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Find video protocols related to scientific articles indexed in Pubmed.
Comparing near-infrared conventional diffuse reflectance spectroscopy and hyperspectral imaging for determination of the bulk properties of solid samples by multivariate regression: determination of Mooney viscosity and plasticity indices of natural rubber.
Analyst
PUBLISHED: 11-20-2014
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Conventional reflectance spectroscopy (NIRS) and hyperspectral imaging (HI) in the near-infrared region (1000-2500 nm) are evaluated and compared, using, as the case study, the determination of relevant properties related to the quality of natural rubber. Mooney viscosity (MV) and plasticity indices (PI) (PI0 - original plasticity, PI30 - plasticity after accelerated aging, and PRI - the plasticity retention index after accelerated aging) of rubber were determined using multivariate regression models. Two hundred and eighty six samples of rubber were measured using conventional and hyperspectral near-infrared imaging reflectance instruments in the range of 1000-2500 nm. The sample set was split into regression (n = 191) and external validation (n = 95) sub-sets. Three instruments were employed for data acquisition: a line scanning hyperspectral camera and two conventional FT-NIR spectrometers. Sample heterogeneity was evaluated using hyperspectral images obtained with a resolution of 150 × 150 ?m and principal component analysis. The probed sample area (5 cm(2); 24?000 pixels) to achieve representativeness was found to be equivalent to the average of 6 spectra for a 1 cm diameter probing circular window of one FT-NIR instrument. The other spectrophotometer can probe the whole sample in only one measurement. The results show that the rubber properties can be determined with very similar accuracy and precision by Partial Least Square (PLS) regression models regardless of whether HI-NIR or conventional FT-NIR produce the spectral datasets. The best Root Mean Square Errors of Prediction (RMSEPs) of external validation for MV, PI0, PI30, and PRI were 4.3, 1.8, 3.4, and 5.3%, respectively. Though the quantitative results provided by the three instruments can be considered equivalent, the hyperspectral imaging instrument presents a number of advantages, being about 6 times faster than conventional bulk spectrometers, producing robust spectral data by ensuring sample representativeness, and minimizing the effect of the presence of contaminants.
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Tunable scattering from liquid crystal devices using carbon nanotubes network electrodes.
Nanoscale
PUBLISHED: 11-20-2014
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Liquid crystals are of technological interest as they allow for optical effects which can be electrically controlled. In this paper we present an electro-optical device consisting of nematic liquid crystals addressed by an electrode structure consisting of thin films of polymer wrapped single walled carbon nanotubes (nanohybrids). Thin films of nanohybrids display excellent optical transmission and electrical conduction properties. Due to the randomly organised nanohybrids these composite films produce interesting director profile arrangements within the liquid crystal layers. As a result, enhanced scattering of laser and white light was observed from these liquid crystal cells which bend themselves as electrically controllable optical diffusers and beam shapers.
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Triboelectricity in insulating polymers: evidence for a mechanochemical mechanism.
Faraday Discuss.
PUBLISHED: 11-20-2014
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Transfer of reaction products formed on the surfaces of two mutually rubbed dielectric solids makes an important if not dominating contribution to triboelectricity. New evidence in support of this statement is presented in this report, based on analytical electron microscopy coupled to electrostatic potential mapping techniques. Mechanical action on contacting surface asperities transforms them into hot-spots for free-radical formation, followed by electron transfer producing cationic and anionic polymer fragments, according to their electronegativity. Polymer ions accumulate creating domains with excess charge because they are formed at fracture surfaces of pulled-out asperities. Another factor for charge segregation is the low polymer mixing entropy, following Flory and Huggins. The formation of fractal charge patterns that was previously described is thus the result of polymer fragment fractal scatter on both contacting surfaces. The present results contribute to the explanation of the centuries-old difficulties for understanding the "triboelectric series" and triboelectricity in general, as well as the dissipative nature of friction, and they may lead to better control of friction and its consequences.
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Resistance to bacteriocins produced by Gram-positive bacteria.
Microbiology (Reading, Engl.)
PUBLISHED: 11-20-2014
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Bacteriocins are prokaryotic proteins or peptides with antimicrobial activity. Most of them exhibit a broad spectrum of activity, inhibiting micro-organisms belonging to different genera and species, including many bacterial pathogens which cause human, animal or plant infections. Therefore, these substances have potential biotechnological applications in either food preservation or prevention and control of bacterial infectious diseases. However, there is concern that continuous exposure of bacteria to bacteriocins may select cells resistant to them, as observed for conventional antimicrobials. Based on the models already investigated, bacteriocin resistance may be either innate or acquired and seems to be a complex phenomenon, arising at different frequencies (generally from 10-9 to 10-2) and by different mechanisms, even among strains of the same bacterial species. In the present review, we will discuss the prevalence, development, and molecular mechanisms involved in resistance to bacteriocins produced by Gram-positive bacteria. These mechanisms generally involve changes in the bacterial cell envelope, which result in (i) reduction or loss of bacteriocin binding or insertion, (ii) bacteriocin sequestering, (iii) bacteriocin efflux pumping (export), and (iii) bacteriocin degradation, among others. Strategies that can be used to overcome this resistance will also be addressed.
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Photoreactivity of a Quantum Dot--Ruthenium Nitrosyl Conjugate.
J Phys Chem A
PUBLISHED: 11-19-2014
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We describe the use of cadmium telluride quantum dots (CdTe QDs) as antennas for the photosensitization of nitric oxide release from a ruthenium nitrosyl complex with visible light excitation. The CdTe QDs were capped with mercaptopropionic acid to make them water-soluble and the ruthenium nitrosyl complex was cis-[Ru(NO)(4-ampy)(bpy)2]3+ (Ru-NO bpy is 2,2' bipyridine and 4-ampy is 4-aminopyridine). Solutions of these two components demonstrated concentration dependent quenching of the QD photoluminescence (PL) as well as photo-induced release of NO from Ru-NO when irradiated by 530 nm light. A NO release enhancement of ~ 8 times resulted from this association was observed under longer wavelength excitation in visible light range. The dynamics of the quenching determined by both PL and transient absorption measurements were probed by ultrafast flash photolysis. A charge transfer mechanism is proposed to explain the quenching of the QD excited states as well as the photo-sensitized release of NO from Ru-NO.
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Unraveling Mycobacterium tuberculosis genomic diversity and evolution in Lisbon, Portugal, a highly drug resistant setting.
BMC Genomics
PUBLISHED: 11-18-2014
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Multidrug- (MDR) and extensively drug resistant (XDR) tuberculosis (TB) presents a challenge to disease control and elimination goals. In Lisbon, Portugal, specific and successful XDR-TB strains have been found in circulation for almost two decades.
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Genome Sequence of Corynebacterium pseudotuberculosis MB20 bv. equi Isolated from a Pectoral Abscess of an Oldenburg Horse in California.
Genome Announc
PUBLISHED: 11-15-2014
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The genome of Corynebacterium pseudotuberculosis MB20 bv. equi was sequenced using the Ion Personal Genome Machine (PGM) platform, and showed a size of 2,363,089 bp, with 2,365 coding sequences and a GC content of 52.1%. These results will serve as a basis for further studies on the pathogenicity of C. pseudotuberculosis bv. equi.
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Draft Genome Sequence of Non-O1 and Non-O139 Vibrio cholerae Strain VCC19.
Genome Announc
PUBLISHED: 11-08-2014
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Vibrio cholerae O1 is the causative agent of cholera and is ubiquitous in the aquatic environment, while V. cholerae strains non-O1 and non-O139 are recognized as causative agents of sporadic and localized outbreaks of diarrhea. Here, we report the complete sequence of a non-O1 and non-O139 V. cholerae strain (VCC19), which was isolated from the environment in Brazil. The sequence includes the integrative conjugative element (ICE). This paper is the first report of the presence of such an element in a V. cholerae strain isolated in Brazil.
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Malignant syphilis in an AIDS patient.
Infection
PUBLISHED: 09-25-2014
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Malignant syphilis is an uncommon, but not unknown, ulcerative variation of secondary syphilis. The lesions typically begin as papules, which quickly evolve to pustules and then to ulcers with elevated edges and central necrosis. It is usually, but not mandatory, found in patients with some level of immunosuppression, such as HIV patients, when the TCD4(+) cell count is >200 cells/mm(3). Despite the anxiety the lesions cause, this form of the disease has a good prognosis. The general symptoms disappear right after the beginning of treatment, and lesions disappear over a variable period. This study reports the case of a 27-year-old man who has been HIV positive for 6 years, uses antiretroviral therapy incorrectly, has a TCD4(+) cell count of 340 cells/mm(3), a VDRL of 1:128 and itchy disseminated hyperchromic maculopapular lesions with rupioid crusts compatible with malignant syphilis.
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C. pseudotuberculosis Phop confers virulence and may be targeted by natural compounds.
Integr Biol (Camb)
PUBLISHED: 09-13-2014
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The bacterial two-component system (TCS) regulates genes that are crucial for virulence in several pathogens. One of such TCS, the PhoPR system, consisting of a transmembrane sensory histidine kinase protein (PhoR) and an intracellular response regulator protein (PhoP), has been reported to have a major role in mycobacterial pathogenesis. We knocked out the phoP in C. pseudotuberculosis, the causal organism of caseous lymphadenitis (CLA), and using a combination of in vitro and in vivo mouse system, we showed for the first time, that the PhoP of C. pseudotuberculosis plays an important role in the virulence and pathogenicity of this bacterium. Furthermore, we modeled the PhoP of C. pseudotuberculosis and our docking results showed that several natural compounds including Rhein, an anthraquinone from Rheum undulatum, and some drug-like molecules may target PhoP to inhibit the TCS of C. pseudotuberculosis, and therefore may facilitate a remarkable attenuation of bacterial pathogenicity being the CLA. Experiments are currently underway to validate these in silico docking results.
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An improved interolog mapping-based computational prediction of protein-protein interactions with increased network coverage.
Integr Biol (Camb)
PUBLISHED: 09-12-2014
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Automated and efficient methods that map ortholog interactions from several organisms and public databases (pDB) are needed to identify new interactions in an organism of interest (interolog mapping). When computational methods are applied to predict interactions, it is important that these methods be validated and their efficiency proven. In this study, we compare six Blast+ metrics over three datasets to identify the best metric for protein-protein interaction predictions. Using Blast+ to align the protein pairs, the ortholog interactions from DIP were mapped to String, Intact and Psibase pDBs. For each interaction mapped to each pDBs, we retrieved the alignment score, e-value, bitscore, similarity, identity and coverage. We evaluated these Blast+ values, and combinations thereof, with the Receiver Operating Characteristic (ROC) curves and computed the Area Under Curve (AUC). To validate these predictions, we used a subset of the Database of Interacting Proteins (DIP) composed of experimental interactions curated by the International Molecular Exchange (IMEx). The cut-off point for each metric/pDB was computed aiming to identify the best one that separates the true and false predicted interactions. In contrast to other methods that only compute the first Blast hit, we considered the first 20 hits, thus increasing the number of predicted interaction pairs. In addition, we identified the contribution of each individual pDB, as well as their combined contribution to the prediction. The best metric had an AUC of 0.96 for a single pDB and AUC of 0.93 for combined pDBs. Compared to other studies, with a cut-off point of 0.70 representing a specificity of 0.95 and a sensitivity of 0.90 for individual pDB, our method efficiently predicts protein-protein interactions.
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Antimicrobial activity of natural products against Helicobacter pylori : a review.
Ann. Clin. Microbiol. Antimicrob.
PUBLISHED: 08-20-2014
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Throughout the genetic and physiological evolution of microorganisms, the microbiological sciences have been expanding the introduction of new therapeutic trials against microbial diseases. Special attention has been paid to the bacterium Helicobacter pylori, which induces gastric infections capable of causing damage, ranging from acute and chronic gastritis to the development of gastric cancer and death. The use of compounds with natural origins has gained popularity in scientific research focused on drug innovation against H. pylori because of their broad flexibility and low toxicity. The aim of this study was to describe the use of natural products against H. pylori in order to clarify important parameters for related fields. The study demonstrated the vast therapeutic possibilities for compounds originating from natural sources and revealed the need for innovations from future investigations to expand the therapeutic arsenal in the fight against H. pylori infection.
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Draft Genome Sequence of Haloferax sp. Strain ATB1, Isolated from a Semi-Arid Region in the Brazilian Caatinga.
Genome Announc
PUBLISHED: 08-14-2014
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Organisms in the Haloferax genus are extreme halophiles that grow in environments with pH values between 4 and 12, and temperatures between 0°C and 60°C. In the present study, a draft of the first Haloferax sp. strain ATB1 genome isolated from the region of Cariri (in Paraíba State, Brazil) is presented.
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Recurrence in intracranial atherosclerotic disease: a stenosis-based analysis.
J Stroke Cerebrovasc Dis
PUBLISHED: 08-08-2014
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Intracranial atherosclerotic disease is a common cause of stroke; its incidence and prevalence vary widely by ethnicity. The aim of our study was to analyze the recurrence rate of cerebrovascular events in patients with symptomatic and asymptomatic intracranial stenosis (IS).
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Evaluation of the sensitivity to zinc of ciliates Euplotes vannus and Euplotes crassus and their naturally associated bacteria isolated from a polluted tropical bay.
Environ Sci Pollut Res Int
PUBLISHED: 08-07-2014
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The aim of this study was to evaluate the Zn sensitivity of Euplotes vannus, Euplotes crassus, and their naturally associated bacteria sampled from sediments in the northwest and east regions of Guanabara Bay. The unexposed ciliates and bacteria did not appear to be negatively affected by 96 h of assay. In the control group, E. vannus exhibited an increase in the biomass content from 2.3?×?10(2) to 2.3?×?10(3) ?g C cm(-3) between 0 and 96 h, and E. crassus increased up to 7.07?×?10(2) ?g C cm(-3) at 48 h. The maximum biomass was pointed by E. crassus (1.33?×?10(3) ?g C cm(-3)) in the presence of 0.005 mg Zn L(-1) and E. vannus was naturally associated bacteria (2.40?×?10(-1) ?g C cm(-3)) in the presence of 1.0 mg Zn L(-1) (96 h). The growth of E. vannus from the northwest region showed concentration-dependent manners, and it is more sensitive to zinc than E. crassus from the southeast. Naturally associated bacteria showed better adaptation to increasing concentrations of Zn, and the Dunnett test showed that previous environmental selection is important. These results show that new bioremediation tools are necessary.
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Hybrid metal grid-polymer-carbon nanotube electrodes for high luminance organic light emitting diodes.
Nanotechnology
PUBLISHED: 08-06-2014
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Organic light emitting diodes (OLEDs) incorporating grid transparent conducting electrodes (TCEs) with wide grid line spacing suffer from an inability to transfer charge carriers across the gaps in the grids to promote light emission in these areas. High luminance OLEDs fabricated using a hybrid TCE composed of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS PH1000) or regioregular poly(3-hexylthiophene)-wrapped semiconducting single-walled carbon nanotubes (rrP3HT-SWCNT) in combination with a nanometre thin gold grid are reported here. OLEDs fabricated using the hybrid gold grid/PH1000 TCE have a luminance of 18 000 cd m(-2) at 9 V; the same as the reference indium tin oxide (ITO) OLED. The gold grid/rrP3HT-SWCNT OLEDs have a lower luminance of 8260 cd m(-2) at 9 V, which is likely due to a rougher rrP3HT-SWCNT surface. These results demonstrate that the hybrid gold grid/PH1000 TCE is a promising replacement for ITO in future plastic electronics applications including OLEDs and organic photovoltaics. For applications where surface roughness is not critical, e.g. electrochromic devices or discharge of static electricity, the gold grid/rrP3HT-SWCNT hybrid TCE can be employed.
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Heart rate, arterial distensibility, and optimal performance of the arterial tree.
J Biomech
PUBLISHED: 07-30-2014
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In this study we explore the ability of a previously developed model of pulsatile flow for explaining the observed reduction of arterial distensibility with heart rate. The parameters relevant for the analysis are arterial wall distensibility together with permeability and reflection coefficients of the end capillaries. A non-specific artery and the ensemble of tissues supplied by that artery were considered in the model. The blood current within that artery was equalized to the sum of all micro currents in the tissues supplied by that artery. A formula emerged that relates changes in arterial distensibility with heart rate, and also with some particular aspects of microcirculation. Then, that formula was tested with data of distensibilities of the radial and carotid arteries observed at the heart rates of 63, 90, and 110 b.p.m. The formula correctly predicted the trend of decreased distensibility with heart rate for both arteries. Moreover, due to the fact that the carotid artery supplies the brain, and because the Blood-Brain barrier is highly restrictive to colloids in the blood, for the carotid artery the formula predicted a less marked decrease in distensibility than in the case of the radial artery feeding muscle tissue, which has a greater permeability to colloids, a trend that was confirmed by data. It was found that reduction of arterial distensibility with heart rate was greater in arteries that supply end capillaries with high permeability and low reflection coefficients.
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Feline sporotrichosis due to Sporothrix brasiliensis : an emerging animal infection in São Paulo, Brazil.
BMC Vet. Res.
PUBLISHED: 07-07-2014
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BackgroundSporotrichosis is a mycotic infectious disease that is generally acquired by traumatic inoculation of contaminated materials especially from plant debris or through bites and scratches from diseased animals, such as domestic cats. It affects the skin, lymphatic system, and other organs in the warm-blooded host. Etiological agents are embedded in the plant-associated order Ophiostomatales. With essential differences between possible outbreak sources and ecological niche, host-environment interactions are classic determinants of risk factors for disease acquisition. Sporotrichosis outbreaks with zoonotic transmission, such as those that are ongoing in southern and southeastern Brazil, have highlighted the threat of cross-species pathogen transmission. Sporothrix brasiliensis has emerged as a human threat owing to the intimate contact pattern between diseased cats and humans in endemic areas.ResultsWe describe the recent emergence of feline sporotrichosis in the metropolitan region of São Paulo, Brazil, with an overwhelming occurrence of S. brasiliensis as the etiological agent. A phylogenetic and a haplotype approach were used to investigate the origin of this epidemic and the impact of feline transmission on genetic diversity. During the last 3-year period, 163 cases of feline sporotrichosis were reported in São Paulo with proven S. brasiliensis culture. The haplotype diversity of feline S. brasiliensis isolates revealed the expansion of a clonal population with low genetic diversity. Haplotype analysis confirmed that isolates from São Paulo shared the haplotype originated in the long-lasting outbreak of cat-transmitted sporotrichosis in Rio de Janeiro, which differed from the haplotype circulating in the Rio Grande do Sul epidemic.ConclusionsThe fast spread of sporotrichosis in a short period of time highlights the potential for outbreaks and suggests that the mycosis may affect an urban population with a high concentration of susceptible felines. The feline sporotrichosis epidemic shows no signs of slowing, and this epidemiological pattern may require specific public health strategies to control future outbreaks.
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Highly conductive and dispersible graphene and its application in P3HT-based solar cells.
Chem. Commun. (Camb.)
PUBLISHED: 06-25-2014
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A simple reduction method without the need for high-temperature annealing is proposed for highly conductive and dispersible graphene sheets. This method consists of the grafting of graphene oxide (GO) with 1-pyrenecarboxylic acid (PCA) and the exothermic reduction of the PCA-grafted GO, followed by an endothermic decarboxylation with refluxing hot water. The PCA-grafted reduced graphene oxide (PCA-rGO) has a high conductivity of ~1.52 × 10(5) S m(-1). Upon incorporating the rGO-PCA in active and electron transport layers of organic solar cells, compared to P3HT-only devices (0.18%) a 16-fold increase in the power conversion efficiency (2.85%) is obtained, attributed to a substantial increase in the short-circuit current density from 0.017 to 12.09 mA cm(-2).
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Safety and neurological assessments after autologous transplantation of bone marrow mesenchymal stem cells in subjects with chronic spinal cord injury.
Stem Cell Res Ther
PUBLISHED: 06-17-2014
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The administration of stem cells holds promise as a potential therapy for spinal cord injury (SCI). Mesenchymal stem cells have advantages for clinical applications, since they can be easily obtained, are suitable for autologous transplantation and have been previously shown to induce regeneration of the spinal cord in experimental settings. Here we evaluated the feasibility, safety and potential efficacy of autologous transplantation of mesenchymal stem cells in subjects with chronic complete SCI.
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?(ECF) factors of gram-positive bacteria: a focus on Bacillus subtilis and the CMNR group.
Virulence
PUBLISHED: 06-12-2014
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The survival of bacteria to different environmental conditions depends on the activation of adaptive mechanisms, which are intricately driven through gene regulation. Because transcriptional initiation is considered to be the major step in the control of bacterial genes, we discuss the characteristics and roles of the sigma factors, addressing (1) their structural, functional and phylogenetic classification; (2) how their activity is regulated; and (3) the promoters recognized by these factors. Finally, we focus on a specific group of alternative sigma factors, the so-called ?(ECF) factors, in Bacillus subtilis and some of the main species that comprise the CMNR group, providing information on the roles they play in the microorganisms' physiology and indicating some of the genes whose transcription they regulate.
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Enzymatic synthesis of poly(catechin)-antibiotic conjugates: an antimicrobial approach for indwelling catheters.
Appl. Microbiol. Biotechnol.
PUBLISHED: 06-06-2014
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Biofilm formation in urinary indwelling catheters is one of the most critical issues that patients face. Catheters were coated with poly(catechin)-antibiotic conjugates with enhanced antimicrobial properties. Catechin was conjugated with two antibiotics, namely trimethoprim (TMP) and sulfamethoxazole (SMZ) via activation with N,N'-disuccinimidyl carbonate (DSC) and subsequent coupling to molecules containing ?-amine moieties. Silicone and polyurethane catheters were functionalized in situ through laccase oxidation of catechin-antibiotic conjugates. Four antimicrobial coatings were produced, namely with poly(catechin), poly(catechin)-TMP, poly(catechin)-SMZ and poly(catechin)-TMP-SMZ. The bacterial adhesion reduction was tested on the functionalized devices using gram-negative and gram-positive strains. The most significant reduction in adhesion was observed with poly(catechin)-TMP (gram-negative -85 % and gram-positive -87 %) and with poly(catechin)-TMP-SMZ (gram-negative -85 % and gram-positive -91 %). The cytotoxicity to mammalian cells was tested by indirect contact for 5 days and revealed that all the tested coatings supported more than 90 % of viable cells. A promising approach for the increase of the indwelling catheter lifespan was developed aiming to reduce catheter-associated chronic infections.
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Structure and adaptation of arteries to pulsatile flow: the case of the ascending aorta.
Med Phys
PUBLISHED: 06-01-2014
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The objectives are: (i) assess the development of the impedance of some arteries during the first decades of life; (ii) determine the influence of pulse rate in arterial impedance; (iii) compare the structure of some arterial segments with optimized structures with respect to blood flow; and (iv) explain the elongation of the ascending aorta throughout life in healthy subjects.
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Reference genes for RT-qPCR studies in Corynebacterium pseudotuberculosis identified through analysis of RNA-seq data.
Antonie Van Leeuwenhoek
PUBLISHED: 05-06-2014
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Reference genes presenting stable expression profiles over a wide variety of conditions are required in relative expression studies of specific bacterial genes by quantitative reverse transcription PCR (RT-qPCR). High-throughput sequencing of bacterial transcriptomes using the RNA-seq methodology now provides a wealth of data that may be searched for identification of the most stably expressed genes of a given bacterium. Herein, we searched a RNA-seq dataset from various experiments with the pathogenic bacterium Corynebacterium pseudotuberculosis, grown under different stress conditions, in order to select appropriate candidate reference genes for this species. Nineteen genes involved in maintenance of basic cellular functions, so-called housekeeping genes, were chosen for study and their expression profiles in C. pseudotuberculosis were evaluated throughout all growth conditions. Eight of these genes (atpA, dnaG, efp, fusA, gyrA, gyrB, rpoB, and rpoC), mostly participating in DNA replication and transcription, matched the defined criteria to be included as candidate reference genes. Transcriptional levels of these genes were quantified by RT-qPCR assays after growth of C. pseudotuberculosis under two additional conditions. Expression stability analysis by NormFinder indicated the combination of genes encoding DNA gyrase subunit A (gyrA) and elongation factor P (fusA) as the most suitable for normalization of RT-qPCR studies in C. pseudotuberculosis.
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[Carotid Atherosclerosis and White Matter Hypodensities: a Controversial Relationship.]
Acta Med Port
PUBLISHED: 04-21-2014
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Introduction: White matter hypodensities of presumed vascular origin, are recognized as an important cause of morbidity with established clinical and cognitive consequences. Nonetheless, many doubts remain on its physiopathology. Our goal is to clarify the potential role of carotid atherosclerosis and other vascular risk factors in the development of white matter hypodensities of presumed vascular origin.Material and Methods: We included patients that underwent CT brain scan and neurosonologic evaluation within a one-month period. Full assessment of vascular risks factors was performed. We seek to find independent associations between white matter hypodensities of presumed vascular origin, carotid intima-media thickness and vascular risk factors.Results: 472 patients were included, mean age was 67.32 (SD: 14.75), 274 (58.1%) were male. The independent predictors of white matter hypodensities of presumed vascular origin were age (OR: 1.067, 95% IC: 1.049 - 1.086, p < 0.001) and hypertension (OR: 1.726, 95% IC: 1.097 - 2.715, p = 0.018). No association was found between IMT (OR: 2.613, 95% IC: 0.886 - 7.708, p = 0.082) or carotid artery stenosis (OR: 1.021, 95% IC: 0.785 - 1.328, p = 0.877) and white matter hypodensities of presumed vascular origin.Discussion: Only age and hypertension proved to have an independent association with white matter hypodensities of presumed vascular origin. Carotid atherosclerosis, evaluated by IMT and the degree of carotid artery stenosis, showed no association with white matter hypodensities of presumed vascular origin. Since atherosclerosis is a systemic pathology, these results suggest that alternative mechanisms are responsible for the development of white matter hypodensities of presumed vascular origin.Conclusion: Age and hypertension seem to be the main factors in the development of white matter hypodensities of presumed vascular origin. No association was found between carotid atherosclerosis and white matter hypodensities of presumed vascular origin.
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Mycobacterial interspersed repetitive unit typing and mutational profile for multidrug-resistant and extensively drug-resistant tuberculosis surveillance in Portugal: a 3-year period overview.
Int. J. Antimicrob. Agents
PUBLISHED: 04-10-2014
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Multidrug tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) cases constitute a serious health problem in Portugal, of which the majority of isolates belong to the Lisboa family and the Q1 cluster, highly related to the Lisboa family. Here we sought to investigate the molecular basis of resistant TB as well as to determine the prevalence of specific drug resistance mutations and their association with MDR-TB and/or XDR-TB. In total, 74 Mycobacterium tuberculosis clinical isolates collected in Lisbon Health Region were genotyped by 24-loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR), and the mutational profile associated with first- and second-line drug resistance was studied. Seven new mutations were found, whilst the remaining 28 mutations had been previously associated with drug resistance. None of the mutations was specifically associated with MDR-TB. The mutational patterns observed among isolates belonging to Lisboa3 and Q1 clusters were also observed in isolates with unique MIRU-VNTR patterns but closely related to these strains. Such data suggest that the genotyping technique employed discriminates isolates with the same mutational profile. To establish the most adequate genotyping technique, the discriminatory power of three different MIRU-VNTR sets was analysed. The 15-loci MIRU-VNTR set showed adequate discriminatory power, comparable with the 24-loci set, allowing clustering of 60% and 86% of the MDR-TB and XDR-TB isolates, respectively, the majority of which belonged to the Lisboa3 and Q1 clusters. From an epidemiological standpoint, this study suggests combined mutational and genotyping analysis as a valuable tool for drug resistance surveillance.
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Ruthenium complexes as NO donors for vascular relaxation induction.
Molecules
PUBLISHED: 04-08-2014
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Nitric oxide (NO) donors are substances that can release NO. Vascular relaxation induction is among the several functions of NO, and the administration of NO donors is a pharmacological alternative to treat hypertension. This review will focus on the physicochemical description of ruthenium-derived NO donor complexes that release NO via reduction and light stimulation. In particular, we will discuss the complexes synthesized by our research group over the last ten years, and we will focus on the vasodilation and arterial pressure control elicited by these complexes. Soluble guanylyl cyclase (sGC) and potassium channels are the main targets of the NO species released from the inorganic compounds. We will consider the importance of the chemical structure of the ruthenium complexes and their vascular effects.
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Design of novel BSA/hyaluronic acid nanodispersions for transdermal pharma purposes.
Mol. Pharm.
PUBLISHED: 04-01-2014
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A novel transdermal hyaluronic acid (HA) conjugated with bovine serum albumin (BSA) was developed in the form of solid-in-oil (S/O) nanodispersion (129.7 nm mean diameter). Ex vivo skin penetration analysis by fluorescence and confocal observation of histological skin sections revealed the ability of BSA/HA nanodispersions to cross the stratum corneum and penetrate into the dermis. Furthermore, no significant toxicity was found in fibroblast and keratinocyte cells in vitro. These results proved the potential of the developed nanodispersion for transdermal delivery of hyaluronic acid constituting a high value to biopharmaceutical and cosmetics industries.
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ZnO nanodisk based UV detectors with printed electrodes.
Langmuir
PUBLISHED: 03-25-2014
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The fabrication of highly functional materials for practical devices requires a deep understanding of the association between morphological and structural properties and applications. A controlled hydrothermal method to produce single crystal ZnO hexagonal nanodisks, nanorings, and nanoroses using a mixed solution of zinc sulfate (ZnSO4) and hexamethylenetetramine (HMTA) without the need of catalysts, substrates, or templates at low temperature (75 °C) is introduced. Metal-semiconductor-metal (MSM) ultraviolet (UV) detectors were fabricated based on individual and multiple single-crystal zinc oxide (ZnO) hexagonal nanodisks. High quality single crystal individual nanodisk devices were fabricated with inkjet-printed silver electrodes. The detectors fabricated show record photoresponsivity (3300 A/W) and external quantum efficiency (1.2 × 10(4)), which we attribute to the absence of grain boundaries in the single crystal ZnO nanodisk and the polarity of its exposed surface.
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Characterization of the Opp peptide transporter of Corynebacterium pseudotuberculosis and its role in virulence and pathogenicity.
Biomed Res Int
PUBLISHED: 03-07-2014
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Despite the economic importance of caseous lymphadenitis (CLA), a chronic disease caused by Corynebacterium pseudotuberculosis, few genes related to the virulence of its etiologic agent have been characterized. The oligopeptide permease (Opp) transporters are located in the plasma membrane and have functions generally related to the uptake of peptides from the extracellular environment. These peptide transporters, in addition to having an important role in cell nutrition, also participate in the regulation of various processes involving intercellular signaling, including the control of the expression of virulence genes in pathogenic bacteria. To study the role of Opp in C. pseudotuberculosis, an OppD deficient strain was constructed via simple crossover with a nonreplicative plasmid carrying part of the oppD gene sequence. As occurred to the wild-type, the ?oppD strain showed impaired growth when exposed to the toxic glutathione peptide (GSH), indicating two possible scenarios: (i) that this component can be internalized by the bacterium through an Opp-independent pathway or (ii) that there is toxicity while the peptide is extracellular. Additionally, the ?oppD mutant presented a reduced ability to adhere to and infect macrophages compared to the wild-type, although both strains exhibit the same potential to colonize spleens and cause injury and death to infected mice.
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Omics profiles used to evaluate the gene expression of Exiguobacterium antarcticum B7 during cold adaptation.
BMC Genomics
PUBLISHED: 02-26-2014
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Exiguobacterium antarcticum strain B7 is a Gram-positive psychrotrophic bacterial species isolated in Antarctica. Although this bacteria has been poorly studied, its genome has already been sequenced. Therefore, it is an appropriate model for the study of thermal adaptation. In the present study, we analyzed the transcriptomes and proteomes of E. antarcticum B7 grown at 0[degree sign]C and 37[degree sign]C by SOLiD RNA-Seq, Ion Torrent RNA-Seq and two-dimensional difference gel electrophoresis tandem mass spectrometry (2D-DIGE-MS/MS).
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An iron-acquisition-deficient mutant of Corynebacterium pseudotuberculosis efficiently protects mice against challenge.
Vet. Res.
PUBLISHED: 02-25-2014
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Caseous lymphadenitis (CLA) is a chronic disease that affects sheep and goats worldwide, and its etiological agent is Corynebacterium pseudotuberculosis. Despite the economic losses caused by CLA, there is little information about the molecular mechanisms of bacterial pathogenesis, and current immune prophylaxis against infection has been unable to reduce the incidence of CLA in goats. Recently, 21 different mutant strains of C. pseudotuberculosis were identified by random mutagenesis. In this study, these previously generated mutants were used in mice vaccination trials to develop new immunogens against CLA. Based on this analysis, CZ171053, an iron-acquisition-deficient mutant strain, was selected. After challenge with a virulent strain, 80% of the animals that were immunized with the CZ171053 strain survived. Furthermore, this vaccination elicited both humoral and cellular responses. Intracellular survival of the bacterium was determined using murine J774 cells; in this assay, the CZ171053 had reduced intracellular viability. Because iron acquisition in intracellular bacteria is considered one of their most important virulence factors during infection, these results demonstrate the immunogenic potential of this mutant against CLA.
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Antiproliferative effect of the jararhagin toxin on B16F10 murine melanoma.
BMC Complement Altern Med
PUBLISHED: 02-03-2014
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Malignant melanoma is a less common but highly dangerous form of skin cancer; it starts in the melanocytes cells found in the outer layer of the skin. Jararhagin toxin, a metalloproteinase isolated from Bothrops jararaca snake venom acts upon several biological processes, as inflammation, pain, platelet aggregation, proliferation and apoptosis, though not yet approved for use, may one day be employed to treat tumors.
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Different locations but common associations in subcortical hypodensities of presumed vascular origin: cross-sectional study on clinical and neurosonologic correlates.
BMC Neurol
PUBLISHED: 02-03-2014
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Subcortical hypodensities of presumed vascular etiology (SHPVO) are a clinical, radiological and neuropathological syndrome with a still largely unexplained pathophysiology. Parallel to the clinical heterogeneity, there is also recognised cerebral topographical diversity with undetermined etiological implications. Our aim is to assess clinical and neurosonological predictors of SHPVO according to their location.
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[Birth Rate and Fertility: Knowledge and Expectations Analysis of 3585 University Students.]
Acta Med Port
PUBLISHED: 01-22-2014
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Introduction: Nowadays, Portuguese birth rate is insufficient to ensure renewal of generations. Women high education levels and labor market integration and increased economic difficulties are some of multiple factors leading to a delay in average parenting age and an increase of infertility; also subject to others such as obesity, smoking and alcohol consumption.Material and Methods: Transversal epidemiological study, analytical, uncontrolled, from self-filled online questionnaires, promoted by students' university unions. A sample of 3585 university students was considered and a global and by gender statistic analysis was done through SPSS, Excel was used to build graphics and tables and ArcMap to represent maps. Results: Mainly students from the Health Sciences (40.6%), Universidade de Lisboa (59.4%), female (76.9%), median age of 22; intention to marry/ union 71.0%, parenthood 85.7%. A total of 18.4% smoke, 22.3% consume alcohol and obesity 15.4%; employment (47.4%) and the partner's will (39.9%) were important determinants for parenthood decision as well as having financial stability to provide a good education (33.6%) and healthcare (38.6%); A total of 53.6% have considered the hypothesis of infertility and highlight above 35 year old maternal age (18.7%), obesity (18%) and female smoking (19.0) as factors. Higher and more significant values for smoking (p = 0.001) and alcohol consumption (p = 0.000) in males were found.Discussion: The sample seems representative, well distributed among different areas of study, with more female respondents than the university portuguese ratio. There are more students with parenting projects than marriage/cohabitation, in accordance with Portuguese data. Nevertheless, the same students identify the family as a priority in comparison with employment and career. Parenting decisions are tied by social-economic situation but an important factor is the low fertility due to the maternal age delay of the first pregnancy.Conclusion: University student unions are an excellent instrument to access them; a high number of respondents consider having children but delay the decision; there is a lack of information about the consequences of delaying parenting age and about infertility factors. The negative trend of fertility must be seen as a necessity to develop specific policies.
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Micro RNA Expression and Prognosis in Low-grade Non-invasive Urothelial Carcinoma.
Int Braz J Urol
PUBLISHED: 01-22-2014
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Purpose: To analyze a possible correlation between a miRNA expression profile and important prognostic factors for pTa urothelial carcinomas (UC), including tumor size, multiplicity and episodes of recurrence. Materials and Methods: Thirty low-grade non-invasive pTa bladder UC from patients submitted to transurethral resection were studied, in a mean follow-up of 17.7 months. As controls, we used normal bladder tissue from five patients submitted to retropubic prostatectomy to treat benign prostatic hyperplasia. Extraction, cDNA and amplification were performed for 14 miRNAs (miR-100, -10a, -21, -205, -let7c, -143, -145, -221, -223, -15a, -16, -199a and -452) using specific kits, and RNU-43 and -48 were used as endogenous controls. Statistical tests were used to compare tumor size, multiplicity and episodes of recurrence with miRNAs expression profiles. Results: There was a marginal correlation between multiplicity and miR-let7c over-expression. For all others miRNA no correlation between their expression and prognostic factors was found. Conclusion: We did not find differences for miRNAs expression profiles associated with prognostic factors in tumor group studied. The majority of miRNAs are down-regulated, except mir-10a, over-expressed in most of cases, seeming to have increased levels as tumor with more unfavorable prognostic factors. More studies are needed in order to find a miRNA profile able to provide prognosis in pTa UC to be used in clinical practice.
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MicroRNAs 143 and 145 may be involved in benign prostatic hyperplasia pathogenesis through regulation of target genes and proteins.
Int. J. Biol. Markers
PUBLISHED: 01-22-2014
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The aim of this study was to analyze the roles of miR-143 and miR-145, as well as the gene and protein expression of their targets (KRAS, ERK5, MAP3K3, and MAP4K4) in the pathogenesis of benign prostatic hyperplasia (BPH).
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Ultrasonic pilot-scale reactor for enzymatic bleaching of cotton fabrics.
Ultrason Sonochem
PUBLISHED: 01-16-2014
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The potential of ultrasound-assisted technology has been demonstrated by several laboratory scale studies. However, their successful industrial scaling-up is still a challenge due to the limited pilot and commercial sonochemical reactors. In this work, a pilot reactor for laccase-hydrogen peroxide cotton bleaching assisted by ultrasound was scaled-up. For this purpose, an existing dyeing machine was transformed and adapted by including piezoelectric ultrasonic devices. Laboratory experiments demonstrated that both low frequency, high power (22 kHz, 2100 W) and high frequency, low power ultrasounds (850 kHz, 400 W) were required to achieve satisfactory results. Standard half (4 g/L H2O2 at 90 °C for 60 min) and optical (8 g/L H2O2 at 103 °C for 40 min) cotton bleaching processes were used as references. Two sequential stages were established for cotton bleaching: (1) laccase pretreatment assisted by high frequency ultrasound (850 kHz, 400 W) and (2) bleaching using high power ultrasound (22 kHz, 2100 W). When compared with conventional methods, combined laccase-hydrogen peroxide cotton bleaching with ultrasound energy improved the whitening effectiveness. Subsequently, less energy (temperature) and chemicals (hydrogen peroxide) were needed for cotton bleaching thus resulting in costs reduction. This technology allowed the combination of enzyme and hydrogen peroxide treatment in a continuous process. The developed pilot-scale reactor offers an enhancement of the cotton bleaching process with lower environmental impact as well as a better performance of further finishing operations.
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Value of a newly sequenced bacterial genome.
World J Biol Chem
PUBLISHED: 01-14-2014
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Next-generation sequencing (NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also heightened expectations that NGS would boost antibacterial discovery and vaccine development. Although many possible drug and vaccine targets have been discovered, the success rate of genome-based analysis has remained below expectations. Furthermore, NGS has had consequences for genome quality, resulting in an exponential increase in draft (partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome and annotation will not be undertaken. It is important to know what is lost when we settle for a draft genome and to determine the "scientific value" of a newly sequenced genome. This review addresses the expected impact of newly sequenced genomes on antibacterial discovery and vaccinology. Also, it discusses the factors that could be leading to the increase in the number of draft deposits and the consequent loss of relevant biological information.
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Serological proteome analysis of Corynebacterium pseudotuberculosis isolated from different hosts reveals novel candidates for prophylactics to control caseous lymphadenitis.
Vet. Microbiol.
PUBLISHED: 01-11-2014
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Caseous lymphadenitis (CLA) is a highly prevalent disease in goats and sheep worldwide, which is caused by Corynebacterium pseudotuberculosis. Although several prophylactic methods against CLA have been proposed previously, the identification of new C. pseudotuberculosis proteins that are really produced during the infectious process is still needed to improve efficiency and accuracy in vaccines and diagnostics. In this study, we used optimized conditions for serological proteome analysis (SERPA) in order to identify new immune-reactive proteins in C. pseudotuberculosis culture supernatants of two strains, 1002 and C231, isolated from goats and sheep, respectively. Using a sheep and goat serum pool, 13 novel immune-reactive exoproteins common to the two strains were identified. Four of these proteins present known functions and were already described as immune-reactive proteins in other microorganisms, whereas the other nine are of unknown function and show low similarity with proteins from other bacterial species. These data reveal promising targets for immunoprophylactic methods against CLA.
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Differential transcriptional profile of Corynebacterium pseudotuberculosis in response to abiotic stresses.
BMC Genomics
PUBLISHED: 01-09-2014
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The completion of whole-genome sequencing for Corynebacterium pseudotuberculosis strain 1002 has contributed to major advances in research aimed at understanding the biology of this microorganism. This bacterium causes significant loss to goat and sheep farmers because it is the causal agent of the infectious disease caseous lymphadenitis, which may lead to outcomes ranging from skin injury to animal death. In the current study, we simulated the conditions experienced by the bacteria during host infection. By sequencing transcripts using the SOLiDTM 3 Plus platform, we identified new targets expected to potentiate the survival and replication of the pathogen in adverse environments. These results may also identify possible candidates useful for the development of vaccines, diagnostic kits or therapies aimed at the reduction of losses in agribusiness.
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Hybrid graphene-metal oxide solution processed electron transport layers for large area high-performance organic photovoltaics.
Adv. Mater. Weinheim
PUBLISHED: 01-02-2014
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Solution processed core-shell nano-structures of metal oxide-reduced graphene oxide (RGO) are used as improved electron transport layers (ETL), leading to an enhancement in photocurrent charge transport in PCDTBT:PC70 BM for both single cell and module photovoltaic devices. As a result, the power conversion efficiency for the devices with RGO-metal oxides for ETL increases 8% in single cells and 20% in module devices.
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Staphylococcus aureus Manganese Transport Protein C (MntC) Is an Extracellular Matrix- and Plasminogen-Binding Protein.
PLoS ONE
PUBLISHED: 01-01-2014
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Infections caused by Staphylococcus aureus - particularly nosocomial infections - represent a great concern. Usually, the early stage of pathogenesis consists on asymptomatic nasopharynx colonization, which could result in dissemination to other mucosal niches or invasion of sterile sites, such as blood. This pathogenic route depends on scavenging of nutrients as well as binding to and disrupting extracellular matrix (ECM). Manganese transport protein C (MntC), a conserved manganese-binding protein, takes part in this infectious scenario as an ion-scavenging factor and surprisingly as an ECM and coagulation cascade binding protein, as revealed in this work. This study showed a marked ability of MntC to bind to several ECM and coagulation cascade components, including laminin, collagen type IV, cellular and plasma fibronectin, plasminogen and fibrinogen by ELISA. The MntC binding to plasminogen appears to be related to the presence of surface-exposed lysines, since previous incubation with an analogue of lysine residue, ?-aminocaproic acid, or increasing ionic strength affected the interaction between MntC and plasminogen. MntC-bound plasminogen was converted to active plasmin in the presence of urokinase plasminogen activator (uPA). The newly released plasmin, in turn, acted in the cleavage of the ? and ? chains of fibrinogen. In conclusion, we describe a novel function for MntC that may help staphylococcal mucosal colonization and establishment of invasive disease, through the interaction with ECM and coagulation cascade host proteins. These data suggest that this potential virulence factor could be an adequate candidate to compose an anti-staphylococcal human vaccine formulation.
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Comprehensive Study of Gene and microRNA Expression Related to Epithelial-Mesenchymal Transition in Prostate Cancer.
PLoS ONE
PUBLISHED: 01-01-2014
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Prostate cancer is the most common cancer in men, and most patients have localized disease at the time of diagnosis. However, 4% already present with metastatic disease. Epithelial-mesenchymal transition is a fundamental process in carcinogenesis that has been shown to be involved in prostate cancer progression. The main event in epithelial-mesenchymal transition is the repression of E-cadherin by transcription factors, but the process is also regulated by microRNAs. The aim of this study was to analyze gene and microRNA expression involved in epithelial-mesenchymal transition in localized prostate cancer and metastatic prostate cancer cell lines and correlate with clinicopathological findings. We studied 51 fresh frozen tissue samples from patients with localized prostate cancer (PCa) treated by radical prostatectomy and three metastatic prostate cancer cell lines (LNCaP, DU145, PC3). The expression of 10 genes and 18 miRNAs were assessed by real-time PCR. The patients were divided into groups according to Gleason score, pathological stage, preoperative PSA, biochemical recurrence, and risk group for correlation with clinicopathological findings. The majority of localized PCa cases showed an epithelial phenotype, with overexpression of E-cadherin and underexpression of the mesenchymal markers. MiRNA-200 family members and miRNAs 203, 205, 183, 373, and 21 were overexpressed, while miRNAs 9, 495, 29b, and 1 were underexpressed. Low-expression levels of miRNAs 200b, 30a, and 1 were significantly associated with pathological stage. Lower expression of miR-200b was also associated with a Gleason score ?8 and shorter biochemical recurrence-free survival. Furthermore, low-expression levels of miR-30a and high-expression levels of Vimentin and Twist1 were observed in the high-risk group. Compared with the primary tumor, the metastatic cell lines showed significantly higher expression levels of miR-183 and Twist1. In summary, miRNAs 200b, 30a, 1, and 183 and the genes Twist1 and Vimentin might play important roles in the progression of prostate cancer and may eventually become important prognostic markers.
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Alouatta Trichromatic Color Vision: Cone Spectra and Physiological Responses Studied with Microspectrophotometry and Single Unit Retinal Electrophysiology.
PLoS ONE
PUBLISHED: 01-01-2014
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The howler monkeys (Alouatta sp.) are the only New World primates to exhibit routine trichromacy. Both males and females have three cone photopigments. However, in contrast to Old World monkeys, Alouatta has a locus control region upstream of each opsin gene on the X-chromosome and this might influence the retinal organization underlying its color vision. Post-mortem microspectrophotometry (MSP) was performed on the retinae of two male Alouatta to obtain rod and cone spectral sensitivities. The MSP data were consistent with only a single opsin being expressed in each cone and electrophysiological data were consistent with this primate expressing full trichromacy. To study the physiological organization of the retina underlying Alouatta trichromacy, we recorded from retinal ganglion cells of the same animals used for MSP measurements with a variety of achromatic and chromatic stimulus protocols. We found MC cells and PC cells in the Alouatta retina with similar properties to those previously found in the retina of other trichromatic primates. MC cells showed strong phasic responses to luminance changes and little response to chromatic pulses. PC cells showed strong tonic response to chromatic changes and small tonic response to luminance changes. Responses to other stimulus protocols (flicker photometry; changing the relative phase of red and green modulated lights; temporal modulation transfer functions) were also similar to those recorded in other trichromatic primates. MC cells also showed a pronounced frequency double response to chromatic modulation, and with luminance modulation response saturation accompanied by a phase advance between 10-20 Hz, characteristic of a contrast gain mechanism. This indicates a very similar retinal organization to Old-World monkeys. Cone-specific opsin expression in the presence of a locus control region for each opsin may call into question the hypothesis that this region exclusively controls opsin expression.
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Pasteurella pneumotropica Evades the Human Complement System by Acquisition of the Complement Regulators Factor H and C4BP.
PLoS ONE
PUBLISHED: 01-01-2014
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Pasteurella pneumotropica is an opportunist Gram negative bacterium responsible for rodent pasteurellosis that affects upper respiratory, reproductive and digestive tracts of mammals. In animal care facilities the presence of P. pneumotropica causes severe to lethal infection in immunodeficient mice, being also a potential source for human contamination. Indeed, occupational exposure is one of the main causes of human infection by P. pneumotropica. The clinical presentation of the disease includes subcutaneous abscesses, respiratory tract colonization and systemic infections. Given the ability of P. pneumotropica to fully disseminate in the organism, it is quite relevant to study the role of the complement system to control the infection as well as the possible evasion mechanisms involved in bacterial survival. Here, we show for the first time that P. pneumotropica is able to survive the bactericidal activity of the human complement system. We observed that host regulatory complement C4BP and Factor H bind to the surface of P. pneumotropica, controlling the activation pathways regulating the formation and maintenance of C3-convertases. These results show that P. pneumotropica has evolved mechanisms to evade the human complement system that may increase the efficiency by which this pathogen is able to gain access to and colonize inner tissues where it may cause severe infections.
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A Protocol for mtGenome Analysis on Large Sample Numbers.
Bioinform Biol Insights
PUBLISHED: 01-01-2014
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The mitochondrial genome is widely studied in a variety of fields, such as population, forensic, and human and medical genetics. Most studies have been limited to a small portion of the sequence that, although highly diverse, does not describe the total variability. The arrival of modern high-throughput sequencing technologies has made it possible to investigate larger sequences in a shorter amount of time as well as in a more affordable fashion. This work aims to describe a protocol for sequencing and analyzing the complete mitochondrial genome with the Ion PGM™ platform. To evaluate the protocol, the mitochondrial genome was sequenced to approximately 210 Mbp, with high-quality sequences distributed between 12 samples that had an average coverage of 1023× per sample. Several variant callers were compared to improve the protocol outcome. The results suggest that it is possible to run up to 120 samples per run without any loss of any significant quality. Therefore, this protocol is an efficient and accurate tool for full mitochondrial genome analysis.
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Voice disorder in cystic fibrosis patients.
PLoS ONE
PUBLISHED: 01-01-2014
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Cystic fibrosis is a common autosomal recessive disorder with drastic respiratory symptoms, including shortness of breath and chronic cough. While most of cystic fibrosis treatment is dedicated to mitigating the effects of respiratory dysfunction, the potential effects of this disease on vocal parameters have not been systematically studied. We hypothesized that cystic fibrosis patients, given their characteristic respiratory disorders, would also present dysphonic symptoms. Given that voice disorders can severely impair quality of life, the identification of a potential cystic fibrosis-related dysphonia could be of great value for the clinical evaluation and treatment of this disease. We tested our hypothesis by measuring vocal parameters, using both objective physical measures and the GRBAS subjective evaluation method, in male and female cystic fibrosis patients undergoing conventional treatment and compared them to age and sex matched controls. We found that cystic fibrosis patients had a significantly lower vocal intensity and harmonic to noise ratio, as well as increased levels of jitter and shimmer. In addition, cystic fibrosis patients also showed higher scores of roughness, breathiness and asthenia, as well as a significantly altered general grade of dysphonia. When we segregated the results according to sex, we observed that, as a group, only female cystic fibrosis patients had significantly lower values of harmonic to noise ratio and an abnormal general grade of dysphonia in relation to matched controls, suggesting that cystic fibrosis exerts a more pronounced effect on vocal parameters of women in relation to men. Overall, the dysphonic characteristics of CF patients can be explained by dysfunctions in vocal fold movement and partial upper airway obstruction, potentially caused by the accumulation of mucus and chronic cough characteristic of CF symptomatology. Our results show that CF patients exhibit significant dysphonia and suggest they may potentially benefit from voice therapy as a parallel treatment strategy.
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MiRNA expression profile for the human gastric antrum region using ultra-deep sequencing.
PLoS ONE
PUBLISHED: 01-01-2014
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MicroRNAs are small non-coding nucleotide sequences that regulate gene expression. These structures are fundamental to several biological processes, including cell proliferation, development, differentiation and apoptosis. Identifying the expression profile of microRNAs in healthy human gastric antrum mucosa may help elucidate the miRNA regulatory mechanisms of the human stomach.
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Draft Genome Sequence of Serratia fonticola UTAD54, a Carbapenem-Resistant Strain Isolated from Drinking Water.
Genome Announc
PUBLISHED: 11-29-2013
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Serratia fonticola UTAD54 is an environmental isolate that is resistant to carbapenems due to the presence of a class A carbapenemase and a metallo-?-lactamase that are unique to this strain. Its draft genome sequence was obtained to clarify the molecular basis of its carbapenem resistance and identify the genomic context of its carbapenem resistance determinants.
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Draft Genome Sequence of Serratia fonticola LMG 7882T Isolated from Freshwater.
Genome Announc
PUBLISHED: 11-23-2013
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Serratia fonticola is a Gram-negative bacterium with a wide distribution in aquatic environments. On some occasions, it has also been regarded as a significant human pathogen. In this work, we report the first draft genome sequence of an S. fonticola strain (LMG 7882(T)), which was isolated from freshwater.
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Draft Genome Sequence of Mycobacterium abscessus subsp. bolletii INCQS 00594.
Genome Announc
PUBLISHED: 11-09-2013
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An epidemic of surgical-site infections by a single strain of Mycobacterium abscessus subsp. bolletii affected >1,700 patients in Brazil from 2004 to 2008. The genome of the epidemic prototype strain M. abscessus subsp. bolletii INCQS 00594, deposited in the collection of the National Institute for Health Quality Control (INCQS), was sequenced.
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From 1D and 2D ZnO nanostructures to 3D hierarchical structures with enhanced gas sensing properties.
Nanoscale
PUBLISHED: 11-01-2013
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Facile and low cost hydrothermal routes are developed to fabricate three-dimensional (3D) hierarchical ZnO structures with high surface-to-volume ratios and an increased fraction of (0001) polar surfaces. Hierarchical ZnO nanowires (ZNWs) and nanodisks (ZNDs) assembled from initial ZnO nanostructures are prepared from sequential nucleation and growth following a hydrothermal process. These hierarchical ZnO structures display an enhancement of gas sensing performance and exhibit significantly improved sensitivity and fast response to acetone in comparison to other mono-morphological ZnO, such as nanoparticles, NWs, or NDs. In addition to the high surface-to-volume ratio due to its small size, the nanowire building blocks show the enhanced gas sensing properties mainly ascribed to the increased proportion of exposed active (0001) planes, and the formation of many nanojunctions at the interface between the initial ZnO nanostructure and secondary NWs. This work provides the route for structure induced enhancement of gas sensing performance by designing a desirable nanostructure, which could also be extended to synthesize other metal oxide nanostructures with superior gas sensing performance.
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Immune Evasion by Pathogenic Leptospira Strains: The Secretion of Proteases that Directly Cleave Complement Proteins.
J. Infect. Dis.
PUBLISHED: 10-26-2013
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Leptospirosis is an infectious disease of public health importance. To successfully colonize the host, pathogens have evolved multiple strategies to escape the complement system. Here we demonstrate that the culture supernatant of pathogenic but not saprophytic Leptospira inhibit the three complement pathways. We showed that the proteolytic activity in the supernatants of pathogenic strains targets the central complement molecule C3 and specific proteins from each pathway, such as factor B, C2, and C4b. The proteases cleaved ? and ? chains of C3 and work in synergy with host regulators to inactivate C3b. Proteolytic activity was inhibited by 1,10-phenanthroline, suggesting the participation of metalloproteases. A recombinant leptospiral metalloprotease from the thermolysin family cleaved C3 in serum and could be one of the proteases responsible for the supernatant activity. We conclude that pathogenic leptospiral proteases can deactivate immune effector molecules and represent potential targets to the development of new therapies in leptospirosis.
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Congestive heart failure as a determinant of postoperative delirium.
Rev Port Cardiol
PUBLISHED: 09-06-2013
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Postoperative delirium (POD) is a frequent post-surgical complication that is associated with increased mortality and poor patient outcomes. POD is a complex disorder with multiple risk factors such as pre-existing patient comorbidities and perioperative complications. The aim of this study was to evaluate the incidence of POD and to identify risk factors for the development of POD in a post-anesthesia care unit (PACU).
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Confined crystals of the smallest phase-change material.
Nano Lett.
PUBLISHED: 09-03-2013
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The demand for high-density memory in tandem with limitations imposed by the minimum feature size of current storage devices has created a need for new materials that can store information in smaller volumes than currently possible. Successfully employed in commercial optical data storage products, phase-change materials, that can reversibly and rapidly change from an amorphous phase to a crystalline phase when subject to heating or cooling have been identified for the development of the next generation electronic memories. There are limitations to the miniaturization of these devices due to current synthesis and theoretical considerations that place a lower limit of 2 nm on the minimum bit size, below which the material does not transform in the structural phase. We show here that by using carbon nanotubes of less than 2 nm diameter as templates phase-change nanowires confined to their smallest conceivable scale are obtained. Contrary to previous experimental evidence and theoretical expectations, the nanowires are found to crystallize at this scale and display amorphous-to-crystalline phase changes, fulfilling an important prerequisite of a memory element. We show evidence for the smallest phase-change material, extending thus the size limit to explore phase-change memory devices at extreme scales.
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Draft Genome Sequence of the Brazilian Toxic Bloom-Forming Cyanobacterium Microcystis aeruginosa Strain SPC777.
Genome Announc
PUBLISHED: 08-03-2013
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Microcystis aeruginosa strain SPC777 is an important toxin-producing cyanobacterium, isolated from a water bloom of the Billings reservoir (São Paulo State, Brazil). Here, we report the draft genome sequence and initial findings from a preliminary analysis of strain SPC777, including several gene clusters involved in nonribosomal and ribosomal synthesis of secondary metabolites.
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Inorganics-in-organics: recent developments and outlook for 4G polymer solar cells.
Nanoscale
PUBLISHED: 08-01-2013
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Recent developments in solution processable single junction polymer solar cells have led to a significant improvement in power conversion efficiencies from ?5% to beyond 9%. While much of the initial efficiency improvements were driven through judicious design of donor polymers, it is the engineering of device architectures through the incorporation of inorganic nanostructures and better processing that has continued the efficiency gains. Inorganic nano-components such as carbon nanotubes, graphene and its derivatives, metal nanoparticles and metal oxides have played a central role in improving device performance and longevity beyond those achieved by conventional 3G polymer solar cells. The present work aims to summarise the diverse roles played by the nanosystems and features in state of the art next generation (4G) polymer solar cells. The challenges associated with the engineering of such devices for future deployment are also discussed.
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Exploring the contribution of mycobacteria characteristics in their interaction with human macrophages.
Microsc. Microanal.
PUBLISHED: 06-24-2013
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Tuberculosis (TB) is a major health problem. The emergence of multidrug resistant (MDR) Mycobacterium tuberculosis (Mtb) isolates confounds treatment strategies. In Portugal, cases of MDR-TB are reported annually with an increased incidence noted in Lisbon. The majority of these MDR-TB cases are due to closely related mycobacteria known collectively as the Lisboa family and Q1 cluster. Genetic determinants linked to drug resistance have been exhaustively studied resulting in the identification of family and cluster specific mutations. Nevertheless, little is known about other factors involved in development of mycobacteria drug resistance. Here, we complement genetic analysis with the study of morphological and structural features of the Lisboa family and Q1 cluster isolates by using scanning and transmission electron microscopy. This analysis allowed the identification of structural differences, such as cell envelope thickness, between Mtb clinical isolates that are correlated with antibiotic resistance. The infection of human monocyte derived macrophages allowed us to document the relative selective advantage of the Lisboa family isolates over other circulating Mtb isolates.
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Draft Genome Sequence of Methylobacterium mesophilicum Strain SR1.6/6, Isolated from Citrus sinensis.
Genome Announc
PUBLISHED: 06-22-2013
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Methylobacterium mesophilicum strain SR1.6/6 is an endophytic bacterium isolated from a surface-sterilized Citrus sinensis branch. Ecological and biotechnological aspects of this bacterium, such as the genes involved in its association with the host plant and the primary oxidation of methanol, were annotated in the draft genome.
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Complete genome sequence of Streptococcus agalactiae strain SA20-06, a fish pathogen associated to meningoencephalitis outbreaks.
Stand Genomic Sci
PUBLISHED: 06-15-2013
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Streptococcus agalactiae (Lancefield group B; GBS) is the causative agent of meningoencephalitis in fish, mastitis in cows, and neonatal sepsis in humans. Meningoencephalitis is a major health problem for tilapia farming and is responsible for high economic losses worldwide. Despite its importance, the genomic characteristics and the main molecular mechanisms involved in virulence of S. agalactiae isolated from fish are still poorly understood. Here, we present the genomic features of the 1,820,886 bp long complete genome sequence of S. agalactiae SA20-06 isolated from a meningoencephalitis outbreak in Nile tilapia (Oreochromis niloticus) from Brazil, and its annotation, consisting of 1,710 protein-coding genes (excluding pseudogenes), 7 rRNA operons, 79 tRNA genes and 62 pseudogenes.
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High efficiency application of a mate-paired library from next-generation sequencing to postlight sequencing: Corynebacterium pseudotuberculosis as a case study for microbial de novo genome assembly.
J. Microbiol. Methods
PUBLISHED: 06-03-2013
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With the advent of high-throughput DNA sequencing platforms, there has been a reduction in the cost and time of sequencing. With these advantages, new challenges have emerged, such as the handling of large amounts of data, quality assessment, and the assembly of short reads. Currently, benchtop high-throughput sequencers enable the genomes of prokaryotic organisms to be sequenced within two hours with a reduction in coverage compared with the SOLiD, Illumina and 454 FLX Titanium platforms, making it necessary to evaluate the efficiency of less expensive benchtop instruments for prokaryotic genomics. In the present work, we evaluate and propose a methodology for the use of the Ion Torrent PGM platform for decoding the gram-positive bacterium Corynebacterium pseudotuberculosis, for which 15 complete genome sequences have already been deposited based on fragment and mate-paired libraries with a 3-kb insert size. Despite the low coverage, a single sequencing run using a mate-paired library generated 39 scaffolds after de novo assembly without data curation. This result is superior to that obtained by sequencing using libraries generated from fragments marketed by the equipments manufacturer, as well as that observed for mate-pairs sequenced by SOLiD. The generated sequence added an extra 91kb to the genome available at NCBI.
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Complete Genome of a Methanosarcina mazei Strain Isolated from Sediment Samples from an Amazonian Flooded Area.
Genome Announc
PUBLISHED: 05-25-2013
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Methanosarcina mazei is a strictly anaerobic methanogen from the Methanosarcinales order, which is known for its broad catabolic range among methanogens and is widespread throughout diverse environments. The draft genome of the strain presented here was cultivated from sediment samples collected from the Tucuruí hydroelectric power station reservoir.
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Sonochemical and hydrodynamic cavitation reactors for laccase/hydrogen peroxide cotton bleaching.
Ultrason Sonochem
PUBLISHED: 05-15-2013
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The main goal of this work is to develop a novel and environmental-friendly technology for cotton bleaching with reduced processing costs. This work exploits a combined laccase-hydrogen peroxide process assisted by ultrasound. For this purpose, specific reactors were studied, namely ultrasonic power generator type K8 (850kHz) and ultrasonic bath equipment Ultrasonic cleaner USC600TH (45kHz). The optimal operating conditions for bleaching were chosen considering the highest levels of hydroxyl radical production and the lowest energy input. The capacity to produce hydroxyl radicals by hydrodynamic cavitation was also assessed in two homogenizers, EmulsiFlex®-C3 and APV-2000. Laccase nanoemulsions were produced by high pressure homogenization using BSA (bovine serum albumin) as emulsifier. The bleaching efficiency of these formulations was tested and the results showed higher whiteness values when compared to free laccase. The combination of laccase-hydrogen peroxide process with ultrasound energy produced higher whiteness levels than those obtained by conventional methods. The amount of hydrogen peroxide was reduced 50% as well as the energy consumption in terms of temperature (reduction of 40°C) and operating time (reduction of 90min).
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Prima-1 induces apoptosis in bladder cancer cell lines by activating p53.
Clinics (Sao Paulo)
PUBLISHED: 05-07-2013
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Bladder cancer represents 3% of all carcinomas in the Brazilian population and ranks second in incidence among urological tumors, after prostate cancer. The loss of p53 function is the main genetic alteration related to the development of high-grade muscle-invasive disease. Prima-1 is a small molecule that restores tumor suppressor function to mutant p53 and induces cancer cell death in various cancer types. Our aim was to investigate the ability of Prima-1 to induce apoptosis after DNA damage in bladder cancer cell lines.
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Efficient coupling of optical energy for rapid catalyzed nanomaterial growth: high-quality carbon nanotube synthesis at low substrate temperatures.
ACS Appl Mater Interfaces
PUBLISHED: 04-29-2013
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The synthesis of high-quality nanomaterials depends on the efficiency of the catalyst and the growth temperature. To produce high-quality material, high-growth temperatures (often up to 1000 °C) are regularly required and this can limit possible applications, especially where temperature sensitive substrates or tight thermal budgets are present. In this study, we show that high-quality catalyzed nanomaterial growth at low substrate temperatures is possible by efficient coupling of energy directly into the catalyst particles by an optical method. We demonstrate that using this photothermal-based chemical vapor deposition method that rapid growth (under 4 min, which includes catalyst pretreatment time) of high-density carbon nanotubes can be grown at substrate temperatures as low as 415 °C with proper catalyst heat treatment. The growth process results in nanotubes that are high quality, as judged by a range of structural, Raman, and electrical characterization techniques, and are compatible with the requirements for interconnect technology.
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Vapor-phase testing of the memory-effects in benzene- and toluene-imprinted polymers conditioned at elevated temperature.
Anal. Chim. Acta
PUBLISHED: 04-25-2013
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The preparation of polymers imprinted with common aromatic solvents such as benzene and toluene is an under-exploited subject of research. The present study was aimed at the understanding of whether true solvent memory effects can be achieved by molecular imprinting, as well as if they are stable at elevated temperature. A set of copolymers, comprising low and high cross-linking levels, was prepared from four different combinations of functional monomer and cross-linker, namely methacrylic acid (MAA)/ethylene glycol dimethacrylate (EGDMA), methyl methacrylate (MMA)/EGDMA, MAA/divinyl benzene (DVB) and MMA/DVB. Each possible combination was prepared separately in benzene, toluene and acetonitrile. The obtained materials were applied as coatings onto nickel-titanium (Ni-Ti) alloy wires which were incorporated into solid-phase microextraction devices and finally tested for their ability to competitively adsorb vapors from the headspace of an aqueous solution containing a few volatile organic compounds. Porosity analysis showed that, regardless of the solvent used, only a high cross-linking level permitted the preparation of mesoporous copolymers (BJH radius typically in the range 13-15 nm), a requirement for providing accessibility to the targeted nanoscale-imprinted cavities. A noticeable exception was, however, observed for the MMA/DVB copolymers which exhibited much diminished BJH radius. The porosity data correlated well with the extraction profiles found, which suggested the presence of benzene-imprinted sites in all the highly cross-linked copolymers prepared in benzene, except for the MMA/DVB copolymers. Concerning the effect of an elevated conditioning temperature on the memory-effects created by the imprinting process, the results were clearly indicative that the tested copolymers, including the more robust highly cross-linked ones, are not suitable for high temperature applications such as solid-phase microextraction coupled to gas chromatography.
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Identification of 11 new exoproteins in Corynebacterium pseudotuberculosis by comparative analysis of the exoproteome.
Microb. Pathog.
PUBLISHED: 04-23-2013
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This study involves the comparison between the exoproteomes of two different strains of Corynebacterium pseudotuberculosis, the etiologic agent of caseous lymphadenitis in small ruminants. In a previous study, based on a gel-free system (TPP-LC/MS(E)), 70 exoproteins for the strain 1002 and 67 for the strain C231, totaling 93 different extracellular proteins for C. pseudotuberculosis, were identified. In the present work, we have used 2D gel electrophoresis to resolve the extracellular proteins of both strains, which were then digested with trypsin, analyzed by MALDI-TOF/TOF and identified with the software MASCOT(®). A total of 45 extracellular proteins of C. pseudotuberculosis were identified by this approach. The comparative analysis between the strains 1002 and C231 identified 13 and 3 strain-specific proteins, respectively, 11 of which are novel. These newly identified proteins may play an important role in the physiology and virulence of C. pseudotuberculosis.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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