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Find video protocols related to scientific articles indexed in Pubmed.
Trisulfur Radical Anion as the Key Intermediate for the Synthesis of Thiophene via the Interaction between Elemental Sulfur and NaOtBu.
Org. Lett.
PUBLISHED: 11-20-2014
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A facile base-promoted sulfur-centered radical generation mode and a single-step protocol for the synthesis of thiophene derivatives using 1,3-diynes via the interaction between elemental sulfur and NaOtBu has been reported. EPR experiments revealed that the trisulfur radical anion acts as a key intermediate of this process. A plausible mechanism has been proposed.
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Protective Effects of Kojic Acid on the Periphery Blood and Survival of Beagle Dogs after Exposure to a Lethal Dose of Gamma Radiation.
Radiat. Res.
PUBLISHED: 11-20-2014
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In previous studies, it has been shown that pretreatment with kojic acid (KA) not only increased the 30 day survival rate of mice after exposed to a lethal dose of gamma radiation but also had significant radioprotective effects on the hematopoietic system, the immune system and DNA of mice exposed to a 4 Gy sublethal dose of radiation. Furthermore, pretreatment with KA has also been shown to protect Chinese hamster ovary (CHO) cells against ionizing radiation-induced damage. In this investigation, beagle dogs were used to evaluate whether KA could also be radioprotective in a large animal model. Dogs in the group pretreated with kojic acid after whole-body exposure to a lethal dose of 3 Gy gamma radiation had a 51 day survival rate of 66.7% versus the dogs in the 3 Gy irradiation only group, which all died within 16 days of postirradiation. General vital signs (body weight or temperature) of animals in the kojic acid pretreated group reduced and increased maximally at day 14 postirradiation and then reverted to normal levels gradually. The hematopoiesis studies indicated that the white blood cells/red blood cells, hemoglobin content and hematocrit of dogs pretreated with kojic acid decreased sharply at day 23/day 21 postirradiation, and then gradually elevated. In addition, the DNA content of dogs pretreated with KA were significantly increased compared with that of dogs in the irradiation group at day 4 postirradiation and the number of micronuclei in the group pretreated with kojic acid declined sharply compared with that of the irradiation only group. KA appears to possess marked protective effects from radiation-induced damage and therefore, may be a promising novel radioprotective agent.
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Revealing the halide effect on the kinetics of the aerobic oxidation of Cu(i) to Cu(ii).
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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In situ infrared (IR) and X-ray absorption near-edge structure (XANES) spectroscopic investigations reveal that different halide ligands have distinct effects on the aerobic oxidation of Cu(i) to Cu(ii) in the presence of TMEDA (tetramethylethylenediamine). The iodide ligand gives the lowest rate and thus leads to the lowest catalytic reaction rate of aerobic oxidation of hydroquinone to benzoquinone. Further DFT calculations suggest that oxidation of CuI-TMEDA involves a side-on transition state, while oxidation of CuCl-TMEDA involves an end-on transition state which has a lower activation energy.
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[Surgical treatment of lumbar spondylolisthesis by transforaminal lumbar interbody fusion].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 11-14-2014
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To explore the clinical outcomes of transforminal lumbar interbody fusion (TLIF) technique in treatment of lumbar spondylolisthesis.
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Cu(II)/Cu(I)-Synergistic Cooperation to Lead the Alkyne C-H Activation.
J. Am. Chem. Soc.
PUBLISHED: 11-11-2014
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An efficient alkyne C-H activation procedure has been well studied which indicated that a Cu(II)/Cu(I) synergistic co-operation might be involved. In situ Raman spectroscopy was engaged to study kinetic behavior, drawing the conclusion that Cu(II) didn't participate in the rate determining step. IR and X-ray absorption spectroscopy evidence were provided for structural information, indicating that Cu(II) alone couldn't accelerate the reduction procedure by simply coordinating with C-C triple bond to activate the terminal alkynes; meanwhile, X-band EPR spectra and solubility showed that Cu(I) and Cu(II) could affect the complication environment of each other. A distinctive Cu(I)-Cu(II) synergistic cooperation intermediate was proposed for the putative mechanism.
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Construction of N-containing heterocycles via oxidative intramolecular N-H/X-H coupling.
Chem. Commun. (Camb.)
PUBLISHED: 11-07-2014
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The preparation of N-containing heterocycles is always the core of synthetic chemistry. Recently, oxidative coupling between two R-H nucleophiles is gaining more attention due to its atom-economy and step-economy, thus there are numerous reports focusing on the N-heterocycle construction via oxidative coupling. This feature article is going to cover the methodology related to the construction of N-heterocycles through oxidative intramolecular N-H/X-H coupling.
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The association between insulin resistance and vascularization of thyroid nodules.
J. Clin. Endocrinol. Metab.
PUBLISHED: 11-05-2014
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Insulin resistance (IR) is an important factor for the growth and progression of thyroid nodules, which might be associated with the distribution, construction and density of nodular vascularization.
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Recent Advances of Transition-Metal Catalyzed Radical Oxidative Cross-Couplings.
Acc. Chem. Res.
PUBLISHED: 11-04-2014
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Conspectus Oxidative cross-coupling reactions between two nucleophiles are a powerful synthetic strategy to synthesize various kinds of functional molecules. Along with the development of transition-metal-catalyzed oxidative cross-coupling reactions, chemists are applying more and more first-row transition metal salts (Fe, Co, etc.) as catalysts. Since first-row transition metals often can go through multiple chemical valence changes, those oxidative cross-couplings can involve single electron transfer processes. In the meantime, chemists have developed diverse mechanistic hypotheses of these types of reactions. However, none of these hypotheses have led to conclusive reaction pathways until now. From studying both our own work and that of others in this field, we believe that radical oxidative cross-coupling reactions can be classified into four models based on the final bond formations. In this Account, we categorize and summarize these models. In model I, one of the starting nucleophiles initially loses one electron to generate its corresponding radical under oxidative conditions. Then, bond formations between this radical and another nucleophile create a new radical, [Nu(1)-Nu(2)](•), followed by a further radical oxidation step to generate the cross-coupling product. The radical oxidative alkenylation with olefin, radical oxidative arylative-annulation, and radical oxidative amidation are examples of this model. In model II, one of the starting nucleophiles loses its two electrons via two steps of single-electron-transfer to generate an electrophilic intermediate, followed by a direct bond formation with the other nucleophile. For example, the oxidative C-O coupling of benzylic sp(3) C-H bonds with carboxylic acids and oxidative C-N coupling of aldehydes with amides are members of this model group. For model III, both nucleophiles are oxidized to their corresponding radicals. Then, the radicals combine to form the final coupling product. The dioxygen-involved radical oxidative cross-couplings between sulfinic acids and olefins or alkynes belong to this bond formation model. Lastly, in model IV, one nucleophile loses two electrons to generate an electrophilic intermediate, while the other nucleophile loses one electron to generate a radical. Then, a bond forms between the cation and the radical to generate a cationic radical, followed by a one-electron reduction to afford the final coupling product. The oxidative coupling between arylboronic acids and simple ethers was classified in this model. At the current stage, there are only a few examples presented for models III and IV, but they represent two types of potentially important transformations. More and more examples of these two models will be developed in the future.
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Chlorination of Iodide-Containing Waters in the Presence of CuO: Formation of Periodate.
Environ. Sci. Technol.
PUBLISHED: 10-31-2014
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It has been shown previously that the disproportionation of halogen-containing oxidants (e.g., HOCl, HOBr, and ClO2) is enhanced by a CuO-catalyzed process. In this study, the transformation of iodine during chlorination in the presence of CuO was investigated. There is no significant enhancement of the disproportionation of hypoiodous acid (HOI) in the presence of CuO. The formation rate of iodate (IO3(-)) in the CuO-HOCl-I(-) system significantly increased when compared to homogeneous solutions, which was ascribed to the activation of HOCl by CuO enhancing its reactivity toward HOI. In this reaction system, iodate formation rates increase with increasing CuO (0-0.5 g L(-1)) and bromide (0-2 ?M) doses and with decreasing pH (9.6-6.6). Iodate does not adsorb to the CuO surfaces used in this study. Nevertheless, iodate concentrations decreased after a maximum was reached in the CuO-HOCl-I(-)(-Br(-)) systems. Similarly, the iodate concentrations decrease as a function of time in the CuO-HOCl-IO3(-) or CuO-HOBr-IO3(-) system, and the rates increase with decreasing pH (9.6-6.6) due to the enhanced reactivity of HOCl or HOBr in the presence of CuO. It could be demonstrated that iodate is oxidized to periodate by a CuO-activated hypohalous acid, which is adsorbed on the CuO surface. No periodate could be measured in filtered solutions because it was mainly adsorbed to CuO. The adsorbed periodate was identified by scanning electron microscopy plus energy dispersive spectroscopy and X-ray photoelectron spectroscopy.
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Changes of the Abdomen in Patients with Ankylosing Spondylitis Kyphosis.
Spine
PUBLISHED: 10-25-2014
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Study Design. A retrospective clinical study.Objective. To investigate changes of the abdomen in patients with ankylosing spondylitis kyphosis.Summary of Background Date. Since 1945, many authors had reported the good clinical and radiographic outcomes and and higher patient satisfaction rates of spinal osteotomy techniques. However, to our knowledge, whether the visceral and diaphragmatic compression that results from the inferior edge of the thoracic cage is relieved by the surgery have not yet been reported.Materials and Methods. From July 2010 to July 2013, 26 patients (24 male, and 2 female) in our department with severe ankylosing spondylitis kyphosis underwent pedicle subtraction osteotomy were studied. Preoperative and postoperative computed tomographic scan, three dimensional reconstruction and preoperative pulmonary function test were performed. Via those tests the minimum distance on the median sagittal plane of the abdomen (MD), the acreage of the abdominal median sagittal plane (AMSP), the diaphragm angle on median sagittal plane(DA) can be gained. A paired sample t test was performed to determine the differences between the preoperative and postoperative AMSPA and MD and DA, respectively. Postoperative-MD/preoperative-MD and postoperative-AMSPA/preoperative-AMSPA and GK were also analyzed by performing independent sample t test for the two groups.Results. The DA has changed significantly in all the patients. There was significant change of both MD and AMSPA in patients whose abdominal wall were folded into abdomen, while neither MD nor AMSPA in patients without the factor. CONCLUSION:To a certain degree, the diaphragmatic compression and the visceral compression could be compensated for by turning to flattening or even developing into kyphosis of the lumbar lordosis before surgery, which could be corrected by a spinal osteotomy. Sagittal rotation of diaphragm in ankylosing spondylitis kyphosis could also be improved by a spinal osteotomy.
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The effective equivalence of geometric irregularity and surface roughness in determining particle single-scattering properties.
Opt Express
PUBLISHED: 10-17-2014
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This study investigates the effects of geometric irregularity and surface roughness on the single-scattering properties of randomly oriented dielectric particles. Starting from a regular crystal with smooth faces, effects of roughening are compared with effects of perturbing the regular configuration of the smooth faces. Using the same slope distribution for small roughness facets and tilted faces provides a natural way to compare the effects on the single-scattering properties. It is found that the geometric irregularity and surface roughness have similar effects on the single-scattering properties of an ensemble of randomly oriented particles. In other words, particles with irregular geometries and those with surface roughness are optically equivalent if the slope distributions are the same. Furthermore, an ensemble of particles with irregular geometries can be used as an effective approximation for simulation of the scattering properties of roughened particles, and vice versa. This approach also provides new interpretation of the observed, relatively featureless and smooth, scattering phase functions of naturally occurring particles.
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I2-catalyzed oxidative C(sp(3))-H/S-H coupling: utilizing alkanes and mercaptans as the nucleophiles.
Chem. Commun. (Camb.)
PUBLISHED: 10-10-2014
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By using alkanes and mercaptans as the nucleophiles with di-tert-butyl peroxide (DTBP) as the oxidant, I2-catalyzed oxidative C(sp(3))-H/S-H coupling was achieved. This protocol provides a novel process to construct C(sp(3))-S bonds from commercially available hydrocarbons and mercaptans.
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Relay cooperation of K2S2O8 and O2 in oxytrifluoromethylation of alkenes using CF3SO2Na.
Chem. Commun. (Camb.)
PUBLISHED: 10-04-2014
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A new radical oxytrifluoromethylation of alkenes via an aerobic Cvinyl-heteroatom bond oxygenation process is reported, in which O2 and a catalytic amount of K2S2O8 work in concert to activate CF3SO2Na. Mechanistic investigation disclosed that CF3SO2? could react with O2 to reinitiate radical chain process.
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Elevated expression of nuclear protein kinase CK2? as a poor prognosis indicator in lymph node cancerous metastases of human thyroid cancers.
Asian Pac. J. Cancer Prev.
PUBLISHED: 09-18-2014
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To investigate the expression of protein kinase CK2? (CK2?) in human thyroid disease and its relationship with thyroid cancer metastasis.
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Oxidative coupling of benzylamines to imines by molecular oxygen catalyzed by cobalt(II) ?-tetrakis(trifluoromethyl)-meso-tetraphenylporphyrin.
J. Org. Chem.
PUBLISHED: 09-04-2014
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Oxidative coupling of benzylamines to imines by molecular oxygen is efficiently realized in the presence of very low catalyst loadings of Co(II) ?-tetrakis(trifluoromethyl)-meso-tetraphenylporphyrin. Due to the effect of four ?-CF3 groups, the catalyst shows good selectivity and very high turnover number. The reaction is easily scaled up and may provide a convenient way to prepare many imines in large scale.
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Genetic effects of single nucleotide polymorphisms in JAK2 and STAT5A genes on susceptibility of Chinese Holsteins to mastitis.
Mol. Biol. Rep.
PUBLISHED: 09-03-2014
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The JAK-STAT pathway plays a key role in host immunity. The present study was designed to evaluate the effects of single nucleotide polymorphisms (SNPs) in STAT5A and JAK2 genes on some serum cytokines, mastitis and milk production traits. Two SNPs (SNP1 43046497A/C and SNP2 43047829G/A) in STAT5A, and four SNPs in JAK2 (SNP3 39652267A/G, SNP4 39630048C/T, SNP5 39631044G/A, and SNP6 39631175T/C) were revealed and genotyped in 268 Chinese Holstein cattle. Fixed model was used to analyze the association of SNPs with phenotypes by general linear model procedure of SAS 9.1. SNP1 and SNP4 were significantly associated with IL-6 and IL-17 (P < 0.05), respectively. In JAK2 gene, SNP3 was highly significant (P < 0.01) and SNP5 was significant (P < 0.05) in association with SCC, whereas, the association of SNP6 was found significant (P < 0.05) with both SCC and SCS. Combination genotype analysis revealed that SNPs in JAK2 gene significantly associated with SCC and SCS were associated significantly with the corresponding phenotypes in combinations as well. The GG genotype of SNP3 individually and in any combination genotypes showed lowest SCC. The dominant effect of SNP1, SNP5 and SNP6 was found highly significant (P < 0.01) on the corresponding phenotypes (IL-6, SCC and SCS). As for haplotype analysis, two haplotypes were revealed between the two SNPs of STAT5A gene and four haplotypes amongst four SNPs in JAK2 gene; strong linkage disequilibrium (D' > 0.9) was observed between all these haplotypes. The results imply that the identified SNPs could be powerful markers to select dairy cattle with improved genetic resistance against mastitis.
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Ultrafast, superhigh gain visible-blind UV detector and optical logic gates based on nonpolar a-axial GaN nanowire.
Nanoscale
PUBLISHED: 09-02-2014
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Nonpolar a-axial GaN nanowire (NW) was first used to construct the MSM (metal-semiconductor-metal) symmetrical Schottky contact device for application as visible-blind ultraviolet (UV) detector. Without any surface or composition modifications, the fabricated device demonstrated a superior performance through a combination of its high sensitivity (up to 10(4) A W(-1)) and EQE value (up to 10(5)), as well as ultrafast (<26 ms) response speed, which indicates that a balance between the photocurrent gain and the response speed has been achieved. Based on its excellent photoresponse performance, an optical logic AND gate and OR gate have been demonstrated for performing photo-electronic coupled logic devices by further integrating the fabricated GaN NW detectors, which logically convert optical signals to electrical signals in real time. These results indicate the possibility of using a nonpolar a-axial GaN NW not only as a high performance UV detector, but also as a stable optical logic device, both in light-wave communications and for future memory storage.
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Pentraxin-3 as a prognostic marker in patients with small-cell lung cancer.
Med. Oncol.
PUBLISHED: 09-02-2014
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The aim of this study was to determine the incidence and role of pentraxin-3 (PTX-3) overexpression as a predictive/prognostic marker in small-cell lung carcinoma (SCLC). We performed a retrospective study on subjects with a biopsy-proven diagnosis of SCLC. A chart review for demographic and clinical data was performed on patients with SCLC diagnosed between 2005 and 2008. PTX-3 overexpression was evaluated using immunohistochemistry performed on archival paraffin-embedded specimens. 125 patients with SCLC were identified (23 females, 102 males; median age 62.91±8.55 years, range 37-82) all of whom had adequate tissue specimens available for PTX-3 testing. High PTX-3 expression was detected in 25.6% SCLCs and was significantly associated with male gender and smokers. Moreover, elevated PTX-3 levels were correlated with reduced overall (OS) and disease-free survival, and were an independent negative prognostic factor for OS in SCLC. Our findings suggest that high PTX-3 expression appeared to correlate with aggressive behavior in SCLC, and it may be a useful prognostic marker for SCLC patients and a potential molecular target for SCLC treatment.
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Synthesis and anticancer evaluation of benzyloxyurea derivatives.
Chem. Pharm. Bull.
PUBLISHED: 09-02-2014
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A series of novel benzyloxyurea derivatives was designed, synthesized by substituting different benzyls or phenyls on N,N'-positions of the hydroxyurea (HU). These target compounds were evaluated for their anticancer activity in vitro against human leukemia cell line K562 and murine leukemia cell line L1210 in comparison with HU by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Some of the compounds showed promising anticancer activity against the cells. Molecular docking experiments with Saccharomyces cerevisiae R1 domain indicated that 4a and 4f' have stronger affinity than 4m and 4n. Flow cytometry study showed that compound 4g exerted greater apoptotic activity against K562 cells line than HU.
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Uracil-DNA glycosylase (UNG) rs246079 G/A polymorphism is associated with decreased risk of esophageal cancer in a Chinese population.
Med. Oncol.
PUBLISHED: 08-31-2014
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Esophageal cancer is the sixth leading cause of cancer-associated death worldwide. In addition to environmental risk factors, genetic factors might play an important role in esophageal cancer carcinogenesis. We conducted a hospital-based case-control study to evaluate the association between functional single nucleotide polymorphisms (SNPs) in uracil-DNA glycosylase (UNG) and the development of esophageal cancer. A total of 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for this study. The UNG rs3219218 A/G and UNG rs246079 G/A genotypes were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). When the UNG rs246079 GG homozygote genotype was used as the reference group, the GA genotype was associated with a significantly decreased risk for ESCC (GA vs. GG: adjusted OR 0.67, 95 % CI 0.49-0.91, P = 0.011); the AA genotype was not associated with the risk of ESCC. In stratification analyses, a significantly decreased risk of ESCC associated with the UNG rs246079 G/A polymorphism was evident among women, younger patients and never-smokers and never-drinkers. The UNG rs3219218 A/G polymorphism was not associated with the risk for ESCC. These findings indicated that UNG rs246079 G/A might contribute to a decreased risk of ESCC in specific populations. Because of the limited sample size, further studies including a larger and more diverse population, as well as tissue-specific biological characterization, are required to confirm the current findings.
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Neuroprotective Effect of Biatractylenolide Against Memory Impairment in D-Galactose-induced Aging Mice.
J. Mol. Neurosci.
PUBLISHED: 08-31-2014
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Biatractylenolide, a sesquiterpene lactone, which exerted the neuroprotective effect against glutamate-induced excitotoxicity, was isolated from Atractylodis macrocephala in our previous study. In this study, we evaluated the neuroprotective effect of biatractylenolide against D-galactose-induced memory impairment and explored the potential mechanism of its action. The results showed that administration of biatractylenolide could significantly improve behavioral performance of D-galactose-treated mice in passive avoidance test and spatial learning-memory test. Administration of biatractylenolide could significantly decrease the formation of reactive oxygen species (ROS), decrease the activity of acetylcholinesterase (AChE), and increase the expression of synapsin I and protein kinase C (PKC) in D-galactose-treated mice. Our findings provide first evidence for the neuroprotective effect of biatractylenolide against D-galactose-induced memory impairment. The potential mechanisms underlying the neuroprotective effect of biatractylenolide in D-galactose-treated mice might be (i) attenuating oxidative damage via decreasing ROS formation, (ii) restoring cholinergic neurotransmission via decreasing AChE activity, and (iii) increasing the expression of memory-related proteins (synapsin I and PKC). Biatractylenolide may have therapeutic potential in aging-related memory impairment.
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Outcomes of surgery for unstable odontoid fractures combined with instability of adjacent segments.
J Orthop Surg Res
PUBLISHED: 08-28-2014
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At present, traumatic atlantoaxial dislocation or C2-3 instability complicating odontoid fractures remains rarely reported. The aim of this study was to further investigate the surgical treatment strategies and curative effects for odontoid fractures combined with instability of adjacent segments.
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MicroRNA-107 promotes proliferation of gastric cancer cells by targeting cyclin dependent kinase 8.
Diagn Pathol
PUBLISHED: 08-28-2014
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The biological processes and molecular mechanisms underlying miR-107 remain unclear in gastric cancer(GC). In this study, we aimed to investigate the expression, biological functions and mechanisms of miR-107 in GC.
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Steroidal saponins from Tribulus terrestris.
Phytochemistry
PUBLISHED: 08-26-2014
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Sixteen steroidal saponins, including seven previously unreported compounds, were isolated from Tribulus terrestris. The structures of the saponins were established using 1D and 2D NMR spectroscopy, mass spectrometry, and chemical methods. They were identified as: 26-O-?-d-glucopyranosyl-(25R)-furost-4-en-2?,3?,22?,26-tetrol-12-one (terrestrinin C), 26-O-?-d-glucopyranosyl-(25R)-furost-4-en-22?,26-diol-3,12-dione (terrestrinin D), 26-O-?-d-glucopyranosyl-(25S)-furost-4-en-22?,26-diol-3,6,12-trione (terrestrinin E), 26-O-?-d-glucopyranosyl-(25R)-5?-furostan-3?,22?,26-triol-12-one (terrestrinin F), 26-O-?-d-glucopyranosyl-(25R)-furost-4-en-12?,22?,26-triol-3-one (terrestrinin G), 26-O-?-d-glucopyranosyl-(1?6)-?-d-glucopyranosyl-(25R)-furost-4-en-22?,26-diol-3,12-dione (terrestrinin H), and 24-O-?-d-glucopyranosyl-(25S)-5?-spirostan-3?,24?-diol-12-one-3-O-?-d-glucopyranosyl-(1?4)-?-d-galactopyranoside (terrestrinin I). The isolated compounds were evaluated for their platelet aggregation activities. Three of the known saponins exhibited strong effects on the induction of platelet aggregation.
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Methyl-CpG binding domain 4 tagging polymorphisms and esophageal cancer risk in a Chinese population.
Eur. J. Cancer Prev.
PUBLISHED: 08-26-2014
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In 2009, esophageal cancer was recorded as the fifth most commonly diagnosed cancer and the fourth leading cause of cancer-related death in China. Esophageal squamous cell carcinoma (ESCC) accounts for more than 90% of esophageal cancers. Genetic factors might play an important role in the carcinogenesis of ESCC. We conducted a hospital-based case-control study to evaluate the association between methyl-CpG binding domain 4 (MBD4) rs3138373 A>G, rs2005618 T>C, and rs3138355 G>A tag single nucleotide polymorphisms and the risk of developing ESCC. A total of 629 ESCC patients and 686 controls were recruited. Genotypes were determined using the ligation detection reaction method. When the MBD4 rs3138355 GG homozygous genotype was used as the reference group, the GA, AA, and GA/AA genotypes were not associated with ESCC risk. In the recessive model, when the MBD4 rs3138355 GG/GA genotypes were used as the reference group, the AA homozygous genotype was associated with a 28% decreased risk for ESCC (AA vs.
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A new pregnane glycoside from Rubus phoenicolasius and its antiproliferative activity.
Nat. Prod. Res.
PUBLISHED: 08-26-2014
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Chemical investigations of the whole plant ethanol extract of Rubus phoenicolasius led to the isolation and identification of a new pregnane glycoside, 3-O-?-glucopyranosyl-3?,15?-dihydroxypregn-5-en-20-one (1), along with other nine known compounds (2-10). All the isolates were reported from this plant for the first time. The structure of compound 1 was determined by detailed analysis of its spectral data including 1D and 2D NMR. In vitro anti-proliferative activities of compounds 1-3 on MCF-7 and NCI-H460 tumour cell lines were evaluated, and compound 1 was active against the two cell lines with IC50 values of 15.6 and 13.5 ?M, respectively.
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Synergistic contribution of SMAD signaling blockade and high localized cell density in the differentiation of neuroectoderm from H9 cells.
Biochem. Biophys. Res. Commun.
PUBLISHED: 08-21-2014
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Directed neural differentiation of human embryonic stem cells (ESCs) enables researchers to generate diverse neuronal populations for human neural development study and cell replacement therapy. To realize this potential, it is critical to precisely understand the role of various endogenous and exogenous factors involved in neural differentiation. Cell density, one of the endogenous factors, is involved in the differentiation of human ESCs. Seeding cell density can result in variable terminal cell densities or localized cell densities (LCDs), giving rise to various outcomes of differentiation. Thus, understanding how LCD determines the differentiation potential of human ESCs is important. The aim of this study is to highlight the role of LCD in the differentiation of H9 human ESCs into neuroectoderm (NE), the primordium of the nervous system. We found the initially seeded cells form derived cells with variable LCDs and subsequently affect the NE differentiation. Using a newly established method for the quantitative examination of LCD, we demonstrated that in the presence of induction medium supplemented with or without SMAD signaling blockers, high LCD promotes the differentiation of NE. Moreover, SMAD signaling blockade promotes the differentiation of NE but not non-NE germ layers, which is dependent on high LCDs. Taken together, this study highlights the need to develop innovative strategies or techniques based on LCDs for generating neural progenies from human ESCs.
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Inverse correlation between Alzheimer¿s disease and cancer: implication for a strong impact of regenerative propensity on neurodegeneration?
BMC Neurol
PUBLISHED: 08-15-2014
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BackgroundRecent studies have revealed an inverse epidemiological correlation between Alzheimer¿s disease (AD) and cancer¿¿¿patients with AD show a reduced risk of cancer, while cancer survivors are less likely to develop AD. These late discoveries in human subjects call for explorative studies to unlock the underlying biological mechanism, but also may shed new light on conceptual interrogation of the principal pathogenic players in AD etiology.DiscussionHere we hypothesize that this negative correlation reflects a rebalance of biosynthetic propensity between body systems under the two disease statuses. In normal condition the body cellular systems are maintained homeostatically under a balanced cell degenerative vs. surviving/regenerative propensities, determined by biosynthetic resources for anabolic processing. AD pathogenesis involves neurodegeneration but also aberrant regenerative, or reactive anabolic, burden, while cancer development is driving by uncontrolled proliferation inherent with excessive anabolic activity. The aberrant neural regenerative propensity in AD pathogenesis and the uncontrolled cellular proliferative propensity in cancer pathogeneses can manifest as competitive processes, which could result in the inverse epidemiological correlation seen among the elderly.SummaryThe reduced prevalence of AD in cancer survivors may implicate a strong impact of aberrant neural regenerative burden in neurodegeneration. Further explorative studies into the inverse correlation between AD and cancer should include examinations of the proliferative propensity of tumor cells in AD models, and the development of AD-like neuropathology in cancer models as well as following anti-proliferative drug treatment.
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Insulin-like growth factor binding protein 5 (IGFBP5) mediates methamphetamine-induced dopaminergic neuron apoptosis.
Toxicol. Lett.
PUBLISHED: 08-13-2014
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Overexposure to methamphetamine (METH), a psychoactive drug, induces a variety of adverse effects to the nervous system, including apoptosis of dopaminergic neurons. Insulin-like growth factor binding protein 5 (IGFBP5), a member of insulin-like growth factor (IGF) system, is a pro-apoptotic factor that plays important roles in neuronal apoptosis. To test the hypothesis that IGFBP5 can mediate METH-induced neuronal apoptosis, we examined IGFBP5 mRNA and protein expression changes in PC12 cells exposed to METH (3.0mM) for 24h and in the striatum of rats following 15mg/kg×8 intraperitoneal injections of METH at 12h interval. We also checked the effect on neuronal apoptosis after silencing IGFBP5 expression with TUNEL staining and flow cytometry; Western blot was used for detecting the expression of apoptotic markers active-caspase3 and PARP. To elucidate the mechanisms underlying IGFBP5-mediated neuronal apoptosis, we determined the release of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria after METH treatment with or without IGFBP5 knockdown. Our results showed that IGFBP5 expression was increased significantly after METH exposure in PC12 cells and in the METH-treated rats' striatum. Further, METH-exposed PC12 cells exhibited higher apoptosis-positive cell number and activity of caspase3 and PARP compared with control cells, while these changes can be blocked by silencing IGFBP5 expression. In addition, a significant increase of cyto c release from mitochondria after METH exposure was observed and it was inhibited after silencing IGFBP5 expression in PC12 cells. These results indicate that IGFBP5 plays key roles in METH-induced neuronal apoptosis and may be a potential gene target for therapeutics in METH-caused neurotoxicity.
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[Reconstruction of full-thickness nasal alar defect with combined nasolabial flap and free auricular composite flap].
Zhonghua Zheng Xing Wai Ke Za Zhi
PUBLISHED: 08-13-2014
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To investigate the technique and its effect of combined nasolabial flap and free auricular composite flap for full-thickness nasal alar defect.
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Triterpenoids of Ganoderma theaecolum and their hepatoprotective activities.
Fitoterapia
PUBLISHED: 08-10-2014
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Five new lanostane triterpenoids, ganoderic acid XL1 (1), ganoderic acid XL2 (2), 20-hydroxy-ganoderic acid AM1 (3), ganoderenic acid AM1 (4) and ganoderesin C (5), together with five known triterpenoids (6-10) were isolated from the fruiting bodies of Ganoderma theaecolum. Chemical structures were elucidated on the basis of spectroscopic evidence, including 1D, 2D NMR, mass spectrometric data and circular dichroism spectra. Compounds 1, 4, 5, 8, 9 and 10 (10 ?M) exhibited hepatoprotective activities against DL-galactosamine-induced cell damage in HL-7702 cells.
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Assessment of Transfection of AdCMV-EGFP to Rat Submandibular Gland Cells.
Cell Biochem. Biophys.
PUBLISHED: 08-10-2014
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We evaluated the efficiency of transfecting adenoviral vectors encoding enhanced green fluorescent protein (AdCMV-EGFP) into rat submandibular gland cells and the effects of gene transfer on cell proliferation and secretory function. Isolated submandibular gland cells were transfected with different titers (or multiplicity of infection, MOI) of AdCMV-EGFP. The transfection efficiency was evaluated by quantifying EGFP-positive cells by inverted fluorescence microscopy, cell proliferation by MTT assay, and cell secretory activity by measuring ?-amylase in culture medium. A transfection efficiency of up to 70.8 % was achieved in submandibular gland cells. MTT assay showed that increased viral titers resulted in significant inhibition of cell proliferation, which occurs on day 5 post-transfection. Simultaneously, the amylase levels started to reduce with a significant decrease on day 7 after transfection. The results show that AdCMV-EGFP transfection of submandibular gland cells at higher MOI results in cytotoxicity, decreased cell proliferation, and secretory function. However, the lower adenoviral titers (e.g., 200 particles/cell) could be an efficient and safe labeling tool for gene transfer to submandibular gland cells.
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Synthesis and biological evaluation of 1?,25-dihydroxyvitamin D3 analogues with aromatic side chains attached at C-17.
Eur J Med Chem
PUBLISHED: 08-09-2014
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Two new analogues of the steroid hormone 1?,25-dihydroxyvitamin D3 with aromatic side chains attached at C-17 were designed to investigate their effects on VDR, HL-60 cell differentiation and tumor cell proliferation. These analogues were prepared by the classical photochemical ring opening approach. After the protection of both the 1?- and 3?-hydroxyl in 1?-hydroxydehydroepiandrosterone with TBS groups, followed by bromination with NBS and debromination in the presence of ?-collidine, the diene intermediate was obtained. Hydrazone formation followed by iodine oxidation gave a vinyl iodide. The aromatic side chain at C-17 was introduced via the Negishi coupling of the resulting intermediate with an in situ generated zinc reagent with the substituted aryl bromide (CD-side chain) in the presence of catalytic amount of Pd(PPh3)4. After the removal of the TBDMS and MOM protective groups, followed by UV irradiation and the subsequent thermal reaction, the 1?,25-(OH)2-D3 analogues with a substituted phenyl ring attached at C-17 to replace the C-20 and C-21 were prepared. In the VDR competitive binding assay, compounds 2 and 3 almost lost their binding ability, and were only 0.01% and 0.015% as potent as the 1?,25-dihydroxyvitamin D3. However, compounds 2 and 3 were as potent as 1?,25-(OH)2-D3 in inducing HL-60 cell differentiation at concentrations of 30, 100, 300, 1000 nM, respectively. Moreover, compounds 2 and 3 exhibited similar or better antiproliferative potency against MCF-7 human breast cancer cells, the IC50 values for analogues 2, 3 and the natural hormone were 7.08, 7.56, and 12.5 ?M, respectively.
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Novel bending-resistant design of two-layer low-index trench fiber with parabolic-profile core.
Opt Express
PUBLISHED: 08-05-2014
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A novel design, two-layer low-index trench fiber with parabolic-profile core, is proposed and investigated numerically in this paper. Based on scalar FD-BPM algorithm, the excellent performance over other types of structures and great potential in mode area enlargement are demonstrated. The effective mode area of our design (D = 100?m) is approximately 890 ?m2. Both the high order mode (HOM) suppression and bending resistance of our design are better than that of Multi-Trench Fiber (MTF). The mode loss ratio and effective mode area are independent on the bending radius. Due to the circular symmetry of our proposed configuration design, the bending property is not varied with the changing of bending directions.
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Yolk-shell Fe(0)@SiO2 nanoparticles as nanoreactors for fenton-like catalytic reaction.
ACS Appl Mater Interfaces
PUBLISHED: 08-01-2014
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Yolk-shell nanoparticles (YSNs) with active metal cores have shown promising applications in nanoreactors with excellent catalytic performance. In this work, Fe(0)@SiO2 YSNs were synthesized by a sequential "two-solvents" impregnation-reduction approach. Specifically, FeSO4 aqueous solution was introduced into the preformed hollow mesoporous silica spheres (HMSS), dispersed in n-hexane, via a "two-solvent" impregnation way. Subsequently, aqueous solution of sodium borohydride (NaBH4) was introduced into the cavity of HMSS by the same way, leading to the formation of Fe core inside the HMSS through the reaction between Fe(2+) and NaBH4. The resulting Fe(0)@SiO2 YSNs possess distinctive structures, including active cores, accessible mesoporous channels, protective shells, and hollow cavities. To present the catalytic performance of YSNs nanoreactors, Fenton-like catalytic oxidation of phenol was chosen as the model catalysis reaction. In addition to the Fe(0)@SiO2 YSNs, two other materials were also applied to the catalytic system for comparison, including Fe@SiO2 composites with iron nanoparticles sticking on the outer shells of HMSS (Fe@SiO2-DI) and bare iron nanoparticles without HMSS (bare Fe(0)), respectively. The catalytic results show that Fe(0)@SiO2 YSNs exhibit higher catalytic rate toward phenol removal at 2-fold and 4-fold as compared to that of Fe@SiO2-DI and bare Fe(0), indicating the outstanding catalytic property of YSNs nanoreactors. To further clarify the relationship between catalytic properties and structural characteristics, the adsorption experiments of the three samples were also performed in the absence of H2O2. Other than catalytic results, Fe(0)@SiO2 YSNs show slightly higher adsorption efficiency than the other two samples, indicating the accessibility of nanoreactors. This result demonstrates that the removal of phenol in the oxidation system of Fe(0)@SiO2 YSNs may have contributed to the structure-enhanced effect of YSNs as nanoreactors.
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[Diatoms in drowned and postmortem immersed rabbits' lungs].
Fa Yi Xue Za Zhi
PUBLISHED: 07-31-2014
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To investigate the numbers, sizes and types distribution of diatoms in drowned and postmortem immersed rabbits' lungs.
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Reconstruction of the lower vermilion with a musculomucosal flap from the upper lip in the repair of extensive lower lip and chin defects.
J Craniofac Surg
PUBLISHED: 07-30-2014
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In the repair of extensive lower lip and chin defects, the reconstruction of vermilion at the same time is a great challenge to plastic surgeons. We describe a novel method for the reconstruction of lower vermilion with musculomucosal flap from the upper lip in the repair of extensive lower lip and chin defects. Two patients underwent extensive lower lip and chin reconstruction together with vermilion reconstruction. This technique used 3 basic components: musculomucosal flap from the upper lip, buccal mucosal advancement flap, and cutaneous rotational flap from the neck. All the flaps survived without significant complications. Labial function in the motions of expression and speaking was maintained. The patients could basically close their mouths completely, and there were no drooping or small-mouth deformities postoperatively. Functional and cosmetically acceptable lower-lip and chin reconstructions in both patients were achieved.
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miR-429 represses cell proliferation and induces apoptosis in HBV-related HCC.
Biomed. Pharmacother.
PUBLISHED: 07-29-2014
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MicroRNAs are a class of endogenous non-coding RNAs that regulate gene expression at post-transcriptional level, thus participating in diverse biological pathways. Increasing miRNAs are found to dysregulate hepatocellular carcinoma (HCC) and are involved in liver tumorigenesis. In this study, miR-429 was found to obviously downregulate much more in hepatitis B virus (HBV)-related hepatocellular carcinoma. To evaluate the effects of miR-429, miR-429 was over-expressed in HepG2.2.15 cells. The results have proved that overexpression of miR-429 decreased cell proliferation and induced cell apoptosis. Further, overexpression of miR-429 can suppress the secretion of HBsAg and HBeAg. In concordance to this, the level of NOTCH1 expression was high in human HBV-related HCC tissues and HepG2.2.15 cells. MiR-429 directly targeted NOTCH1 and reduced both mRNA and protein levels of NOTCH1 which stimulated proliferation and suppressed apoptosis in HCC cells. Our results provide new insight into the function of miR-429 in HBV-related HCC. It is beneficial to insight into the mechanism of HBV infection and pathophysiology of HBV-related HCC.
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Carbon-centered radical addition to o?c of amides or esters as a route to c?o bond formations.
Chemistry
PUBLISHED: 07-27-2014
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Among various types of radical reactions, the addition of carbon radicals to unsaturated bonds is a powerful tool for constructing new chemical bonds, in which the typical applied unsaturated substrates include alkenes, alkynes and imines. Carbonyl is perhaps the most common unsaturated group in nature. This work demonstrates a novel C?O bond formation through carbon-centered radical addition to the carbonyl oxygen of amide or ester, in which amide and ester groups are easily activated through the radical process. EPR spectroscopy and radical clock experiments support the radical process for this transformation, and density functional theory (DFT) calculations support the possibility of carbon-centered radical addition to the carbonyl oxygen of amides or esters.
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Direct oxidative esterification of alcohols.
Dalton Trans
PUBLISHED: 07-25-2014
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Esterification is a fundamental transformation in chemistry. Traditional esterification only largely occurs between carboxylic acid derivatives and alcohols, and often involves multistep processes. Developments in the transition-metal-catalysed and metal-free direct esterification of alcohols under oxidative conditions has opened a door to the efficient, sustainable and environmentally friendly synthesis of esters from readily available materials. This Perspective gives an overview which covers the recent development of this emerging field.
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How does airway exposure of aflatoxin B1 affect serum albumin adduct concentrations? Evidence based on epidemiological study and animal experimentation.
J Toxicol Sci
PUBLISHED: 07-25-2014
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Aflatoxin B1 (AFB1) airway inhalation represents an additional route of exposure to this toxin. However, the association between AFB1 inhalation and serum AFB1 albumin adducts remains unclear. The aim of this study was to explore the association between airway exposure to AFB1 and serum AFB1 albumin adduct concentrations via an epidemiological study, as well as in an AFB1 airway exposure animal model. Our epidemiological study was conducted in a sugar factory in the Guangxi Autonomous Region of China. In order to examine fungal contamination, air samples were obtained in the workshop and areas outside the workshop, such as the office and nearby store. Dust samples were also collected from the bagasse warehouse and presser workshop, and were analyzed using an indirect competitive enzyme-linked immunosorbent assay (ELISA). Additionally, blood samples were collected from a total of 121 workshop workers, and a control group (n = 80) was comprised of workers who undertook administrative tasks or other work outside the workshop. The animal experiment was conducted in the laboratory animal center of Guangxi Medical University, where a total of 60 adult male rabbits were involved in this study. By intubation, AFB1 was administered in three groups of rabbits daily, at dose rates of 0.075, 0.05 and 0.025 mg/kg/day for a period of 7 days. Blood samples were collected on day 1, day 3, day 7 and day 21, and the measurements of the AFB1 albumin adducts in the serum were performed by a double antibody sandwich ELISA. The epidemiological study showed that serum albumin adducts were detected in 67 workshop workers (55.37%), and the values ranged 6.4 pg/mg albumin to 212 pg/mg albumin (mean value: 51 ± 4.62 pg/mg albumin). In contrast, serum albumin adducts were detected in only 7 control group participants, with the values ranging from 9 pg AFB1/mg albumin to 59 pg/mg albumin (mean value: 20 ± 13.72 pg/mg albumin). The animal experiment revealed that the rabbits had detectable levels of AFB1 in their serum with a minimum effective dose of 0.05 mg/kg/day; while 11 of 17 (64.71%) rabbits had detectable levels of AFB1 albumin adducts in the high exposure group (0.075 mg/kg/day), and only 5 rabbits (26.32%) had detectable levels of AFB1 albumin adducts in the moderate exposure group (0.05 mg/kg/day). No rabbits had detectable levels of AFB1 albumin adducts in the low exposure group (0.025 mg/kg/day). Our results demonstrated that only exposure to a certain level of AFB1 would result in detectable levels of serum AFB1 albumin adducts. Interventional programs aimed at reducing exposure to AFB1 by inhalation are urgently needed in high-risk populations. Additional large-sample, well-designed randomized controlled trials are needed to further confirm our results.
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miR-185-3p regulates nasopharyngeal carcinoma radioresistance by targeting WNT2B in vitro.
Cancer Sci.
PUBLISHED: 07-24-2014
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Aberrant microRNA (miRNA) expression contributes to a series of malignant cancer behaviors, including radioresistance. Our previous study showed differential expression of miR-185-3p in post-radiation nasopharyngeal carcinoma (NPC) cells. To investigate the role of miR-185-3p in NPC radioresistance, CNE-2 and 5-8F cells were transfected with miR-185-3p mimic and miR-185-3p inhibitor, respectively. CCK-8 assay and colony formation experiment confirmed that the expression of miR-185-3p affected the radioresistance of NPC cells. A negative correlation between miR-185-3p and WNT2B expression was observed in NPC cells and tissues. Luciferase reporter assays confirmed that miR-185-3p directly targeted the coding region of WNT2B. Furthermore, we found radioresistance decreased in WNT2B-silenced NPC cells. Activation of the WNT2B/?-catenin pathway was accompanied by epithelial-mesenchymal transition biomarker changes in NPC. We concluded that miR-185-3p contributed to the radioresistance of NPC via modulation of WNT2B expression in vitro.
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[Preliminary research on multi-neurotransmitters' change regulation in 120 depression patients' brains].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 07-22-2014
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In view of the effective traditional Chinese medicine (TCM) in the treatment of clinical depression, the mechanism is not clear, this study attempts to research the cause of depression in a complex situation to lay the foundation for the next step of TCM curative effect evaluation. Based on the brain wave of 120 depression patients and 40 ordinary person, the change regulation of acetylcholine, dopamine, norepinephrine, depression neurotransmitters and excited neurotransmitters in the whole and various encephalic regions' multi-neurotransmitters of depression patients-serotonin are analysed by search of encephalo-telex (SET) system, which lays the foundation for the diagnosis of depression. The result showed that: contrased with the normal person group, the mean value of the six neurotransmitters in depression patients group are: (1) in the whole encephalic region of depression patients group the dopamine fall (P < 0.05), and in the double centralregions, right temporal region and right parietal region distinct fall (P < 0.01); (2) in the right temporal region of depression patients group the serotonin rise (P < 0.05); (3) in the right central region, left parietal region of depression patients group the acetylcholine fall (P < 0.05), left rear temporal region fall obviously (P < 0.01). The correlation research between antagonizing pairs of neurotransmitters and neurotransmitters: (1) the three antagonizing pairs of neurotransmitters-serotonin and dopamine, acetylcholine and norepinephrine, depression neurotransmitters and excited neurotransmitters, in ordinary person group and depression patients group are characterizeed by middle or strong negative correlation. Serotonin and dopamine, which are characterized by weak negative correlation in the right rear temporal region of ordinary person group, are characterized by strong negative correlation in the other encephalic regions and the whole encephalic (ordinary person group except the right rear temporal region: the range of [r] is [0.82, 0.92], P < 0.01)/(depression patients group:the range of [r] is [0.88, 0.94], P < 0.01); acetylcholine and norepinephrine, in the whole and various encephalic region are characterized by middle negative correlation(ordinary person group:the range of [r] is [0.39, 0.76], P < 0.01 or P < 0.05)/(depression patients group: the range of [Ir] is [0.56, 0.64], P < 0.01); depression neurotransmitters and excited neurotransmitters are characterized by middle strong negative correlation (ordinary person group: the range of [r] is [0.57, 0.80], P < 0.01)/(depression patients group: the range of [r] is [0.68, 0.78], P < 0.01). (2) The two neurotransmitters which are not antagonizing pairs of neurotransmitters, serotonin and excited neurotransmitters, or acetylcholine and depression neurotra-nsmitters, or dopamine and depression neurotransmitters in the various encephalic regions are characterized by weak negative correlation. Serotonin and excited neurotransmitters are characterizeed by weak negative correlation (ordinary person group: in the right central region, left parietal region, double front temporal regions, right rear temporal region, the range of [r] is [0.25, 0.50], P < 0.01 or P < 0.05)/(depression patients group: in the whole encephalic regions, double parietal regions, double occipital regions, right front temporal region, left central region, left frontal region, the range of [r] is [0.18, 0.37], P < 0.01 or P < 0.05); acetylcholine and depression, neurotransmitters are characterized by weak negative correlation (ordinary person group: in the double frontal regions, left parietal region, left front temporal region, right rear temporal region, the range of [r] is [0.31, 0.46], P < 0.01 or P < 0.05)/(depression patients group: in double rear temporal regions, right front temporal region, double occipital regions, left central region, the range of [r] is [0.20, 0.32] , P < 0.01 or P < 0.05); do-pamine and depression neurotransmitters are characterized by weak middle negative correlation (ordinary person group: in left parietal region, right central region, left frontal region, left occipital region, double front temporal regions, the range of [r] is [0.33, 0.68], P < 0.01 or P < 0.05)/(depression patients group: in the whole region and other various regions except the left frontal region, right central region, the range of Irl is [0.21, 0.34], P < 0.01 or P < 0.05). Dopamine and acetylcholine or norepinephrine and serotonin are characterized by weak positive correlation in all encephalic regions. Dopamine and acetylcholine are characterized by weak positive correlation (ordinary person group: in left frontal region, right parietal region, left front temporal region and left rear temporal region, the range of [r] is [0.37, 0.46], P < 0.01)/(depression patients group: in the whole region and the orther various regions except the double central regions, the range of [r] is [0.23, 0.5], P < 0.01 or P < 0.05); norepinephrine and serotonin are characterized by weak positive correlation (ordinary person group: in double front temporal regions, double rear temporal regions, right frontal region and left parietal region, the range of [r] is [0.34, 0.48], P < 0.01 or P < 0.05)/(depression patients group: in the whole and various regions, the range of [r] is [0.18, 0.42], P < 0.01). The main differences between the depression patients group and ordinary person group are: (1) In the whole regin, left frontal region and right central region of depression patients group, the six neurotransmitters all fall normally (P < 0.05). (2) The percent of dopamine falling or including dopamine falling, or including dopamine falling and serotonin rising in depression patients group increases. The percent of dopamine falling or including dopamine falling in the whole region, right frontal region, right central region increases (P < 0.01), such as dopamine decreasing, serotonin increasing dopamine decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing, dopamine decreasing norepinephrine increasing depression neurotransmitters decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing neurotransmitters increasing and so on. (3) The percent of acetylcholine falling, or including acetylcholine falling, or including acetylcholine falling and neurotransmitters (beta)-receptor)rising in depression patients group increases. The percent of acetylcholine falling, or including acetylcholine falling in the right temporal region, double central regions increases (P < 0.05 or P < 0.01), such as acetylcholine decreasing, acetylcholine decreasing neurotransmitters increaseng, acetylcholine decreasing neurotransmitters increasing depression neurotransmitters decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing neurotransmitters increasing and so on. It's showed in research that depression patients' brain are characterized by multi-neurotransmitters abnormal, the synchronous change of multi-neurotransmitters has some certain regularities, which are not the simple linear relation. It's conformed that the three antagonizing pairs, neurotransmitters-serotonin and dopamine, acetylcholine and norepinephrine, depression eurotransmitters and excited neurotransmitters of ordinary person group and depression patients group, are both characterized by strong antagonizing relation, that the two neurotransmitters which are not antagonizing pairs of neurotransmitters are characterized by weak positive correlation or negative correlation, prompt maybe has the indirect causal relationship. And the change of six neurotransmitters in depression patients' various encephalic regions is rather complex. It's conformed preliminarily that the right frontal region and right central region are characterized by dopamine decreasing, acetylcholine decreasing, serotonin increasing dopamine decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing, dopamine decreasing norepinephrine increasing excited neurotransmitters decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing neurotransmitters increasing, acetylchoine decreasing neurotransmitters increasing, acetylcholine decreasing neurotransmitters increasing excited neurotransmitters decreasing and so on. Contrasted with the ordinary person group, the depression patients group have the notable difference.
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Surface grafted chitosan gels. Part I. Molecular insight into the formation of chitosan and poly(acrylic acid) multilayers.
Langmuir
PUBLISHED: 07-18-2014
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Composite polyelectrolyte multilayers of chitosan and low molecular weight poly(acrylic acid) (PAA) have been assembled by sequential adsorption as a first step toward building a surface anchored chitosan gel. Silane chemistry was used to graft the first chitosan layer to prevent film detachment and decomposition. The assembly process is characterized by nonlinear growth behavior, with different adsorption kinetics for chitosan and PAA. In situ analysis of the multilayer by means of surface sensitive total internal reflection Raman (TIRR) spectroscopy, combined with target factor analysis of the spectra, provided information regarding composition, including water content, and ionization state of weak acidic and basic groups present in the thin composite film. Low molecular weight PAA, mainly in its protonated form, diffuses into and out of the composite film during adsorption and rinsing steps. The higher molecular weight chitosan shows a similar behavior, although to a much lower extent. Our data demonstrate that the charged monomeric units of chitosan are mainly compensated by carboxylate ions from PAA. Furthermore, the morphology and mechanical properties of the multilayers were investigated in situ using atomic force microscopy operating in PeakForce tapping mode. The multilayer consists of islands that grow in lateral dimension and height during the build-up process, leading to close to exponentially increasing roughness with deposition number. Both diffusion in and out of at least one of the two components (PAA) and the island-like morphology contribute to the nonlinear growth of chitosan/PAA multilayers.
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Surface grafted chitosan gels. Part II. Gel formation and characterization.
Langmuir
PUBLISHED: 07-18-2014
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Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After cross-linking the chitosan present in the polyelectrolyte multilayer, poly(acrylic acid) is partly removed by exposing the multilayer structure to a concentrated carbonate buffer solution at a high pH, leaving a surface-grafted cross-linked gel. Chemical cross-linking enhances the gel stability against detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross-linking density. The amount of poly(acrylic acid) trapped inside the surface grafted films was found to decrease with decreasing cross-linking density, as confirmed in situ using TIRR, and ex situ by Fourier transform infrared (FTIR) measurements on dried films. The responsiveness of the chitosan-based gels with respect to pH changes was probed by quartz crystal microbalance with dissipation (QCM-D) and TIRR. Highly cross-linked gels show a small and fully reversible behavior when the solution pH is switched between pH 2.7 and 5.7. In contrast, low cross-linked gels are more responsive to pH changes, but the response is fully reversible only after the first exposure to the acidic solution, once an internal restructuring of the gel has taken place. Two distinct pKa's for both chitosan and poly(acrylic acid), were determined for the cross-linked structure using TIRR. They are associated with populations of chargeable groups displaying either a bulk like dissociation behavior or forming ionic complexes inside the hydrogel film.
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Lipid profiling reveals different therapeutic effects of metformin and glipizide in patients with type 2 diabetes and coronary artery disease.
Diabetes Care
PUBLISHED: 07-10-2014
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We recently demonstrated a beneficial effect of metformin compared with glipizide in type 2 diabetic patients regarding cardiovascular outcomes for 3-year treatment in the SPREAD-DIMCAD study. However, the potential mechanism for the clinical effects remains unclear. Here, we performed a comprehensive lipidomics study to evaluate the different lipid metabolites in serum samples obtained from participants in this study.
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Effects of propofol,ginsenoside Rg-1,protein phosphatae-2a,and lithium on the learning and memory in rats and the content of glutamic acid in hippocampus after the electmconrulsive therapy.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao
PUBLISHED: 07-07-2014
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To explore and compare the effects of propofol,ginsenoside Rg-1,protein phosphatae-2A,and lithium on the learning and memory and the concentration of glutamic acid in hippocampus after the electmconrulsive therapy(ECT)in the model of depressed rats induced after the removal of olfactory bulb.
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Proteomic analysis of solid pseudopapillary tumor of the pancreas reveals dysfunction of the endoplasmic reticulum protein processing pathway.
Mol. Cell Proteomics
PUBLISHED: 07-05-2014
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Solid pseudopapillary tumor of the pancreas (SPTP) is a low-grade malignant tumor with a favorable prognosis after surgery. Many previous studies have focused on clinical features or pathological biomarkers of the disease, but a better understanding of the molecular mechanisms underlying SPTP may help guide future therapeutic strategies. Here, we used isobaric tags for relative and absolute quantitation (iTRAQ) technology integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify differentially expressed proteins in SPTP specimens. A total of 1171 proteins with a threshold of a 1.5-fold change and a p value ? 0.05 between SPTP tissue and matched normal pancreas tissue were identified for bioinformatics analysis. Mass spectrometry results were then further confirmed by assessing six representative proteins (ACADL, EPHX2, MSI2, DKK4, JUP, and DAD1) in individual specimens with immunohistochemistry. Upon mapping of the differentially expressed proteins to the Kyoto Encyclopedia of Genes and Genomes pathways database, we found several new cell-adhesion molecules that could be used as pathologic biomarkers. Furthermore, we observed that many endoplasmic reticulum-associated proteins were altered, suggesting that endoplasmic reticulum stress may play an important role in SPTP tumorigenesis. Seven proteins (ERO1LB, TRIM1, GRP94, BIP, SEC61B, P4HB, and PDIA4) in this pathway were further validated by immunohistochemistry, and six of them (except SEC61B) coincided to the LC-MS/MS results. This first comprehensive analysis of the SPTP proteome confirms proteins that have been implicated in earlier reports and reveals novel candidates and pathways that could be investigated further for clinical applications.
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Two new 2,3-seco-hopane triterpene derivatives from Megacodon stylophorus and their antiproliferative and antimicrobial activities.
Planta Med.
PUBLISHED: 07-04-2014
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Chemical investigation of the ethanol extract of the whole plant of Megacodon stylophorus led to the isolation and identification of two new seco-hopane triterpenoids, 2,3-seco-22(29)-hopene-2-carboxyl-3-aldehyde (1) and 2,3-seco-4(23),22(29)-hopene-2-carboxyl-3-aldehyde (2), along with 10 known compounds, 3-12. All the isolates were reported from this plant for the first time. The structures of compounds 1 and 2 were determined by detailed analysis of their spectral data including 1D and 2D?NMR. In addition, compound 1 was further analyzed by X-ray crystallography. Compounds 1-3 were evaluated for their in vitro anti-proliferative activities on HeLa, MCF-7, and Hep-G2 tumor cell lines. Compound 2 was active against the three cell lines with IC50 values of 3.6, 7.5, and 13.6 µM, respectively, while compound 1 exhibited cytotoxicity on MCF-7 (IC50 14.0 µM) and HeLa (IC50 18.2 µM) cell lines. Antimicrobial activities of compounds 1-2 (minimum inhibitory concentration values in the range of 3.12-12.50 mg/mL) were also observed.
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Activation of the AT1R/HIF-1 ? /ACE Axis Mediates Angiotensin II-Induced VEGF Synthesis in Mesenchymal Stem Cells.
Biomed Res Int
PUBLISHED: 06-30-2014
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A local renin-angiotensin system (RAS) is expressed in mesenchymal stem cells (MSCs) and regulates stem cell function. The local RAS influences the survival and tissue repairing ability of transplanted stem cells. We have previously reported that angiotensin II (Ang II) pretreatment can significantly increase vascular endothelial growth factor (VEGF) synthesis in MSCs through the ERK1/2 and Akt pathways via the Ang II receptor type 1 (AT1R). However, the role of angiotensin-converting enzyme (ACE) has not been clarified. Furthermore, whether Ang II pretreatment activates hypoxia-inducible factor-1? (HIF-1?) in MSCs has not been elucidated. Our data show that both ACE and HIF-1? are involved in promoting VEGF expression in MSCs, and that both are upregulated by Ang II stimulation. The upregulation of ACE appeared after the rapid degradation of exogenous Ang II, and led to the formation of endogenous Ang II. On the other hand, the ACE inhibitor, captopril, attenuated Ang II-enhanced HIF-1? upregulation, while HIF-1? suppression markedly attenuated ACE expression. This interesting finding suggests an interaction between ACE and HIF-1?. We conclude that Ang II pretreatment, as a trigger, activated the AT1R/HIF-1?/ACE axis that then mediated Ang II-induced VEGF synthesis in MSCs.
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Use of genome sequencing to assess nucleotide structure variation of Staphylococcus aureus strains cultured in spaceflight on Shenzhou-X, under simulated microgravity and on the ground.
Microbiol. Res.
PUBLISHED: 06-12-2014
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The extreme environment of space could affect microbial behavior and may increase the risk of infectious disease during spaceflight. However, the molecular genetic changes of methicillin-resistant Staphylococcus aureus (MRSA) in response to the spaceflight environment have not been fully clarified. In the present study, we determined the draft genome sequences for an ancestral S. aureus strain (LCT-SAO) isolated from a clinical sample and three derivative strains, LCT-SAS, LCT-SAM and LCT-SAG, cultured in parallel during the spaceflight Shenzhou-X, under simulated microgravity and on the ground, respectively. To evaluate the impact of short-term spaceflight on the MRSA strains, comparative genomic analysis was implemented. Genome-based mapping of toxin genes and antibiotic resistance genes confirmed that these strains have the conventional pathogenicity and resistance to drugs, as none of the strains showed significant changes in these regions after culturing in the three different environments; this result suggests that spaceflight may not change bacterial virulence or drug resistance. Thirty-nine strain-specific sequence variants (SVs) were identified throughout the genomes, and the three derivatives exhibited almost the same mutation rates. Fifty-nine percent of SVs were located in the intergenic regions of the genomes, indicating that S. aureus may have an extremely robust repair mechanism responsible for recognizing and repairing DNA replication mismatches. It is noteworthy that strain LCT-SAS, cultured in space, presented the most unique SVs (n=9) and shared the fewest SVs with LCT-SAM (n=5) and LCT-SAG (n=4). Furthermore, we identified 10 potential deletion regions and 2 potential insertion regions, with LCT-SAS appearing more fragile than other strains by this measure. These results suggest that the environment of space is inherently complicated, with multiple variables, and cannot be simulated in a simple manner. Our results represent the first analysis of nucleotide structure variation of S. aureus strains in a spaceflight environment and also provide a valuable insight for understanding the mutation strategies of MRSA on earth.
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Understanding the commonalities and differences in genomic organizations across closely related bacteria from an energy perspective.
Sci China Life Sci
PUBLISHED: 05-25-2014
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The availability of a large number of sequenced bacterial genomes facilitates in-depth studies about why genes (operons) in a bacterial genome are globally organized the way they are. We have previously discovered that (the relative) transcription- activation frequencies among different biological pathways encoded in a genome have a dominating role in the global arrangement of operons. One complicating factor in such a study is that some operons may be involved in multiple pathways with different activation frequencies. A quantitative model has been developed that captures this information, which tends to be minimized by the current global arrangement of operons in a bacterial (and archaeal) genome compared to possible alternative arrangements. A study is carried out here using this model on a collection of 52 closely related E. coli genomes, which revealed interesting new insights about how bacterial genomes evolve to optimally adapt to their environments through adjusting the (relative) genomic locations of the encoding operons of biological pathways once their utilization and hence transcription activation frequencies change, to maintain the above energy-efficiency property. More specifically we observed that it is the frequencies of the transcription activation of pathways relative to those of the other encoded pathways in an organism as well as the variation in the activation frequencies of a specific pathway across the related genomes that play a key role in the observed commonalities and differences in the genomic organizations of genes (and operons) encoding specific pathways across different genomes.
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Location deterministic biosensing from quantum-dot-nanowire assemblies.
Appl Phys Lett
PUBLISHED: 05-21-2014
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Semiconductor quantum dots (QDs) with high fluorescent brightness, stability, and tunable sizes, have received considerable interest for imaging, sensing, and delivery of biomolecules. In this research, we demonstrate location deterministic biochemical detection from arrays of QD-nanowire hybrid assemblies. QDs with diameters less than 10?nm are manipulated and precisely positioned on the tips of the assembled Gold (Au) nanowires. The manipulation mechanisms are quantitatively understood as the synergetic effects of dielectrophoretic (DEP) and alternating current electroosmosis (ACEO) due to AC electric fields. The QD-nanowire hybrid sensors operate uniquely by concentrating bioanalytes to QDs on the tips of nanowires before detection, offering much enhanced efficiency and sensitivity, in addition to the position-predictable rationality. This research could result in advances in QD-based biomedical detection and inspires an innovative approach for fabricating various QD-based nanodevices.
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Quantitative characterization of the impact of pulp refining on enzymatic saccharification of the alkaline pretreated corn stover.
Bioresour. Technol.
PUBLISHED: 05-14-2014
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In this work, corn stover was refined by a pulp refining instrument (PFI refiner) after NaOH pretreatment under varied conditions. The quantitative characterization of the influence of PFI refining on enzymatic hydrolysis was studied, and it was proved that the enhancement of enzymatic saccharification by PFI refining of the pretreated corn stover was largely due to the significant increment of porosity of substrates and the reduction of cellulose crystallinity. Furthermore, a linear relationship between beating degree and final total sugar yields was found, and a simple way to predict the final total sugar yields by easily testing the beating degree of PFI refined corn stover was established. Therefore, this paper provided the possibility and feasibility for easily monitoring the fermentable sugar production by the simple test of beating degree, and this will be of significant importance for the monitoring and controlling of industrial production in the future.
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S-Nitrosylating protein disulphide isomerase mediates ?-synuclein aggregation caused by methamphetamine exposure in PC12 cells.
Toxicol. Lett.
PUBLISHED: 05-02-2014
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Methamphetamine (METH) belongs to Amphetamine-type stimulants, METH abusers are at high risk of neurodegenerative disorders, including Parkinson's disease (PD). However, there are still no effective treatments to METH-induced neurodegeneration because its mechanism remains unknown. In order to investigate METH's neurotoxic mechanism, we established an in vitro PD pathology model by exposing PC12 cells to METH. We found the expression of nitric oxide synthase (NOS), nitric oxide (NO) and ?-synuclein (?-syn) was significantly increased after METH treatment for 24h, in addition, the aggregattion of ?-syn and the S-nitrosylation of protein disulphideisomerase(PDI) were also obviously enhanced. When we exposed PC12 cells to the NOS inhibitor N-nitro-L-arginine(L-NNA) with METH together, the L-NNA obviously inhibited these changes induced by METH. While when we exposed PC12 cells to the precursor of NO L-Arginine together with METH, the L-Arginine resulted in the opposite effect compared to L-NNA. And when we knocked down the PDI gene, the L-NNA did not have this effect. Therefore, PDI plays a significant role in neurological disorders related to ?-syn aggregation, and it suggests that PDI could be as a potential target to prevent METH-induced neurodegeneration.
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The association of menstrual and reproductive factors with thyroid nodules in Chinese women older than 40 years of age.
Endocrine
PUBLISHED: 04-08-2014
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The purpose of the study was to explore the association of menstrual and reproductive factors with thyroid nodules in Chinese women older than 40 years of age. A questionnaire was completed by 6,571 women aged 40 years or older in a community-based epidemiological investigation of thyroid nodules conducted from June to November 2011 in Nanjing City. Thyroid nodules were measured by ultrasound. The Thyroid Imaging Reporting and Data System score was used to differentiate between benign and possibly malignant nodules. Menopausal age (>55 vs. <50 years: RR = 1.17, 95 % CI 1.00-1.34) and number of reproductive years (>40 vs. <35 years: RR = 1.12, 95 % CI 1.01-1.24) increased the risk of thyroid nodules, but were not associated with suspected malignant nodules. Women who experienced more pregnancies (?5 vs. ?1: RR = 2.09, 95 % CI 1.79-2.40) and abortions (?3 vs. 0: RR = 1.61, 95 % CI 1.41-1.81) were prone to development of thyroid nodules, and more likely to form suspected malignant nodules (pregnancies, RR = 3.59, 95 % CI 1.60-7.20; abortions, RR = 2.36, 95 % CI 1.31-4.06). Furthermore, higher risks of thyroid nodules (RR = 1.36, 95 % CI 1.14-1.59) and suspected malignant nodules (RR = 2.80, 95 % CI 1.08-6.53) were observed in women who had undergone artificial compared with natural abortion. Periods of elevated estrogen and progesterone levels in women, such as pregnancy, were the key occasions for occurrence of both benign and suspiciously malignant thyroid nodules, while longer lifetime length of exposure to female sex hormones might promote the growth of thyroid nodules.
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Mechanisms of TNF? antagonist-induced lupus in a murine model.
PUBLISHED: 04-01-2014
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Objective. TNF? antagonists are effective for treating rheumatoid arthritis and other inflammatory diseases, but their use can be complicated by lupus-like phenomena. We investigated the role of TNF? in murine lupus. Methods. TLR7 ligand-driven lupus was induced in B6 and B6- TNF?(-/-) mice using pristane. Autoantibodies and type I interferon (IFN-I) production were measured and the effects on IFN-I-producing plasmacytoid dendritic cells (pDCs), Ly6C(hi) monocytes, and TNF?-producing neutrophils were determined. Results. TNF?(-/-) mice did not spontaneously develop autoantibodies or clinical manifestations, suggesting that TNF? deficiency alone is insufficient to cause lupus. Although IFN-I levels were comparable in untreated TNF?(-/-) and B6 mice, untreated TNF?(-/-) mice had increased circulating pDCs and "pDC-like" cells, enhancing their potential to make IFN-I. When treated with pristane, TNF?(-/-) mice developed more severe lupus than controls with increased levels of anti-Sm/RNP autoantibodies, IFN-I, pDCs, and peritoneal inflammatory (Ly6C(hi) ) monocytes. Neutrophils, which promoted resolution of inflammation, were decreased considerably in pristane-treated TNF?(-/-) mice, whereas the inflammatory monocyte and pDC responses and IFN-I were increased and prolonged. Conclusions. Low levels of TNF? increased circulating pDC numbers, enhancing the potential to make IFN-I. But this did not lead to IFN-I production or autoimmunity unless there was concomitant exposure to endogenous TLR7 ligands released from dead cells following pristane treatment. In patients, the rate of clearance of dead cells along with TNF? levels may influence who will develop lupus when treated with TNF? inhibitors. © 2014 American College of Rheumatology.
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Protective effect of alpha-synuclein knockdown on methamphetamine-induced neurotoxicity in dopaminergic neurons.
Neural Regen Res
PUBLISHED: 03-24-2014
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The over-expression of ?-synuclein is a major factor in the death of dopaminergic neurons in a methamphetamine-induced model of Parkinson's disease. In the present study, ?-synuclein knockdown rats were created by injecting ?-synuclein-shRNA lentivirus stereotaxically into the right striatum of experimental rats. At 2 weeks post-injection, the rats were injected intraperitoneally with methamphetamine to establish the model of Parkinson's disease. Expression of ?-synuclein mRNA and protein in the right striatum of the injected rats was significantly downregulated. Food intake and body weight were greater in ?-synuclein knockdown rats, and water intake and stereotyped behavior score were lower than in model rats. Striatal dopamine and tyrosine hydroxylase levels were significantly elevated in ?-synuclein knockdown rats. Moreover, superoxide dismutase activity was greater in ?-synuclein knockdown rat striatum, but the levels of reactive oxygen species, malondialdehyde, nitric oxide synthase and nitrogen monoxide were lower compared with model rats. We also found that ?-synuclein knockdown inhibited methamphetamine-induced neuronal apoptosis. These results suggest that ?-synuclein has the capacity to reverse methamphetamine-induced apoptosis of dopaminergic neurons in the rat striatum by inhibiting oxidative stress and improving dopaminergic system function.
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Posterior pedicle screw fixation for complex atlantoaxial fractures with atlanto-dental interval of ¿5 mm or C2-C3 angulation of ¿11°
J Orthop Surg Res
PUBLISHED: 03-06-2014
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ObjectivePrevious studies have demonstrated that the posterior pedicle screw fixation is an effective and safe method to treat atlantoaxial fractures. However, no report focuses on only the complex atlantoaxial fractures with atlanto-dental interval (ADI) of ¿5 mm or C2-C3 angulation of ¿11°.MethodsThis study was to retrospectively evaluate the outcome of 15 patients (six females and nine males; age, 27¿55 years) who underwent posterior pedicle screw fixation for the above complex atlantoaxial fractures between July 2006 and March 2011. Fracture combinations included three Jefferson-type II odontoid, four anterior ring-type II odontoid, two posterior ring-type II odontoid, one lateral mass-type II odontoid, one Jefferson-hangman¿s fracture, three anterior ring-hangman¿s fracture, and one lateral mass-hangman¿s fracture. Fracture healing and bone fusion were determined on X-ray scan. Upper limbs, lower limbs, and sphincter functions were assessed using the Japanese Orthopaedic Association (JOA) score. The Frankel grading system was used to determine the neurological situation.ResultsThe mean operative time, blood loss, and hospital stays were 108.9¿±¿25.8 min, 508.0¿±¿209.6 ml, and 13.3¿±¿2.0 days. Fracture healing and graft fusion were obtained in all patients within 9 months. The ADI or C2-C3 angulation was reduced to ¿5 mm or ¿11°. The JOA score was significantly improved from 7.27¿±¿1.10 preoperatively to 15.7¿±¿2.1 postoperatively (P <0.001), with 88.1¿±¿18.3% recovery rate and 93.3% excellent and good rate. The neurological situation was improved in all patients by at least 1 grade in the Frankel scale. After a mean of 36.5 months of follow-up (range, 18 to 58 months), no operative complications (spinal cord injury, vertebral artery injury, or cerebrospinal fluid leakage) were observed.ConclusionPosterior pedicle screw fixation is a reliable, effective, and minimally invasive procedure for patients suffering from complex atlantoaxial fractures.
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Relationship between lipids levels and right ventricular volume overload in congestive heart failure.
J Geriatr Cardiol
PUBLISHED: 02-26-2014
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The relationship between lipids and coronary artery disease has been well established. However, this is not the case between lipids and heart failure. Ironically, high lipid levels are associated with better outcomes in heart failure, but the mechanisms underlying the phenomenon are not fully understood. This study was performed to test the hypothesis that reduced intestinal lipid absorption due to venous congestion may lead to low lipid levels.
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Photobleaching-induced changes in photosensitizing properties of dissolved organic matter.
Water Res.
PUBLISHED: 02-04-2014
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Photosensitizing properties of different dissolved organic matter (DOM) were investigated according to their performance in singlet oxygen ((1)O2), triplet state of DOM ((3)DOM*), and hydroxyl radical (·OH) productions. The photobleaching of DOM solutions after irradiation was characterized by fluorescence excitation-emission matrix and UV-Vis spectroscopy. The photosensitizing properties of pre-irradiated DOM solutions were changed in a sunlight simulator. The performance of DOMs in photosensitized degradation of several contaminants was investigated. For a 20 h exposure, the observed degradation rate constant (kobs) of some contaminants decreased as a function of exposure time, and highly depended on the properties of both DOM and contaminant. Degradation of contaminants with lower kobs was more susceptible to DOM photobleaching-induced decrease in kobs. Under the current experimental conditions, the photobleaching-induced decrease of DOM photo-reactivity in contaminant degradation was mainly attributed to indirect phototransformation of DOM caused by the interactions between photo-inductive DOM moieties and photochemically-produced reactive species. Reactive contaminants can inhibit DOM indirect photobleaching by scavenging reactive species, photosensitized degradation of these contaminants exhibited a stable kobs as a result. This is the first study to report DOM photobleaching-induced changes in the simultaneous DOM photosensitized degradation of contaminants and the inhibitory effect of reactive contaminants on DOM photobleaching.
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Postmortem genetic screening of SNPs in RyR2 gene in sudden unexplained nocturnal death syndrome in the southern Chinese Han population.
Forensic Sci. Int.
PUBLISHED: 01-23-2014
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To investigate the genetic variants of the RyR2 gene in sudden unexplained nocturnal death syndrome (SUNDS) in the southern Chinese Han population, we genetically screened 29 of the 105 coding exons of the RyR2 gene associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) and arrhythmogenic right ventricular cardiomyopathy (ARVC) in sporadic SUNDS victims using polymerase chain reaction (PCR) and direct sequencing methods. Genomic DNA was extracted from blood samples of 127 SUNDS cases and 165 healthy unrelated controls. None of the published or novel RyR2 missense mutations were found in 127 SUNDS cases. A total of sixteen genetic variants of the RyR2 gene were identified, comprised of: one novel synonymous coding mutation (c.13710C>A), one novel synonymous rare polymorphism (c.14871C>T), and fourteen previously reported polymorphisms. The genotype and allele frequency of previously reported missense polymorphism c.5656G>A (G1886S) was of no statistical difference between SUNDS cases and controls (x(2)=0.390, P>0.05; x(2)=0.271, P>0.05). This is the first report of genetic phenotype of RyR2 gene of SUNDS in the southern Chinese Han population. Previously reported plausible pathogenic missense polymorphism G1886S may not be an independent predisposition factor of SUNDS in the southern Chinese Han population. The association of genetic variants of the RyR2 gene with SUNDS needs further elucidation.
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Impulsive control for synchronizing delayed discrete complex networks with switching topology.
Neural Comput Appl
PUBLISHED: 01-14-2014
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In this paper, global exponential synchronization of a class of discrete delayed complex networks with switching topology has been investigated by using Lyapunov-Ruzimiki method. The impulsive scheme is designed to work at the time instant of switching occurrence. A time-varying delay-dependent criterion for impulsive synchronization is given to ensure the delayed discrete complex networks switching topology tending to a synchronous state. Furthermore, a numerical simulation is given to illustrate the effectiveness of main results.
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A Simple Digestion Method with a Lefort Aqua Regia Solution for Diatom Extraction.
J. Forensic Sci.
PUBLISHED: 01-09-2014
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Presence of diatoms in tissues has been considered as a significant sign of drowning. However, there are limitations in the present extraction methods. We developed a new digestion method using the Lefort aqua regia solution (3:1 nitric acid to hydrochloric acid) for diatom extraction and evaluated the digestive capability, diatom destruction, and diatoms' recovery of this new method. The kidney tissues from rabbit mixed with water rich in diatoms were treated by the Lefort aqua regia digestion method (n = 10) and the conventional acid digestion method (n = 10). The results showed that the digestive capability of Lefort aqua regia digestion method was superior to conventional acid digestion method (p < 0.01); the structure of diatom remained almost intact; and the recovery of diatom was comparable to the conventional acid digestion method (p > 0.05). The Lefort aqua regia reagent is an improvement over the conventional acid digestion for recovery of diatoms from tissue samples.
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Dexamethasone attenuates bleomycin-induced lung fibrosis in mice through TGF-?, Smad3 and JAK-STAT pathway.
Int J Clin Exp Med
PUBLISHED: 01-01-2014
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In order to find the possible mechanism of Dexamethasone (Dex) during curing fibrosis, the bleomycin (BLM)-induced mice model was used. After fibrosis were induced by BLM, histopathological evaluation and RT-PCR were employed to detect the expression of TGF-?1, Smad3 and STAT1. It was found that BLM promoted the development of inflammation, leading to severe pulmonary fibrosis with the increasing of TGF-?1, Smad3 and STAT1. After Dex treatment, the expression of TGF-?1, Smad3 and STAT1 showed a little higher with alleviation of the fibrosis. Thus it is concluded that there is a possible pathway of mouse pulmonary fibrosis model through TGF-?, Smad3 and JAK-STAT pathway.
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Association of Notch1 with vasculogenic mimicry in human hepatocellular carcinoma cell lines.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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According to recent findings, some tumor cells function as endothelial progenitor cells to initiate tumor vasculogenesis, known as "vasculogenic mimicry" (VM). Notch1, the key regulator of vasculogenesis and embryonic differentiation, has shown a correlation with a poor prognosis in hepatocellular carcinoma (HCC). We attempted to elucidate the relationship between Notch1 and the vascularization of HCC.
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Management of combination fractures of the atlas and axis: a report of four cases and literature review.
Int J Clin Exp Med
PUBLISHED: 01-01-2014
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Four cases of combination fractures of the atlas and axis are presented. Three types of management were performed: plaster immobilization, odontoid screw fixation combined with atlantoaxial pedicle screw fixation, occipito-cervical fusion with anterior operation by staged. Based on a literature review and our experience, treatment strategies is discussed according to the stability of the upper cervical spine and neurological involvement, with a reminder that combined injuries in the upper cervical spine should be sought in any patient with a cervical injury and early surgical solution may bring benefits once injury attack.
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Cross-talk between cAMP and MAPK pathways in HSD11B2 induction by hCG in placental trophoblasts.
PLoS ONE
PUBLISHED: 01-01-2014
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Overexposure of the fetus to glucocorticoids in gestation is detrimental to fetal development. The passage of maternal glucocorticoids into the fetal circulation is governed by 11beta-Hydroxysteroid Dehydrogenase Type 2 (HSD11B2) in the placental syncytiotrophoblasts. Human chorionic gonadotropin (hCG) plays an important role in maintaining placental HSD11B2 expression via activation of the cAMP pathway. In this study, we investigated the relationship between the activation of the cAMP pathway by hCG and subsequent phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2) or p38 mitogen-activated protein kinase (MAPK) pathways in the regulation of placental HSD11B2 expression in human placental syncytiotrophoblasts. We found that treatment of the placental syncytiotrophoblasts with either hCG or dibutyl cAMP (dbcAMP) could promote the phosphorylation of p38 and ERK1/2. Inhibition of p38 MAPK with SB203580 not only reduced the basal HSD11B2 mRNA and protein levels but also attenuated HSD11B2 levels induced by either hCG or dbcAMP. By contrast, inhibition of ERK1/2 with PD98059 increased the basal mRNA and protein levels of HSD11B2 and had no effect on HSD11B2 mRNA and protein levels induced by either hCG or dbcAMP. These data suggest that p38 MAPK is involved in both basal and hCG/cAMP-induced expression of HSD11B2, and ERK1/2 may play a role opposite to p38 MAPK at least in the basal expression of HSD11B2 in human placental syncytiotrophoblasts and that there is complicated cross-talk between hCG/cAMP and MAPK cascades in the regulation of placental HSD11B2 expression.
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BMPRIA mediated signaling is essential for temporomandibular joint development in mice.
PLoS ONE
PUBLISHED: 01-01-2014
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The central importance of BMP signaling in the development and homeostasis of synovial joint of appendicular skeleton has been well documented, but its role in the development of temporomandibular joint (TMJ), also classified as a synovial joint, remains completely unknown. In this study, we investigated the function of BMPRIA mediated signaling in TMJ development in mice by transgenic loss-of- and gain-of-function approaches. We found that BMPRIA is expressed in the cranial neural crest (CNC)-derived developing condyle and glenoid fossa, major components of TMJ, as well as the interzone mesenchymal cells. Wnt1-Cre mediated tissue specific inactivation of BmprIa in CNC lineage led to defective TMJ development, including failure of articular disc separation from a hypoplastic condyle, persistence of interzone cells, and failed formation of a functional fibrocartilage layer on the articular surface of the glenoid fossa and condyle, which could be at least partially attributed to the down-regulation of Ihh in the developing condyle and inhibition of apoptosis in the interzone. On the other hand, augmented BMPRIA signaling by Wnt1-Cre driven expression of a constitutively active form of BmprIa (caBmprIa) inhibited osteogenesis of the glenoid fossa and converted the condylar primordium from secondary cartilage to primary cartilage associated with ectopic activation of Smad-dependent pathway but inhibition of JNK pathway, leading to TMJ agenesis. Our results present unambiguous evidence for an essential role of finely tuned BMPRIA mediated signaling in TMJ development.
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