate strength of the magnetic field. Ultimately, the fluctuation of the locked laser frequency is confined to below 0.5 MHz in a long term, exhibiting efficient suppression of frequency noise.
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Cord blood C-peptide, insulin, HbA1c, and lipids levels in small- and large-for-gestational-age newborns.
Med. Sci. Monit.
PUBLISHED: 10-31-2014
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Small- and large-for-gestational-age (SGA, LGA) newborns are associated with metabolic syndrome in their later life. Cord blood C-peptide, insulin, glycosylated hemoglobin (HbA1c), and lipids levels may be altered in SGA and LGA newborns; however, the results are conflicting. Therefore, this study aimed to determine the effect of cord blood markers on SGA and LGA newborns.
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A bivalent typhoid live vector vaccine expressing both chromosomal and plasmid-encoded Y. pestis antigens fully protects against murine lethal pulmonary plague infection.
Infect. Immun.
PUBLISHED: 10-22-2014
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Live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. A major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without over-attenuating the live vaccine. Here we have used a live attenuated Salmonella enterica serovar Typhi strain to create a bivalent mucosal plague vaccine that produces both the protective F1 capsular antigen of Yersinia pestis as well as the LcrV protein required for secretion of virulence effector proteins. To reduce metabolic burden associated with the co-expression of F1 and LcrV within the live vector, we balanced expression of both antigens by combining plasmid-based expression of F1 with chromosomal expression of LcrV from three independent loci. The immunogenicity and protective efficacy of this novel vaccine were assessed in mice using a heterologous prime-boost immunization strategy, and compared to a conventional strain in which F1 and LcrV were expressed from a single low copy number plasmid. The serum antibody responses to LPS induced by the optimized bivalent vaccine were indistinguishable from those elicited by the parent strain, suggesting adequate immunogenic capacity maintained through preservation of bacterial fitness; by contrast, LPS titers were 10-fold lower in mice immunized with the conventional vaccine strain. Importantly, mice receiving the optimized bivalent vaccine were fully protected against lethal pulmonary challenge. These results demonstrate the feasibility of distributing foreign antigen expression across both chromosomal and plasmid locations within a single vaccine organism for induction of protective immunity.
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Effects of acetaldehyde and L-carnitine on morphology and enzyme activity of myocardial mitochondria in rats.
Mol. Biol. Rep.
PUBLISHED: 09-02-2014
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This study aimed to investigate the effects of acetaldehyde (AA) and L-carnitine (LC) on morphology and enzyme activity of myocardial mitochondria in rats. Sixty-five Wistar rats were randomly divided into 4 groups: the control group (n = 20), the AA low-dose group (n = 15), the AA high-dose group (n = 15) and the AA + LC group (n = 15). Different doses (110 mg/kg and 220 mg/kg) AA was injected intraperitoneally once a day for 4 weeks. After 4 weeks administration, transmission electron microscope (TEM) observation of morphology of rat myocardial mitochondria was performed. Serum levels of succinate dehydrogenase (SDH), superoxide dismutase (SOD), malondialdehyde (MDA) and cardiac troponin I (cTnI) were detected to evaluate mitochondrial enzymes activities. Light micrograph of rat myocardiocytes in the control group showing normal architecture of myocytes. The numerical density and number of mitochondria in both low-dose and high-dose AA groups were lower than that of the control group. After administration of LC, the rats in the AA + LC group showed an obvious increase in the numerical density and number of mitochondria. TEM showed that both low-dose and high-dose AA could induce myocardial mitochondrial damage in rats in a dose-dependent manner, such as mitochondrial swelling, disruptions of crest and membrane, mitochondrial deficiency. The degree of mitochondrial damage of the AA + LC group was significantly decreased after administration of LC. Our results showed that serum levels of SDH and SOD in the AA + LC and control groups were also higher than those of the low-dose and high-dose AA groups; while the MDA level in the AA + LC and control groups were lower than that of the low-dose and high-dose AA groups. The low-dose AA, high-dose AA and AA + LC groups exhibited a higher level of serum cTnI than that of the control group. However, there was no significant difference in serum cTnI level among the low-dose AA, high-dose AA and AA + LC groups. Our findings indicate that AA may lead to myocardial mitochondrial damage and the induction of enzyme activity in rats, while administration of LC could alleviate AA-related damage of rat myocardial mitochondria.
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Clinical and the prognostic characteristics of lung adenocarcinoma patients with ROS1 fusion in comparison with other driver mutations in East Asian populations.
J Thorac Oncol
PUBLISHED: 08-27-2014
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The prevalence, demographic features, and clinical outcomes of lung adenocarcinoma patients with novel ROS1 oncogenic rearrangement in East Asian populations are not clear. This study aimed to investigate the clinical and prognostic characteristics of lung adenocarcinoma in patients with ROS1 fusion compared with other driver mutations.
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Feature selection for the identification of antitumor compounds in the alcohol total extracts of Curcuma longa.
Planta Med.
PUBLISHED: 08-21-2014
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Antitumor activity has been reported for turmeric, the dried rhizome of Curcuma longa. This study proposes a new feature selection method for the identification of the antitumor compounds in turmeric total extracts. The chemical composition of turmeric total extracts was analyzed by gas chromatography-mass spectrometry (21 ingredients) and high-performance liquid chromatography-mass spectrometry (22 ingredients), and their cytotoxicity was detected through an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against HeLa cells. A support vector machine for regression and a generalized regression neural network were used to research the composition-activity relationship and were later combined with the mean impact value to identify the antitumor compounds. The results showed that six volatile constituents (three terpenes and three ketones) and seven nonvolatile constituents (five curcuminoids and two unknown ingredients) with high absolute mean impact values exhibited a significant correlation with the cytotoxicity against HeLa cells. With the exception of the two unknown ingredients, the identified 11 constituents have been reported to exhibit cytotoxicity. This finding indicates that the feature selection method may be a supplementary tool for the identification of active compounds from herbs.
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Corilagin Protects Against HSV1 Encephalitis Through Inhibiting the TLR2 Signaling Pathways In Vivo and In Vitro.
Mol. Neurobiol.
PUBLISHED: 08-19-2014
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In this study, we tried to explore the molecular mechanism that Corilagin protected against herpes simplex virus-1 encephalitis through inhibiting the TLR2 signaling pathways in vivo and in vitro. As a result, Corilagin significantly prevented increase in the levels of TLR2 and its downstream mediators following Malp2 or HSV-1 challenge. On the other hand, in spite of TLR2 knockdown, Corilagin could still significantly suppress the expression of P38 and NEMO, phosphor-P38, and nuclear factor kappa B. The mRNA and protein expression of TLR2 and its downstream mediators in the brain tissue were also significantly lowered in mice treated with Corilagin. In addition, Corilagin inhibited expression of tumor necrosis factor-? (TNF-?) and interleukin (IL)-6 protein. In conclusion, Corilagin shows the potential to protect against HSV-1-induced encephalitis, and the beneficial effects may be mediated by inhibiting TLR2 signaling pathways.
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LC-MS/MS analysis of Gegen Qinlian Decoction and its pharmacokinetics after oral administration to rats.
Biomed. Chromatogr.
PUBLISHED: 08-18-2014
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A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of 12 constituents of Gegen Qinlian Decoction (GQD), namely puerarin, daidzein, baicalin, wogonoside, wogonin, liquiritin, liquiritigenin, berberine, jatrorrhizine, palmatine, coptisine and glycyrrhetic acid, in rat plasma. The plasma samples were spiked with the internal standard (IS) carbamazepine acidified with HCl and extracted by liquid-liquid extraction with ethyl acetate. Chromatographic separation was achieved on a Shiseido Capcell PAK C18 column utilizing a gradient elution profile and a mobile phase consisting of (A) 0.1% formic acid in water and (B) acetonitrile. Detection was performed in the multiple reaction monitoring mode using electrospray ionization in the positive ion mode at a flow rate of 0.3?mL/min and a run time of 8?min. All of the calibration curves gave good linearity (r?>?0.9930) over the concentration range from 0.6-360 to 16.2-9720?ng/mL for all components. The intra- and inter-day precisions were <15.0% in terms of the relative standard deviation, and the accuracies were within ±13.7% in terms of the relative error. The method was successfully applied to investigate the pharmacokinetics of the major active compounds of Gegen Qinlian Decoction after its oral administration to rats. Copyright © 2014 John Wiley & Sons, Ltd.
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Effect of Vestibulosympathetic Reflex and Baroreflex on Expression of pERK in the Nucleus Tractus Solitarius following Acute Hypotension in Conscious Rats.
Korean J. Physiol. Pharmacol.
PUBLISHED: 08-13-2014
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Control of blood pressure is maintained by the interaction between the arterial baroreflex and vestibulosympathetic reflex during postural changes. In this study, the contributions of vestibular receptors and baroreceptors to the maintenance of blood pressure following acute hypotension were compared in terms of phosphorylated extracellular regulated protein kinase (pERK) expression in the nucleus tractus solitaries (NTS). Expression of pERK in the NTS was measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or sinoaortic denervation (SAD) 5, 10, 20, and 40 min following acute hypotension induced by sodium nitroprusside (SNP) infusion. Expression of pERK increased significantly in the NTS in the control group following SNP infusion, and the expression peaked at 10 min after SNP infusion. The number of pERK positive neurons increased following SNP infusion in BL, SAD, and BL+SAD groups, although the increase was smaller than in control group. The BL group showed a relatively higher reduction in pERK expression than the SAD group, and the pERK expression in the NTS was localized to the caudal portion of the nuclei in the BL and SAD groups. These results suggest that the vestibular receptors may play a key role in maintaining blood pressure following acute hypotension; thus, the vestibular system may contribute to compensate for orthostatic hypotension.
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ABCB1 C3435T polymorphism and the risk of ischemic heart disease: a meta-analysis.
Genet Test Mol Biomarkers
PUBLISHED: 08-13-2014
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ATP binding cassette transporter 1 (ABCB1) plays a critical role in the development and progression of cardiovascular disease. Emerging evidence suggests that common functional polymorphisms in the ABCB1 gene might have an impact on an individual's susceptibility to ischemic heart disease, but individually published results are inconclusive. The MEDLINE (1966-2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980-2013), CINAHL (1982-2013), Web of Science (1945-2013), and the Chinese Biomedical Database (CBM; 1982-2013) were searched without language restrictions. Meta-analysis was performed with the use of the STATA statistical software. Odds ratios (OR) with their 95% confidence intervals (95% CIs) were calculated. Seven case-control studies with a total of 2310 myocardial infarction (MI) patients and 10,506 acute coronary syndrome (ACS) patients met the inclusion criteria. Our meta-analysis results indicated that ABCB1 C3435T polymorphism may be associated with an increased risk of MI and ACS, especially among Asian populations (T allele vs. C allele: OR=1.40, 95% CI=1.31-1.49, ph=0.058). Meta-regression analyses showed that clinical subtype and ethnicity may be the main sources of heterogeneity (T allele vs. C allele: OR=1.16, 95% CI=0.97-1.37, ph=0.036). Our findings provide empirical evidence that ABCB1 C3435T polymorphism may contribute to the risk of MI and ACS, especially among Caucasian populations. Thus, detection of ABCB1 C3435T polymorphism may be a promising biomarker for the early detection of MI and ACS.
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A murine model of neurofibromatosis type 2 that accurately phenocopies human schwannoma formation.
Hum. Mol. Genet.
PUBLISHED: 08-11-2014
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Neurofibromatosis type 2 (NF2) is an autosomal dominant genetic disorder resulting from germline mutations in the NF2 gene. Bilateral vestibular schwannomas, tumors on cranial nerve VIII, are pathognomonic for NF2 disease. Furthermore, schwannomas also commonly develop in other cranial nerves, dorsal root ganglia and peripheral nerves. These tumors are a major cause of morbidity and mortality, and medical therapies to treat them are limited. Animal models that accurately recapitulate the full anatomical spectrum of human NF2-related schwannomas, including the characteristic functional deficits in hearing and balance associated with cranial nerve VIII tumors, would allow systematic evaluation of experimental therapeutics prior to clinical use. Here, we present a genetically engineered NF2 mouse model generated through excision of the Nf2 gene driven by Cre expression under control of a tissue-restricted 3.9kbPeriostin promoter element. By 10 months of age, 100% of Postn-Cre; Nf2(flox/flox) mice develop spinal, peripheral and cranial nerve tumors histologically identical to human schwannomas. In addition, the development of cranial nerve VIII tumors correlates with functional impairments in hearing and balance, as measured by auditory brainstem response and vestibular testing. Overall, the Postn-Cre; Nf2(flox/flox) tumor model provides a novel tool for future mechanistic and therapeutic studies of NF2-associated schwannomas.
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A genome-wide identification of genes undergoing recombination and positive selection in Neisseria.
Biomed Res Int
PUBLISHED: 08-10-2014
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Currently, there is particular interest in the molecular mechanisms of adaptive evolution in bacteria. Neisseria is a genus of gram negative bacteria, and there has recently been considerable focus on its two human pathogenic species N. meningitidis and N. gonorrhoeae. Until now, no genome-wide studies have attempted to scan for the genes related to adaptive evolution. For this reason, we selected 18 Neisseria genomes (14 N. meningitidis, 3 N. gonorrhoeae and 1 commensal N. lactamics) to conduct a comparative genome analysis to obtain a comprehensive understanding of the roles of natural selection and homologous recombination throughout the history of adaptive evolution. Among the 1012 core orthologous genes, we identified 635 genes with recombination signals and 10 genes that showed significant evidence of positive selection. Further functional analyses revealed that no functional bias was found in the recombined genes. Positively selected genes are prone to DNA processing and iron uptake, which are essential for the fundamental life cycle. Overall, the results indicate that both recombination and positive selection play crucial roles in the adaptive evolution of Neisseria genomes. The positively selected genes and the corresponding amino acid sites provide us with valuable targets for further research into the detailed mechanisms of adaptive evolution in Neisseria.
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An internet-based epidemiological investigation of the outbreak of H7N9 Avian Influenza a in China since early 2013.
J. Med. Internet Res.
PUBLISHED: 08-08-2014
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In early 2013, a new type of avian influenza, H7N9, emerged in China. It quickly became an issue of great public concern and a widely discussed topic on the Internet. A considerable volume of relevant information was made publicly available on the Internet through various sources.
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Bcl-2-like protein 11 deletion polymorphism predicts survival in advanced non-small-cell lung cancer.
J Thorac Oncol
PUBLISHED: 07-25-2014
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Germline Bcl-2-like protein 11 (BIM) deletion polymorphism in Asian is a poor predictive factor for treatment outcomes to tyrosine kinase inhibitors (TKIs) in malignancies. We explored the impact of BIM deletion polymorphism on treatment outcome of advanced non-small-cell lung cancer (NSCLC).
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LC-MS/MS determination and pharmacokinetics study of puerarin and daidzein in rat plasma after oral administration of Gegenqinlian decoction and Radix Puerariae extract.
Pharmacogn Mag
PUBLISHED: 07-24-2014
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Gegenqinlian decoction (GQD) is a famous traditional medicine recipe. It is composed of four herbs including Radix Puerariae (GG), Radix Scutellariae (HQ), Rhizoma Coptidis (HL) and Radix Glycyrrhizae (GC), which is widely used for treating gastro-intestinal disorders in the clinical practice of Traditional Chinese medicine (TCM). The aim of this study was to compare the pharmacokinetics of puerarin and daidzein in rats following oral administration of Gegenqinlian Decoction and Radix Puerariae extract. Thus, a sensitive and selective liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous determination of puerarin and daidzein in rat plasma following oral administration of Gegenqinlian Decoction and Radix Puerariae extract.
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TGF-? regulates the proliferation of lung adenocarcinoma cells by inhibiting PIK3R3 expression.
Mol. Carcinog.
PUBLISHED: 07-23-2014
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PIK3R3, an isoform of class IA phosphoinositide 3-kinase (PI3K), specifically interacts with cell proliferation regulators, such as retinoblastoma and proliferation cell nuclear antigen, to promote cell proliferation. However, the mechanisms behind the upstream signaling pathway of PIK3R3 remain unclear to date. This study showed that PIK3R3 expression was regulated by transforming growth factor-? (TGF-?) signaling and that PIK3R3 mediated the TGF-?-induced inhibition of lung adenocarcinoma cell proliferation. TGF-? down-regulated PIK3R3 expression in lung adenocarcinoma cells. However, this TGF-?-induced inhibition of cell proliferation can be attenuated by PIK3R3 overexpression. In addition, TGF-? can attenuate the transcriptional activity of NKX2.1, a transcription factor that binds to the promoter of PIK3R3. This result indicated that TGF-? regulated PIK3R3 expression by targeting NKX2.1. We confirmed the correlation between NKX2.1 and PIK3R3 in clinical samples. Therefore, the TGF-?/NKX2.1/PIK3R3 axis is crucial in the TGF-?-induced inhibition of cell proliferation, and the NKX2.1/PIK3R3 axis might become a target in TGF-? receptor-repressed lung adenocarcinoma. © 2014 Wiley Periodicals, Inc.
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Organ transplantation from donors (cadaveric or living) with a history of malignancy: review of the literature.
Transplant Rev (Orlando)
PUBLISHED: 07-23-2014
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The evolution of organ transplantation has resulted in extended lifespan as well as better life quality of patients with end-stage diseases, which in turn causes an increased demand for organs. The persistent organ shortage requires a careful reconsideration of potential donors (living or cadaveric) that have current or historical malignancies. Donors with low-grade skin tumors, carcinomas in situ of the uterine cervix, and primary central nervous system (CNS) tumors can be considered as potential donors for recipients dying on wait list longing for organ transplantation. Recently, transplant centers have turned to other types of malignancies including low grade renal cell carcinoma, prostate, ureteral, endometrial and breast cancer, and favorable outcomes have been shown in such innovations. When considering donors with a history of malignancy, general biologic behavior of the tumor type, histology and stage at the time of diagnosis, and the length of disease-free interval should be considered (Transplantation 2002;74(12):1657-1663). With the review of literatures, we illustrate the organ utilization from donors with malignancies all around the world since earlier times and give some suggestions for decision making under the circumstance of whether to choose those marginal donors or not on the basis of reviewed literatures.
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Synthetic microbial consortia: from systematic analysis to construction and applications.
Chem Soc Rev
PUBLISHED: 07-14-2014
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Synthetic biology is an emerging research field that focuses on using rational engineering strategies to program biological systems, conferring on them new functions and behaviours. By developing genetic parts and devices based on transcriptional, translational, post-translational modules, many genetic circuits and metabolic pathways had been programmed in single cells. Extending engineering capabilities from single-cell behaviours to multicellular microbial consortia represents a new frontier of synthetic biology. Herein, we first reviewed binary interaction modes of microorganisms in microbial consortia and their underlying molecular mechanisms, which lay the foundation of programming cell-cell interactions in synthetic microbial consortia. Systems biology studies on cellular systems enable systematic understanding of diverse physiological processes of cells and their interactions, which in turn offer insights into the optimal design of synthetic consortia. Based on such fundamental understanding, a comprehensive array of synthetic microbial consortia constructed in the last decade were reviewed, including isogenic microbial communities programmed by quorum sensing-based cell-cell communications, sender-receiver microbial communities with one-way communications, and microbial ecosystems wired by two-way (bi-directional) communications. Furthermore, many applications including using synthetic microbial consortia for distributed bio-computations, chemicals and bioenergy production, medicine and human health, and environments were reviewed. Synergistic development of systems and synthetic biology will provide both a thorough understanding of naturally occurring microbial consortia and rational engineering of these complicated consortia for novel applications.
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Low-magnitude high-frequency loading, by whole-body vibration, accelerates early implant osseointegration in ovariectomized rats.
Mol Med Rep
PUBLISHED: 07-04-2014
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Osteoporosis deteriorates jaw bone quality and may compromise early implant osseointegration and early implant loading. The influence of low?magnitude, high?frequency (LMHF) vibration on peri?implant bone healing and implant integration in osteoporotic bones remains poorly understood. LMHF loading via whole?body vibration (WBV) for 8 weeks has previously been demonstrated to significantly enhance bone?to?implant contact, peri?implant bone fraction and implant mechanical properties in osteoporotic rats. In the present study, LMHF loading by WBV was performed in osteoporotic rats, with a loading duration of 4 weeks during the early stages of bone healing. The results indicated that 4?week LMHF loading by WBV partly reversed the negative effects of osteoporosis and accelerated early peri?implant osseointegration in ovariectomized rats.
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Dissection of the mechanism of traditional Chinese medical prescription-Yiqihuoxue formula as an effective anti-fibrotic treatment for systemic sclerosis.
BMC Complement Altern Med
PUBLISHED: 06-30-2014
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Systemic sclerosis (SSc) is a connective tissue fibrotic disease for which there is no effective treatment. Traditional Chinese Medicine (TCM), such as the Yiqihuoxue formula used in Shanghai TCM-integrated Hospital, has shown the efficacy of anti-fibrosis in clinical applications. This study was aiming to dissect the anti-fibrotic mechanism of Yiqihuoxue treatment for SSc.
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Transarterial chemoembolization combined with sorafenib for unresectable hepatocellular carcinoma: a systematic review and meta-analysis.
Mol. Biol. Rep.
PUBLISHED: 06-19-2014
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Sorafenib in combination with Transarterial chemoembolization (TACE) is increasingly used in patients with unresectable hepatocellular carcinoma (HCC), but the current evidence is still controversial. The aim of this systematic review was to evaluate the effectiveness and safety of TACE plus sorafenib versus TACE alone for unresectable HCC. We searched PubMed, EMBASE and the Cochrane Library for clinical trials comparing TACE plus sorafenib with TACE alone for unresectable HCC. The study outcomes included overall survival (OS), time to progression (TTP), objective response and adverse events (AEs). Six studies including 1,181 patients were included. Meta-analysis of all studies suggested that the combination therapy group had significant longer OS than TACE group [hazard ratio (HR) = 0.64, 95 % confidence interval (CI) = 0.43-0.97], but the pooled HR of randomized controlled trials (RCTs) failed to achieve statistical significance. For TTP, meta-analysis in both RCTs subgroup and retrospective studies subgroup suggested that combination therapy was superior to TACE group. The combination therapy was also associated with better response to treatment (risk ratio = 1.45, 95 % CI = 1.04-2.02) when both RCTs and retrospective studies were pooled. However, the sorafenib associated AEs were more frequent in the combination therapy group. In conclusion, the combination of TACE and sorafenib is likely to improve OS, TTP and response to treatment when compared with TACE monotherapy. The combination group is also associated with more sorafenib-related AEs.
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RADOM, an Efficient In Vivo Method for Assembling Designed DNA Fragments up to 10 kb Long in Saccharomyces cerevisiae.
ACS Synth Biol
PUBLISHED: 06-05-2014
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We describe rapid assembly of DNA overlapping multifragments (RADOM), an improved assembly method via homologous recombination in Saccharomyces cerevisiae, which combines assembly in yeasto with blue/white screening in Escherichia coli. We show that RADOM can successfully assemble ?3 and ?10 kb DNA fragments that are highly similar to the yeast genome rapidly and accurately. This method was tested in the Build-A-Genome course by undergraduate students, where 125 ?3 kb "minichunks" from the synthetic yeast genome project Sc2.0 were assembled. Here, 122 out of 125 minichunks achieved insertions with correct sizes, and 102 minichunks were sequenced verified. As this method reduces the time-consuming and labor-intensive efforts of yeast assembly by improving the screening efficiency for correct assemblies, it may find routine applications in the construction of DNA fragments, especially in hierarchical assembly projects.
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Pathogenicity and genomic characterization of a pseudorabies virus variant isolated from Bartha-K61-vaccinated swine population in China.
Vet. Microbiol.
PUBLISHED: 05-22-2014
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Pseudorabies (PR) or Aujeszky's disease (AD), caused by pseudorabies virus (PRV), is an economically important viral disease worldwide. Recently, PR outbreaks occurred in a large number of Bartha-K61-vaccinated swine herds in many regions of China. Here, we isolated a PRV variant, named TJ strain, from a Bartha-K61-vaccinated pig farm in China, evaluated the pathogenicity of the TJ strain in susceptible animals and analyzed its complete genomic sequence obtained by 454 pyrosequencing. Vaccination-challenge experiment in sheep showed that the classical Bartha-K61 vaccine could not provide complete protection against the challenge with the PRV TJ strain. In mice, the 50% lethal dose (LD50) of the TJ strain (10(2.3) TCID50) was lower than that of the classical PRV SC strain (10(3.0) TCID50). Furthermore, the TJ strain displayed higher mortality for pigs, as compared with the SC strain. The PRV TJ strain genome was determined to be 143,642bp in length, encoding 67 open reading frames. The TJ strain was clustered to an independent branch together with some recent PRV isolates in China in the phylogenetic tree, which was relatively distant from previous PRV isolates. The TJ strain showed unique variations in the viral proteins that play key roles in the viral replication cycle. Taken together, the TJ strain is a highly pathogenic PRV variant with unique molecular signatures. Further studies are needed to explore the relevance of the sequence differences to the virulence alteration of the PRV variant.
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Assessment of immune cells and function of the residual spleen after subtotal splenectomy due to splenomegaly in cirrhotic patients.
BMC Immunol.
PUBLISHED: 05-15-2014
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BackgroundThe spleen is thought to be central in regulating the immune system, a metabolic asset involved in endocrine function. Overwhelming postsplenectomy infection leads to a mortality rate of up to 50%. However, there is still controversy on performing subtotal splenectomy as treatment of splenomegaly due to portal hypertension in cirrhotic patients. In the present study, immunocytes and the indexes of splenic size, hemodynamics, hematology and immunology in the residual spleen were analyzed to support subtotal splenectomy due to splenomegaly.ResultsIn residual spleen, T lymphocytes mainly were focal aggregation in the periarterial lymphatic sheath. While B lymphocytes densely distributed in splenic corpuscle. In red pulp, macrophages were equally distributed in the splenic cord and adhered to the wall of splenic sinus with high density. The number of unit area T and B lymphocytes of splenic corpuscle and marginal zone as well as macrophages of red pulp were obviously increased in the residual spleen, while the number of macrophages didn¿t be changed among the three groups in white pulp. While there were some beneficial changes (i.e., Counts of platelet and leucocyte as well as serum proportion of CD3+ T cells, CD4+ T cells, CD8+ T cells were increased markedly; serum levels of M-CSF and GM-CSF were decreased significantly; The proportion of granulocyte, erythrocyte, megakaryocyte in bone marrow were changed obviously; But serum IgA, IgM, IgG, Tuftsin level, there was no significant difference; splenic artery flow volume, portal venous diameter and portal venous flow volume, a significant difference was observed in residual spleen) in the clinical indices.ConclusionAfter subtotal splenectomy with splenomegaly due to portal hypertension in cirrhotic patients, the number of unit area T and B lymphocytes, and MØ in red pulp of residual spleen increased significantly. However, whether increase of T, B lymphocytes and MØs in residual splenic tissue can enhance the immune function of the spleen, still need further research to confirm.
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JSI124 inhibits breast cancer cell growth by suppressing the function of B cells via the downregulation of signal transducer and activator of transcription 3.
Oncol Lett
PUBLISHED: 05-13-2014
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JSI-124, also known as cucurbitacin I, is a selective inhibitor of Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3), and in vitro and in vivo studies have found that it has anti-tumor and anti-proliferative properties. However, the role of JSI124 in tumor-associated B cells has yet to be elucidated. The present study demonstrated that STAT3 is significantly activated in the B cells of patients with breast cancer. Furthermore, a 4T1 tumor-bearing mouse model revealed that JSI124 effectively inhibited tumor growth. Moreover, the STAT3 levels in the B cells of the JSI124-treated mice were found to be significantly decreased. B cells from normal Balb/c mice, the 4T1-bearing mice and the JSI124-treated 4T1 mice were purified and intravenously injected into the 4T1-bearing Balb/c mice. Tumor growth data showed that the 4T1 tumor mouse-derived B cells, which exhibited a higher level of STAT3, promoted tumor growth, while the JSI124-treated 4T1 mouse-derived B cells had a tumor suppressor function. Furthermore, the B cells from the normal Balb/c mice were treated with phosphate-buffered saline, JSI124 and 4T1 tumor cells, then the B cell STAT3 levels were analyzed. Following injection into the 4T1 mice, the 4T1 cell-treated B cells were observed to enhance tumor growth, while the JSI124-treated B cells were found to inhibit the growth of 4T1 tumors in vivo. These findings show a novel role of JSI124 in tumor suppression through the downregulation of the expression of STAT3 in tumor-associated B cells.
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Simultaneous saccharification and co-fermentation of aqueous ammonia pretreated corn stover with an engineered Saccharomyces cerevisiae SyBE005.
Bioresour. Technol.
PUBLISHED: 05-07-2014
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Co-fermentation of glucose and xylose from lignocelluloses is an efficient approach to increasing ethanol production. Simultaneous saccharification and co-fermentation (SSCF) of corn stover pretreated with aqueous ammonia was performed using engineered yeast with xylose utilization pathway. Thus far, the effect of the several key factors on SSCF was investigated, including temperature, inoculation size, pre-hydrolysis and pH. Ethanol concentration was achieved to 36.5 g/L during SSCF process with 6% glucan loading. The addition of Tween 20 reduced enzyme loading, i.e., from 15 to 7.5 FPU/gglucan with the same final ethanol concentration. The ethanol concentration was achieved to 70.1g/L at 12% glucan loading. Yeast feeding, combined with substrate and enzyme feeding, was proved to be an efficient approach for SSCF with high solid loading.
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FCGR3B copy number loss rather than gain is a risk factor for systemic lupus erythematous and lupus nephritis: a meta-analysis.
Int J Rheum Dis
PUBLISHED: 03-29-2014
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Some studies have been performed to elucidate the association between Fc gamma receptor 3B (FCGR3B) copy number (CN) and the risk of systemic lupus erythematosus (SLE) and/or lupus nephritis (LN), yet the results remain conflicting. Therefore, we have undertaken a systematic review of all the studies published and carried out a meta-analysis to obtain a better understanding of the role of FCGR3B CN in the susceptibility of SLE and LN.
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Regulation of extracellular oxidoreduction potential enhanced (R,R)-2,3-butanediol production by Paenibacillus polymyxa CJX518.
Bioresour. Technol.
PUBLISHED: 03-25-2014
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Cellular redox status and oxygen availability influence the product formation. Herein, decreasing agitation speed or adding vitamin C (Vc) achieved the 2,3-BDL yield of 0.40 g g(-1) or 0.39 g g(-1)glucose under batch fermentation, respectively. To our knowledge, this is the highest 2,3-BDL yield reported so far for Paenibacillus polymyxa without adding acetic acid. The NADH/NAD(+) ratio and 2,3-BDL titer could be increased significantly by reducing the agitation speed or adding Vc, indicating that the enhancement of 2,3-BDL is closely associated with the adjustment of NADH/NAD(+) ratio. Especially, Vc addition elevated the 2,3-BDL titer from 43.66 g L(-1) to 71.71 g L(-1) within 54 h under fed-batch fermentation. This is the highest titer of 2,3-BDL so far reported for P. polymyxa from glucose fermentation. This work provides a new strategy to improve 2,3-BDL production and helps us to understand the responses of P. polymyxa to extracellular oxidoreduction potential.
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Identification of active VQ motif-containing genes and the expression patterns under low nitrogen treatment in soybean.
Gene
PUBLISHED: 03-20-2014
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Plant VQ motif-containing protein family plays crucial roles in plant growth, seed development, and defense responses in Arabidopsis. However, its function in soybean is still not well defined. We aim to identify the VQ gene family, and explore the genetic variation of active GmVQ genes in soybean and their expression patterns under low nitrogen stresses. A total of 74 VQ motif-containing genes were identified in soybean genome, and were clustered into five distinct subfamilies (GmVQI-V) with each gene having two or three copies except GmVQ55 (GmVQIV) with single copy. Fourteen genes with relatively high expression level, at least in one tissue, were defined as active GmVQ genes. Most of these active GmVQ genes specifically expressed in soybean pod shell (7/74), root (9/74) and/or nodule (10/74) respectively. Single nucleotide polymorphism (SNP) analysis in cultivated and wild soybeans revealed there were selected site(s) in GmVQ6, GmVQ7, GmVQ10, GmVQ26 and GmVQ61, which means that these genes have undergone artificial selection during soybean domestication. After low nitrogen treatment, enhanced expression of VQ genes was noticed in specific tissues, such as GmVQ53, GmVQ26, GmVQ58, GmVQ61, GmVQ70 and GmVQ6 in shoot, and GmVQ53, GmVQ58, GmVQ48 in root. On the contrary, suppressed expression of GmVQ57, GmVQ21 and GmVQ1 genes was noticed in root after the treatment. Duplicated copy of the active GmVQ genes showed similar expression pattern, suggesting that these genes might be complete copies. The results suggested that soybean VQ-motif containing genes may act as positive or negative regulators in soybean growth, development and nitrogen metabolism. Taken together, our results provided useful information for functional characterization of soybean GmVQ genes to unravel their biological roles.
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Comparison of deep anterior lamellar keratoplasty and penetrating keratoplasty with respect to postoperative corneal sensitivity and tear film function.
Graefes Arch. Clin. Exp. Ophthalmol.
PUBLISHED: 03-18-2014
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To investigate tear film function, central and peripheral corneal sensitivity and corneal subbasal nerve morphology in the cornea after deep anterior lamellar keratoplasty (DALK) compared with penetrating keratoplasty (PK).
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OM85-BV induced the productions of IL-1?, IL-6, and TNF-? via TLR4- and TLR2-mediated ERK1/2/NF-?B pathway in RAW264.7 cells.
J. Interferon Cytokine Res.
PUBLISHED: 03-07-2014
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Broncho-Vaxom (OM85-BV) is an extract mixture from 8 strains of Gram(+) and Gram(-) bacteria and plays an important role in anti-infection immune response by regulating macrophage activity and cytokine productions. However, the mechanism by which OM85-BV enhances the cytokine expression is still obscure. In this study, we evaluated the effects of OM85-BV on the productions of interleukin (IL)-1?, IL-6, and tumor necrosis factor-? (TNF-?) in RAW264.7 murine macrophages. Exposure of RAW264.7 cells to 100 ?g/mL OM85-BV upregulated the expression of IL-1?, IL-6, and TNF-? at the mRNA and protein levels in a time- and dose-dependent manner. In addition, OM85-BV induced extracellular signal-regulated kinase (ERK) 1/2 and nuclear factor-kappa B (NF-?B) phosphorylation. Pretreatment with U0126 or Bay11-7082, respectively, could decrease IL-1?, IL-6, and TNF-? productions induced by OM85-BV. Application of Toll-like receptor (TLR) 4 or TLR2 small-interfering RNA (siRNA) into RAW264.7 cells could inhibit the productions of cytokines and ERK1/2 and NF-?B phosphorylation induced by OM85-BV. Consistent with this, downregulating either myeloid differentiation factor 88 (MyD88) or TRIF-related adaptor molecule (TRAM) gene with MyD88-siRNA or TRAM-siRNA separately could reduce the productions of cytokines and ERK1/2 and NF-?B phosphorylation induced by OM85-BV. Our study demonstrated that the productions of IL-1?, IL-6, and TNF-? induced by OM85-BV in RAW264.7 cells were through TLR4 and TLR2 signaling pathway-mediated activation of ERK1/2 and NF-?B.
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Advanced non-small cell lung cancer in the elderly: The impact of age and comorbidities on treatment modalities and patient prognosis.
J Geriatr Oncol
PUBLISHED: 02-20-2014
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Data on the treatment modalities and prognostic factors for elderly patients with advanced non-small cell lung cancer (NSCLC) remain limited. This study investigates the impact of age and comorbidities on treatment modalities and patient prognosis.
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Exceptional temperature-dependent coordination sites from acylamide groups.
Dalton Trans
PUBLISHED: 02-12-2014
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Herein, through altering the reaction temperature, the coordination mode of the acylamide ligand is well controlled with or without the oxygen coordination site. The resulting two new coordination polymers have the formulas Cd3(L)2(bdc)3·4(H2O) (1) and Cd(L)(bdc)·2(H2O) (2) (L = N(1),N(4)-bis(pyridin-3-ylmethyl)terephthalamide, H2bdc = terephthalic acid).
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The role of noncoding regions of classical swine fever virus C-strain in its adaptation to the rabbit.
Virus Res.
PUBLISHED: 02-06-2014
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Classical swine fever (CSF) is a devastating disease of swine caused by classical swine fever virus (CSFV). C-strain, a modified live vaccine against CSF, was developed through hundreds of passages of a highly virulent CSFV in the rabbit in China in the mid-1950s. To identify the role of noncoding regions (NCRs) of C-strain in its adaptation to the rabbit, we generated and evaluated a series of chimeric viruses derived from C-strain and the highly virulent Shimen strain. The results demonstrated that the NCRs of the C-strain were essential for its fever induction in rabbits and the coding region but not NCRs was necessary for its replication in the spleen of rabbits.
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A novel gE-deleted pseudorabies virus (PRV) provides rapid and complete protection from lethal challenge with the PRV variant emerging in Bartha-K61-vaccinated swine population in China.
Vaccine
PUBLISHED: 01-30-2014
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The currently used Bartha-K61 strain is a very safe and effective vaccine against pseudorabies (PR) and has played a critical role in the control and eradication of PR worldwide. Since late 2011, however, PR reemerged among Bartha-K61-vaccinated pig population in many regions in China. Our previous studies demonstrated that the Bartha-K61 vaccine was unable to provide complete protection from the challenge with the PRV TJ strain (PRVTJ), a representative emerging PRV variant that was isolated from a Bartha-K61-immunized pig farm in Tianjin, China. Here, we generated a gE-deleted PRV, named as rPRVTJ-delgE, based on PRVTJ and evaluated its safety and immunogenicity in pigs. Our results showed that groups of piglets (n=5) immunized with 10(3), 10(4) or 10(5)TCID50 rPRVTJ-delgE did not exhibit clinical signs following immunization and challenge and were protected clinically and virologically from the lethal challenge with PRVTJ as early as 1 week post-immunization, in contrast with the incomplete protection provided by the Bartha-K61 vaccine. These indicate that rPRVTJ-delgE is a promising candidate vaccine for updating Bartha-K61 for the control of the currently epidemic PR in China.
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Galectin-9 ameliorates anti-GBM glomerulonephritis by inhibiting Th1 and Th17 immune responses in mice.
Am. J. Physiol. Renal Physiol.
PUBLISHED: 01-29-2014
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Antiglomerular basement membrane glomerulonephritis (anti-GBM GN) is a Th1- and Th17-predominant autoimmune disease. Galectin-9 (Gal-9), identified as the ligand of Tim-3, functions in diverse biological processes and leads to the apoptosis of CD4(+)Tim-3(+) T cells. It is still unclear how Gal-9 regulates the functions of Th1 and Th17 cells and prevents renal injury in anti-GBM GN. In this study, Gal-9 was administered to anti-GBM GN mice for 7 days. We found that Gal-9 retarded the increase of Scr, ameliorated renal tubular injury, and reduced the formation of crescents. The infiltration of Th1 and Th17 cells into the spleen and kidneys significantly decreased in Gal-9-treated nephritic mice. The reduced infiltration of Th1 and Th17 cells might be associated with the downregulation of CCL-20, CXCL-9, and CXCL-10 mRNAs in the kidney. In parallel, the blood levels of IFN-? and IL-17A declined in Gal-9-treated nephritic mice at days 21 and 28. In addition, an enhanced Th2 cell-mediated immune response was observed in the kidneys of nephritic mice after a 7-day injection of Gal-9. In conclusion, the protective role of Gal-9 in anti-GBM GN is associated with the inhibition of Th1 and Th17 cell-mediated immune responses and enhanced Th2 immunity in the kidney.
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SELP genetic polymorphisms may contribute to the pathogenesis of coronary heart disease and myocardial infarction: a meta-analysis.
Mol. Biol. Rep.
PUBLISHED: 01-25-2014
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We conducted a meta-analysis of case-control studies to determine whether SELP genetic polymorphisms contribute to the pathogenesis of coronary heart disease (CHD) and myocardial infarction (MI). A range of electronic databases were searched: MEDLINE (1966-2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980-2013), CINAHL (1982-2013), Web of Science (1945-2013) and the Chinese biomedical database (1982-2013) without language restrictions. Meta-analysis was performed with the use of the STATA statistical software. Nine case-control studies with a total of 3,154 CHD patients, 1,608 MI patients and 17,304 healthy controls were involved in this meta-analysis. Six common polymorphisms in the SELE gene were assessed, including -1969G/A (rs1800805 G>A), -1817T/C (rs1800808 T>C), -2123C/G (rs1800807 C>G), Thr715Pro (rs6136 A>C), Leu599Val (rs6133 G>T), and Ser290Asn (rs6131 C>T). Our findings illustrated significantly positive associations of SELE genetic polymorphisms with the development of CHD and MI. The results of subgroup analysis by SNP type indicated that -1969G/A, -1817T/C, -2123C/G, Thr715Pro and Ser290Asn in the SELP gene might be strongly correlated with CHD and MI risk, but no similar results were found in SELP Leu599Val polymorphism. In the subgroup analysis by ethnicity, our results indicated significant relationships between SELE genetic polymorphisms and the pathogenesis of CHD and MI among Asians and Caucasians. However, we observed no significant associations between SELP genetic polymorphisms and the risk of CHD and MI among Africans. Our findings provide empirical evidence that SELE genetic polymorphisms may contribute to the pathogenesis of CHD and MI, especially among Asians and Caucasians. Thus, SELP genetic polymorphisms could be potential and practical biomarkers for early diagnosis of CHD and MI.
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Proteomic analysis reveals complex metabolic regulation in Saccharomyces cerevisiae cells against multiple inhibitors stress.
Appl. Microbiol. Biotechnol.
PUBLISHED: 01-19-2014
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Toxic compounds including acids, furans, and phenols (AFP) were generated from the pretreatment of lignocellulose. We cultivated Saccharomyces cerevisiae cells in a batch mode, besides the cell culture of original yeast strain in AFP-free medium which was referred as C0, three independent subcultures were cultivated under multiple inhibitors AFP and were referred as C1, C2, and C3 in time sequence. Comparing to C0, the cell density was lowered while the ethanol yield was maintained stably in the three yeast cultures under AFP stress, and the lag phase of C1 was extended while the lag phases of C2 and C3 were not extended. In proteomic analysis, 194 and 215 unique proteins were identified as differently expressed proteins at lag phase and exponential phase, respectively. Specifically, the yeast cells co-regulated protein folding and protein synthesis process to prevent the generation of misfolded proteins and to save cellular energy, they increased the activity of glycolysis, redirected metabolic flux towards phosphate pentose pathway and the biosynthesis of ethanol instead of the biosynthesis of glycerol and acetic acid, and they upregulated several oxidoreductases especially at lag phase and induced programmed cell death at exponential phase. When the yeast cells were cultivated under AFP stress, the new metabolism homeostasis in favor of cellular energy and redox homeostasis was generated in C1, then it was inherited and optimized in C2 and C3, enabling the yeast cells in C2 and C3 to enter the exponential phase in a short period after inoculation, which thus significantly shortened the fermentation time.
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Comparative analysis of vestibular receptor and baroreceptor inputs to the nucleus tractus solitarius following acute hypotension in conscious rats.
Neurosci. Lett.
PUBLISHED: 01-14-2014
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Blood pressure is maintained by the interaction between the arterial baroreflexes and the vestibulo-cardiovascular reflexes during postural changes. In this study, the influence of the vestibular receptors on the maintenance of blood pressure following acute hypotension was quantitatively compared with the role of baroreceptors in terms of c-Fos protein expression in the nucleus tractus solitarius (NTS). Expression of c-Fos protein in the NTS was measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or sinoaortic denervation (SAD). Expression of c-Fos protein increased significantly in the NTS in the sham group after sodium nitroprusside (SNP) administration. However, the BL, SAD, and SAD+BL groups showed significant decreases in c-Fos protein expression compared to that of the sham group. The SAD group showed relatively more reduction in c-Fos protein expression than the BL group, and the SAD+BL group showed the least expression among the three experimental groups. The c-Fos protein expression in the NTS following acute hypotension was localized to the caudal portions of the nuclei in the BL and SAD groups. These results suggest that the role of vestibular receptors in maintaining blood pressure following acute hypotension is less potent than that of the baroreceptors but more potent than other afferent inputs in conscious rats. In addition, afferent signals for maintaining blood pressure originating from the vestibular receptors and the baroreceptors may converge in the caudal portion of the NTS.
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Comparative metabolic profiling revealed limitations in xylose-fermenting yeast during co-fermentation of glucose and xylose in the presence of inhibitors.
Biotechnol. Bioeng.
PUBLISHED: 01-10-2014
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During lignocellulosic ethanol fermentation, yeasts are exposed to various lignocellulose-derived inhibitors, which disrupt the efficiency of hexose and pentose co-fermentation. To understand the metabolic response of fermentation microbes to these inhibitors, a comparative metabolomic investigation was performed on a xylose-fermenting Saccharomyces cerevisiae 424A (LNH-ST) and its parental strain 4124 with and without three typical inhibitors (furfural, acetic acid, and phenol). Three traits were uncovered according to fermentation results. First, the growth of strain 424A (LNH-ST) was more sensitive to inhibitors than strain 4124. Through metabolomic analysis, the variance of trehalose, cadaverine, glutamate and g-aminobutyric acid (GABA) suggested that strain 424A (LNH-ST) had a lower capability to buffer redox changes caused by inhibitors. Second, lower ethanol yield in glucose and xylose co-fermentation than glucose fermentation was observed in strain 424A (LNH-ST), which was considered to be correlated with the generation of xylitol, as well as the reduced levels of lysine, glutamate, glycine and isoleucine in strain 424A (LNH-ST). Accumulation of glycerol, galactinol and mannitol was also observed in strain 424A (LNH-ST) during xylose fermentation. Third, xylose utilization of strain 424A (LNH-ST) was more significantly disturbed by inhibitors than glucose utilization. Through the analysis of fermentation and metabolomic results, it was suggested that xylose catabolism and energy supply, rather than xylose uptake, were the limiting steps in xylose utilization in the presence of inhibitors.
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miR-155 suppresses bacterial clearance in Pseudomonas aeruginosa-induced keratitis by targeting Rheb.
J. Infect. Dis.
PUBLISHED: 01-07-2014
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miR-155 (microRNA-155) is an important noncoding RNA in regulating host inflammatory responses. However, its regulatory role in ocular infection remains unclear. Our study first explored the function of miR-155 in Pseudomonas aeruginosa-induced keratitis, one of the most common sight-threatening ocular diseases. We found that miR-155 expression was enhanced in human and mouse corneas after P. aeruginosa infection and was mainly expressed in macrophages but not neutrophils. In vivo studies demonstrated that miR-155 knockout mice displayed more resistance to P. aeruginosa keratitis, with a higher inducible nitric oxide synthase level and a lower bacterial burden. More importantly, in vitro data indicated that miR-155 suppressed the macrophage-mediated bacterial phagocytosis and intracellular killing of P. aeruginosa by targeting Rheb (Ras homolog enriched in brain). To the best of our knowledge, this is the first study to explore the role of miR-155 in bacterial keratitis, which may provide a promising target for clinical treatment of P. aeruginosa keratitis and other infectious diseases.
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Biosynthesis of Taxadiene in Saccharomyces cerevisiae : Selection of Geranylgeranyl Diphosphate Synthase Directed by a Computer-Aided Docking Strategy.
PLoS ONE
PUBLISHED: 01-01-2014
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Identification of efficient key enzymes in biosynthesis pathway and optimization of the fitness between functional modules and chassis are important for improving the production of target compounds. In this study, the taxadiene biosynthesis pathway was firstly constructed in yeast by transforming ts gene and overexpressing erg20 and thmgr. Then, the catalytic capabilities of six different geranylgeranyl diphosphate synthases (GGPPS), the key enzyme in mevalonic acid (MVA) pathway catalyzing famesyl diphosphate (FPP) to geranylgeranyl diphosphate (GGPP), were predicted using enzyme-substrate docking strategy. GGPPSs from Taxus baccata x Taxus cuspidate (GGPPSbc), Erwinia herbicola (GGPPSeh), and S. cerevisiae (GGPPSsc) which ranked 1st, 4th and 6th in docking with FPP were selected for construction. The experimental results were consistent with the computer prediction that the engineered yeast with GGPPSbc exhibited the highest production. In addition, two chassis YSG50 and W303-1A were chosen, and the titer of taxadiene reached 72.8 mg/L in chassis YSG50 with GGPPSbc. Metabolomic study revealed that the contents of tricarboxylic acid cycle (TCA) intermediates and their precursor amino acids in chassis YSG50 was lower than those in W303-1A, indicating less carbon flux was divided into TCA cycle. Furthermore, the levels of TCA intermediates in the taxadiene producing yeasts were lower than those in chassis YSG50. Thus, it may result in more carbon flux in MVA pathway in chassis YSG50, which suggested that YSG50 was more suitable for engineering the taxadiene producing yeast. These results indicated that computer-aided protein modeling directed isoenzyme selection strategy and metabolomic study could guide the rational design of terpenes biosynthetic cells.
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Metabolomic analysis of cooperative adaptation between co-cultured Bacillus cereus and Ketogulonicigenium vulgare.
PLoS ONE
PUBLISHED: 01-01-2014
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The cooperative adaptation of subcultivated Bacillus cereus and Ketogulonicigenium vulgare significantly increased the productivity of 2-keto-L-gulonic acid, the precursor of vitamin C. The mechanism of cooperative adaptation of the serial subcultivated B. cereus and K. vulgare was investigated in this study by culturing the two strains orthogonally on agar plates. It was found that the swarming distance of B. cereus along the trace of K. vulgare on the plate decreased after 150 days' subcultivation. Metabolomic analysis on these co-cultured B. cereus and K. vulgare strains showed that their cooperative adaptation was accomplished by three key events: (i) the ability of nutrients (e.g., amino acids and purines) searching and intaking, and proteins biosynthesis is increased in the evolved B. cereus; (ii) the capability of protein degradation and amino acids transportation is enhanced in evolved K. vulgare; (iii) the evolved B. cereus was found to provide more nutrients (mostly amino acids and purines) to K. vulgare, thus strengthening the oxidation and energy generation of K. vulgare. Our results provided novel insights into the systems-level understanding of the cooperative adaptation between strains in synergistic consortium.
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Comparative proteomic analysis of experimental evolution of the Bacillus cereus-Ketogulonicigenium vulgare co-culture.
PLoS ONE
PUBLISHED: 01-01-2014
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The microbial co-culture system composing of Ketogulonicigenium vulgare and Bacillus cereus was widely adopted in industry for the production of 2-keto-gulonic acid (2-KGA), the precursor of vitamin C. We found serial subcultivation of the co-culture could enhance the yield of 2-KGA by 16% in comparison to that of the ancestral co-culture. To elucidate the evolutionary dynamics and interaction mechanisms of the two microbes, we performed iTRAQ-based quantitative proteomic analyses of the pure cultures of K. vulgare, B. cereus and their co-culture during serial subcultivation. Hierarchy cluster analyses of the proteomic data showed that the expression level of a number of crucial proteins associated with sorbose conversion and oligopeptide transport was significantly enhanced by the experimental evolution. In particular, the expression level of sorbose/sorbosone dehydrogenase was enhanced in the evolved K. vulgare, while the expression level of InhA and the transport efficiency of oligopeptides were increased in the evolved B. cereus. The decreased sporulating protein expression and increased peptide transporter expression observed in evolved B. cereus, together with the increased amino acids synthesis in evolved K. vulgare suggested that serial subcultivation result in enhanced synergistic cooperation between K. vulgare and B. cereus, enabling an increased production of 2-KGA.
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Meta-analysis on the relationship between HLA-DRBl gene polymorphism and cervical cancer in Chinese population.
PLoS ONE
PUBLISHED: 01-01-2014
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To determine the association between HLA-DRB1 haplotypes and risk of cervical cancer in unselected and samples from Chinese ethnicities.
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Seven functional polymorphisms in the CETP gene and myocardial infarction risk: a meta-analysis and meta-regression.
PLoS ONE
PUBLISHED: 01-01-2014
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This meta-analysis aims to evaluate the relationships between seven functional polymorphisms in the CETP gene and myocardial infarction (MI) risk.
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Loss of Asxl1 leads to myelodysplastic syndrome-like disease in mice.
Blood
PUBLISHED: 11-19-2013
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ASXL1 is mutated/deleted with high frequencies in multiple forms of myeloid malignancies and its alterations are associated with poor prognosis. De novo ASXL1 mutations cause Bohring-Opitz syndrome characterized by multiple congenital malformations. We show that Asxl1-deletion in mice led to developmental abnormalities including dwarfism, anophthalmia and 80% embryonic lethality. Surviving Asxl1(-/-) mice lived for up to 42 days and developed features of MDS, including dysplastic neutrophils and multiple lineage cytopenia. Asxl1(-/-) mice had a reduced HSC-pool and Asxl1(-/-) HSCs exhibited decreased hematopoietic repopulating capacity with skewed cell differentiation favoring granulocytic lineage. Importantly, Asxl1(+/-) mice also developed mild MDS-like disease, which could progress to MDS/MPN, demonstrating a haploinsufficient effect of Asxl1 in the pathogenesis of myeloid malignancies. Asxl1-loss led to an increased apoptosis and mitosis in LK cells, consistent with human MDS. Furthermore, Asxl1(-/-) LK cells exhibited decreased global levels of H3K27me3 and H3K4me3, and altered expression of genes regulating apoptosis (Bcl2, Bcl2l12 and Bcl2l13). Collectively, we report a novel ASXL1 murine model which recapitulates human myeloid malignancies, implying that Asxl1 functions as a tumor suppressor to maintain hematopoietic cell homeostasis. Future work is necessary to clarify the contribution of microenvironment to the hematopoietic phenotypes observed in the constitutional Asxl1(-/-) mice.
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[COX-2 Inhibitor Celecoxib Can Suppress the Proliferation of FLT3-ITD Positive Acute Myeloid Leukemia Cells with Prominent Down Regulation of MEK/MCL-1 Expression in Vitro].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 10-26-2013
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The purpose of this study was to investigate the effects of Celecoxib on the proliferation of the FLT3-ITD positive and negative acute myeloid leukemia cells and its mechanism. The proliferation inhibition effect of Celecoxib with different doses on the FLT3-ITD positive cells MV4-11 and the FLT3-ITD negative K562 cells was detected by CCK-8 method, the cell apoptosis was determined by flow cytometry, and the MEK, Mcl-1, pAKT expression was tested by Western blot. The results showed that Celecoxib inhibited the proliferation of both MV4-11 and K562 cells, but the IC50 for MV4-11 was (29.14 ± 2.4) µmol/L, which was significantly lower than that of K562 cells (39.84 ± 1.0) µmol/L (P < 0.05); The induced apoptosis rate of Celecoxib at 20-80 µmol/L on MV4-11 was not observed, but there was apparent influence on K562 at the same concentration. Western blot showed that Celecoxib down-regulated the expression of MEK and Mcl-1 but did not change the expression of pAKT obviously on MV4-11 cells, while the expression of Mcl-1 was reduced a little, but no obvious change were found in the expression of MEK and pAKT on K562 cells. It is concluded that the Celecoxib can inhibit the proliferation of FLT3-ITD positive AML cells distinctly, and the potential mechanism may be related to the inhibition of the MEK/Mcl-1 signaling pathway.
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Releasing polysaccharide and protein from yeast cells by ultrasound: Selectivity and effects of processing parameters.
Ultrason Sonochem
PUBLISHED: 10-15-2013
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A 20kHz high-intensity ultrasound was employed for the selective release of polysaccharide and protein from yeast cells. While the release of polysaccharide and protein was affected by most of the processing parameters, the release selectivity, which is the ratio of the amount of polysaccharide released to that of protein, designated as T/P value, was only influenced by sonication time, temperature and ionic strength, among which temperature had the greatest influence. The T/P value at 85°C was a factor of 9.3 of the one at 25°C. The underlying mechanism of this selectivity is speculated to be thermal denaturation and aggregation of protein within yeast cells at elevated temperatures leading to the decrease of protein release by ultrasound. This finding may be useful in exploring a novel selective process for producing polysaccharide and protein fractions from yeast biomass.
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Simple, reliable, and nondestructive method for the measurement of vacuum pressure without specialized equipment.
Appl Opt
PUBLISHED: 10-03-2013
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We present a simple, reliable, and nondestructive method for the measurement of vacuum pressure in a magneto-optical trap. The vacuum pressure is verified to be proportional to the collision rate constant between cold atoms and the background gas with a coefficient k, which can be calculated by means of the simple ideal gas law. The rate constant for loss due to collisions with all background gases can be derived from the total collision loss rate by a series of loading curves of cold atoms under different trapping laser intensities. The presented method is also applicable for other cold atomic systems and meets the miniaturization requirement of commercial applications.
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Hyperactive Ras/MAPK signaling is critical for tibial nonunion fracture in neurofibromin-deficient mice.
Hum. Mol. Genet.
PUBLISHED: 07-17-2013
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Neurofibromatosis type 1 (NF1) is a common genetic disorder affecting 1 in 3500 individuals. Patients with NF1 are predisposed to debilitating skeletal manifestations, including osteopenia/osteoporosis and long bone pseudarthrosis (nonunion fracture). Hyperactivation of the Ras/mitogen-activated protein kinase (MAPK) pathway in NF1 is known to underlie aberrant proliferation and differentiation in cell lineages, including osteoclast progenitors and mesenchymal stem cells (MSCs) also known as osteoblast progenitors (pro-OBLs). Our current study demonstrates the hyper Ras/MAPK as a critical pathway underlying the pathogenesis of NF1-associated fracture repair deficits. Nf1-deficient pro-OBLs exhibit Ras/MAPK hyperactivation. Introduction of the NF1 GTPase activating-related domain (NF1 GAP-related domain) in vitro is sufficient to rescue hyper Ras activity and enhance osteoblast (OBL) differentiation in Nf1(-/-) pro-OBLs and NF1 human (h) MSCs cultured from NF1 patients with skeletal abnormalities, including pseudarthrosis or scoliosis. Pharmacologic inhibition of mitogen-activated protein kinase kinase (MEK) signaling with PD98059 partially rescues aberrant Erk activation while enhancing OBL differentiation and expression of OBL markers, osterix and osteocalcin, in Nf1-deficient murine pro-OBLs. Similarly, MEK inhibition enhances OBL differentiation of hMSCs. In addition, PD98059 rescues aberrant osteoclast maturation in Nf1 haploinsufficient bone marrow mononuclear cells (BMMNCs). Importantly, MEK inhibitor significantly improves fracture healing in an NF1 murine model, Col2.3Cre;Nf1(flox/-). Collectively, these data indicate the Ras/MAPK cascade as a critical pathway in the pathogenesis of bone loss and pseudarthrosis related to NF1 mutations. These studies provide evidence for targeting the MAPK pathway to improve bone mass and treat pseudarthrosis in NF1.
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Common and pathogen-specific virulence factors are different in function and structure.
Virulence
PUBLISHED: 07-15-2013
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In the process of host-pathogen interactions, bacterial pathogens always employ some special genes, e.g., virulence factors (VFs) to interact with host and cause damage or diseases to host. A number of VFs have been identified in bacterial pathogens that confer upon bacterial pathogens the ability to cause various types of damage or diseases. However, it has been clarified that some of the identified VFs are also encoded in the genomes of nonpathogenic bacteria, and this finding gives rise to considerable controversy about the definition of virulence factor. Here 1988 virulence factors of 51 sequenced pathogenic bacterial genomes from the virulence factor database (VFDB) were collected, and an orthologous comparison to a non-pathogenic bacteria protein database was conducted using the reciprocal-best-BLAST-hits approach. Six hundred and twenty pathogen-specific VFs and 1368 common VFs (present in both pathogens and nonpathogens) were identified, which account for 31.19% and 68.81% of the total VFs, respectively. The distribution of pathogen-specific VFs and common VFs in pathogenicity islands (PAIs) was systematically investigated, and pathogen-specific VFs were more likely to be located in PAIs than common VFs. The function of the two classes of VFs were also analyzed and compared in depth. Our results indicated that most but not all T3SS proteins are pathogen-specific. T3SS effector proteins tended to be distributed in pathogen-specific VFs, whereas T3SS translocation proteins, apparatus proteins, and chaperones were inclined to be distributed in common VFs. We also observed that exotoxins were located in both pathogen-specific and common VFs. In addition, the architecture of the two classes of VFs was compared, and the results indicated that common VFs had a higher domain number and lower domain coverage value, revealed that common VFs tend to be more complex and less compact proteins.
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Galectin-9 in combination with rapamycin induces cardiac allograft tolerance in mice.
Transplantation
PUBLISHED: 07-11-2013
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Galectin-9 serves opposing roles in the innate and adaptive immune systems. Galectin-9 triggers T-cell immunoglobulin mucin-3 (Tim-3) on T helper type 1 (Th1) cells, thereby terminating Th1 immunity and protecting allografts from host immune attacks. Meanwhile, galectin-9 promotes the maturation of dendritic cells (DCs) that deliver proinflammatory signals. We previously showed that galectin-9 significantly prolongs cardiac allograft survival in mice but failed to induce tolerance. This study aimed at improving the administration protocol to induce allograft tolerance. We examined whether rapamycin can reverse the proinflammatory effects of galectin-9 on DCs and whether rapamycin synergizes with galectin-9 to induce cardiac allograft tolerance.
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Emulsifying, Flocculating, and Physicochemical Properties of Exopolysaccharide Produced by Cyanobacterium Nostoc flagelliforme.
Appl. Biochem. Biotechnol.
PUBLISHED: 07-08-2013
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The emulsifying, flocculating, and physicochemical properties of purified exopolysaccharide (EPS) of terrestrial cyanobacterium Nostoc flagelliforme cultured in liquid media were investigated. The EPS was defined as heteropolysaccharide composed by 41.2 % glucose, 21.1 % galactose, 21.0 % mannose, 2.5 % fructose, 3.6 % ribose, 1.7 % xylose, 0.6 % arabinose, 3.0 % rhamnose, 0.9 % fucose, and 4.3 % glucuronic acid. The EPS possessed higher intrinsic viscosity than other cyanobacterial strains as reported and displayed pseudoplastic behavior in aqueous solution. The EPS produced more stable emulsions with tested hydrocarbons and oils than xanthan gum, and the emulsification indexes with n-hexadecane, liquid paraffin, and peanut oil were higher than 50 %, indicating the strong emulsion-stabilizing capacity. The EPS showed peak flocculating rates of 93.5 and 86.1 % in kaolin and MgO suspension, respectively, and exhibited a better flocculation performance than Al2(SO4)3 and xanthan gum. These results demonstrated that the EPS of N. flagelliforme was a very promising candidate for numerous industrial applications, as it had higher intrinsic viscosity, good emulsification activity, and excellent flocculation capability.
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Multi-gene analyses from waste brushing specimens for patients with peripheral lung cancer receiving EBUS-assisted bronchoscopy.
Lung Cancer
PUBLISHED: 07-05-2013
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Although flexible bronchoscopy with the assistance of miniature radial-probe endobronchial ultrasound (EBUS) is increasingly employed to diagnose peripheral lung cancer, transbronchial biopsies typically offer an insufficient amount of tissue to conduct additional molecular analysis. We evaluated the feasibility of multi-gene analyses from waste brushing samples obtained by EBUS-assisted bronchoscopy.
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[Effects of immunization with recombinant fusion protein of extracellular near-transmembrane domain of Tibet minipig leptin receptor on fat deposition in SD rats].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 06-28-2013
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To investigate the effect of immunization with prokaryotically expressed recombinant fusion protein of extracellular near-transmembrane domain of Tibet minipig leptin receptor (OBR) on fat deposition in SD rats.
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High temperature aqueous ammonia pretreatment and post-washing enhance the high solids enzymatic hydrolysis of corn stover.
Bioresour. Technol.
PUBLISHED: 05-30-2013
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Aqueous ammonia pretreatment was optimized and the limiting factors in high solids enzymatic hydrolysis were assessed. The recommended pretreatment condition to achieve high enzymatic yield was: 180 °C, 20% (w/w) ammonia, 30 min, and 20% solids content. FT-IR and GC-MS results indicated that most of the lignin was degraded to soluble fragments after pretreatment. The pretreated solids after post-washing showed higher enzymatic digestibility at high solids loading than that without washing. The washed solids required lower cellulase and xylanase dosage than unwashed solids to achieve high sugar yield. Enzymatic conversions were declined with the increased solids loading of pretreated solids, pretreated-washed solids, and filter papers. The results indicated that solids loading in enzymatic hydrolysis was an important factor affecting sugar yield. The increasing concentration of glucose and ligno-phenolics mainly inhibited the enzymatic hydrolysis of aqueous ammonia pretreated corn stover.
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Systematic reviews and meta-analyses of traditional chinese medicine must search chinese databases to reduce language bias.
Evid Based Complement Alternat Med
PUBLISHED: 05-28-2013
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Systematic reviews (SRs) that fail to search non-English databases may miss relevant studies and cause selection bias. The bias may be particularly severe in SRs of traditional Chinese medicine (TCM) as most randomized controlled trials (RCT) in TCM are published and accessible only in Chinese. In this study we investigated how often Chinese databases were not searched in SRs of TCM, how many trials were missed, and whether a bias may occur if Chinese databases were not searched. We searched 5 databases in English and 3 in Chinese for RCTs of Chinese herbal medicine for coronary artery disease and found that 96.64% (115/119) eligible studies could be identified only from Chinese databases. In a random sample of 80 Cochrane reviews on TCM, we found that Chinese databases were only searched in 43 or 53.75%, in which almost all the included studies were identified from Chinese databases. We also compared SRs of the same topic and found that they may draw a different conclusion if Chinese databases were not searched. In conclusion, an overwhelmingly high percentage of eligible trials on TCM could only be identified in Chinese databases. Reviewers in TCM are suggested to search Chinese databases to reduce potential selection bias.
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Combinational expression of sorbose/sorbosone dehydrogenases and cofactor pyrroloquinoline quinone increases 2-keto-L-gulonic acid production in Ketogulonigenium vulgare-Bacillus cereus consortium.
Metab. Eng.
PUBLISHED: 05-26-2013
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The expression levels of sorbose/sorbosone dehydrogenase genes (sdh and sndh) and the synthesis genes (pqqABCDEN) of the adjoint cofactor pyrroloquinoline quinone (PQQ) were genetically manipulated in Ketogulonigenium vulgare to increase the production of 2-keto-l-gulonic acid (2-KLG), the precursor of vitamin C, in the consortium of K. vulgare and Bacillus cereus. We found that overexpression of sdh-sndh alone in K. vulgare could not significantly enhance the production of 2-KLG, revealing the cofactor PQQ was required for the biosynthesis of 2-KLG. Various expression levels of PQQ were achieved by differential expression of pqqA, pqqABCDE and pqqABCDEN, respectively. The combinatorial expression of sdh/sndh and pqqABCDEN in K. vulgare enabled a 20% increase in the production of 2-KLG (79.1±0.6gl(-1)) than that of the parental K. vulgare (65.9±0.4gl(-1)) in shaking flasks. Our results demonstrated the balanced co-expression of both the key enzymes and the related cofactors was an efficient strategy to increase chemicals biosynthesis.
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Additive role of the vestibular end organ and baroreceptors on the regulation of blood pressure in rats.
Korean J. Physiol. Pharmacol.
PUBLISHED: 05-22-2013
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Contribution of the vestibular end organ to regulation of arterial pressure was quantitatively compared with the role of baroreceptors in terms of baroreflex sensitivity and c-Fos protein expression in the rostral ventrolateral medulla (RVLM). Baroreflex sensitivity and c-Fos protein expression in the RVLM were measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or baroreceptor unloading. BL attenuated baroreflex sensitivity during intravenous infusion of sodium nitroprusside (SNP), but did not significantly affect the sensitivity following infusion of phenylephrine (PE). Baroreflex sensitivity became positive following sinoaortic denervation (SAD) during infusion of PE and attenuated sensitivity during infusion of SNP. Baroreflex sensitivity also became positive following double ablation (BL+SAD) during infusion of PE, and attenuated sensitivity during infusion of SNP. c-Fos protein expression increased significantly in the RVLM in the sham group after SNP administration. However, the BL, SAD, and SAD+BL groups showed significant decreases in c-Fos protein expression compared with that in the sham group. The SAD group showed more reduced c-Fos protein expression than that in the BL group, and the SAD+BL group showed less expression than that in the SAD group. These results suggest that the vestibular system cooperates with baroreceptors to maintain arterial pressure during hypotension but that baroreceptors regulate arterial pressure during both hypotension and hypertension. Additionally, afferent signals for maintaining blood pressure from the vestibular end organs and the baroreceptors may be integrated in the RVLM.
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Simplified serum neutralization test based on enhanced green fluorescent protein-tagged classical swine fever virus.
J. Clin. Microbiol.
PUBLISHED: 05-22-2013
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The neutralization immunofluorescence test (NIFT), currently used for detecting neutralizing antibodies (NAbs) against classical swine fever virus (CSFV), is time-consuming. Here, a simplified neutralization test based on enhanced green fluorescent protein (EGFP)-tagged CSFV (EGFP-NT) was developed for direct detection of anti-CSFV NAbs without immunostaining. The relative sensitivity and specificity between EGFP-NT and NIFT or blocking enzyme-linked immunosorbent assay (ELISA) were both 100%. The NAb titers by EGFP-NT and the blocking rates by blocking ELISA showed a good correlation.
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Interleukin-18 promoter polymorphisms and plasma levels are associated with increased risk of periodontitis: a meta-analysis.
Inflamm. Res.
PUBLISHED: 05-20-2013
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Emerging evidence has showed that interleukin-18 (IL-8) promoter polymorphisms and plasma IL-18 levels may be associated with increased risk of periodontitis, but individually published results are inconclusive. The aim of this meta-analysis was to derive a more precise estimation of these associations.
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Early Healing of Hydroxyapatite-Coated Implants in Grafted Bone of Zoledronate Acid Treated Osteoporotic Rabbits.
J. Periodontol.
PUBLISHED: 05-20-2013
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Background: Resorption of grafted bone and delayed osseointegration of implants are main problems associated with alveolar bone augmentation in dental implantology, especially for patients with osteoporosis. The aim of this study was to investigate the early healing response of implants to systemic treatment of Zoledronate acid (ZA) in autogenous grafted iliac bone of osteoporotic rabbits. Methods: Ovariectomy (OVX) or sham-operation was performed in 46 rabbits and osteoporotic changes were verified in ovariectomized animals 3 months later. Then the remaining animals were divided into 3 groups (n=12): Sham, OVX and ZA (ZA treatment) group. Autogenous iliac bone grafting was performed in bilateral tibiae and hydroxyapatite-coated titanium implants were simultaneously placed into the grafted bone. The animals were sacrificed at 2 and 8 weeks later for various examinations. Results: At both two time points, systemic treatment of ZA efficiently promoted bone healing of implants in grafted bone and all histological and Micro-CT bone indices, including mineralized bone volume (BV/TV), implant-bone contact rate (IBCR), connectivity density (Conn.D), trabecular thickness (Tb.Th), and trabecular number (Tb.N), were significantly increased in ZA group when compared with OVX group (P<0.01). The increased IBCR were even restored to normal level in Sham animals (P>0.05). Furthermore, biomechanical testing demonstrated that removal torque of implants was significantly increased in ZA group when compared with OVX group (P<0.01). Conclusion: Systemic treatment with ZA could efficiently promote early bone healing of implants in autogenous grafted bone of osteoporotic rabbits by increasing early osseointegration and fixation of implants.
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In vitro studies on the structure and properties of silk fibroin aqueous solutions in silkworm.
Int. J. Biol. Macromol.
PUBLISHED: 05-08-2013
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The spinning process of silkworm in vivo attracts great attentions. In this work, the structures and properties of the silk fibroin (SF) aqueous solutions from different divisions of silk glands of silkworms were investigated by using polarized microscope, rotational rheometer, Raman spectrometer and dynamic laser light scattering instrument. It was found that only the anterior (A) division and the anterior part of middle division (MA) of silk gland showed birefringence. With flowing from the posterior part (MP) to the MA part in the middle division of silk gland, the SF aqueous solutions was gradually transformed from random coil/?-helix to ?-sheet conformation. Meantime, the elastic and viscous nature of the SF aqueous solution changed, and the mean diameter of SF aggregates increased from 118nm to 331nm. It could be concluded that the structures and properties of the SF aqueous solutions were gradually changed along the silk gland and the liquid crystal structure was initially formed in the MA part of silk gland.
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Insights into the roles of exogenous glutamate and proline in improving streptolydigin production of Streptomyces lydicus with metabolomic analysis.
J. Ind. Microbiol. Biotechnol.
PUBLISHED: 05-05-2013
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The addition of precursors was one strategy to improve antibiotic production. The exogenous proline and glutamate, as precursors of streptolydigin, could significantly improve the streptolydigin production, but their underlying molecular mechanisms remain unknown. Herein, metabolomic analysis was carried out to explore the metabolic responses of Streptomyces lydicus to the additions of proline and glutamine. The significant differences in the quantified 53 metabolites after adding the exogenous proline and glutamate were enunciated by gas chromatography coupled to time-of-flight mass spectrometry. Among them, the levels of some fatty acids (e.g., dodecanoic acid, octadecanoic acid, hexadecanoic acid) were significantly decreased after adding glutamate and proline, indicating that the inhibition of fatty acid synthesis might be benefit for the accumulation of streptolydigin. Particularly, the dramatic changes of the identified metabolites, which are involved in glycolysis, the tricarboxylic acid cycle, and the amino acid and fatty acid metabolism, revealed that the additions of glutamate and proline possibly caused the metabolic cross-talk in S. lydicus. Additionally, the level of intracellular glutamate dramatically enhanced at 12 h after adding proline, showing that exogenous proline may be firstly convert into glutamate and consequently result in crease of the streptolydigin production. The high levels of streptolydigin at 12 and 24 h after adding glutamate unveiled that part glutamate were rapidly used to synthesize the streptolydigin. Furthermore, there is the significant difference in metabolomic characteristics of S. lydicus after adding glutamate and proline, uncovering that multiple regulatory pathways are involved in responses to the additions of exogenous glutamate and proline. Taken together, exogenous glutamate and proline not only directly provided the precursors of streptolydigin biosynthesis, but also might alter the metabolic homeostasis of S. lydicus E9 during improving the production of streptolydigin.
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Anti-inflammatory and anti-oxidative effects of corilagin in a rat model of acute cholestasis.
BMC Gastroenterol
PUBLISHED: 04-26-2013
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Nowadays, treatments for cholestasis remain largely nonspecific and often ineffective. Recent studies showed that inflammatory injuries and oxidative stress occur in the liver with cholestasis. In this study, we would use corilagin to treat the animal model of acute cholestasis in order to define the activity to interfere with inflammation-related and oxidative stress pathway in cholestatic pathogenesis.
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Pericentric chromatin loops function as a nonlinear spring in mitotic force balance.
J. Cell Biol.
PUBLISHED: 03-20-2013
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The mechanisms by which sister chromatids maintain biorientation on the metaphase spindle are critical to the fidelity of chromosome segregation. Active force interplay exists between predominantly extensional microtubule-based spindle forces and restoring forces from chromatin. These forces regulate tension at the kinetochore that silences the spindle assembly checkpoint to ensure faithful chromosome segregation. Depletion of pericentric cohesin or condensin has been shown to increase the mean and variance of spindle length, which have been attributed to a softening of the linear chromatin spring. Models of the spindle apparatus with linear chromatin springs that match spindle dynamics fail to predict the behavior of pericentromeric chromatin in wild-type and mutant spindles. We demonstrate that a nonlinear spring with a threshold extension to switch between spring states predicts asymmetric chromatin stretching observed in vivo. The addition of cross-links between adjacent springs recapitulates coordination between pericentromeres of neighboring chromosomes.
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The enforced expression of c-Myc in pig fibroblasts triggers mesenchymal-epithelial transition (MET) via F-actin reorganization and RhoA/Rock pathway inactivation.
Cell Cycle
PUBLISHED: 03-06-2013
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In previous studies from other labs it has been well demonstrated that the ectopic expression of c-Myc in mammary epithelial cells can induce epithelial-mesenchymal transition (EMT), whereas in our pilot experiment, epithelial-like morphological changes were unexpectedly observed in c-Myc-expressing pig fibroblasts [i.e., porcine embryonic fibroblasts (PEFs) and porcine dermal fibroblasts (PDFs)] and pig mesenchymal stem cells, suggesting that the same c-Myc gene is entitled to trigger EMT in epithelial cells and mesenchymal-epithelial transition (MET) in fibroblasts. This prompted us to characterize the existence of a MET in c-Myc-expressing PEFs and PDFs at the molecular level. qRT-PCR, immunofluorescence and western blot analysis illustrated that epithelial-like morphological changes were accompanied by the increased expression of epithelial markers [such as cell adhesion proteins (E-cadherin, ?-catenin and Bves), tight junction protein occludin and cytokeratins (Krt8 and Krt18)], the reduced expression of mesenchymal markers [vimentin, fibronectin 1 (FN1), snail1, collagen family of proteins (COL1A1, COL5A2) and matrix metalloproteinase (MMP) family (MMP12 and MMP14)] and the decreased cell motility and increased cell adhesion in c-Myc-expressing PEFs and PDFs. Furthermore, the ectopic expression of c-Myc in pig fibroblasts disrupted the stress fiber network, suppressed the formation of filopodia and lamellipodia, and resulted in RhoA/Rock pathway inactivation, which finally participates in epithelial-like morphological conversion. Taken together, these findings demonstrate, for the first time, that the enforced expression of c-Myc in fibroblasts can trigger MET, to which cytoskeleton depolymerization and RhoA/Rock pathway inactivation contribute.
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Systematic review and meta-analysis of application of fibrin sealant after liver resection.
Curr Med Res Opin
PUBLISHED: 02-27-2013
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Fibrin sealant (FS) has been increasingly used on the raw surface after liver resection but its clinical value has not been established to date. The aim of this study was to evaluate the efficacy and safety of the employment of FS after liver resection.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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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.