JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Injury News Coverage, Relative Concern, and Support for Alcohol-Control Policies: An Impersonal Impact Explanation.
J Health Commun
PUBLISHED: 05-30-2014
Show Abstract
Hide Abstract
Research on the impersonal impact hypothesis suggests that news (especially print) coverage of health and safety risks primarily influences perceptions of risk as a societal issue, and not perceptions of personal risk. The authors propose that the impersonal impact of news-impact primarily on concerns about social-level risks-will mediate effects of news stories on support for public health policies; such effects substantively matter as evidence suggests health policies, in turn, have important effects on protective behaviors and health outcomes. In an experiment using 60 randomly selected violent crime and accident news stories manipulated to contain or not contain reference to alcohol use as a causative factor, the authors find that the effect of stories that mention alcohol as a causative factor on support for alcohol-control policies is mediated by social-level concern and not by personal-level concern. In so doing, the authors provide a theoretical explanation as well as empirical evidence regarding the potential for news coverage-including breaking or episodic news-to influence health-related public policy.
Related JoVE Video
Eco-Taxonomic Insights into Actinomycete Symbionts of Termites for Discovery of Novel Bioactive Compounds.
Adv. Biochem. Eng. Biotechnol.
PUBLISHED: 05-11-2014
Show Abstract
Hide Abstract
: Termites play a major role in foraging and degradation of plant biomass as well as cultivating bioactive microorganisms for their defense. Current advances in "omics" sciences are revealing insights into function-related presence of these symbionts, and their related biosynthetic activities and genes identified in gut symbiotic bacteria might offer a significant potential for biotechnology and biodiscovery. Actinomycetes have been the major producers of bioactive compounds with an extraordinary range of biological activities. These metabolites have been in use as anticancer agents, immune suppressants, and most notably, as antibiotics. Insect-associated actinomycetes have also been reported to produce a range of antibiotics such as dentigerumycin and mycangimycin. Advances in genomics targeting a single species of the unculturable microbial members are currently aiding an improved understanding of the symbiotic interrelationships among the gut microorganisms as well as revealing the taxonomical identity and functions of the complex multilayered symbiotic actinofloral layers. If combined with target-directed approaches, these molecular advances can provide guidance towards the design of highly selective culturing methods to generate further information related to the physiology and growth requirements of these bioactive actinomycetes associated with the termite guts. This chapter provides an overview on the termite gut symbiotic actinoflora in the light of current advances in the "omics" science, with examples of their detection and selective isolation from the guts of the Sunshine Coast regional termite Coptotermes lacteus in Queensland, Australia.
Related JoVE Video
Cuelure but not zingerone make the sex pheromone of male Bactrocera tryoni (Tephritidae: Diptera) more attractive to females.
J. Insect Physiol.
PUBLISHED: 05-09-2014
Show Abstract
Hide Abstract
In tephritid fruit flies of the genus Bactrocera Macquart, a group of plant derived compounds (sensu amplo 'male lures') enhance the mating success of males that have consumed them. For flies responding to the male lure methyl eugenol, this is due to the accumulation of chemicals derived from the male lure in the male rectal gland (site of pheromone synthesis) and the subsequent release of an attractive pheromone. Cuelure, raspberry ketone and zingerone are a second, related group of male lures to which many Bactrocera species respond. Raspberry ketone and cuelure are both known to accumulate in the rectal gland of males as raspberry ketone, but it is not known if the emitted male pheromone is subsequently altered in complexity or is more attractive to females. Using Bactrocera tryoni as our test insect, and cuelure and zingerone as our test chemicals, we assess: (i) lure accumulation in the rectal gland; (ii) if the lures are released exclusively in association with the male pheromone; and (iii) if the pheromone of lure-fed males is more attractive to females than the pheromone of lure-unfed males. As previously documented, we found cuelure was stored in its hydroxyl form of raspberry ketone, while zingerone was stored largely in an unaltered state. Small but consistent amounts of raspberry ketone and ?-(4-hydroxy-3-methoxyphenyl)-propionic acid were also detected in zingerone-fed flies. Males released the ingested lures or their analogues, along with endogenous pheromone chemicals, only during the dusk courtship period. More females responded to squashed rectal glands extracted from flies fed on cuelure than to glands from control flies, while more females responded to the pheromone of calling cuelure-fed males than to control males. The response to zingerone treatments in both cases was not different from the control. The results show that male B. tryoni release ingested lures as part of their pheromone blend and, at least for cuelure, this attracts more females.
Related JoVE Video
Isolated limb perfusion with melphalan, tumour necrosis factor-alpha and oncolytic vaccinia virus improves tumour targeting and prolongs survival in a rat model of advanced extremity sarcoma.
Int. J. Cancer
PUBLISHED: 05-08-2014
Show Abstract
Hide Abstract
Isolated limb perfusion (ILP) is a treatment for advanced extremity sarcoma and in-transit melanoma. Advancing this procedure by investigating the addition of novel agents, such as cancer-selective oncolytic viruses, may improve both the therapeutic efficacy of ILP and the tumour-targeted delivery of oncolytic virotherapy. Standard in vitro assays were used to characterise single agent and combinatorial activities of melphalan, tumour necrosis factor-alpha (TNF-?) and Lister strain vaccinia virus (GLV-1h68) against BN175 rat sarcoma cells. An orthotopic model of advanced extremity sarcoma was used to evaluate survival of animals after ILP with combinations of TNF-?, melphalan and GLV-1h68. We investigated the efficiency of viral tumour delivery by ILP compared to intravenous therapy, the locoregional and systemic biodistribution of virus after ILP, and the effect of mode of administration on antibody response. The combination of melphalan and GLV-1h68 was synergistic in vitro. The addition of virus to standard ILP regimens was well tolerated and demonstrated superior tumour targeting compared to intravenous administration. Triple therapy (melphalan/TNF-?/GLV-1h68) resulted in increased tumour growth delay and enhanced survival compared to other treatment regimens. Live virus was recovered in large amounts from perfused regions, but in smaller amounts from systemic organs. The addition of oncolytic vaccinia virus to existing TNF-?/melphalan-based ILP strategies results in survival advantage in an immunocompetent rat model of advanced extremity sarcoma. Virus administered by ILP has superior tumour targeting compared to intravenous delivery. Further evaluation and clinical translation of this approach is warranted.
Related JoVE Video
The mutational burden of acral melanoma revealed by whole-genome sequencing and comparative analysis.
Pigment Cell Melanoma Res
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
Acral melanoma is a subtype of melanoma with distinct epidemiological, clinical and mutational profiles. To define the genomic alterations in acral melanoma, we conducted whole-genome sequencing and SNP array analysis of five metastatic tumours and their matched normal genomes. We identified the somatic mutations, copy number alterations and structural variants in these tumours and combined our data with published studies to identify recurrently mutated genes likely to be the drivers of acral melanomagenesis. We compared and contrasted the genomic landscapes of acral, mucosal, uveal and common cutaneous melanoma to reveal the distinctive mutational characteristics of each subtype.
Related JoVE Video
BRAF inhibitors induce metastasis in RAS mutant or inhibitor-resistant melanoma cells by reactivating MEK and ERK signaling.
Sci Signal
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
Melanoma is a highly metastatic and lethal form of skin cancer. The protein kinase BRAF is mutated in about 40% of melanomas, and BRAF inhibitors improve progression-free and overall survival in these patients. However, after a relatively short period of disease control, most patients develop resistance because of reactivation of the RAF-ERK (extracellular signal-regulated kinase) pathway, mediated in many cases by mutations in RAS. We found that BRAF inhibition induces invasion and metastasis in RAS mutant melanoma cells through a mechanism mediated by the reactivation of the MEK (mitogen-activated protein kinase kinase)-ERK pathway, increased expression and secretion of interleukin 8, and induction of protease-dependent invasion. These events were accompanied by a cell morphology switch from predominantly rounded to predominantly elongated cells. We also observed similar responses in BRAF inhibitor-resistant melanoma cells. These data show that BRAF inhibitors can induce melanoma cell invasion and metastasis in tumors that develop resistance to these drugs.
Related JoVE Video
Optimal management of primary retroperitoneal sarcoma: an update.
Expert Rev Anticancer Ther
PUBLISHED: 02-13-2014
Show Abstract
Hide Abstract
Soft tissue sarcomas are a group of heterogeneous neoplasms with more than 50 histological subtypes exhibiting major differences in terms of pathogenesis, genetic alterations and clinical behavior. Sarcomas represent approximately 1% of malignancies with retroperitoneal sarcomas representing 10-15% of all soft tissue sarcomas. Surgery is currently the only modality which offers the chance of cure. Surgery for retroperitoneal sarcomas presents specific challenges due their location in a complex space surrounded by vital structures and visceral organs often prohibiting resection with wide margins. Furthermore, even after complete resection local recurrence is common and the leading cause of death. In this article the authors describe the initial investigations, prognostic factors and optimal surgical management. The evidence and current research as regards the role of multimodality treatment is reviewed and discussed.
Related JoVE Video
Oncological outcome of primary non-metastatic soft tissue sarcoma treated by neoadjuvant isolated limb perfusion and tumor resection.
J Surg Oncol
PUBLISHED: 02-11-2014
Show Abstract
Hide Abstract
Isolated limb perfusion (ILP) is an effective limb salvage strategy in patients with advanced soft tissue sarcoma (STS) where surgery alone would result in significant functional morbidity or mandate an amputation. Most previous reports of patients undergoing ILP focus on limb salvage rates rather than local and distant relapse rates. Here, we report the oncological outcome of sarcoma patients treated by ILP and surgery.
Related JoVE Video
Surgical outcomes following resection for sporadic abdominal wall fibromatosis.
Ann. Surg. Oncol.
PUBLISHED: 01-09-2014
Show Abstract
Hide Abstract
Fibromatosis can be classified according to site of origin, namely, extraabdominal, abdominal wall, or intraabdominal. This study reports on the surgical management and long-term outcomes from a single center in the management of sporadic abdominal wall fibromatosis.
Related JoVE Video
The relative trustworthiness of inferential tests of the indirect effect in statistical mediation analysis: does method really matter?
Psychol Sci
PUBLISHED: 08-16-2013
Show Abstract
Hide Abstract
A content analysis of 2 years of Psychological Science articles reveals inconsistencies in how researchers make inferences about indirect effects when conducting a statistical mediation analysis. In this study, we examined the frequency with which popularly used tests disagree, whether the method an investigator uses makes a difference in the conclusion he or she will reach, and whether there is a most trustworthy test that can be recommended to balance practical and performance considerations. We found that tests agree much more frequently than they disagree, but disagreements are more common when an indirect effect exists than when it does not. We recommend the bias-corrected bootstrap confidence interval as the most trustworthy test if power is of utmost concern, although it can be slightly liberal in some circumstances. Investigators concerned about Type I errors should choose the Monte Carlo confidence interval or the distribution-of-the-product approach, which rarely disagree. The percentile bootstrap confidence interval is a good compromise test.
Related JoVE Video
Relatedness communicated in lemur scent.
Naturwissenschaften
PUBLISHED: 05-30-2013
Show Abstract
Hide Abstract
Lemurs are the most olfactory-oriented of primates, yet there is still only a basic level of understanding of what their scent marks communicate. We analyzed scent secretions from Milne-Edwards sifakas (Propithecus edwardsi) collected in their natural habitat of Ranomafana National Park, Madagascar. We sought to test whether the scent mark could signal genetic relatedness in addition to species, sex, season, and individuality. We not only found correlations (r (2)?=?0.38, P?=?0.017) between the total olfactory fingerprint and genetic relatedness but also between relatedness and specific components of the odor, despite the complex environmental signals from differences in diet and behavior in a natural setting. To the best of our knowledge, this is the first demonstration of an association between genetic relatedness and chemical communication in a wild primate population. Furthermore, we found a variety of compounds that were specific to each sex and each sampling period. This research shows that scent marks could act as a remote signal to avoid inbreeding, optimize mating opportunities, and potentially aid kin selection.
Related JoVE Video
Statistical mediation analysis with a multicategorical independent variable.
Br J Math Stat Psychol
PUBLISHED: 04-22-2013
Show Abstract
Hide Abstract
Virtually all discussions and applications of statistical mediation analysis have been based on the condition that the independent variable is dichotomous or continuous, even though investigators frequently are interested in testing mediation hypotheses involving a multicategorical independent variable (such as two or more experimental conditions relative to a control group). We provide a tutorial illustrating an approach to estimation of and inference about direct, indirect, and total effects in statistical mediation analysis with a multicategorical independent variable. The approach is mathematically equivalent to analysis of (co)variance and reproduces the observed and adjusted group means while also generating effects having simple interpretations. Supplementary material available online includes extensions to this approach and Mplus, SPSS, and SAS code that implements it.
Related JoVE Video
Genome sequencing of mucosal melanomas reveals that they are driven by distinct mechanisms from cutaneous melanoma.
J. Pathol.
PUBLISHED: 02-12-2013
Show Abstract
Hide Abstract
Mucosal melanoma displays distinct clinical and epidemiological features compared to cutaneous melanoma. Here we used whole genome and whole exome sequencing to characterize the somatic alterations and mutation spectra in the genomes of ten mucosal melanomas. We observed somatic mutation rates that are considerably lower than occur in sun-exposed cutaneous melanoma, but comparable to the rates seen in cancers not associated with exposure to known mutagens. In particular, the mutation signatures are not indicative of ultraviolet light- or tobacco smoke-induced DNA damage. Genes previously reported as mutated in other cancers were also mutated in mucosal melanoma. Notably, there were substantially more copy number and structural variations in mucosal melanoma than have been reported in cutaneous melanoma. Thus, mucosal and cutaneous melanomas are distinct diseases with discrete genetic features. Our data suggest that different mechanisms underlie the genesis of these diseases and that structural variations play a more important role in mucosal than in cutaneous melanomagenesis.
Related JoVE Video
The forkhead transcription factor FOXK2 promotes AP-1-mediated transcriptional regulation.
Mol. Cell. Biol.
PUBLISHED: 11-14-2011
Show Abstract
Hide Abstract
The transcriptional control circuitry in eukaryotic cells is complex and is orchestrated by combinatorially acting transcription factors. Forkhead transcription factors often function in concert with heterotypic transcription factors to specify distinct transcriptional programs. Here, we demonstrate that FOXK2 participates in combinatorial transcriptional control with the AP-1 transcription factor. FOXK2 binding regions are widespread throughout the genome and are often coassociated with AP-1 binding motifs. FOXK2 acts to promote AP-1-dependent gene expression changes in response to activation of the AP-1 pathway. In this context, FOXK2 is required for the efficient recruitment of AP-1 to chromatin. Thus, we have uncovered an important new molecular mechanism that controls AP-1-dependent gene expression.
Related JoVE Video
Retroperitoneal tumours: review of management.
Ann R Coll Surg Engl
PUBLISHED: 09-28-2011
Show Abstract
Hide Abstract
The retroperitoneum can host a wide spectrum of pathologies, including a variety of rare benign tumours and malignant neoplasms that can be either primary or metastatic lesions. Retroperitoneal tumours can cause a diagnostic dilemma and present several therapeutic challenges because of their rarity, relative late presentation and anatomical location, often in close relationship with several vital structures in the retroperitoneal space.
Related JoVE Video
Absolute and relative quantification of mRNA expression (transcript analysis).
Methods Mol. Biol.
PUBLISHED: 08-25-2011
Show Abstract
Hide Abstract
In this protocol, we describe a pipeline for transcript analysis in yeast via the quantification of mRNA expression levels. In the first section, we consider the well-established, proprietary Affymetrix GeneChip® approach to generating transcriptomics data. In the next section, we concentrate on providing a detailed protocol for the validation of these data using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The protocol provides suggested examples of hardware, software, and consumables/reagents required to perform these experiments. There are of course many other options available using alternative approaches (or indeed suppliers), but this protocol is intended to provide an approach that is flexible, inexpensive, sensitive, and easy to use.
Related JoVE Video
A patient presenting with a perivascular epithelioid cell tumor in the broad ligament: a case report.
J Med Case Rep
PUBLISHED: 08-16-2011
Show Abstract
Hide Abstract
Perivascular epithelioid cell tumors are a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. They can originate in any visceral organ or soft tissue and include a range of lesions such as angiomyolipoma, clear cell sugar tumor of the lung, lymphangioleiomyomatosis and clear cell myomelanocytic tumors of the falciparum ligament/ligament teres. Due to their rarity and varied sites and presentation, management of these tumors remains highly challenging.
Related JoVE Video
Management of benign retroperitoneal schwannomas: a single-center experience.
Am. J. Surg.
PUBLISHED: 08-04-2011
Show Abstract
Hide Abstract
We describe the presentation, diagnostic pathway, and management of 28 patients with benign retroperitoneal schwannomas.
Related JoVE Video
Surgical management of radiation-induced angiosarcoma after breast conservation therapy.
Am. J. Surg.
PUBLISHED: 06-11-2011
Show Abstract
Hide Abstract
Radiation-induced angiosarcoma (RA) is a well-recognized complication of breast conservation therapy (BCT).
Related JoVE Video
Phenomic and transcriptomic analyses reveal that autophagy plays a major role in desiccation tolerance in Saccharomyces cerevisiae.
Mol Biosyst
PUBLISHED: 10-20-2010
Show Abstract
Hide Abstract
Saccharomyces cerevisiae can survive extreme desiccation, but the molecular mechanisms are poorly understood. To define genes involved in desiccation tolerance, two complementary genome-wide approaches, phenomics and transcriptomics, have been used, together with a targeted analysis of gene deletion mutants tested individually for their ability to survive drying. Genome-wide phenotypic analyses carried out on a pooled library of single-gene deletion mutants subjected to three cycles of desiccation and re-growth to post-diauxic phase identified about 650 genes that contributed to strain survival in the drying process. Air-drying desiccation-tolerant post-diauxic phase cells significantly altered transcription in 12% of the yeast genome, activating expression of over 450 genes and down-regulating 330. Autophagy processes were significantly over-represented in both the phenomics study and the genes up-regulated on drying, indicating the importance of the clearance of protein aggregates/damaged organelles and the recycling of nutrients for the survival of desiccation in yeast. Functional carbon source sensing networks governed by the PKA, Tor and Snf1 protein kinase complexes were important for the survival of desiccation, as indicated by phenomics, transcriptomics, and individual analyses of mutant strains. Changes in nitrogen metabolism were evident during the drying process and parts of the environmental stress response were activated, repressing ribosome production and inducing genes for coping with oxidative and osmotic stress.
Related JoVE Video
The Influence of Youth Music Television Viewership on Changes in Cigarette Use and Association with Smoking Peers: A Social Identity, Reinforcing Spirals Perspective.
Communic Res
PUBLISHED: 09-29-2010
Show Abstract
Hide Abstract
Prior research has found strong evidence of a prospective association between R movie exposure and teen smoking. Using parallel process latent-growth modeling, the present study examines prospective associations between viewing of music video channels on television (e.g., MTV and VH-1) and changes over time in smoking and association with smoking peers. Results showed that baseline viewing of music-oriented channels such as MTV and VH-1 robustly predicted increasing trajectories of smoking and of associating with smoking peers, even after application of a variety of controls including parent reports of monitoring behavior. These results are consistent with the arguments from the reinforcing spirals model that such media use serves as a means of developing emergent adolescent social identities consistent with associating with smoking peers and acquiring smoking and other risk behaviors; evidence also suggests that media choice in reinforcing spiral processes are dynamic and evolve as social identity evolves.
Related JoVE Video
Does the two-week rule pathway improve the diagnosis of soft tissue sarcoma? A retrospective review of referral patterns and outcomes over five years in a regional sarcoma centre.
Ann R Coll Surg Engl
PUBLISHED: 05-19-2010
Show Abstract
Hide Abstract
The NHS Cancer Plan was introduced in 2000 and included guidelines for the rapid assessment and referral of cases of suspected malignancy. We wished to assess the efficiency and appropriateness of patients referred under the Department of Healths general practitioner referral guidelines implemented for sarcomas in December 2000.
Related JoVE Video
Conditional cell-wall mutants of Saccharomyces cerevisiae as delivery vehicles for therapeutic agents in vivo to the GI tract.
J. Biotechnol.
PUBLISHED: 01-19-2010
Show Abstract
Hide Abstract
Strains of Saccharomyces cerevisiae capable of lysis upon conditional down-regulation of cell-wall biogenesis genes (SRB1 and PKC1) have been reported. Here, we show that they lyse and release recombinant protein not only under laboratory conditions, but (more importantly) under conditions found in the human stomach and duodenum. These findings provide proof that, in principle, such conditional lysis strains could be used as an integral part of a system for the oral delivery of therapeutic proteins. However, the current mechanism of conditional lysis is based on the use of the MET3 promoter which requires addition of methionine and cysteine for down-regulation of SRB1 and PKC1. This requirement makes it difficult to apply in vivo. We reasoned that promoters, suitable for in vivo down-regulation of lysis-inducing genes, could be identified amongst yeast genes whose transcript abundance is reduced under conditions found in the human gut. A microarray experiment identified a number of candidate genes with significantly reduced transcript levels under simulated human gut conditions. The greatest effects were seen with ANB1, TIR1, and MF(ALPHA)2), and we propose that their promoters have the potential to be used in vivo to achieve yeast lysis in the gut.
Related JoVE Video
Newspaper Coverage of Cancer Prevention: Multilevel Evidence for Knowledge Gap Effects.
J Commun
PUBLISHED: 08-19-2009
Show Abstract
Hide Abstract
Prior research on knowledge gap effects, in health as well as in other domains, has focused largely on assessing individual-level differences in exposure to news based on self-report of media use. Inherent inferential limitations of this approach are addressed by testing the hypothesis that the relationship between education and cancer prevention knowledge will be moderated by regional differences in U.S. news coverage of cancer prevention. The study also tests, using these methods, findings by Kwak (1999) suggesting that the importance of attention to relevant news in predicting knowledge decreases as information available in the news increases. Using a representative national sample of newspaper coverage to assess regional differences in cancer prevention coverage, a representative national probability sample to assess respondent education and cancer prevention knowledge, and multilevel analyses of the relationship between regional coverage differences and knowledge of persons in those regions, support is found for both of these propositions.
Related JoVE Video
Computational procedures for probing interactions in OLS and logistic regression: SPSS and SAS implementations.
Behav Res Methods
PUBLISHED: 07-10-2009
Show Abstract
Hide Abstract
Researchers often hypothesize moderated effects, in which the effect of an independent variable on an outcome variable depends on the value of a moderator variable. Such an effect reveals itself statistically as an interaction between the independent and moderator variables in a model of the outcome variable. When an interaction is found, it is important to probe the interaction, for theories and hypotheses often predict not just interaction but a specific pattern of effects of the focal independent variable as a function of the moderator. This article describes the familiar pick-a-point approach and the much less familiar Johnson-Neyman technique for probing interactions in linear models and introduces macros for SPSS and SAS to simplify the computations and facilitate the probing of interactions in ordinary least squares and logistic regression. A script version of the SPSS macro is also available for users who prefer a point-and-click user interface rather than command syntax.
Related JoVE Video
Breast sarcoma--a review of diagnosis and management.
Int J Surg
PUBLISHED: 07-08-2009
Show Abstract
Hide Abstract
Sarcoma of the breast is a rare condition. The biological differences from other primary breast tumours necessitate a corresponding difference in approach to diagnostic and management strategies. The rarity of the condition has made clinicopathological study difficult, with most series limited to less than 50 patients. We review the current literature on the diagnosis and management of breast sarcoma, and highlight areas of likely future development.
Related JoVE Video
Hip resurfacing using the trochanteric flip osteotomy.
Hip Int
PUBLISHED: 05-23-2009
Show Abstract
Hide Abstract
We report the early results and complications of resurfacing arthroplasty using the Trochanteric Flip Osteotomy approach to the hip. There are no published clinical results of this approach used for resurfacing arthroplasty. One hundred consecutive patients were assessed prospectively for a minimum follow-up of 2 years (range 2-5 years). The Oxford Hip Score fell from a median of 30 pre-operatively to 5 at two years. Similar improvement was found in the UCLA Activity Score. There were no cases of component failure or fractures. However, nine patients had minor complications related to the osteotomy. Resurfacing Arthroplasty of the hip may be successfully performed through a trochanteric flip osteotomy. This surgical approach may avoid some of the complications associated with avascular necrosis of the femoral head.
Related JoVE Video
Corymbia species and hybrids: chemical and physical foliar attributes and implications for herbivory.
J. Chem. Ecol.
PUBLISHED: 05-04-2009
Show Abstract
Hide Abstract
Hybridization is an important biological phenomenon that can be used to understand the evolutionary process of speciation of plants and their associated pests and diseases. Interactions between hybrid plants and the herbivores of the parental taxa may be used to elucidate the various cues being used by the pests for host location or other processes. The chemical composition of plants, and their physical foliar attributes, including leaf thickness, trichome density, moisture content and specific leaf weight were compared between allopatric pure and commercial hybrid species of Corymbia, an important subtropical hardwood taxon. The leaf-eating beetle Paropsis atomaria, to which the pure taxa represented host (C. citriodora subsp. variegata) and non-host (C. torelliana) plants, was used to examine patterns of herbivory in relation to these traits. Hybrid physical foliar traits, chemical profiles, and field and laboratory beetle feeding preference, while showing some variability, were generally intermediate to those exhibited by parent taxa, thus suggesting an additive inheritance pattern. The hybrid susceptibility hypothesis was not supported by our field or laboratory studies, and there was no strong relationship between adult preference and larval performance. The most-preferred adult host was the sympatric taxon, although this species supported the lowest larval survival, while the hybrid produced significantly smaller pupae than the pure species. The results are discussed in relation to plant chemistry and physical characteristics. The findings suggest a chemical basis for host selection behavior and indicate that it may be possible to select for resistance to this insect pest in these commercially important hardwood trees.
Related JoVE Video
Ontogenetic variation in the chemical defenses of cane toads (Bufo marinus): toxin profiles and effects on predators.
J. Chem. Ecol.
PUBLISHED: 02-11-2009
Show Abstract
Hide Abstract
We conducted a quantitative and qualitative chemical analysis of cane toad bufadienolides--the cardioactive steroids that are believed to be the principal cane toad toxins. We found complex shifts in toxin composition through toad ontogeny: (1) eggs contain at least 28 dominant bufadienolides, 17 of which are not detected in any other ontogenetic stage; (2) tadpoles present a simpler chemical profile with two to eight dominant bufadienolides; and (3) toxin diversity decreases during tadpole life but increases again after metamorphosis (larger metamorph/juvenile toads display five major bufadienolides). Total bufadienolide concentrations are highest in eggs (2.64 +/- 0.56 micromol/mg), decreasing during tadpole life stages (0.084 +/- 0.060 micromol/mg) before rising again after metamorphosis (2.35 +/- 0.45 micromol/mg). These variations in total bufadienolide levels correlate with toxicity to Australian frog species. For example, consumption of cane toad eggs killed tadpoles of two Australian frog species (Limnodynastes convexiusculus and Litoria rothii), whereas no tadpoles died after consuming late-stage cane toad tadpoles or small metamorphs. The high toxicity of toad eggs reflects components in the egg itself, not the surrounding jelly coat. Our results suggest a dramatic ontogenetic shift in the danger that toads pose to native predators, reflecting rapid changes in the types and amounts of toxins during toad development.
Related JoVE Video
Microbial biotransformation as a source of chemical diversity in cane toad steroid toxins.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-20-2009
Show Abstract
Hide Abstract
The cane toad is an invasive pest that is rapidly colonising northern Australia. The cane toad parotoid gland secretes cardiotoxic steroids (bufadienolides) that are poisoning native predator species. This study reveals bufadienolide diversity within the secretions of Australian cane toads is different to cane toads from overseas, being far more structurally diverse than previously assumed. It is proposed that this variation is mediated by in situ bacterial biotransformation.
Related JoVE Video
Peritoneal dialysis technique success during the initial 90 days of therapy.
Adv Perit Dial
Show Abstract
Hide Abstract
Comparisons of technique success by peritoneal dialysis (PD) modality have typically excluded the initial 90 days of therapy. We analyzed a database of 51,469 new PD starts from 2004 to 2008 in the United States. The analysis concentrated on the initial 90 days of therapy to determine technique success and the impact of the continuous ambulatory PD (CAPD) and automated PD (APD) modalities. Overall, 13.3% of patients stopped PD within 90 days. Of patients starting directly on APD, 14.3% stopped PD within 90 days. Of patients starting on CAPD, 12.6% stopped PD within 90 days, and 63.4% changed to APD within 90 days. Only 3.3% of the latter patients failed to reach 90 days of therapy. By comparison, technique failure occurred in 28.8% of those initiating with and remaining on CAPD. We conclude that initial training to perform CAPD, with timely transfer to APD within the first 3 months, was associated with the greatest technique success at 90 days. The reasons for that success are unclear, and further research should be directed to determining factors responsible. It is possible that patients trained initially to CAPD but converted to APD have a greater understanding of the total therapy, which improves confidence. Those converted to APD may be more appreciative of the lifestyle benefits of APD, which translates into improved compliance; alternatively, technical factors associated with APD may be responsible. Those technical factors may include improved catheter function in the recumbent position during APD or the reduced infection risk associated with just 2 connect/disconnect procedures in APD compared with 8 in CAPD.
Related JoVE Video
Inhibiting EGF receptor or SRC family kinase signaling overcomes BRAF inhibitor resistance in melanoma.
Cancer Discov
Show Abstract
Hide Abstract
We generated cell lines resistant to BRAF inhibitors and show that the EGF receptor (EGFR)-SRC family kinase (SFK)-STAT3 signaling pathway was upregulated in these cells. In addition to driving proliferation of resistant cells, this pathway also stimulated invasion and metastasis. EGFR inhibitors cooperated with BRAF inhibitors to block the growth of the resistant cells in vitro and in vivo, and monotherapy with the broad specificity tyrosine kinase inhibitor dasatinib blocked growth and metastasis in vivo. We analyzed tumors from patients with intrinsic or acquired resistance to vemurafenib and observed increased EGFR and SFK activity. Furthermore, dasatinib blocked the growth and metastasis of one of the resistant tumors in immunocompromised mice. Our data show that BRAF inhibitor-mediated activation of EGFR-SFK-STAT3 signaling can mediate resistance in patients with BRAF-mutant melanoma. We describe 2 treatments that seem to overcome this resistance and could deliver therapeutic efficacy in patients with drug-resistant BRAF-mutant melanoma.
Related JoVE Video
Heterologous osteosarcomatous and rhabdomyosarcomatous elements in dedifferentiated solitary fibrous tumor: further support for the concept of dedifferentiation in solitary fibrous tumor.
Ann Diagn Pathol
Show Abstract
Hide Abstract
Dedifferentiation within solitary fibrous tumor is a rare and only recently characterized phenomenon. It differs from malignant solitary fibrous tumor in that there is abrupt transition between classical solitary fibrous tumor and the dedifferentiated component. The latter is a high-grade sarcoma, which can exhibit a number of morphologies, but heterologous differentiation is exceptionally rare. We report a case of dedifferentiated solitary fibrous tumor, with heterologous osteosarcomatous and rhabdomyosarcomatous elements, arising in the deep soft tissue of the thigh of a 59-year-old man. This comprised morphologically and immunohistochemically typical solitary fibrous tumor, juxtaposed to pleomorphic, high-grade malignant neoplasm of 2 distinct lineages. The sharp demarcation between well-differentiated and dedifferentiated components is typical of the dedifferentiation seen in other mesenchymal neoplasms. This expands the range of histopathology of this rare, newly characterized type of malignant progression in solitary fibrous tumor.
Related JoVE Video
Self-efficacy mediates the impact of craving on smoking abstinence in low to moderately anxious patients: results of a moderated mediation approach.
Psychol Addict Behav
Show Abstract
Hide Abstract
Little is known about the effect of craving on smoking abstinence among cardiac patients who smoked prior to admission and the mechanisms that might facilitate success in smoking cessation after discharge from hospital. This study examined the mediating effect of self-efficacy on the relationship between craving and smoking abstinence and how this mechanism may be contingent on emotional state at the time of hospital admission. Cardiac patients who smoked prior to admission were recruited from cardiac nursing units in Dutch hospitals. On hospitalization, 244 patients completed a questionnaire on craving, self-efficacy to smoking cessation, and anxiety and depression levels. Six months after discharge patients were interviewed to ascertain their smoking status. Simple mediation and moderated mediation effects of craving and self-efficacy on smoking abstinence were tested. Of the patients who successfully completed the baseline questionnaire and the follow-up interview, 38% were not smoking at 6 months. Self-efficacy mediated the effect of craving on smoking abstinence. However, this indirect effect was more pronounced among patients with relatively low to moderate anxiety at the time of hospitalization. Our findings suggest that craving reduces self-efficacy, which in turn reduces the likelihood of smoking abstinence, although this process applies only to those patients with low to moderate anxiety levels at the time of hospitalization. Interventions for smoking cardiac patients should aim to reduce craving and to enhance patients self-efficacy to smoking cessation after discharge from hospital.
Related JoVE Video
Technical considerations in surgery for retroperitoneal sarcomas: position paper from E-Surge, a master class in sarcoma surgery, and EORTC-STBSG.
Ann. Surg. Oncol.
Show Abstract
Hide Abstract
Surgery is the principal treatment for retroperitoneal sarcoma. These tumors typically involve or abut multiple organs and therefore require multivisceral resections. Despite the complexity of such operations, a standardized approach has not been described. As a result, referral centers often see patients who have undergone suboptimal surgery, with gross disease left behind. This is one of the causes of the dismal prognosis of this disease.
Related JoVE Video
Increasing support for alcohol-control enforcement through news coverage of alcohols role in injuries and crime.
J Stud Alcohol Drugs
Show Abstract
Hide Abstract
Prior research has shown that the proportion of news stories about violent crimes, car crashes, and other unintended injuries that mention the possible contributing role of alcohol is far lower than the actual proportion of alcohol-related crimes and unintended injuries. An experiment was conducted to test the hypothesis that inclusion of such mention can increase concern about alcohol risks and support for alcohol-control measures, which have elsewhere been shown to decrease alcohol-related problems in community settings. Methodologically, we provide a model for experiments permitting generalization across randomly selected message stimuli.
Related JoVE Video
Genome-wide occupancy links Hoxa2 to Wnt-?-catenin signaling in mouse embryonic development.
Nucleic Acids Res.
Show Abstract
Hide Abstract
The regulation of gene expression is central to developmental programs and largely depends on the binding of sequence-specific transcription factors with cis-regulatory elements in the genome. Hox transcription factors specify the spatial coordinates of the body axis in all animals with bilateral symmetry, but a detailed knowledge of their molecular function in instructing cell fates is lacking. Here, we used chromatin immunoprecipitation with massively parallel sequencing (ChIP-seq) to identify Hoxa2 genomic locations in a time and space when it is actively instructing embryonic development in mouse. Our data reveals that Hoxa2 has large genome coverage and potentially regulates thousands of genes. Sequence analysis of Hoxa2-bound regions identifies high occurrence of two main classes of motifs, corresponding to Hox and Pbx-Hox recognition sequences. Examination of the binding targets of Hoxa2 faithfully captures the processes regulated by Hoxa2 during embryonic development; in addition, it uncovers a large cluster of potential targets involved in the Wnt-signaling pathway. In vivo examination of canonical Wnt-?-catenin signaling reveals activity specifically in Hoxa2 domain of expression, and this is undetectable in Hoxa2 mutant embryos. The comprehensive mapping of Hoxa2-binding sites provides a framework to study Hox regulatory networks in vertebrate developmental processes.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.