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.
Two-strain competition in quasineutral stochastic disease dynamics.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 10-31-2014
Show Abstract
Hide Abstract
We develop a perturbation method for studying quasineutral competition in a broad class of stochastic competition models and apply it to the analysis of fixation of competing strains in two epidemic models. The first model is a two-strain generalization of the stochastic susceptible-infected-susceptible (SIS) model. Here we extend previous results due to Parsons and Quince [Theor. Popul. Biol. 72, 468 (2007)], Parsons et al. [Theor. Popul. Biol. 74, 302 (2008)], and Lin, Kim, and Doering [J. Stat. Phys. 148, 646 (2012)]. The second model, a two-strain generalization of the stochastic susceptible-infected-recovered (SIR) model with population turnover, has not been studied previously. In each of the two models, when the basic reproduction numbers of the two strains are identical, a system with an infinite population size approaches a point on the deterministic coexistence line (CL): a straight line of fixed points in the phase space of subpopulation sizes. Shot noise drives one of the strain populations to fixation, and the other to extinction, on a time scale proportional to the total population size. Our perturbation method explicitly tracks the dynamics of the probability distribution of the subpopulations in the vicinity of the CL. We argue that, whereas the slow strain has a competitive advantage for mathematically "typical" initial conditions, it is the fast strain that is more likely to win in the important situation when a few infectives of both strains are introduced into a susceptible population.
Related JoVE Video
Cerium tetrakis(diisopropylamide) - a useful precursor for cerium(iv) chemistry.
Chem. Commun. (Camb.)
PUBLISHED: 10-16-2014
Show Abstract
Hide Abstract
Homoleptic cerium(iv) diisopropylamide was synthesized via oxidation of ate complex Ce(NiPr2)4Li(thf) with trityl chloride or hexachloroethane. Due to its ready accessibility, and high pKa value of the proligand HNiPr2, Ce(NiPr2)4 features a promising candidate for protonolysis reactions, as shown for the synthesis of dimeric cerium(iv) tetrakis(1,1,3,3-N,N,N',N'-tetramethylguanidinate).
Related JoVE Video
Fidelity of northern pine snakes (Pituophis m. melanoleucus) to natural and artificial hibernation sites in the New Jersey Pine Barrens.
J. Toxicol. Environ. Health Part A
PUBLISHED: 10-01-2014
Show Abstract
Hide Abstract
Environmental managers require information on whether human-made hibernacula are used by rare snakes before constructing large numbers of them as mitigation measures. Fidelity of northern pine snakes (Pituophis m. melanoleucus) was examined in a 6-year study in the New Jersey Pine Barrens to determine whether they used natural and artificial hibernacula equally. Pine snakes used both artificial (human-made) and natural (snake-adapted) hibernacula. Most natural hibernacula were in abandoned burrows of large mammals. Occupancy rates were similar between natural and artificial hibernacula. Only 6 of 27 radio-tracked snakes did not shift hibernacula between years, whereas 78% shifted sites at least once, and fidelity from one year to the next was 42%. For snakes that switched hibernacula (n = 21), one switched among artificial hibernacula, 14 (65%) switched among natural hibernacula, and 6 (29%) switched from artificial to natural hibernacula. Data indicate that most pine snakes switch among hibernacula, mainly selecting natural hibernacula, suggesting that artificial dens are used, but protecting natural hibernacula should be a higher conservation priority.
Related JoVE Video
Hu Antigen R (HuR) Is a Positive Regulator of the RNA-binding Proteins TDP-43 and FUS/TLS: IMPLICATIONS FOR AMYOTROPHIC LATERAL SCLEROSIS.
J. Biol. Chem.
PUBLISHED: 09-19-2014
Show Abstract
Hide Abstract
Posttranscriptional gene regulation is governed by a network of RNA-binding proteins (RBPs) that interact with regulatory elements in the mRNA to modulate multiple molecular processes, including splicing, RNA transport, RNA stability, and translation. Mounting evidence indicates that there is a hierarchy within this network whereby certain RBPs cross-regulate other RBPs to coordinate gene expression. HuR, an RNA-binding protein we linked previously to aberrant VEGF mRNA metabolism in models of SOD1-associated amyotrophic lateral sclerosis, has been identified as being high up in this hierarchy, serving as a regulator of RNA regulators. Here we investigated the role of HuR in regulating two RBPs, TDP-43 and FUS/TLS, that have been linked genetically to amyotrophic lateral sclerosis. We found that HuR promotes the expression of both RBPs in primary astrocytes and U251 cells under normal and stressed (hypoxic) conditions. For TDP-43, we found that HuR binds to the 3' untranslated region (UTR) and regulates its expression through translational efficiency rather than RNA stability. With HuR knockdown, there was a shift of TDP-43 and FUS mRNAs away from polysomes, consistent with translational silencing. The TDP-43 splicing function was attenuated upon HuR knockdown and could be rescued by ectopic TDP-43 lacking the 3' UTR regulatory elements. Finally, conditioned medium from astrocytes in which HuR or TDP-43 was knocked down produced significant motor neuron and cortical neuron toxicity in vitro. These findings indicate that HuR regulates TDP-43 and FUS/TLS expression and that loss of HuR-mediated RNA processing in astrocytes can alter the molecular and cellular landscape to produce a toxic phenotype.
Related JoVE Video
A user's guide to the ribosomal DNA in Saccharomyces cerevisiae.
Methods Mol. Biol.
PUBLISHED: 09-13-2014
Show Abstract
Hide Abstract
Messenger RNA synthesis (mRNA) accounts for a small fraction of total RNA synthesis in growing eukaryotic cells. The bulk of cellular transcription is devoted to ribosomal RNA (rRNA) synthesis (Warner, Trends Biochem Sci 24:437-440, 1999). Several unique characteristics of the rDNA and RNA polymerase I must be considered in order to accurately quantify the synthesis rate of rRNA or to characterize its processing. Indeed, an entirely different set of techniques must be applied to the study of rRNA synthesis than is routinely to study mRNA synthesis. Five of the most useful strategies for genetic and molecular analysis of rRNA synthesis and regulation are outlined in this chapter. The techniques described were developed for characterization of the model eukaryote Saccharomyces cerevisiae; however, many of these strategies can be adapted for studies in other eukaryotic cells.
Related JoVE Video
Using heterogeneity of the patient-derived xenograft model to identify the chemoresistant population in ovarian cancer.
Oncotarget
PUBLISHED: 09-12-2014
Show Abstract
Hide Abstract
A cornerstone of preclinical cancer research has been the use of clonal cell lines. However, this resource has underperformed in its ability to effectively identify novel therapeutics and evaluate the heterogeneity in a patient's tumor. The patient-derived xenograft (PDX) model retains the heterogeneity of patient tumors, allowing a means to not only examine efficacy of a therapy, but also basic tenets of cancer biology in response to treatment. Herein we describe the development and characterization of an ovarian-PDX model in order to study the development of chemoresistance. We demonstrate that PDX tumors are not simply composed of tumor-initiating cells, but recapitulate the original tumor's heterogeneity, oncogene expression profiles, and clinical response to chemotherapy. Combined carboplatin/paclitaxel treatment of PDX tumors enriches the cancer stem cell populations, but persistent tumors are not entirely composed of these populations. RNA-Seq analysis of six pair of treated PDX tumors compared to untreated tumors demonstrates a consistently contrasting genetic profile after therapy, suggesting similar, but few, pathways are mediating chemoresistance. Pathways and genes identified by this methodology represent novel approaches to targeting the chemoresistant population in ovarian cancer.
Related JoVE Video
Justified Follow-Up: A Final Intraoperative Parathyroid Hormone (ioPTH) Over 40 pg/mL is Associated with an Increased Risk of Persistence and Recurrence in Primary Hyperparathyroidism.
Ann. Surg. Oncol.
PUBLISHED: 09-06-2014
Show Abstract
Hide Abstract
After parathyroidectomy for sporadic primary hyperparathyroidism (PHPT), overall rates of persistence/recurrence are extremely low. A marker of increased risk for persistence/recurrence is needed. We hypothesized that final intraoperative parathyroid hormone (FioPTH) ?40 pg/mL is indicative of increased risk for disease persistence/recurrence, and can be used to selectively determine the degree of follow-up.
Related JoVE Video
Variation of electronic transitions and reduction potentials of cerium(iv) complexes.
Dalton Trans
PUBLISHED: 08-23-2014
Show Abstract
Hide Abstract
The trivalent compound K[Ce[N(SiHMe2)2]4] was synthesized and oxidized, providing a convenient route to the reported cerium(iv) compound Ce[N(SiHMe2)2]4. Protonolysis reactions of Ce[N(SiHMe2)2]4 with tert-butanol, substituted benzyl alcohols, and 2,6-diphenylphenol yielded the neutral tetravalent compounds Ce(O(t)Bu)4(py)2, Ce2(OCH2C6R5)8(thf)2 (R = Me, F), and Ce(Odpp)4 (dpp = 2,6-(C6H5)2-C6H3). Spectroscopic and electrochemical characterization of the monometallic cerium(iv) silylamide, alkoxide, and aryloxide compounds revealed variable ligand-to-metal charge transfer transitions and metal-based reduction potentials. Computational bonding analyses were performed to complement the physical characterization of the complexes.
Related JoVE Video
Infertility following retained products of conception: is it the surgical procedure or the presence of trophoblastic tissue?
Eur. J. Obstet. Gynecol. Reprod. Biol.
PUBLISHED: 08-16-2014
Show Abstract
Hide Abstract
To compare the reproductive outcome of women who underwent re-evacuation of the uterine cavity due to suspected retained products of conception (RPOC) and in whom trophoblastic tissue was confirmed by histopathologic examination to those with negative pathologic findings.
Related JoVE Video
Pharmacodynamic effects during the transition between cangrelor and prasugrel.
Coron. Artery Dis.
PUBLISHED: 08-05-2014
Show Abstract
Hide Abstract
The aim of this study was to determine the impact of cangrelor and prasugrel on the pharmacodynamic effects of each agent.
Related JoVE Video
Influence of local administration of pamidronate on extraction socket healing - a histomorphometric proof-of-principle pre-clinical in vivo evaluation.
Clin Oral Implants Res
PUBLISHED: 08-04-2014
Show Abstract
Hide Abstract
To evaluate the influence of local administration of pamidronate histomorphometrically, adsorbed on a collagenated porcine bone substitute, on extraction socket healing.
Related JoVE Video
Mild primary hyperparathyroidism: a literature review.
Oncologist
PUBLISHED: 07-25-2014
Show Abstract
Hide Abstract
The biochemical profile of classic primary hyperparathyroidism (pHPT) consists of both elevated calcium and parathyroid hormone levels. The standard of care is parathyroidectomy unless prohibited by medical comorbidities. Because more patients are undergoing routine bone density evaluation and neck imaging studies for other purposes, there is a subset of people identified with a biochemically mild form of the pHPT that expresses itself as either elevated calcium or parathyroid hormone levels. These patients often do not fall into the criteria for operation based on the National Institutes of Health consensus guidelines, and they can present a challenge of diagnosis and management. The purpose of this paper is to review the available literature on mild pHPT in an effort to better characterize this patient population and to determine whether patients benefit from parathyroidectomy. Evidence suggests that there are patients with mild pHPT who have overt symptoms that are found to improve after parathyroidectomy. There is also a group of patients with biochemically mild pHPT who are found to progress to classic pHPT over time; however, it is not predictable which group of patients this will be. Early intervention for this group with mild pHPT may prevent progression of bone, psychiatric, and renal complications, and parathyroidectomy has proven safe in appropriately selected patients at high volume centers.
Related JoVE Video
Toxicological and pharmacokinetic properties of QPI-1007, a chemically modified synthetic siRNA targeting caspase 2 mRNA, following intravitreal injection.
Nucleic Acid Ther
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
We report the toxicological and pharmacokinetic properties of the synthetic, small interfering RNA (siRNA), QPI-1007, following intravitreal administration. QPI-1007 is a chemically modified siRNA designed to act via the RNA interference (RNAi) pathway to temporarily inhibit expression of the caspase 2 protein and is being developed as a neuroprotectant for the treatment of nonarteritic anterior ischemic optic neuropathy and other optic neuropathies such as glaucoma that result in the death of retinal ganglion cells. The half-life of QPI-1007 in the vitreous and retina/choroid in the Dutch Belted rabbit was about 2 days, and there was no sign of accumulation after repeated administrations at either 2- or 4-week dosing intervals in the rabbit. QPI-1007 was well tolerated in Dutch Belted rabbits following single or repeated intravitreal administrations of up to 11 doses over 9 months. Test-article-related effects were limited to the eyes, with minimal to mild vitreal cellular infiltration being the major finding, which was reversible. In repeated-dose studies, a modest reduction in B-wave amplitude obtained by electroretinography was observed in animals treated with the highest dose level tested (3 mg, which is equivalent to a 12 mg/eye human dose) that was not considered to be clinically meaningful. Administration in the rat of either a single bolus intravenous (i.v.) injection of 100 mg/kg or daily bolus i.v. injections of 75 mg/kg/day for 28 days failed to elicit any macroscopic or microscopic changes, suggesting a low risk for systemic toxicity. QPI-1007 was negative in three genetic toxicity studies. Overall, the nonclinical studies support the further development of QPI-1007.
Related JoVE Video
CaPTHUS Scoring Model in Primary Hyperparathyroidism: Can It Eliminate the Need for ioPTH Testing?
Ann. Surg. Oncol.
PUBLISHED: 07-03-2014
Show Abstract
Hide Abstract
The CaPTHUS model was reported to have a positive predictive value of 100 % to correctly predict single-gland disease in patients with primary hyperparathyroidism, thus obviating the need for intraoperative parathyroid hormone (ioPTH) testing. We sought to apply the CaPTHUS scoring model in our patient population and assess its utility in predicting long-term biochemical cure.
Related JoVE Video
Clinical and Socioeconomic Factors Influence Treatment Decisions in Graves' Disease.
Ann. Surg. Oncol.
PUBLISHED: 06-11-2014
Show Abstract
Hide Abstract
Definitive treatment of Graves' disease includes radioactive iodine (RAI) and thyroidectomy, but utilization varies. We hypothesize that, in addition to clinical reasons, there are socioeconomic factors that influence whether a patient undergoes thyroidectomy or RAI.
Related JoVE Video
Surgeon and staff radiation exposure during radioguided parathyroidectomy at a high-volume institution.
Ann. Surg. Oncol.
PUBLISHED: 05-12-2014
Show Abstract
Hide Abstract
Radioguided parathyroidectomy (RGP) uses technetium-99 m sestamibi causing gamma ray emission during RGP to aid dissection and confirm parathyroid excision. Source (the patient) proximity and exposure duration determine degree of exposure. The purpose of this study was to quantify surgeon and staff radiation exposure during RGP.
Related JoVE Video
Preventing Postoperative Hypocalcemia in Patients with Graves Disease: A Prospective Study.
Ann. Surg. Oncol.
PUBLISHED: 05-02-2014
Show Abstract
Hide Abstract
Hypocalcemia occurs after total thyroidectomy (TT) for Graves disease via parathyroid injury and/or from increased bone turnover. Current management is to supplement calcium after surgery. This study evaluates the impact of preoperative calcium supplementation on hypocalcemia after Graves TT.
Related JoVE Video
Lymph Node Metastases do not Impact Survival in Follicular Variant Papillary Thyroid Cancer.
Ann. Surg. Oncol.
PUBLISHED: 04-23-2014
Show Abstract
Hide Abstract
Follicular variant of papillary thyroid cancer (FVPTC) is the most common and fastest growing subtype of papillary thyroid cancer (PTC) with features of both PTC and follicular thyroid cancer (FTC). The purpose of this study was to determine the patient and tumor features associated with lymph node metastases (LNM) in FVPTC.
Related JoVE Video
Outcomes After Subtotal Parathyroidectomy for Primary Hyperparathyroidism due to Hyperplasia: Significance of Whole vs. Partial Gland Remnant.
Ann. Surg. Oncol.
PUBLISHED: 04-21-2014
Show Abstract
Hide Abstract
Primary hyperparathyroidism (PHPT) due to multigland hyperplasia is managed by subtotal parathyroidectomy (sPTX), with a partial gland left in situ. However, smaller, hyperplastic glands may be encountered intraoperatively, and it is unclear if leaving an intact gland is an equivalent alternative. This study evaluates the rates of permanent hypoparathyroidism and cure of PHPT patients with four-gland hyperplasia that were left with either a whole gland remnant (WGR) or a partial gland remnant (PGR) after sPTX.
Related JoVE Video
Failure of radioactive iodine in the treatment of hyperthyroidism.
Ann. Surg. Oncol.
PUBLISHED: 04-16-2014
Show Abstract
Hide Abstract
Persistent or recurrent hyperthyroidism after treatment with radioactive iodine (RAI) is common and many patiedlxnts require either additional doses or surgery before they are cured. The purpose of this study was to identify patterns and predictors of failure of RAI in patients with hyperthyroidism.
Related JoVE Video
Tunnel technique with connective tissue graft versus coronally advanced flap with enamel matrix derivative for root coverage: a RCT using 3D digital measuring methods. Part II. Volumetric studies on healing dynamics and gingival dimensions.
J. Clin. Periodontol.
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
The aim of this randomized clinical trial (RCT) was to compare the clinical performance of the tunnel technique with subepithelial connective tissue graft (TUN) versus a coronally advanced flap with enamel matrix derivative (CAF) in the treatment of gingival recession defects. The use of innovative 3D digital measuring methods allowed to study healing dynamics at connective tissue (CT)-grafted sites and to evaluate the influence of the thickness of the root covering soft tissues on the outcome of surgical root coverage.
Related JoVE Video
All Thyroid Ultrasound Evaluations are Not Equal: Sonographers Specialized in Thyroid Cancer Correctly Label Clinical N0 Disease in Well Differentiated Thyroid Cancer.
Ann. Surg. Oncol.
PUBLISHED: 03-21-2014
Show Abstract
Hide Abstract
Ultrasound (US) is a standard preoperative study in thyroid cancer. Accurate identification of lymph node (LN) disease in the central neck by US is debated, leading some surgeons to perform prophylactic central dissection. The purpose of this study was to evaluate if US performed by a surgeon with specialization in thyroid sonography correctly determined clinical N0 status.
Related JoVE Video
Pharmacodynamic effects during the transition between cangrelor and ticagrelor.
JACC Cardiovasc Interv
PUBLISHED: 03-19-2014
Show Abstract
Hide Abstract
This study sought to determine pharmacodynamic effects during transition from intravenous cangrelor to oral ticagrelor and from oral ticagrelor to intravenous cangrelor.
Related JoVE Video
Novel thyroidectomy difficulty scale correlates with operative times.
World J Surg
PUBLISHED: 03-12-2014
Show Abstract
Hide Abstract
The aim of this study was to evaluate a new thyroidectomy difficulty scale (TDS) for its inter-rater agreement, correspondence with operative times, and correlation with complications.
Related JoVE Video
Optimization of kiloelectron volt settings in cerebral and cervical dual-energy CT angiography determined with virtual monoenergetic imaging.
Acad Radiol
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
Dual-energy computed tomography (DECT) offers various fields of application, especially in angiography using virtual monoenergetic imaging. The aim of this study was to evaluate objective image quality indices of calculated low-kiloelectron volt monoenergetic DECT angiographic cervical and cerebral data sets compared to virtual 120-kV polyenergetic images.
Related JoVE Video
Analysis of the small RNA spf in the plant pathogen Pseudomonas syringae pv. tomato strain DC3000.
Microbiology (Reading, Engl.)
PUBLISHED: 03-05-2014
Show Abstract
Hide Abstract
Bacteria contain small non-coding RNAs (ncRNAs) that are typically responsible for altering transcription, translation or mRNA stability. ncRNAs are important because they often regulate virulence factors and susceptibility to various stresses. Here, the regulation of a recently described ncRNA of Pseudomonas syringae DC3000, spot 42 (now referred to as spf), was investigated. A putative RpoE binding site was identified upstream of spf in strain DC3000. RpoE is shown to regulate the expression of spf. Also, deletion of spf results in increased sensitivity to hydrogen peroxide compared with the wild-type strain, suggesting that spf plays a role in susceptibility to oxidative stress. Furthermore, expression of alg8 is shown to be influenced by spf, suggesting that this ncRNA plays a role in alginate biosynthesis. Structural and comparative genomic analyses show this ncRNA is well conserved among the pseudomonads. The findings provide new information on the regulation and role of this ncRNA in P. syringae.
Related JoVE Video
Distinguishing classical papillary thyroid microcancers from follicular-variant microcancers.
J. Surg. Res.
PUBLISHED: 03-04-2014
Show Abstract
Hide Abstract
Papillary thyroid microcarcinomas (mPTCs), tumors less than or equal to 1 cm, have been considered the same clinical entity as microfollicular-variant papillary thyroid microcarcinomas (mFVPTCs). The purpose of this study was to use population-level data to characterize differences between mFVPTC and mPTC.
Related JoVE Video
Using multitype branching processes to quantify statistics of disease outbreaks in zoonotic epidemics.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 03-04-2014
Show Abstract
Hide Abstract
Branching processes have served as a model for chemical reactions, biological growth processes, and contagion (of disease, information, or fads). Through this connection, these seemingly different physical processes share some common universalities that can be elucidated by analyzing the underlying branching process. In this work we focus on coupled branching processes as a model of infectious diseases spreading from one population to another. An exceedingly important example of such coupled outbreaks are zoonotic infections that spill over from animal populations to humans. We derive several statistical quantities characterizing the first spillover event from animals to humans, including the probability of spillover, the first passage time distribution for human infection, and disease prevalence in the animal population at spillover. Large stochastic fluctuations in those quantities can make inference of the state of the system at the time of spillover difficult. Focusing on outbreaks in the human population, we then characterize the critical threshold for a large outbreak, the distribution of outbreak sizes, and associated scaling laws. These all show a strong dependence on the basic reproduction number in the animal population and indicate the existence of a novel multicritical point with altered scaling behavior. The coupling of animal and human infection dynamics has crucial implications, most importantly allowing for the possibility of large human outbreaks even when human-to-human transmission is subcritical.
Related JoVE Video
Labial soft tissue volume evaluation of different techniques for ridge preservation after tooth extraction: a randomized controlled clinical trial.
J. Clin. Periodontol.
PUBLISHED: 02-27-2014
Show Abstract
Hide Abstract
To volumetrically evaluate soft tissue changes of different ridge preservation techniques compared to spontaneous healing 6 months after tooth extraction.
Related JoVE Video
Thyroidectomy as primary treatment optimizes body mass index in patients with hyperthyroidism.
Ann. Surg. Oncol.
PUBLISHED: 02-13-2014
Show Abstract
Hide Abstract
The purpose of this study was to determine how the timing of thyroidectomy influenced postoperative weight change.
Related JoVE Video
How is forearm compliance affected by various circumferential dressings?
Clin. Orthop. Relat. Res.
PUBLISHED: 01-23-2014
Show Abstract
Hide Abstract
The forearm is the second most common location for extremity compartment syndrome. Compliance is a physical property that describes a material's ability to expand with an increasing internal volume. The effect of circumferential dressings on extremity pressures has been investigated in various animal models and in some nonphysiologic mechanical models, but the importance of this effect has not been fully investigated in the human upper extremity. In addition, the physical property of compliance has not been reported in the analysis of compartment volume-pressure relationships.
Related JoVE Video
In-vitro evaluation of the tolerance of surgical instruments in templates for computer-assisted guided implantology produced by 3-D printing.
Clin Oral Implants Res
PUBLISHED: 01-21-2014
Show Abstract
Hide Abstract
The aim of this in-vitro study was to compare the tolerance of surgical instruments in surgical guides produced by 3-D printing, without metal sleeves to a surgical guide with conventional metal sleeves from two different manufacturers.
Related JoVE Video
Recurrent and persistence primary hyperparathyroidism occurs more frequently in patients with double adenomas.
J. Surg. Res.
PUBLISHED: 01-14-2014
Show Abstract
Hide Abstract
The incidence of recurrent primary hyperparathyroidism (PHPT) had been reported to be between 1% and 10%. The purpose of this study was to examine if patients with multigland disease have a different recurrence rate.
Related JoVE Video
Markedly elevated thyroglobulin levels in the preoperative thyroidectomy patient correlates with metastatic burden.
J. Surg. Res.
PUBLISHED: 01-14-2014
Show Abstract
Hide Abstract
Thyroglobulin (Tg) is a marker of tumor recurrence during thyroid cancer follow-up. While helpful in the postoperative setting, the clinical significance of preoperative Tg measurements remains unclear. The aim of the study was to determine if preoperative Tg levels are indicative of underlying malignancy or burden of metastatic disease.
Related JoVE Video
Primary hyperparathyroidism across the ages: presentation and outcomes.
J. Surg. Res.
PUBLISHED: 01-04-2014
Show Abstract
Hide Abstract
Primary hyperparathyroidism (PHPT) is a disease process traditionally thought to present during middle age, but can occur at any age. The purpose of this study was to compare PHPT patient characteristics based on patient age at the time of surgical referral.
Related JoVE Video
A comparison of reproductive outcomes following hysteroscopic management versus dilatation and curettage of retained products of conception.
Int J Gynaecol Obstet
PUBLISHED: 01-03-2014
Show Abstract
Hide Abstract
To compare the reproductive outcome of women who underwent blind dilatation and curettage (D&C) with those who underwent hysteroscopic resection of pathologically confirmed retained products of conception (RPOC).
Related JoVE Video
Surgical site infection after thyroidectomy: a rare but significant complication.
J. Surg. Res.
PUBLISHED: 01-03-2014
Show Abstract
Hide Abstract
Surgical site infections (SSIs) after thyroidectomy are rare but can have significant consequences. Thyroidectomy is a clean case, and the patterns for use of prophylactic antibiotics vary. We hypothesized that patient and operative characteristics may predict a higher risk of SSI, and that SSI are associated with other complications leading to increased resource utilization.
Related JoVE Video
Identifying predictors of a difficult thyroidectomy.
J. Surg. Res.
PUBLISHED: 01-02-2014
Show Abstract
Hide Abstract
A Thyroidectomy Difficulty Scale (TDS) was previously developed that identified more difficult operations, which correlated with longer operative times and higher complication rates. The purpose of this study was to identify preoperative variables predictive of a more difficult thyroidectomy using the TDS.
Related JoVE Video
Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1? intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1? locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine delivery platform.
Related JoVE Video
Differences in the composition of the human antibody repertoire by B cell subsets in the blood.
Front Immunol
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The vast initial diversity of the antibody repertoire is generated centrally by means of a complex series of V(D)J gene rearrangement events, variation in the site of gene segment joining, and TdT catalyzed N-region addition. Although the diversity is great, close inspection has revealed distinct and unique characteristics in the antibody repertoires expressed by different B cell developmental subsets. In order to illustrate our approach to repertoire analysis, we present an in-depth comparison of V(D)J gene usage, hydrophobicity, length, DH reading frame, and amino acid usage between heavy chain repertoires expressed by immature, transitional, mature, memory IgD(+), memory IgD(-), and plasmacytes isolated from the blood of a single individual. Our results support the view that in both human and mouse, the H chain repertoires expressed by individual, developmental B cell subsets appear to differ in sequence content. Sequencing of unsorted B cells from the blood is thus likely to yield an incomplete or compressed view of what is actually happening in the immune response of the individual. Our findings support the view that studies designed to correlate repertoire expression with diseases of immune function will likely require deep sequencing of B cells sorted by subset.
Related JoVE Video
Radioactive iodine remnant uptake after completion thyroidectomy: not such a complete cancer operation.
Ann. Surg. Oncol.
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Given limitations in preoperative diagnostics, thyroid lobectomy followed by completion thyroidectomy (CT) for differentiated thyroid cancer (DTC) may be required. It is unclear whether resection quality by CT differs from that by total thyroidectomy (TT). Additional surgeon or patient factors may also influence the "completeness" of resection. This study evaluated how CT and surgeon volume influence the adequacy of resection as measured by radioactive iodine (RAI) remnant uptake.
Related JoVE Video
Migratory and adhesive properties of Xenopus laevis primordial germ cells in vitro.
Biol Open
PUBLISHED: 11-29-2013
Show Abstract
Hide Abstract
The directional migration of primordial germ cells (PGCs) to the site of gonad formation is an advantageous model system to study cell motility. The embryonic development of PGCs has been investigated in different animal species, including mice, zebrafish, Xenopus and Drosophila. In this study we focus on the physical properties of Xenopus laevis PGCs during their transition from the passive to the active migratory state. Pre-migratory PGCs from Xenopus laevis embryos at developmental stages 17-19 to be compared with migratory PGCs from stages 28-30 were isolated and characterized in respect to motility and adhesive properties. Using single-cell force spectroscopy, we observed a decline in adhesiveness of PGCs upon reaching the migratory state, as defined by decreased attachment to extracellular matrix components like fibronectin, and a reduced adhesion to somatic endodermal cells. Data obtained from qPCR analysis with isolated PGCs reveal that down-regulation of E-cadherin might contribute to this weakening of cell-cell adhesion. Interestingly, however, using an in vitro migration assay, we found that movement of X. laevis PGCs can also occur independently of specific interactions with their neighboring cells. The reduction of cellular adhesion during PGC development is accompanied by enhanced cellular motility, as reflected in increased formation of bleb-like protrusions and inferred from electric cell-substrate impedance sensing (ECIS) as well as time-lapse image analysis. Temporal alterations in cell shape, including contraction and expansion of the cellular body, reveal a higher degree of cellular dynamics for the migratory PGCs in vitro.
Related JoVE Video
Effect of exercise training and weight loss on platelet reactivity in overweight patients with coronary artery disease.
J Cardiopulm Rehabil Prev
PUBLISHED: 10-16-2013
Show Abstract
Hide Abstract
Obesity is associated with increased platelet reactivity. Greater platelet reactivity presages adverse events in patients with coronary artery disease (CAD). We investigated whether exercise training and weight loss reduce platelet reactivity in overweight subjects with CAD.
Related JoVE Video
Tunnel technique with connective tissue graft versus coronally advanced flap with enamel matrix derivative for root coverage: a RCT using 3D digital measuring methods. Part I. Clinical and patient-centred outcomes.
J. Clin. Periodontol.
PUBLISHED: 09-29-2013
Show Abstract
Hide Abstract
The aim of this randomized clinical trial (RCT) was to introduce 3D digital measuring methods for evaluating the outcomes after surgical root coverage (RC) and to assess the clinical performance of the tunnel technique with subepithelial connective tissue graft (TUN) versus the coronally advanced flap (CAF) with enamel matrix derivative in the treatment of shallow localized gingival recession defects.
Related JoVE Video
Follicular variant of papillary thyroid carcinoma is a unique clinical entity: a population-based study of 10,740 cases.
Thyroid
PUBLISHED: 09-11-2013
Show Abstract
Hide Abstract
Follicular variant of papillary thyroid carcinoma (FV-PTC) has been increasingly diagnosed in recent years. However, little is known about its clinical behavior. The purpose of this study was to determine the disease characteristics of FV-PTC, and to compare it with classical papillary thyroid carcinoma (C-PTC) and follicular thyroid carcinoma (FTC).
Related JoVE Video
Ubp-M serine 552 phosphorylation by cyclin-dependent kinase 1 regulates cell cycle progression.
Cell Cycle
PUBLISHED: 09-04-2013
Show Abstract
Hide Abstract
In eukaryotic cells, genomic DNA is organized into a chromatin structure, which not only serves as the template for DNA-based nuclear processes, but also as a platform integrating intracellular and extracellular signals. Although much effort has been spent to characterize chromatin modifying/remodeling activities, little is known about cell signaling pathways targeting these chromatin modulators. Here, we report that cyclin-dependent kinase 1 (CDK1) phosphorylates the histone H2A deubiquitinase Ubp-M at serine 552 (S552P), and, importantly, this phosphorylation is required for cell cycle progression. Mass spectrometry analysis confirmed Ubp-M is phosphorylated at serine 552, and in vitro and in vivo assays demonstrated that CDK1/cyclin B kinase is responsible for Ubp-M S552P. Interestingly, Ubp-M S552P is not required for Ubp-M tetramer formation, deubiquitination activity, substrate specificity, or regulation of gene expression. However, Ubp-M S552P is required for cell proliferation and cell cycle G 2/M phase progression. Ubp-M S552P reduces Ubp-M interaction with nuclear export protein CRM1 and facilitates Ubp-M nuclear localization. Therefore, these studies confirm that Ubp-M is phosphorylated at S552 and identify CDK1 as the enzyme responsible for the phosphorylation. Importantly, this study specifically links Ubp-M S552P to cell cycle G 2/M phase progression.
Related JoVE Video
Identification of human nephron progenitors capable of generation of kidney structures and functional repair of chronic renal disease.
EMBO Mol Med
PUBLISHED: 07-29-2013
Show Abstract
Hide Abstract
Identification of tissue-specific renal stem/progenitor cells with nephrogenic potential is a critical step in developing cell-based therapies for renal disease. In the human kidney, stem/progenitor cells are induced into the nephrogenic pathway to form nephrons until the 34 week of gestation, and no equivalent cell types can be traced in the adult kidney. Human nephron progenitor cells (hNPCs) have yet to be isolated. Here we show that growth of human foetal kidneys in serum-free defined conditions and prospective isolation of NCAM1(+) cells selects for nephron lineage that includes the SIX2-positive cap mesenchyme cells identifying a mitotically active population with in vitro clonogenic and stem/progenitor properties. After transplantation in the chick embryo, these cells-but not differentiated counterparts-efficiently formed various nephron tubule types. hNPCs engrafted and integrated in diseased murine kidneys and treatment of renal failure in the 5/6 nephrectomy kidney injury model had beneficial effects on renal function halting disease progression. These findings constitute the first definition of an intrinsic nephron precursor population, with major potential for cell-based therapeutic strategies and modelling of kidney disease.
Related JoVE Video
Value of monoenergetic low-kV dual energy CT datasets for improved image quality of CT pulmonary angiography.
Eur J Radiol
PUBLISHED: 07-22-2013
Show Abstract
Hide Abstract
High vessel attenuation and high contrast-to-noise ratio (CNR) are prerequisites for high diagnostic confidence in CT pulmonary angiography (CTPA). This study evaluated the impact of calculated monoenergetic dual-energy (DE) CTPA datasets on vessel attenuation and CNR.
Related JoVE Video
Remnant uptake as a postoperative oncologic quality indicator.
Thyroid
PUBLISHED: 07-17-2013
Show Abstract
Hide Abstract
The purpose of this study was to examine the utility of remnant uptake on postoperative radioiodine scans as an oncologic indicator after thyroidectomy for differentiated thyroid cancer (DTC).
Related JoVE Video
Fibroblasts express OvHV-2 capsid protein in vasculitis lesions of American bison (Bison bison) with experimental sheep-associated malignant catarrhal fever.
Vet. Microbiol.
PUBLISHED: 07-06-2013
Show Abstract
Hide Abstract
American bison (Bison bison) are particularly susceptible to developing fatal sheep-associated malignant catarrhal fever (SA-MCF) caused by ovine herpesvirus-2 (OvHV-2), a ?-herpesvirus in the Macavirus genus. This generally fatal disease is characterized by lymphoproliferation, vasculitis, and mucosal ulceration in American bison, domestic cattle (Bos taurus), and other clinically susceptible species which are considered non-adapted, dead-end hosts. The pathogenesis and cellular tropism of OvHV-2 infection have not been fully defined. An earlier study detected OvHV-2 open reading frame 25 (ORF25) transcripts encoding the viral major capsid protein in tissues of bison with SA-MCF, and levels of viral transcript expression positively correlated with lesion severity. To further define the cellular tropism and replication of OvHV-2 infection in vascular lesions of bison, immunofluorescence studies were performed to identify cell type(s) expressing ORF25 protein within tissues. Cytoplasmic and not nuclear ORF25 protein was demonstrated in predominantly perivascular fibroblasts in six bison with experimentally-induced SA-MCF, and there was no evidence of immunoreactivity in vascular endothelium, smooth muscle, or infiltrating leukocytes. The cytoplasmic distribution of viral major capsid protein suggests that viral replication in perivascular fibroblasts may be abortive in this dead-end host. These findings provide a novel foundation for defining the pathogenesis of vasculitis in non-adapted hosts with SA-MCF.
Related JoVE Video
Functional, structural and phylogenetic analysis of domains underlying the Al sensitivity of the aluminum-activated malate/anion transporter, TaALMT1.
Plant J.
PUBLISHED: 07-03-2013
Show Abstract
Hide Abstract
Triticum aestivum aluminum-activated malate transporter (TaALMT1) is the founding member of a unique gene family of anion transporters (ALMTs) that mediate the efflux of organic acids. A small sub-group of root-localized ALMTs, including TaALMT1, is physiologically associated with in planta aluminum (Al) resistance. TaALMT1 exhibits significant enhancement of transport activity in response to extracellular Al. In this study, we integrated structure-function analyses of structurally altered TaALMT1 proteins expressed in Xenopus oocytes with phylogenic analyses of the ALMT family. Our aim is to re-examine the role of protein domains in terms of their potential involvement in the Al-dependent enhancement (i.e. Al-responsiveness) of TaALMT1 transport activity, as well as the roles of all its 43 negatively charged amino acid residues. Our results indicate that the N-domain, which is predicted to form the conductive pathway, mediates ion transport even in the absence of the C-domain. However, segments in both domains are involved in Al(3+) sensing. We identified two regions, one at the N-terminus and a hydrophobic region at the C-terminus, that jointly contribute to the Al-response phenotype. Interestingly, the characteristic motif at the N-terminus appears to be specific for Al-responsive ALMTs. Our study highlights the need to include a comprehensive phylogenetic analysis when drawing inferences from structure-function analyses, as a significant proportion of the functional changes observed for TaALMT1 are most likely the result of alterations in the overall structural integrity of ALMT family proteins rather than modifications of specific sites involved in Al(3+) sensing.
Related JoVE Video
Depletion of systemic concentrations of coagulation factors in blood from patients with atherosclerotic vascular disease.
Coron. Artery Dis.
PUBLISHED: 06-22-2013
Show Abstract
Hide Abstract
Thrombosis complicating the rupture of an atherosclerotic plaque can lead to arterial occlusion. Tissue factor, a membrane-bound glycoprotein, is expressed to a greater extent in atherosclerotic plaques and may be a key mediator of microthrombosis and macrothrombosis. This pilot study was designed to determine whether the angiographic presence or the extent of atherosclerosis was correlated with the activity of coagulation factors in blood. A novel computational model was used to predict whether differences in the activity of coagulation factors would alter the generation of thrombin.
Related JoVE Video
Fine Needle Aspiration and Medullary Thyroid Carcinoma: The Risk of Inadequate Preoperative Evaluation and Initial Surgery When Relying Upon FNAB Cytology Alone.
Endocr Pract
PUBLISHED: 06-13-2013
Show Abstract
Hide Abstract
Objectives: To evaluate the diagnostic accuracy of fine-needle aspiration biopsy (FNAB) to preoperatively diagnose medullary thyroid cancer (MTC) among multiple international centers and evaluate how the cytological diagnosis alone could impact patient management.Methods: We performed a retrospective chart review of sporadic MTC (sMTC) patients from 12 institutions over the last 29 years. FNAB cytology results were compared to final pathologic diagnoses to calculate FNAB sensitivity. To evaluate the impact of cytology sensitivity for MTC according to current practice and to avoid confounding results by local treatment protocols, changes in treatment patterns over time, and the influence of ancillary findings (e.g., serum calcitonin), therapeutic interventions based on FNAB cytology alone were projected into 1 of 4 treatment categories: total thyroidectomy (TT) and central neck dissection (CND), TT without CND, diagnostic hemithyroidectomy, or observation.Results: A total of 313 patients from 4 continents and 7 countries were included, 245 of whom underwent FNAB. FNAB cytology revealed MTC in 43.7% and possible MTC in an additional 2.4%. A total of 113 (46.1%) patients with surgical pathology revealing sMTC had FNAB findings that supported TT with CND, while 37 (15.1%) supported TT alone. In the remaining cases, diagnostic hemithyroidectomy and observation were projected in 32.7% and 6.1%, respectively.Conclusion: FNAB is an important diagnostic tool in the evaluation of thyroid nodules, but the low sensitivity of cytological evaluation alone in sMTC limits its ability to command an optimal preoperative evaluation and initial surgery in over half of affected patients.
Related JoVE Video
Timing of symptom improvement after parathyroidectomy for primary hyperparathyroidism.
Surgery
PUBLISHED: 05-06-2013
Show Abstract
Hide Abstract
The timing of symptom improvement after parathyroidectomy for primary hyperparathyroidism (PHPT) has not been well characterized.
Related JoVE Video
The Socket-Shield Technique: First Histological, Clinical, and Volumetrical Observations after Separation of the Buccal Tooth Segment - A Pilot Study.
Clin Implant Dent Relat Res
PUBLISHED: 05-02-2013
Show Abstract
Hide Abstract
BACKGROUND: The "socket-shield technique" has shown its potential in preserving buccal tissues. However, front teeth often have to be extracted due to vertical fractures in buccolingual direction. It has not yet been investigated if the socket-shield technique can only be used with intact roots or also works with a modified shield design referring to vertical fracture lines. PURPOSE: The aim of this study was to assess histologically, clinically, and volumetrically the effect of separating the remaining buccal root segment in two pieces before immediate implant placement. MATERIAL AND METHODS: Three beagle dogs were selected in the study. The third and fourth premolars on both sides of the upper jaw were hemisected and the clinical crown of the distal root was removed. Then, the implant bed preparation was performed into the distal root so that a buccal segment of healthy tooth structure remained. This segment was then separated in a vertical direction into two pieces and implants placed lingual to it. After 4 months of healing, the specimens were processed for histological diagnosis. In a clinical case, the same technique was applied and impressions taken for volumetric evaluation by digital superimposition. RESULTS: The tooth segments showed healthy periodontal ligament on the buccal side. New bone was visible between implant surface and shield as well as inside the vertical drill line. No osteoclastic remodeling of the coronal part of the buccal plate was observed. The clinical volumetric analysis showed a mean loss of 0.88?mm in labial direction with a maximum of 1.67?mm and a minimum of 0.15?mm. CONCLUSION: The applied modification seems not to interfere with implant osseointegration and may still preserve the buccal plate. It may offer a feasible treatment option for vertically fractured teeth.
Related JoVE Video
Divergent contributions of conserved active site residues to transcription by eukaryotic RNA polymerases I and II.
Cell Rep
PUBLISHED: 05-01-2013
Show Abstract
Hide Abstract
Multisubunit RNA polymerases (msRNAPs) exhibit high sequence and structural homology, especially within their active sites, which is generally thought to result in msRNAP functional conservation. However, we show that mutations in the trigger loop (TL) in the largest subunit of RNA polymerase I (Pol I) yield phenotypes unexpected from studies of Pol II. For example, a well-characterized gain-of-function mutation in Pol II results in loss of function in Pol I (Pol II: rpb1- E1103G; Pol I: rpa190-E1224G). Studies of chimeric Pol II enzymes hosting Pol I or Pol III TLs suggest that consequences of mutations that alter TL dynamics are dictated by the greater enzymatic context and not solely the TL sequence. Although the rpa190-E1224G mutation diminishes polymerase activity, when combined with mutations that perturb Pol I catalysis, it enhances polymerase function, similar to the analogous Pol II mutation. These results suggest that Pol I and Pol II have different rate-limiting steps.
Related JoVE Video
Biodegradation and bone formation of various polyethylene glycol hydrogels in acute and chronic sites in mini-pigs.
Clin Oral Implants Res
PUBLISHED: 05-01-2013
Show Abstract
Hide Abstract
OBJECTIVE: i) To test whether or not pH modifications of a PEG hydrogel matrix influence degradation time and bone regeneration in acute and unprepared (chronic) defects; and ii) to test whether or not the addition of a PEG hydrogel to hydroxyapatite/tricalciumphosphate (HA/TCP) can further enhance bone regeneration compared to HA/TCP alone in acute defects. MATERIALS AND METHODS: In 11 mini-pigs, three acute standardized defects and one chronic site were prepared in each hemi-mandible. The following treatment modalities were applied in acute defects: PEG hydrogel regular (PEG 8.7), PEG hydrogel pH-modified plus (PEG 9.0), PEG hydrogel pH-modified minus (PEG 8.4), PEG 8.7 mixed with HA/TCP granules (PEG-HA/TCP), HA/TCP granules (HA/TCP), and empty control (control). In chronic sites, PEG 8.7 and PEG 9.0 were applied. Subsequently primary wound closure was obtained and animals sacrificed at 10 (n = 6) and 21 days (n = 5). Descriptive histology and histomorphometric analyses were performed including measurements for newly formed bone, remaining hydrogel, and percent defect fill. Standard descriptive statistics were calculated, and regression analysis used to determine the difference between treatments, taking into account relevant factors and correction for multiple comparisons. RESULTS: In acute defects, the amount of newly formed bone increased statistically significantly over time for all treatments. The increase was higher for PEG 8.7 (35.9%) compared with PEG 8.4 and PEG 9.0 and was higher for PEG-HA/TCP (24.7%) than for HA/TCP (14.6%). The remaining hydrogel ranged between 7.6 ± 13.3% for PEG 8.4 and 17.7 ± 12.8% for PEG 8.7 at 10 days. At 21 days, no remaining hydrogel was found except for PEG-HA/TCP (11.5 ± 10.4%). In chronic sites, at 10 days, the remaining hydrogel covered 29.5 ± 10.3% (PEG 9.0) and 25.6 ± 21.8% (PEG 8.7) of the area. At 21 days, the amount of hydrogel (29.7 ± 31.7% for PEG 9.0; 1.4 ± 2.5% for PEG 8.7) decreased, while the amount of bone increased to 14.0 ± 16.3% for PEG 9.0 and to 37.9 ± 15.7% for PEG 8.7. CONCLUSIONS: The PEG hydrogel matrix with a mid-range pH (PEG 8.7) may serve as a matrix for localized bone regeneration with or without the addition of a bone substitute material. This was demonstrated by enhanced bone regeneration in acute and chronic defects compared with control hydrogels and HA/TCP alone.
Related JoVE Video
New developments in the diagnosis and treatment of thyroid cancer.
CA Cancer J Clin
PUBLISHED: 04-24-2013
Show Abstract
Hide Abstract
Answer questions and earn CME/CNE Thyroid cancer exists in several forms. Differentiated thyroid cancers include those with papillary and follicular histologies. These tumors exist along a spectrum of differentiation, and their incidence continues to climb. A number of advances in the diagnosis and treatment of differentiated thyroid cancers now exist. These include molecular diagnostics and more advanced strategies for risk stratification. Medullary cancer arises from the parafollicular cells and not the follicular cells. Therefore, diagnosis and treatment differs from those of differentiated thyroid tumors. Genetic testing and newer adjuvant therapies have changed the diagnosis and treatment of medullary thyroid cancer. This review will focus on the epidemiology, diagnosis, workup, and treatment of both differentiated and medullary thyroid cancers, focusing specifically on newer developments in the field. CA Cancer J Clin 2013. © 2013 American Cancer Society, Inc.
Related JoVE Video
Epidemic fronts in complex networks with metapopulation structure.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 04-17-2013
Show Abstract
Hide Abstract
Infection dynamics have been studied extensively on complex networks, yielding insight into the effects of heterogeneity in contact patterns on disease spread. Somewhat separately, metapopulations have provided a paradigm for modeling systems with spatially extended and "patchy" organization. In this paper we expand on the use of multitype networks for combining these paradigms, such that simple contagion models can include complexity in the agent interactions and multiscale structure. Using a generalization of the Miller-Volz mean-field approximation for susceptible-infected-recovered (SIR) dynamics on multitype networks, we study the special case of epidemic fronts propagating on a one-dimensional lattice of interconnected networks-representing a simple chain of coupled population centers-as a necessary first step in understanding how macroscale disease spread depends on microscale topology. Applying the formalism of front propagation into unstable states, we derive the effective transport coefficients of the linear spreading: asymptotic speed, characteristic wavelength, and diffusion coefficient for the leading edge of the pulled fronts, and analyze their dependence on the underlying graph structure. We also derive the epidemic threshold for the system and study the front profile for various network configurations.
Related JoVE Video
Multigland disease and slower decline in intraoperative PTH characterize mild primary hyperparathyroidism.
Ann. Surg. Oncol.
PUBLISHED: 04-12-2013
Show Abstract
Hide Abstract
Many patients with primary hyperparathyroidism (PHPT) present with less severe biochemical parameters. The purpose of this study was to compare the presentation, operative findings, and outcomes of these patients with "mild" PHPT to patients with "overt" disease.
Related JoVE Video
Dimensional alterations of extraction sites after different alveolar ridge preservation techniques - a volumetric study.
J. Clin. Periodontol.
PUBLISHED: 03-28-2013
Show Abstract
Hide Abstract
The aim of this randomized controlled clinical study was to assess soft tissue contour changes after different alveolar ridge preservation procedures.
Related JoVE Video
Radioactive iodine scanning is not beneficial but its use persists for euthyroid patients.
J. Surg. Res.
PUBLISHED: 03-27-2013
Show Abstract
Hide Abstract
Radioactive iodine (RAI) scanning is a method of determining the functional status of thyroid nodules. Historically, practitioners thought "cold" or inactive nodules were more likely malignant. However, surgeons no longer find these scans helpful for preoperative management of euthyroid patients. The purpose of this study was to evaluate the utility of RAI scans.
Related JoVE Video
Significance of rebounding parathyroid hormone levels during parathyroidectomy.
J. Surg. Res.
PUBLISHED: 03-26-2013
Show Abstract
Hide Abstract
Using minimally invasive parathyroidectomy (MIP), most surgeons require a 50% decline in intraoperative parathyroid hormone (IoPTH) to determine cure, but the significance of IoPTH kinetics occurring after this drop remains unknown. The aim of this study was to determine the impact of IoPTH levels that first meet criteria for cure, but then increase again, or rebound, between 10 and 15 min postexcision.
Related JoVE Video
Presentation, management, and outcomes of hyperparathyroidism in octogenarians and nonagenarians.
Ann. Surg. Oncol.
PUBLISHED: 03-12-2013
Show Abstract
Hide Abstract
Various elective surgical procedures are routinely performed on patients ?80 years of age. With primary hyperparathyroidism (PHPT), surgical management is the only treatment. The goal of this study was to compare presentation and outcome of patients ?80 to that of those <80 years of age.
Related JoVE Video
Minimal benefit to subsequent intraoperative parathyroid hormone testing after all four glands have been identified.
Ann. Surg. Oncol.
PUBLISHED: 02-27-2013
Show Abstract
Hide Abstract
Modern tools, such as intraoperative parathyroid hormone (IoPTH) assay, reduce operative time and extent of parathyroidectomy. However, the utility of a subsequent final set of IoPTH after all four glands are visualized remains questionable. This study was designed to determine the added value of IoPTH assay following parathyroidectomy with four-gland visualization in patients with primary hyperparathyroidism (PHPT).
Related JoVE Video
Optimization of keV-settings in abdominal and lower extremity dual-source dual-energy CT angiography determined with virtual monoenergetic imaging.
Eur J Radiol
PUBLISHED: 02-25-2013
Show Abstract
Hide Abstract
To compare objective image quality indices in dual-energy CT angiography (DE-CTA) studies of the abdomen and lower extremity using conventional polyenergetic images (PEIs) and virtual monoenergetic images (MEIs) at different kiloelectron volt (keV) levels.
Related JoVE Video
Cancer after thyroidectomy: a multi-institutional experience with 1,523 patients.
J. Am. Coll. Surg.
PUBLISHED: 02-08-2013
Show Abstract
Hide Abstract
The incidence of thyroid cancer in patients treated operatively for thyroid disease has been historically low (<5%). Previous series have not specifically addressed cancer rates in both euthyroid and hyperthyroid patients. This study examined cancer frequency in patients referred for removal of benign thyroid disease in a multi-institutional series.
Related JoVE Video
DNA binding by the ribosomal DNA transcription factor rrn3 is essential for ribosomal DNA transcription.
J. Biol. Chem.
PUBLISHED: 02-07-2013
Show Abstract
Hide Abstract
The human homologue of yeast Rrn3 is an RNA polymerase I-associated transcription factor that is essential for ribosomal DNA (rDNA) transcription. The generally accepted model is that Rrn3 functions as a bridge between RNA polymerase I and the transcription factors bound to the committed template. In this model Rrn3 would mediate an interaction between the mammalian Rrn3-polymerase I complex and SL1, the rDNA transcription factor that binds to the core promoter element of the rDNA. In the course of studying the role of Rrn3 in recruitment, we found that Rrn3 was in fact a DNA-binding protein. Analysis of the sequence of Rrn3 identified a domain with sequence similarity to the DNA binding domain of heat shock transcription factor 2. Randomization, or deletion, of the amino acids in this region in Rrn3, amino acids 382-400, abrogated its ability to bind DNA, indicating that this domain was an important contributor to DNA binding by Rrn3. Control experiments demonstrated that these mutant Rrn3 constructs were capable of interacting with both rpa43 and SL1, two other activities demonstrated to be essential for Rrn3 function. However, neither of these Rrn3 mutants was capable of functioning in transcription in vitro. Moreover, although wild-type human Rrn3 complemented a yeast rrn3-ts mutant, the DNA-binding site mutant did not. These results demonstrate that DNA binding by Rrn3 is essential for transcription by RNA polymerase I.
Related JoVE Video
Loss of electrostatic cell-surface repulsion mediates myelin membrane adhesion and compaction in the central nervous system.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 02-04-2013
Show Abstract
Hide Abstract
During the development of the central nervous system (CNS), oligodendrocytes wrap their plasma membrane around axons to form a multilayered stack of tightly attached membranes. Although intracellular myelin compaction and the role of myelin basic protein has been investigated, the forces that mediate the close interaction of myelin membranes at their external surfaces are poorly understood. Such extensive bilayer-bilayer interactions are usually prevented by repulsive forces generated by the glycocalyx, a dense and confluent layer of large and negatively charged oligosaccharides. Here we investigate the molecular mechanisms underlying myelin adhesion and compaction in the CNS. We revisit the role of the proteolipid protein and analyze the contribution of oligosaccharides using cellular assays, biophysical tools, and transgenic mice. We observe that differentiation of oligodendrocytes is accompanied by a striking down-regulation of components of their glycocalyx. Both in vitro and in vivo experiments indicate that the adhesive properties of the proteolipid protein, along with the reduction of sialic acid residues from the cell surface, orchestrate myelin membrane adhesion and compaction in the CNS. We suggest that loss of electrostatic cell-surface repulsion uncovers weak and unspecific attractive forces in the bilayer that bring the extracellular surfaces of a membrane into close contact over long distances.
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.