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Find video protocols related to scientific articles indexed in Pubmed.
Elimination life tables of malignant neoplasm and their impact on life expectancy at birth in Kuwait.
East. Mediterr. Health J.
PUBLISHED: 07-05-2014
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The aim of this study was to show the incidence rate of cancer in Kuwait, trends of malignant neoplasm mortality, and estimate the number of years saved as a consequence of eliminating deaths caused by malignant neoplasm (ICD-10). The study applies the techniques of conventional as well as elimination life tables to demonstrate the importance of controlling deaths caused by cancer to the increase in life expectancy at birth. The results confirm that elimination of cancer as a cause of death among Kuwaitis would add 1.80 years to Kuwaiti male and 1.94 years to Kuwaiti female life expectancy at birth. Elimination of cancer among those who would have died from malignant neoplasm is expected to add 1.40 years to males' and 1.85 years to females' life expectancy at birth.
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Computer-Aided Mandibular Reconstruction with Vascularized Iliac Crest Bone Flap and Simultaneous Implant Surgery.
J Oral Implantol
PUBLISHED: 06-20-2014
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Abstract The intention of oral rehabilitation in patients with mandibular defects is an early prosthetic treatment with maximum possible functionality and a high accuracy. The present study describes a new computer-aided technique for mandibular reconstruction using a free vascularized iliac flap and simultaneous insertion of dental implants into the flap while it is still pedicled at the donor site.Based on preoperative computed tomography data of the facial skeleton and the iliac crest donor site, a surgical guide transferred the virtual plan including information on the transplant dimensions and shape as well as the position of the dental implants into real-time surgery. Using postoperative CT scans, the actual situation were compared with the preoperative simulation. A mean difference of 0.75mm (SD: ±0.72) for the flap shape and 0.70mm (SD: ±0.44) for the implant position analysis were determined. The calculation of the closest point distance showed a surface deviation of <2mm for the shape analysis in 93.3% of the values and <1mm for implant position in 75.2% of the values. The mean angular deviation was 3.65°.Virtual surgical planning is a suitable method for mandibular reconstruction with vascularized iliac crest flaps and simultaneous implant surgery. It can be used to restore the anatomy of the mandible with a high accuracy and can help to shorten subsequent dental rehabilitation.
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Genetic diversity and population structure of Sepia officinalis from the Tunisian cost revealed by mitochondrial COI sequences.
Mol. Biol. Rep.
PUBLISHED: 05-24-2014
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Population substructure of Sepia officinalis sampled along the Tunisian coastline was studied. We have scored the genetic variation of the mitochondrial gene cytochrome oxidase 1. A total of 20 specimens from four sampling sites were analysed and revealed 12 different haplotypes. Haplotype diversity showed a decreasing north to south gradient which may be explained by the hydrogeography of the study area. The overall estimate of genetic divergence (FST) revealed significant genetic differentiation between the pair-wise population comparisons supported by the AMOVA analysis which reveals significant genetic divergence. Finally, populations showed an excess of rare haplotypes. The mismatch distribution and several population genetic statistics indicate that the excess of rare variants is due to a recent expansion for Djerba and Kelibia populations. For Rades and Bizerte populations a constant population size was detected. These findings are important for fisheries management to preserve this marine resource for long-term utilization.
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Micelle dynamic simulation and physicochemical characterization of biorelevant media to reflect gastrointestinal environment in fasted and fed states.
Eur J Pharm Biopharm
PUBLISHED: 04-17-2014
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The characterization of biorelevant media simulating the upper part of the gastrointestinal tract in the fasted and fed states was investigated by classical determination of physicochemical parameters such as pH, osmolality, surface tension and results were compared to in vivo physiological data. Incorporation of fatty material, in order to better simulate the influence of high fat meal was also performed. Stability and characterization of this medium was studied and compared to classical FeSSIF. Micelle characterization and computer dynamic simulation were performed in order to understand the interaction between lecithin and taurocholate and possible interactions between mixed micelle and drugs. The addition of NaTc, lecithin, and/or fatty materials has no influence on pH and osmolality, whereas the presence of fatty material modifies the surface tension. Values of FaSSIF and FeSSIF are in accordance with in vivo parameters and the presence of micelles can simulate the gastrointestinal environment. Modelization of micelles by computer simulation led to a model of mixed micelles in which structures of NaTc interact either by their hydrophilic or hydrophobic phase to give a bilayer stable model in which the lecithin molecule can insert its long carbon chain. The micelle structure is stable and can enhance dissolution of hydrophobic molecules by hydrophobic interaction with the numerous hydrophobic spaces available in the multilayer hydrophilic/hydrophobic layer.
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Reactivity of food phenols with iron and copper ions: binding, dioxygen activation and oxidation mechanisms.
Food Funct
PUBLISHED: 04-04-2014
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In this work, the affinity of common dietary phenols (gallic acid, caffeic acid, catechin, and rutin) for iron and copper ions was quantitatively investigated in neutral phosphate buffer as well as the reactivity of the complexes toward dioxygen. Contrasting behaviors were observed: because of the competing phosphate ions, Fe(III) binding is much slower than Fe(II) binding, which is rapidly followed by autoxidation of Fe(II) into Fe(III). With both ions, O2 consumption and H2O2 production are modest and the phenolic ligands are only slowly oxidized. By contrast, metal-phenol binding is fast with both Cu(I) and Cu(II). With Cu(I), O2 consumption and H2O2 production are very significant and the phenolic ligands are rapidly oxidized into a complex mixture of oligomers. The corresponding mechanism with Cu(II) is hampered by the preliminary rate-determining step of Cu(II) reduction by the phenols. The consequences of these findings for the stability and antioxidant activity of plant phenols are discussed.
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Chitin extraction from shrimp shell using enzymatic treatment. Antitumor, antioxidant and antimicrobial activities of chitosan.
Int. J. Biol. Macromol.
PUBLISHED: 04-01-2014
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Chitin was recovered through enzymatic deproteinization of the shrimp processing by-products. Different microbial and fish viscera proteases were tested for their deproteinization efficiency. High levels of protein removal of about 77±3% and 78±2% were recorded using Bacillus mojavensis A21 and Balistes capriscus proteases, respectively, after 3h of hydrolysis at 45°C using an enzyme/substrate ratio of 20U/mg. Therefore, these two crude proteases were used separately for chitin extraction and then chitosan preparation by N-deacetylation. Chitin and chitosan samples were then characterized by 13 Cross polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy and compared to samples prepared through chemical deproteinization. All chitins and chitosans showed identical spectra. Chitosans prepared through enzymatic deproteinization have practically the same acetylation degree but higher molecular weights compared to that obtained through chemical process. Antimicobial, antioxidant and antitumoral activitities of chitosan-M obtained by treatment with A21 proteases and chitosan-C obtained by alkaline treatment were investigated. Results showed that both chitosans inhibited the growth of most Gram-negative, Gram-positive bacteria and fungi tested. Furthermore, both chitosans exhibited antioxidant and antitumor activities which was dependent on the molecular weight.
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Antidiabetic plants improving insulin sensitivity.
J. Pharm. Pharmacol.
PUBLISHED: 02-23-2014
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Globally, the prevalence of diabetes mellitus is increasing at an alarming rate. This chronic pathology gravely troubled the human health and quality of life. Both insulin deficiency and insulin resistance are involved in the pathophysiology of diabetes mellitus. Moreover, insulin resistance is being diagnosed nowadays in a growing population of diabetic and obese patients, especially in industrialized societies. There are lots of conventional agents available to control and to treat diabetes, but total recovery from this disorder has not been reported up to this date. Plants provided a potential source of hypoglycemic drugs and are widely used in several traditional systems of medicine to prevent diabetes. A few reviews with less attention paid to mechanisms of action have been published on antidiabetic plants.
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Fucans from a Tunisian brown seaweed Cystoseira barbata: structural characteristics and antioxidant activity.
Int. J. Biol. Macromol.
PUBLISHED: 02-18-2014
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Sulfated polysaccharides from brown seaweeds are known to be a topic of numerous studies, due to their beneficial biological properties including antioxidant activity. Fucans were isolated from the brown seaweed Cystoseira barbata harvested in Tunisia. ATR-FTIR and (1)H-NMR spectroscopies demonstrated that C. barbata sulfated polysaccharides (CBSPs) consisted mainly of 3-linked-?-l-fucopyranosyl backbone, acetylated and mostly sulfated at C-4. Molar degrees of sulfation and acetylation of CBSPs were 0.79 and 0.27, respectively. Neutral sugars analysis determined by gas chromatography-mass spectrometry (GC-MS) showed that CBSPs were mainly composed of fucose (44.6%) and galactose (34.32%) with few amounts of other sugars such as glucose (7.55%), rhamnose (6.41%), xylose (4.21%) and mannose (2.91%). CBSPs were examined for in vitro antioxidant properties using various antioxidant assays. CBSPs exhibited important DPPH radical-scavenging activity (100% inhibition at a concentration of 1.5mg/ml) and considerable ferric reducing potential (24.62 mg ascorbic acid equivalents). Effective chelating activity and significant protection activity against hydroxyl radical induced DNA breakage were also recorded for CBSPs. However, in the linoleate-?-carotene system, CBSPs exerted moderate antioxidant activity (62% inhibition at a concentration of 1.5mg/ml). Therefore, CBSPs can be used as a potent natural antioxidant in food industry or in the pharmaceutical field.
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Physical, structural, antioxidant and antimicrobial properties of gelatin-chitosan composite edible films.
Int. J. Biol. Macromol.
PUBLISHED: 02-09-2014
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Physico-chemical and mechanical properties of cuttlefish skin gelatin (G), chitosan (C) from shrimp (Penaeus kerathurus) and composite films (G75/C25, G50/C50, G25/C75) plasticized with glycerol were investigated. The results indicated that chitosan film had higher tensile strength and lower elongation at break when compared with the other films. Composite films show no significant difference in tensile strength (TS), thickness and transparency. The structural properties evaluated by FTIR and DSC showed total miscibility between both polymers. DSC scans showed that the increase of chitosan content in the composite films increases the transition temperature (Tg) and enthalpy (?Hg) of films. The morphology study of gelatin, chitosan and composite films showed a compact and homogenous structure. In addition, gelatin and G75/C25 films demonstrated a high antioxidant activities monitored by ?-carotene bleaching, DPPH radical-scavenging and reducing power activities, while films contained chitosan exhibited higher antimicrobial activity against Gram-positive than Gram-negative bacteria.
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[Bipolar disorder and quality of life: A cross-sectional study including 104 Tunisian patients.]
Encephale
PUBLISHED: 02-07-2014
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Bipolar disorder affects many psychosocial and functional aspects, leading to a real social handicap and an alteration in quality of life.
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Usefulness of adjunctive alpha1-adrenergic antagonists after single extracorporeal shock wave lithotripsy session in ureteral stone expulsion.
Can Urol Assoc J
PUBLISHED: 01-24-2014
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We evaluate the efficiency of ?-adrenergic antagonists on stone clearance after extracorporeal shock wave lithotripsy (ESWL) in patients with lower ureteral stones.
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Interspecific and geographical variations of trace metal concentrations in cephalopods from Tunisian waters.
Environ Monit Assess
PUBLISHED: 01-21-2014
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The concentrations of six metals (Ag, Cd, Cu, Hg, Pb, and Zn) were investigated and compared in three tissues (arms, digestive gland, and mantle) of three cephalopod species from the Tunisian waters: the common octopus (Octopus vulgaris), the common cuttlefish (Sepia officinalis), and the European squid (Loligo vulgaris). Whatever the species or the sites, the digestive gland displayed the highest concentrations of Ag, Cd, Cu, Pb, and Zn, highlighting its major role in their bioaccumulation and detoxification. This is also true for Hg but only for the digestive gland of O. vulgaris. Muscle from the arms and the mantle contained thus relatively low trace metal concentrations except for Hg in L. vulgaris and S. officinalis. Geographic comparison of metal concentrations in Tunisian cephalopods from three locations indicates that higher concentrations of Ag, Pb, and Hg were observed in cephalopods from northern and eastern coasts, whereas the highest Cd levels were detected in the southeastern, reflecting different conditions of exposure. Comparing the trace element concentrations between species, Ag, Cd, Cu, Hg, and Zn concentrations were the highest in the digestive gland of octopuses. This may be related to the differences in ecological features and swimming behavior among different cephalopod species. Effects of length and sex on metal levels were also considered, indicating a limited influence of sex on metal concentration.
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Polymer incompatibility as a potential tool for polyphenol recovery from olive mill wastewater.
Food Chem
PUBLISHED: 01-17-2014
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Experiments were designed and preformed in consideration of polymer type (proteins, i.e. caseinate and ovalbumin, and polysaccharides, i.e. alginate and methylcellulose), charge character and polysaccharide concentrations, intended to understand how the polymer properties determine both phase separation and polyphenol partitioning from olive mill wastewater (OMW). The highest yield of polyphenols (YBP=92.9%) was achieved in an aqueous two-phase system (ATPS) using an ovalbumin-methylcellulose system (OMCS) in comparison to ATPS with caseinate-alginate system (CAS; YBP=85.8%) or caseinate methylcellulose system (CMCS; YBP=74%). The performance of CMCS for the ATPS partitioning of polyphenols in OMW was found to depend on the addition of salt (sodium chloride). The use of centrifugation as assistive technology appears to be necessary for the polyphenol partitioning in ATPS using OMCS. In contrast to these polymer systems, CAS caused a rapid ATPS without resorting to centrifugation and salt, mainly because of strong electrostatic repulsion between alginate and caseinate. In this regard, CAS in phase-separated OMW obtained a partition coefficient of protein (KP1) of 0.04, a tie-line length (TLL) of 10.47% (w/w) and a phase volume ratio (VR) of 0.7. Thus, ATPS based on CAS represent an efficient and environmentally friendly concept in recovery of polyphenols from OMW. The spray drying of the caseinate-polyphenol-rich phase from CAS could become a dry intermediate product with potential use in the food and non-food industry.
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Structural differences between chitin and chitosan extracted from three different marine sources.
Int. J. Biol. Macromol.
PUBLISHED: 01-11-2014
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Three marine sources of chitin from Tunisia were investigated. Structural differences between ?-chitin from shrimp (Penaeus kerathurus) waste, crab (Carcinus mediterraneus) shells, and ?-chitin from cuttlefish (Sepia officinalis) bones were studied by the (13)C NMR, FTIR, and XRD diffractograms. The (13)C NMR analysis showed a splitting of the C3 and C5 carbon signals for ?-chitin, while that of ?-chitin was merged into a single resonance. The bands contour of deconvoluted and curve-fit FTIR spectra showed a more detailed structure of ?-chitin in the region of O-H, N-H and CO stretching regions. IR and (13)C NMR were used to determine the chitin degree of acetylation (DA). XRD analysis indicated that ?-chitins were more crystalline polymorph than ?-chitin. Shrimp chitin was obtained with a good yield (20% on raw material dry weight) and no residual protein and salts. Chitosans, with a DA lower than 20% and relatively low molecular masses were prepared from the wet chitins in the same experimental conditions. They were perfectly soluble in acidic medium. Nevertheless, chitin and chitosan characteristics were depending upon the chitin source.
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Bile acid malabsorption assessed by 7 alpha-hydroxy-4-cholesten-3-one in pediatric inflammatory bowel disease: correlation to clinical and laboratory findings.
J Crohns Colitis
PUBLISHED: 01-02-2014
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Measurement of 7 alpha-hydroxy-4-cholesten-3-one (C4) in serum is a semiquantitative test for bile acid malabsorption (BAM). We have previously established pediatric normal values for C4 with an upper limit of normal of 66.5 ng/mL, independent of age and sex. Here we performed the C4 test in 58 pediatric patients with Crohn's disease (CD) and ulcerative colitis (UC).
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The neutron structure of urate oxidase resolves a long-standing mechanistic conundrum and reveals unexpected changes in protonation.
PLoS ONE
PUBLISHED: 01-01-2014
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Urate oxidase transforms uric acid to 5-hydroxyisourate without the help of cofactors, but the catalytic mechanism has remained enigmatic, as the protonation state of the substrate could not be reliably deduced. We have determined the neutron structure of urate oxidase, providing unique information on the proton positions. A neutron crystal structure inhibited by a chloride anion at 2.3 Å resolution shows that the substrate is in fact 8-hydroxyxanthine, the enol tautomer of urate. We have also determined the neutron structure of the complex with the inhibitor 8-azaxanthine at 1.9 Å resolution, showing the protonation states of the K10-T57-H256 catalytic triad. Together with X-ray data and quantum chemical calculations, these structures allow us to identify the site of the initial substrate protonation and elucidate why the enzyme is inhibited by a chloride anion.
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Consumed ischemia of lower limbs in the newborn: a case report.
J Clin Neonatol
PUBLISHED: 11-20-2013
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The limb ischemia is a rare phenomenon in the newborn. It is most often a postnatal ischemia secondary to arterial or venous catheterization, to neonatal infection. Maternal diabetes is most often implicated. The diagnosis implies an urgent situation which may result in extremity gangrene and ultimate loss of limb.
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Enoxaparin for the treatment of recurrent aphthous stomatitis: a pilot exploratory clinical trial.
Minerva Stomatol
PUBLISHED: 09-05-2013
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Low molecular weight derivatives of heparin have been recently suggested for the treatment of different diseases including oral lichen planus (OLP) due to their effectiveness and limited side effects. However, no studies have concerned the effectiveness of these agents in the treatment of recurrent aphthous stomatitis (RAS). The present study then aimed to assess this effectiveness in vivo.
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Inhibition of histone deacetylation and DNA methylation improves gene expression mediated by the adeno-associated virus/phage in cancer cells.
Viruses
PUBLISHED: 09-03-2013
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Bacteriophage (phage), viruses that infect bacteria only, have become promising vectors for targeted systemic delivery of genes to cancer, although, with poor efficiency. We previously designed an improved phage vector by incorporating cis genetic elements of adeno-associated virus (AAV). This novel AAV/phage hybrid (AAVP) specifically targeted systemic delivery of therapeutic genes into tumors. To advance the AAVP vector, we recently introduced the stress-inducible Grp78 tumor specific promoter and found that this dual tumor-targeted AAVP provides persistent gene expression, over time, in cancer cells compared to silenced gene expression from the CMV promoter in the parental AAVP. Herein, we investigated the effect of histone deacetylation and DNA methylation on AAVP-mediated gene expression in cancer cells and explored the effect of cell confluence state on AAVP gene expression efficacy. Using a combination of AAVP expressing the GFP reporter gene, flow cytometry, inhibitors of histone deacetylation, and DNA methylation, we have demonstrated that histone deacetylation and DNA methylation are associated with silencing of gene expression from the CMV promoter in the parental AAVP. Importantly, inhibitors of histone deacetylases boost gene expression in cancer cells from the Grp78 promoter in the dual tumor-targeted AAVP. However, cell confluence had no effect on AAVP-guided gene expression. Our findings prove that combination of histone deacetylase inhibitor drugs with the Grp78 promoter is an effective approach to improve AAVP-mediated gene expression in cancer cells and should be considered for AAVP-based clinical cancer gene therapy.
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Optimization of chitin extraction from shrimp waste with Bacillus pumilus A1 using response surface methodology.
Int. J. Biol. Macromol.
PUBLISHED: 05-14-2013
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Chitin extraction from shrimp shells by biological treatment, using the Bacilli Bacillus pumilus A1, is a non-polluting method and offers the opportunity to preserve the exceptional qualities of chitin and its derivatives. However, the major disadvantage of the fermentative way is the low efficiency of demineralization and deproteinization. The aim of this study is to improve the yield of extraction which depends on many factors, such as the medium composition and the physical parameters. In order to look for the optimal conditions, a Plackett and Burman design was carried out to screen eight factors influencing the deproteinization and demineralization efficiencies. The four most influencing variables were then examined to achieve the optimization using a central composite design. The results obtained showed that the optimal conditions were: shrimp shell concentration of 70 g/l, glucose concentration of 50 g/l, pH of 5.0 incubated with 0.225 OD of B. pumilus A1 inoculum, at 35 °C and 150 rpm for 6 days in 500 ml flask containing 100 ml of working volume. These conditions led to 88% of demineralization and 94% of deproteinization. (13)C CP/MAS NMR spectral analysis of the chitin prepared was carried out and was found to be similar to that of the commercial ?-chitin.
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Retroportal lamina or mesopancreas? Lessons learned by anatomical and histological study of thirty three cadaveric dissections.
Int J Surg
PUBLISHED: 04-17-2013
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Despite its importance in pancreatic head carcinoma, the retroportal lamina is still under studied, with only two anatomical cadaveric dissections in the English literature, with recent controversies about the concept of a mesopancreas.
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[Rare complication of a post-traumatic left diaphragmatic hernia].
Rev Pneumol Clin
PUBLISHED: 01-08-2013
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Diaphragmatic hernia is a post-traumatic lesion specific trauma that may go unnoticed. The left hemidiaphragm is the most frequently affected. The diagnosis is then made at the occasion of a complication, especially gastric volvulus. The authors report the case of a young man aged 26 years old with a gastric volvulus on post-traumatic diaphragmatic hernia diagnosed by CT.
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Comparison of diet consumption, body composition and lipoprotein lipid values of Kuwaiti fencing players with international norms.
J Int Soc Sports Nutr
PUBLISHED: 10-12-2011
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No published data is currently available that describes the dietary patterns or physiological profiles of athletes participating on the Kuwaiti national fencing team and its potential impact on health and physical performance. The purpose of this investigation was to: 1) collect baseline data on nutrient intake 2) collect, analyze and report baseline for body composition, plasma lipid and lipoprotein concentrations during the competitive season, 3) compare the results with the international norms, 4) and provide necessary health and nutritional information in order to enhance the athletes performance and skills.
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Murine typhus in the homeless.
Comp. Immunol. Microbiol. Infect. Dis.
PUBLISHED: 07-29-2011
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Homeless populations are particularly exposed to many vector-borne diseases because of their poor living conditions. We tested sera from 299 homeless people recruited in 2010 and 2011 in Marseilles, France for antibodies to Rickettsia typhi by microimmunofluorescence using a titer of 1:25 as a cut-off titer, and we confirmed the results by Western blot and cross-adsorption studies. Sixty-three persons (22%) had antibodies against R. typhi. The murine typhus seroprevalence rates have significantly increased in homeless populations between the 2000-2003 and 2010-2011 periods. These findings indicate that the homeless are increasingly exposed to flea-borne murine typhus in Marseilles. One might suggest that multiple strikes of sanitation workers resulting in the increase of waste and construction sites combined with the poor living conditions of the homeless expose this population to rodents and their fleas. Further annual studies are necessary to follow rodent-associated diseases among homeless people in Marseille.
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A hemodynamic study of pulmonary hypertension in sickle cell disease.
N. Engl. J. Med.
PUBLISHED: 07-08-2011
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The prevalence and characteristics of pulmonary hypertension in adults with sickle cell disease have not been clearly established.
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[Usefulness and predictive value of PSA density, adjusted by transition zone volume, in men with PSA levels between 2 and 4 ng/ml].
Actas Urol Esp
PUBLISHED: 05-31-2011
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To assess the diagnostic significance of prostate-specific antigen (PSA), density (PSAD) accuracy, and PSAD adjusted by transition zone volume (PSATZD) in men with PSA levels between 2.0 and 4.0 ng/ml.
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ATM and p53 regulate FOXM1 expression via E2F in breast cancer epirubicin treatment and resistance.
Mol. Cancer Ther.
PUBLISHED: 04-25-2011
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In this report, we investigated the role and regulation of forkhead box M1 (FOXM1) in breast cancer and epirubicin resistance. We generated epirubicin-resistant MCF-7 breast carcinoma (MCF-7-EPI(R)) cells and found FOXM1 protein levels to be higher in MCF-7-EPI(R) than in MCF-7 cells and that FOXM1 expression is downregulated by epirubicin in MCF-7 but not in MCF-7-EPI(R) cells. We also established that there is a loss of p53 function in MCF-7-EPI(R) cells and that epirubicin represses FOXM1 expression at transcription and gene promoter levels through activation of p53 and repression of E2F activity in MCF-7 cells. Using p53(-/-) mouse embryo fibroblasts, we showed that p53 is important for epirubicin sensitivity. Moreover, transient promoter transfection assays showed that epirubicin and its cellular effectors p53 and E2F1 modulate FOXM1 transcription through an E2F-binding site located within the proximal promoter region. Chromatin immunoprecipitation analysis also revealed that epirubicin treatment increases pRB (retinoblastoma protein) and decreases E2F1 recruitment to the FOXM1 promoter region containing the E2F site. We also found ataxia-telangiectasia mutated (ATM) protein and mRNA to be overexpressed in the resistant MCF-7-EPI(R) cells compared with MCF-7 cells and that epirubicin could activate ATM to promote E2F activity and FOXM1 expression. Furthermore, inhibition of ATM in U2OS cells with caffeine or depletion of ATM in MCF-7-EPI(R) with short interfering RNAs can resensitize these resistant cells to epirubicin, resulting in downregulation of E2F1 and FOXM1 expression and cell death. In summary, our data show that ATM and p53 coordinately regulate FOXM1 via E2F to modulate epirubicin response and resistance in breast cancer.
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Urate oxidase purification by salting-in crystallization: towards an alternative to chromatography.
PLoS ONE
PUBLISHED: 03-18-2011
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Rasburicase (Fasturtec® or Elitek®, Sanofi-Aventis), the recombinant form of urate oxidase from Aspergillus flavus, is a therapeutic enzyme used to prevent or decrease the high levels of uric acid in blood that can occur as a result of chemotherapy. It is produced by Sanofi-Aventis and currently purified via several standard steps of chromatography. This work explores the feasibility of replacing one or more chromatography steps in the downstream process by a crystallization step. It compares the efficacy of two crystallization techniques that have proven successful on pure urate oxidase, testing them on impure urate oxidase solutions.
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[Evaluation of HER2 protein overexpression in non-muscle-invasive bladder cancer with emphasis on tumour grade and recurrence].
Actas Urol Esp
PUBLISHED: 03-17-2011
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To evaluate the prognostic value of HER2 expression in non-muscle invasive bladder transitional cell carcinoma (TCC) with special emphasis in the high grade population. MATERIALS AND METHODS (PATIENTS): Tissue microarrays (TMA) were performed with representative TUR-B specimens from 84 patients with non-muscle invasive bladder TCC (40 pT1GII and 44 pT1GIII) treated in our institution. Depth of invasion and grade were uniformly assigned by the same pathologist who performed blind immunohistochemical analysis with Hercep test: 3+ was considered strong positive HER2 overexpression. Other clinico-pathological variables were also assessed.
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Caspase signalling controls microglia activation and neurotoxicity.
Nature
PUBLISHED: 03-09-2011
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Activation of microglia and inflammation-mediated neurotoxicity are suggested to play a decisive role in the pathogenesis of several neurodegenerative disorders. Activated microglia release pro-inflammatory factors that may be neurotoxic. Here we show that the orderly activation of caspase-8 and caspase-3/7, known executioners of apoptotic cell death, regulate microglia activation through a protein kinase C (PKC)-?-dependent pathway. We find that stimulation of microglia with various inflammogens activates caspase-8 and caspase-3/7 in microglia without triggering cell death in vitro and in vivo. Knockdown or chemical inhibition of each of these caspases hindered microglia activation and consequently reduced neurotoxicity. We observe that these caspases are activated in microglia in the ventral mesencephalon of Parkinsons disease (PD) and the frontal cortex of individuals with Alzheimers disease (AD). Taken together, we show that caspase-8 and caspase-3/7 are involved in regulating microglia activation. We conclude that inhibition of these caspases could be neuroprotective by targeting the microglia rather than the neurons themselves.
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[Bone scan findings in a North African ethnic group and relation to PSA level and Gleason score of the biopsy].
Actas Urol Esp
PUBLISHED: 03-06-2011
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A number of large-scaled studies carried out in western countries have proven a positive relationship between serum prostate specific antigen (PSA) level and prevalence of positive bone scan findings, in newly diagnosed prostate cancer patients. The aim of our study is to verify that the tendency occurs as well in north-african population, as well as to establish a possible correlation between PSA level, bone scan result, and Gleason score.
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X-ray, ESR, and quantum mechanics studies unravel a spin well in the cofactor-less urate oxidase.
Proteins
PUBLISHED: 02-09-2011
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Urate oxidase (EC 1.7.3.3 or UOX) catalyzes the conversion of uric acid using gaseous molecular oxygen to 5-hydroxyisourate and hydrogen peroxide in absence of any cofactor or transition metal. The catalytic mechanism was investigated using X-ray diffraction, electron spin resonance spectroscopy (ESR), and quantum mechanics calculations. The X-ray structure of the anaerobic enzyme-substrate complex gives credit to substrate activation before the dioxygen fixation in the peroxo hole, where incoming and outgoing reagents (dioxygen, water, and hydrogen peroxide molecules) are handled. ESR spectroscopy establishes the initial monoelectron activation of the substrate without the participation of dioxygen. In addition, both X-ray structure and quantum mechanic calculations promote a conserved base oxidative system as the main structural features in UOX that protonates/deprotonates and activate the substrate into the doublet state now able to satisfy the Wigners spin selection rule for reaction with molecular oxygen in its triplet ground state.
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WITHDRAWN: Endorectal MRI accuracy in auguring tumour location, tumour extent, capsular perforation and seminal vesicle invasion of prostate cancer in north-African men.
Eur J Radiol
PUBLISHED: 01-29-2011
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This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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[Bone mineral density change: comparison between prostate cancer patients with or without metastases and healthy men (a North African ethnic group)].
Actas Urol Esp
PUBLISHED: 01-28-2011
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To evaluate total body bone mineral density and regional bone mineral density in patients with prostate cancer with and without metastases, and to correlate them with bone scintigraphy findings.
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Water-soluble Cp ruthenium complex containing 1,3,5-triaza-7-phosphaadamantane and 8-thiotheophylline derivatives: synthesis, characterization, and antiproliferative activity.
Inorg Chem
PUBLISHED: 01-12-2011
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The new water-soluble ruthenium(II) mononuclear complexes [RuCp(X)(PTA)(L)] (X = 8-thio-theophyllinate (TTH(-)), L = PTA (1), L = PPh(3) (7)); (X = 8-methylthio-theophyllinate (8-MTT(-)), L = PTA (2), L = PPh(3) (8)), (X = 8-benzylthio-theophyllinate (8-BzTT(-)), L = PTA (3), L = PPh(3) (9)) and binuclear complexes [{RuCp(PTA)(L)}(2)-?-(Y-?N7,N7)] (Y = bis(S-8-thiotheophyllinate)methane (MBTT(2-)), L = PTA (4), L = PPh(3) (10)), (Y = 1,2-bis(S-8-thiotheophyllinate)ethane (EBTT(2-)), L = PTA (5), L = PPh(3) (11)), (Y = 1,3-bis(S-8-thiotheophyllinate)propane (PBTT(2-)); L = PTA (6), L = PPh(3) (12)) have been synthesized and characterized by NMR, IR spectroscopy and elemental analysis. The single crystal X-ray structure of [RuCp(8-MTT-?S)(PTA)(2)] (2) was also obtained. The antiproliferative activity of the complexes on cisplatin-sensitive T2 and cisplatin-resistant SKOV3 cell lines has been evaluated.
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[Hyperbaric oxygen therapy adjunctive to surgical debridement in management of Fourniers gangrene: usefulness of a severity index score in predicting disease gravity and patient survival].
Actas Urol Esp
PUBLISHED: 01-01-2011
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Hyperbaric oxygen therapy (HBOT) concomitant to surgery has been reported to reduce Fourniers gangrene (FG) mortality compared to exclusive surgical debridement. Most report from centers with relatively few patients using only surgical procedure. To assess efficiency of aggressive debridement with adjunctive HBOT. To evaluate Fourniers gangrene severity score index (FGSI) predictive value.
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Nutrient uptake and management under saline conditions in the xerohalophyte: Tecticornia indica (Willd.) subsp. indica.
Acta. Biol. Hung.
PUBLISHED: 11-30-2010
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In the present investigation, we studied uptake and management of the major cations in the xerohalophyte, Tecticornia indica (Willd.) subsp. indica as subjected to salinity. Plants were grown under greenhouse conditions at various salinity levels (0, 100, 200 and 400 mM NaCl) over 110 days. At harvest, they were separated into shoots and roots then analyzed for water contents, dry weights (DW), and Na+, K+, Ca²+, and Mg²+ contents. Plants showed a growth optimum at 200 mM NaCl and much better tissue hydration under saline than non-saline conditions. At this salt concentration (200 mM NaCl), shoot Na+ content reached its highest value (7.9 mmol · g-?¹ DW). In spite of such stressful conditions, salt-treated plants maintained adequate K+, Ca²+, and Mg²+ status even under severe saline conditions. This was mainly due to their aptitude to selectively acquire these essential cations and efficiently use them for biomass production.
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Ligand exchange chromatography: a vital dimension for the reliable characterization of heterocycles in crude oils and refined products.
Anal Bioanal Chem
PUBLISHED: 10-20-2010
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In the present study, we established a statistical distribution pattern of indigenous sulfur, nitrogen, and oxygen species in Arabian Heavy crude oil and its distilled fractions: naphtha, gas oil, and vacuum gas oil (VGO) using chemical derivatization with methyl iodide and subsequent characterization by positive electrospray Fourier transform mass spectrometry. It was observed that sulfur species for naphtha and gas oil were accumulated at lower double bond equivalent values and at lower carbon numbers compared to VGO, whereas crude oil encompassed a complete range of the sulfur species detected in all distilled fractions. Moreover, the use of alumina column chromatography and ligand exchange chromatography (LEC) on a palladium-bonded silica stationary phase revealed additional structural features of sulfur heterocycles in terms of condensed and non-condensed thiophenes. During LEC separation, in addition to sulfur heterocycles, interesting results were obtained for oxygen-containing compounds. Ortho-substituted alkyl phenols were separated from meta- and para-substituted alkyl phenols on a palladium-bonded silica stationary phase.
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Epigenetic regulation of cell life and death decisions and deregulation in cancer.
Essays Biochem.
PUBLISHED: 09-09-2010
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For every cell, there is a time to live and a time to die. It is apparent that cell life and death decisions are taken by individual cells based on their interpretation of physiological or non-physiological stimuli, or their own self-assessment of internal damage or changes in their environment. Apoptosis or programmed cell death is a key regulator of physiological growth control and regulation of tissue homoeostasis. One of the most important advances in cancer research in recent years is the recognition that cell death, mostly by apoptosis, is crucially involved in the regulation of tumour formation and also critically determines treatment response. The initiation and progression of cancer, traditionally seen as a genetic disease, is now realized to involve epigenetic abnormalities along with genetic alterations. The study of epigenetic mechanisms in cancer, such as DNA methylation, histone modifications and microRNA expression, has revealed a plethora of events that contribute to the neoplastic phenotype through stable changes in the expression of genes critical to cell death pathways. A better understanding of the epigenetic molecular events that regulate apoptosis, together with the reversible nature of epigenetic aberrations, should contribute to the emergence of the promising field of epigenetic therapy.
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Apoptosis-inducing factor mediates dopaminergic cell death in response to LPS-induced inflammatory stimulus: evidence in Parkinsons disease patients.
Neurobiol. Dis.
PUBLISHED: 09-06-2010
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We show that intranigral lipopolysaccharide (LPS) injection, which provokes specific degeneration of DA neurons, induced caspase-3 activation in the rat ventral mesencephalon, which was mostly associated with glial cells. In contrast, nigral DA neurons exhibited AIF nuclear translocation in response to LPS. A significant decrease of the Bcl-2/Bax ratio in nigral tissue after LPS injection was observed. We next developed an in vitro co-culture system with the microglial BV2 and the DA neuronal MN9D murine cell lines. The silencing of caspase-3 or AIF by small interfering RNAs exclusively in the DA MN9D cells demonstrated the key role of AIF in the LPS-induced death of DA cells. In vivo chemical inhibition of caspases and poly(ADP-ribose)polymerase-1, an upstream regulator of AIF release and calpain, proved the central role of the AIF-dependent pathway in LPS-induced nigral DA cell death. We also observed nuclear translocation of AIF in the ventral mesencephalon of Parkinsons disease subjects.
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Profile of living related kidney donors: a single center experience.
Saudi J Kidney Dis Transpl
PUBLISHED: 09-04-2010
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The living related donor still represents the unique source for renal transplantation in Morocco. Since 1986, 127 living related potential donors have been evaluated and 100 patients have been transplanted at the Ibn Rochd UHC in Casablanca. We retrospectively studied the potential donors and determined their profile and the exclusion criteria. The mean age at the time of donation was 37 ± 11 years (range 18-66 years) and 60% of donors were women. The predominant sources of donors were sisters, brothers and mothers of recipients in 34%, 31% and 24% respectively. Forty three percent of them were married, 20% housewives and 17% unemployed. In addition, 37% were illiterate, 45% school graduates, and 18% university graduates. Donors and recipients were incomplete HLA match in 72.7%, identical in 19% and different in 8.3%. The cross matching test was negative in all cases. The mean plasma creatinine was 0.8 ± 0.1 mg/dL with mean creatinine clearance of 103.16 ± 18.18 mL/min.
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Association of pica with anemia and gastrointestinal distress among pregnant women in Zanzibar, Tanzania.
Am. J. Trop. Med. Hyg.
PUBLISHED: 07-03-2010
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The etiology of pica, the purposive consumption of non-food substances, is not understood, despite its ubiquity among gravidae. We examined correlates of pica in a representative obstetric population (n = 2,368) on Pemba Island, Zanzibar, Tanzania to examine proposed etiologies. Cross-sectional data were collected on socioeconomic characteristics, food intake, geophagy (earth consumption), amylophagy (raw starch consumption), anthropometry, iron status, parasitic burden, and gastrointestinal morbidities. Amylophagy was reported by 36.3%, geophagy by 5.2%, and any pica by 40.1%. There was a strong additive relationship of geophagy and amylophagy with lower hemoglobin (Hb) concentration and iron deficiency anemia. By multivariate logistic regression, any pica was associated with Hb level (odds ratio [OR] = 0.76, 95% confidence interval [CI] = 0.72-0.81), nausea (OR = 1.45, 95% CI = 1.20-1.73), and abdominal pain (OR = 1.22, 95% CI = 1.01-1.48). These striking results indicate that the nature of the relationship between pica, pregnancy, gastrointestinal distress, and iron deficiency anemia merits further investigation.
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[Iatrogenic meningitis after diagnosis lumbar puncture: 3 cases reports in the paediatric Childrens Hospital of Tunis].
Bull Soc Pathol Exot
PUBLISHED: 06-29-2010
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We have collected cases of iatrogenic meningitis managed in the Childrens Hospital of Tunis, between January 1998 and December 2006. Clinical information about each patient were collected, all bacterial samples were investigated in the microbiology laboratory of the hospital. Bacterial isolates were identified according to conventional criteria. In the interval under study, we recorded three cases of iatrogenic meningitis after lumbar puncture. Two cases occurred in newborn admitted for suspicion of neonatal infection and one in a 2-month-old infant admitted for exploration of hyperpyretic convulsion. In all patients, the initial cerebrospinal fluid was normal. All patients developed symptoms of acute meningitis within 72 hours after lumbar puncture; the second cerebrospinal fluid was, then, typical for purulent meningitis. The causal agents isolated in the three cases were Klebsiella pneumoniae, Enterobacter cloacae, and Serratia marcescens, all resistant to beta-lactams by extended spectrum beta-lactamase production. The use of quinolones was required in all cases. Different complications were recorded: hydrocephalus and brain abscess in one case, respiratory and hemodynamic failure managed in the intensive care unit in the second, and brain hygroma in the third case. This study shows high morbidity of iatrogenic meningitis. Simple aseptic precautions undertaken before the procedure of lumbar puncture can prevent such cases. The urgent need for increasing the awareness among medical personnel in hospitals of developing countries cannot be overemphasized.
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A mathematical study of a syntrophic relationship of a model of anaerobic digestion process.
Math Biosci Eng
PUBLISHED: 06-29-2010
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A mathematical model involving the syntrophic relationship of two major populations of bacteria (acetogens and methanogens), each responsible for a stage of the methane fermentation process is proposed. A detailed qualitative analysis is carried out. The local and global stability analyses of the equilibria are performed. We demonstrate, under general assumptions of monotonicity, relevant from an applied point of view, the global asymptotic stability of a positive equilibrium point which corresponds to the coexistence of acetogenic and methanogenic bacteria.
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Molecular geometry and vibrational studies of 3,5-diamino-1,2,4-triazole using quantum chemical calculations and FT-IR and FT-Raman spectroscopies.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 06-15-2010
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The 3,5-diamino-1,2,4-triazole (guanazole) was investigated by vibrational spectroscopy and quantum methods. The solid phase FT-IR and FT-Raman spectra were recorded in the region 4000-400 cm(-1) and 3600-50 cm(-1) respectively, and the band assignments were supported by deuteration effects. The results of energy calculations have shown that the most stable form is 1H-3,5-diamino-1,2,4-triazole under C1 symmetry. For this form, the molecular structure, harmonic vibrational wave numbers, infrared intensities and Raman activities were calculated by the ab initio/HF and DFT/B3LYP methods using 6-31G* basis set. The calculated geometrical parameters of the guanazole molecule using B3LYP methodology are in good agreement with the previously reported X-ray data, and the scaled vibrational wave number values are in good agreement with the experimental data. The normal vibrations were characterized in terms of potential energy distribution (PEDs) using VEDA 4 program.
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Complete genome sequence of Crohns disease-associated adherent-invasive E. coli strain LF82.
PLoS ONE
PUBLISHED: 06-07-2010
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Ileal lesions of Crohns disease (CD) patients are abnormally colonized by pathogenic adherent-invasive Escherichia coli (AIEC) able to invade and to replicate within intestinal epithelial cells and macrophages.
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Cracking the death code: apoptosis-related histone modifications.
Cell Death Differ.
PUBLISHED: 05-14-2010
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The degradation and compaction of chromatin are long-standing hallmark features of apoptosis. The histones, chief protein components of chromatin, are subjected to a wide range of post-translational modifications. An increasing body of evidence suggests that combinations of epigenetic histone modifications influence the overall chromatin structure and have clear functional consequences in cellular processes including apoptosis. This review describes the work to date on the post-translational modification of histones during apoptosis, their regulation by enzymatic complexes and discusses the existence of the apoptotic histone code.
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Near-atomic resolution structures of urate oxidase complexed with its substrate and analogues: the protonation state of the ligand.
Acta Crystallogr. D Biol. Crystallogr.
PUBLISHED: 02-03-2010
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Urate oxidase (uricase; EC 1.7.3.3; UOX) from Aspergillus flavus catalyzes the oxidation of uric acid in the presence of molecular oxygen to 5-hydroxyisourate in the degradation cascade of purines; intriguingly, catalysis proceeds using neither a metal ion (Fe, Cu etc.) nor a redox cofactor. UOX is a tetrameric enzyme with four active sites located at the interface of two subunits; its structure was refined at atomic resolution (1 A) using new crystal data in the presence of xanthine and at near-atomic resolution (1.3-1.7 A) in complexes with the natural substrate (urate) and two inhibitors: 8-nitroxanthine and 8-thiouric acid. Three new features of the structural and mechanistic behaviour of the enzyme were addressed. Firstly, the high resolution of the UOX-xanthine structure allowed the solution of an old structural problem at a contact zone within the tetramer; secondly, the protonation state of the substrate was determined from both a halochromic inhibitor complex (UOX-8-nitroxanthine) and from the H-atom distribution in the active site, using the structures of the UOX-xanthine and the UOX-uric acid complexes; and thirdly, it was possible to extend the general base system, characterized by the conserved catalytic triad Thr-Lys-His, to a large water network that is able to buffer and shuttle protons back and forth between the substrate and the peroxo hole along the reaction pathway.
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Opposing effects of hMOF and SIRT1 on H4K16 acetylation and the sensitivity to the topoisomerase II inhibitor etoposide.
Oncogene
PUBLISHED: 02-01-2010
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Various inhibitors of histone deacetylase (HDAC) activity can sensitize drug resistant cancer cells to chemotherapeutic agents. However, the mechanisms underlying such effects of distinct HDAC inhibitors (HDACi) remain poorly understood. Here we show that both the HDACi trichostatin A and valproic acid induced a sensitization of multidrug-resistant cancer cells to the topoisomerase II inhibitor etoposide/VP16. This effect was associated with increased acetylation of certain lysines on histones H3 and H4, including lysine 16 on histone H4 (H4K16). Overexpression of the histone acetyltransferase hMOF, known to target H4K16, was sufficient to mimic HDACi treatment on sensitization and H4K16 acetylation, and importantly, small-interfering RNA (siRNA)-mediated knockdown of hMOF abolished the HDACi-mediated sensitizing effects as well as the increase in H4K16 acetylation. Conversely, siRNA-mediated knockdown of the H4K16 deacetylase SIRT1 mimicked HDACi treatment whereas overexpression of SIRT1 abolished H4K16 acetylation and significantly reduced the sensitizing effects of HDACi. Interestingly, the effects of hMOF on H4K16 acetylation and sensitization to the topoisomerase II inhibitor could be directly counteracted by exogenous expression of increasing amounts of SIRT1 and vice versa. Our study results suggest that hMOF and SIRT1 activities are critical parameters in HDACi-mediated sensitization of multidrug-resistant cancer cells to topoisomerase II inhibitor and increased H4K16 acetylation.
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[Conservative treatment of an aortoduodenal fistula after paraaortic lymphadenectomy in hepatobiliary malignancy surgery with aortic endoprosthesis].
J Mal Vasc
PUBLISHED: 01-25-2010
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Lower gastrointestinal bleeding from a primary aortoduodenal fistula is unusual and usually fatal. Postoperative aortoduodenal fistula after biliary surgery is a very rare complication. We report hence a 69-year-old female patient who underwent a main bile duct resection with extended paraaortic lymphadenectomy for a cholangiocarcinoma. Acute melena with hemoglobin drop occurred on postoperative day 24. Initial CT-scan showed an aortic pseudoaneurysm with aortoduodenal fistula. An aortic endoprosthesis with endoscopic drainage of periaortic collections allowed successful treatment.
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Anatomical background of the perforator flap based on the deep branch of the superficial circumflex iliac artery (SCIP Flap): a cadaveric study.
Eplasty
PUBLISHED: 01-18-2010
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The groin flap, based on the superficial circumflex iliac artery, was the first successful free flap. However, its popularity was lost essentially due to variable arterial anatomy. Clinical applications of perforator flap based on superficial circumflex iliac artery suggest that a dominant perforator based on his deep branch is enough to supply a large groin flap.
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A highly thermostable antimicrobial peptide from Aspergillus clavatus ES1: biochemical and molecular characterization.
J. Ind. Microbiol. Biotechnol.
PUBLISHED: 01-12-2010
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Antimicrobial peptides (AMPs) are extremely attractive candidates as therapeutic agents due to their wide spectrum of antimicrobial activity and mechanism of action, which differs from that of small-molecule antibiotics. In this study, a 6.0-kDa antimicrobial peptide from Aspergillus clavatus ES1, designated as AcAMP, was isolated by a one-step heat treatment. AcAMP was sensitive to proteolytic enzymes, stable between pH 5.0 and 10.0, and heat resistant (15 min at 100 degrees C). The acamp gene encoding AcAMP peptide was isolated by reverse-transcriptase polymerase chain reaction (RT-PCR) and cloned in pCRII-TOPO vector. Sequence analysis of the complementary DNA (cDNA) acamp gene revealed an open reading frame of 282 bp encoding a peptide of 94 amino acid residues consisting of a 21-aa signal peptide, a 22-aa pro-peptide, and a 51-aa mature peptide. The deduced amino acid sequence showed high identity with other ascomycete antifungal peptides. AcAMP belongs to the group of small, cysteine-rich, basic proteins with antimicrobial activity. In addition to its antifungal activity, AcAMP is the first fungal peptide exhibiting antibacterial activity against several Gram-positive and Gram-negative bacteria. Based on all these features, AcAMP can be considered as a promising new member of the restraint family of ascomycete antimicrobial peptides that might be used in biological control of plant diseases and also for potential applications in food preservation.
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[A case of pancreatic schwannoma successfully treated by enucleation].
Gastroenterol. Clin. Biol.
PUBLISHED: 01-06-2010
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Benign pancreatic schwannoma is a very rare cystic and solid tumor, which poses a diagnostic and therapeutic challenge. Herein, we present a case of 4-cm solitary benign schwannoma of pancreatic uncinate process, with pancreas divisum, incidentally discovered in a 53-year-old woman. Preoperative diagnosis was established by endoscopic ultrasound and fine needle aspiration. Simple enucleation of the tumor from the surrounding parenchyma was successfully performed. No complications were found after the operation.
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Fibrinolytic enzymes from a newly isolated marine bacterium Bacillus subtilis A26: characterization and statistical media optimization.
Can. J. Microbiol.
PUBLISHED: 11-10-2009
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A fibrinolytic enzyme producing bacterium was isolated and identified as Bacillus subtilis A26 on the basis of the 16S rRNA gene sequence. The fibrin zymography analysis reveals the presence of at least three fibrinolytic enzymes. The crude enzyme exhibited maximal activity at 60 degrees C and pH 8.0. Medium composition and culture conditions for the enzyme production by B. subtilis A26 were optimized using two statistical methods. The Plackett-Burman statistical design was applied to find the key ingredients and conditions for the best yield of enzyme production. Five significant variables (hulled grain of wheat, casein peptone, NaCl, CaCl2, and initial pH) were selected for the optimization studies. The response surface methodological approach was used to determine the optimal concentrations and conditions. The optimized medium contained 40.0 g.L-1 hulled grain of wheat, 3.53 g.L-1 casein peptone, 4.0 g.L-1 CaCl2, 3.99 g.L-1 NaCl, 0.01 g.L-1 MgSO4, and 0.01 g.L-1 KH2PO4, pH 7.78. The medium optimization resulted in a 4.2-fold increased level of fibrinolytic production (269.36 U.mL-1) compared with that obtained with the initial medium (63.45 U.mL-1). A successful and significant improvement in the production of protease by the A26 strain was accomplished using inexpensive carbon substrate (hulled grain of wheat), allowing a significant reduction in the cost of medium constituents.
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Association between competition and obligate mutualism in a chemostat.
J Biol Dyn
PUBLISHED: 11-01-2009
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In this paper, we consider a simple chemostat model involving two obligate mutualistic species feeding on a limiting substrate. Systems of differential equations are proposed as models of this association. A detailed qualitative analysis is carried out. We show the existence of a domain of coexistence, which is a set of initial conditions in which both species survive. We demonstrate, under certain supplementary assumptions, the uniqueness of the stable equilibrium point which corresponds to the coexistence of the two species.
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Vitamin D metabolite-mediated hypercalcemia with suppressed parathormone concentration in Pneumocystis jiroveci pneumonia after kidney transplantation.
Transplant. Proc.
PUBLISHED: 10-28-2009
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Pneumocystis jiroveci pneumonia (PJP) is a severe complication in immunocompromised hosts including transplant recipients. Hypercalcemia (HCa) is not a classic symptom of the disease. However, HCa (mean [SD; range], 2.90 [0.20; 2.71-3.17] mmol/L) was detected in 5 patients with PJP at diagnosis. The HCa was associated with decreased concentrations of circulating parathormone (PTH), from 294 (292) ng/L 3 to 6 months previously to 20 (23.5; 7-53) ng/L. Concentrations of 1,25-(OH)2 vitamin D, measured in 3 patients, were in the high normal range (54.66 [7.23; 225-66] microg/L), whereas 25-(OH) vitamin D concentrations were low (13.9 [2.17; 20-60] microg/L). After treatment with trimethoprim-sulfamethoxazole for 21 days, 4 patients recovered and 1 died. Calcium and PTH concentrations rapidly returned to normal (2.36 [0.05] mmol/L and 89 [29.7] ng/L, respectively) at 2 months after the acute phase of the disease. Although fewer than 10 cases of PJP-associated HCa have been reported to date, it is possible that this association is more frequent than previously thought because our cases were detected during 2 years. As in other granulomatous disease-induced HCa, including fungal infections, it is likely that endogenous extrarenal production of 1-alpha-hydroxylase by activated macrophages and by interferon-gamma involved in granuloma formation results in increased conversion from 25-(OH) vitamin D to 1,25-(OH)2 vitamin D and, consequently, in transient HCa and suppression of PTH secretion. Fortuitous detection of HCa in transplant recipients with pulmonary symptoms must raise suspicion of PJP or fungal infection.
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Microwave-assisted water extraction of green tea polyphenols.
Phytochem Anal
PUBLISHED: 07-18-2009
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Green tea, a popular drink with beneficial health properties, is a rich source of specific flavanols (polyphenols). There is a special interest in the water extraction of green tea polyphenols since the composition of the corresponding extracts is expected to reflect the one of green tea infusions consumed worldwide.
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LPS differentially affects vasoconstrictor responses: a potential role for RGS16?
J. Physiol. Biochem.
PUBLISHED: 07-11-2009
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The profound hypotension in septic shock patients is difficult to treat as it is accompanied by depressed constrictor responses to alpha1-adrenoceptor agonists. Bacterial lipopolysaccharide (LPS) is the main trigger for most of the cardiovascular alterations occurring in septic shock. In this study we investigated the effects of LPS exposure on vascular contractility in general and the role of Regulator of G protein Signalling (RGS) proteins in the LPS-induced vascular alterations. Exposure of rat aortic rings to various LPS concentrations (3, 10, 30 microg/ml) for 22 hours differentially affected agonist-induced contractile responses at four distinct G-protein coupled receptors (alpha1-adrenoceptors, angiotensin II, serotonin and endothelin-1 receptors). While the endothelin-1-induced contraction was unaffected by LPS pre-treatment, phenylephrine- and angiotensin II-induced contraction were significantly reduced whereas serotonin-induced contraction was significantly enhanced. Concomitantly, LPS treatment increased the RGS16 mRNA expression both in aortic rings and cultured vascular smooth muscle cells (VSMCs) but not that of RGS2, RGS3, RGS4 or RGS5. The significant increase in RGS16 mRNA expression in VSMCs by LPS was time- and concentration-dependent but independent of increased inducible NO synthase (iNOS) activity. The changes in RGS16 mRNA might contribute to the differential regulation of the contractile responses to vasoconstrictors upon LPS exposure.
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Detection of AMP-activated protein kinase in human sera by immuno-isoelectric focusing.
J. Immunol. Methods
PUBLISHED: 05-19-2009
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AMPKalpha is a subunit of AMP-activated protein kinase (AMPK), a heterotrimeric enzyme that works as a fuel sensor activated in response to the depletion of cellular ATP. AMPKalpha is considered as a master switch in regulating glucose and lipid metabolism. Determining its presence in patient sera may help in diagnosing metabolic diseases. Using isoelectric focusing and Western blotting, we were able to detect AMPKalpha in human sera. Using specific antibodies, we showed that the AMPKalpha1 and alpha2 isoforms were apparently present in equal amounts in human sera. To characterize normal and abnormal AMPKalpha patterns, we used an antibody which recognized both isoforms (alpha1 and alpha2) to analyze sera of patients and healthy individuals. We also analyzed sera of HIV patients because several studies suggest that AMPK may play a role in the mechanism of lipodystrophy in HIV patients under antiretroviral therapy. We found that patients with type 2 diabetes or liver diseases presented abnormal AMPK IEF patterns. AMPK was poorly detectable in sera of patients with end-stage liver disease. Abnormal AMPK IEF patterns were more frequent in treated HIV-patients compared to those who are untreated suggesting a possible association between AMPK and the side-effects of antivirals. Our findings highlight the potential of serum AMPK as a new diagnostic biomarker and may help to study the regulation of AMPK activity in tissues.
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Fibrinolytic serine protease isolation from Bacillus amyloliquefaciens An6 grown on Mirabilis jalapa tuber powders.
Appl. Biochem. Biotechnol.
PUBLISHED: 04-27-2009
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In this study, Mirabilis jalapa tuber powder (MJTP) was used as a new complex organic substrate for the growth and production of fibrinolytic enzymes by a newly isolated Bacillus amyloliquefaciens An6. Maximum protease activity (1,057 U/ml) with casein as a substrate was obtained when the strain was grown in medium containing (grams per liter) MJTP 30, yeast extract 6, CaCl(2) 1, K(2)HPO(4) 0.1, and K(2)HPO(4) 0.1. The strain was also found to grow and produce extracellular proteases in a medium containing only MJTP, indicating that it can obtain its carbon, nitrogen, and salts requirements directly from MJTP. The B. amyloliquefaciens An6 fibrinase (BAF1) was partially purified, and fibrinolytic activity was assayed in a test tube with an artificial fibrin clot. The molecular weight of the partially purified BAF1 fibrinolytic protease was estimated to be 30 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration. The optimum temperature and pH for the caseinolytic activity were 60 degrees C and 9.0, respectively. The enzyme was highly stable from pH 6.0 to 11.0 and retained 62% of its initial activity after 1 h incubation at 50 degrees C. However, the enzyme was inactivated at higher temperatures. The activity of the enzyme was totally lost in the presence of phenylmethylsulfonyl fluoride, suggesting that BAF1 is a serine protease.
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Effects of muscarinic receptor stimulation on Ca2+ transient, cAMP production and pacemaker frequency of rabbit sinoatrial node cells.
Basic Res. Cardiol.
PUBLISHED: 03-04-2009
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We investigated the contribution of the intracellular calcium (Ca (i) (2+) ) transient to acetylcholine (ACh)-mediated reduction of pacemaker frequency and cAMP content in rabbit sinoatrial nodal (SAN) cells. Action potentials (whole cell perforated patch clamp) and Ca (i) (2+) transients (Indo-1 fluorescence) were recorded from single isolated rabbit SAN cells, whereas intracellular cAMP content was measured in SAN cell suspensions using a cAMP assay (LANCE((R))). Our data show that the Ca (i) (2+) transient, like the hyperpolarization-activated "funny current" (I (f)) and the ACh-sensitive potassium current (I (K,ACh)), is an important determinant of ACh-mediated pacemaker slowing. When I (f) and I (K,ACh) were both inhibited, by cesium (2 mM) and tertiapin (100 nM), respectively, 1 micro M ACh was still able to reduce pacemaker frequency by 72%. In these I (f) and I (K,ACh)-inhibited SAN cells, good correlations were found between the ACh-mediated change in interbeat interval and the ACh-mediated change in Ca (i) (2+) transient decay (r (2) = 0.98) and slow diastolic Ca (i) (2+) rise (r (2) = 0.73). Inhibition of the Ca (i) (2+) transient by ryanodine (3 microM) or BAPTA-AM (5 microM) facilitated ACh-mediated pacemaker slowing. Furthermore, ACh depressed the Ca (i) (2+) transient and reduced the sarcoplasmic reticulum (SR) Ca(2+) content, all in a concentration-dependent fashion. At 1 microM ACh, the spontaneous activity and Ca (i) (2+) transient were abolished, but completely recovered when cAMP production was stimulated by forskolin (10 microM) and I (K,ACh) was inhibited by tertiapin (100 nM). Also, inhibition of the Ca (i) (2+) transient by ryanodine (3 microM) or BAPTA-AM (25 microM) exaggerated the ACh-mediated inhibition of cAMP content, indicating that Ca (i) (2+) affects cAMP production in SAN cells. In conclusion, muscarinic receptor stimulation inhibits the Ca (i) (2+) transient via a cAMP-dependent signaling pathway. Inhibition of the Ca (i) (2+) transient contributes to pacemaker slowing and inhibits Ca (i) (2+) -stimulated cAMP production. Thus, we provide functional evidence for the contribution of the Ca (i) (2+) transient to ACh-induced inhibition of pacemaker activity and cAMP content in rabbit SAN cells.
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Activation of sphingosine kinase by muscarinic receptors enhances NO-mediated and attenuates EDHF-mediated vasorelaxation.
Basic Res. Cardiol.
PUBLISHED: 02-14-2009
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Local formation of the sphingomyelin metabolite sphingosine-1-phosphate (S1P) within the vascular wall has been shown to modulate vascular reactivity. In this study we investigated whether sphingosine kinase, the enzyme responsible for S1P synthesis, plays a role in muscarinic receptor-mediated NO production and vascular relaxation in different blood vessel types. For this purpose, sphingosine kinase translocation and sphingolipid-dependent NO-production after muscarinic receptor stimulation were assessed in an endothelial cell line. Furthermore, we used the sphingosine kinase inhibitor N,N-dimethylsphingosine (DMS) to investigate the role of sphingosine kinase in the relaxant responses to the muscarinic agonist methacholine (MCh) in isolated rat aorta and mesenteric arteries. Activation of M(3)-receptors in an endothelial cell line induced a fast translocation of YFP-tagged sphingosine kinase-1 from the cytosol to the plasma membrane. Concomitant NO-production in this cell line was partially inhibited by DMS. Accordingly, in rat aorta the relaxant responses to MCh were attenuated in the presence of DMS, while the responses to the NO-donor sodium nitroprusside were unaltered. In contrast, DMS enhanced the relaxant responses to MCh in mesenteric artery preparations. This effect could also be observed in the presence of NO synthase and cyclooxygenase inhibitors, indicating that sphingosine kinase inhibition specifically enhanced endothelium-derived hyperpolarizing factor-mediated (i.e. non-NO and non-prostacyclin-dependent) relaxation. We conclude that sphingosine kinase differentially regulates vascular tone in different vessel types, enhancing NO-dependent vasorelaxation but counteracting EDHF-dependent vasorelaxation. This observation enhances our understanding of the complex mechanisms by which sphingolipids regulate vascular homeostasis. Moreover, a disturbed regulation of sphingolipid metabolism in the vascular wall may therefore play a role in the aetiology/pathology of disease states characterized by endothelial dysfunction.
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Li(3)Al(MoO(2))(2)O(2)(AsO(4))(2).
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 02-12-2009
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Single crystals of trilithium(I) aluminium(III) bis-[dioxidomolybdenum(VI)] dioxide bis-[arsenate(V)], Li(3)AlMo(2)As(2)O(14), have been prepared by solid-state reaction at 788?K. The structure consists of AsO(4) tetra-hedra, AlO(6) octa-hedra and Mo(2)O(10) groups sharing corners to form a three-dimensional framework containing channels running respectively along the [100] and [010] directions, where the Li(+) ions are located. This structure is compared with compounds having (MX(2)O(12))(n) chains (M = Mo, Al and X = P, As) and others containing M(2)O(10) (M = Mo, Fe) dimers.
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[Antimicrobial susceptibility and serotype distribution of streptococcus pneumoniae isolates in children in Tunis].
Arch Pediatr
PUBLISHED: 02-11-2009
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Streptococcus pneumoniae is a major causative agent of severe infectious diseases. More than 90 pneumococcal serotypes are known, although most invasive and noninvasive diseases are associated with a much smaller number of serotypes. The aim of this study was to determine the antimicrobial susceptibility of S. pneumoniae isolates in children, the distribution of serogroups and serotypes, and the coverage by the serotypes included in the seven-valent pneumococcal conjugate vaccine toward pneumococcal disease. This study investigated 210 nonrepetitive isolates of S. pneumoniae isolated between 1998 and 2004. Antimicrobial susceptibility was tested using the disk diffusion method as determined by the CA-SFM guidelines. Penicillin susceptibility was determined using the oxacillin 5-microg disk screening test. The MICs of penicillin G, amoxicillin, and cefotaxime were determined using the E-test (ABBIODISK). Serotype was determined using rapid latex agglutination (Pneumotest Latex) and the capsular reaction test used antisera from the Staten Serum Institute. The evaluation of susceptibility to ss-lactamins showed that 52.8% of the strains were penicillin non susceptible strains (PNSs), 16.6% had decreased susceptibility to amoxicillin, and 8.5% to cefotaxime. Among noninvasive isolates, 55.2% were PNSs and 50.4% were invasive PNSs. The PNS strains were more frequently resistant to other antibiotics, with 68.4% resistance to erythromycin, 44.1% to trimethoprim-sulfamethoxazole, and 9.9% to chloramphenicol versus 32.3, 11.1, and 1%, respectively, in penicillin-susceptible strains. The predominant serogroups/serotypes of our study were 14 (22%), 23 (14.3%), 19 (11.9%), and 4 (8.5%). The study of the vaccine serotype distribution showed that the theoretical vaccinal coverage of the seven valent vaccines was 62.8% for all the isolates, 55.2% for the invasive isolates, and 67.9% for the PNSs.
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Practical coexistence of two species in the chemostat - a slow-fast characterization.
Math Biosci
PUBLISHED: 01-15-2009
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We show that the chemostat model with two species having different but close break-even concentrations exhibits a slow-fast dynamics. Considering small perturbations about the dilution rate for which break-even concentrations are identical, we use the Fenichel theory to show the coexistence of species for large times. Then we determine the reduced dynamics, which is non-trivial and characterized by the slopes of the growth functions about their break-even concentrations.
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Sphingosine-1-phosphate regulates RGS2 and RGS16 mRNA expression in vascular smooth muscle cells.
Eur. J. Pharmacol.
PUBLISHED: 01-09-2009
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Regulator of G protein signalling (RGS) protein expression is altered under growth promoting conditions in vascular smooth muscle cells (VSMCs). Since sphingosine-1-phosphate (S1P) is an important growth stimulatory factor, we investigated whether stimulation of VSMCs with S1P results in alterations in mRNA expression levels of several RGS proteins and which signalling components are involved. VSMCs were stimulated with S1P and mRNA expression levels of RGS2, RGS3, RGS4, RGS5 and RGS16 were measured by real-time polymerase chain reaction. S1P caused a time-dependent up-regulation of RGS2 and RGS16 mRNA expression. FTY720-P, a S1P(1)/S1P(3-5) agonist, did not regulate RGS2 mRNA levels although it did up-regulate RGS16 mRNA expression. Pertussis toxin treatment revealed that the S1P-induced RGS16 expression was G(i/o)-dependent whereas up-regulation of RGS2 mRNA was not. Phosphatidylinositol 3-kinase, protein kinase C and mitogen-activated protein kinase kinase apparently were not involved in the S1P-induced up-regulation of both RGS proteins. The present study demonstrates that S1P induces RGS2 and RGS16 mRNA expression but uses distinct S1P receptor subtypes and signalling pathways to regulate expression of these RGS proteins.
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Chitin extraction from shrimp shell waste using Bacillus bacteria.
Int. J. Biol. Macromol.
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The ability of six protease-producing Bacillus species (Bacillus pumilus A1, Bacillus mojavencis A21, Bacillus licheniformis RP1, Bacillus cereus SV1, Bacillus amyloliquefaciens An6 and Bacillus subtilis A26) to ferment media containing only shrimp shell waste, for chitin extraction, was investigated. More than 80% deproteinization was attained by all the strains tested. However, demineralization rates not exceeding 67% were registered. Cultures conducted in media containing shrimp shell waste supplemented with 5% (w/v) glucose were found to remarkably promote demineralization efficiency, without affecting deproteinization rates. The antioxidant activities of hydrolysates, at different concentrations, produced during fermentation in medium supplemented with glucose, were determined using different tests: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging method, reducing power assay and chelating activity. All hydrolysates showed varying degrees of antioxidant activity. Hydrolysate produced by B. pumilus A1 exhibited the highest DPPH radical scavenging activity, with an IC(50) value of 0.3 mg/ml. Highest reducing power (DO 700 nm=1.55 at 1.5 mg/ml) and metal chelating activity (98% at 5mg/ml) were obtained with B. pumilus A1 and B. licheniformis RP1 hydrolysates, respectively.
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Molecular structure and vibrational study of diprotonated guanazolium using DFT calculations and FT-IR and FT-Raman spectroscopies.
Spectrochim Acta A Mol Biomol Spectrosc
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The purpose of this manuscript is to discuss our investigations of diprotonated guanazolium chloride using vibrational spectroscopy and quantum chemical methods. The solid phase FT-IR and FT-Raman spectra were recorded in the regions 4000-400cm(-1) and 3600-50cm(-1) respectively, and the band assignments were supported by deuteration effects. Different sites of diprotonation have been theoretically examined at the B3LYP/6-31G level. The results of energy calculations show that the diprotonation process occurs with the two pyridine-like nitrogen N2 and N4 of the triazole ring. The molecular structure, harmonic vibrational wave numbers, infrared intensities and Raman activities were calculated for this form by DFT/B3LYP methods, using a 6-31G basis set. Both the optimized geometries and the theoretical and experimental spectra for diprotonated guanazolium under a stable form are compared with theoretical and experimental data of the neutral molecule reported in our previous work. This comparison reveals that the diprotonation occurs on the triazolic nucleus, and provide information about the hydrogen bonding in the crystal. The scaled vibrational wave number values of the diprotonated form are in close agreement with the experimental data. The normal vibrations were characterized in terms of potential energy distribution (PED) using the VEDA 4 program.
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Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon.
Nanoscale Res Lett
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Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications.
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