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.
[Tenosynovitis confirmed by MRI during anti-tuberculous treatment suspected due to isoniazid--2 case reports and literature review].
Kekkaku
PUBLISHED: 09-09-2014
Show Abstract
Hide Abstract
The adverse effects of anti-tuberculosis agents is an important problem for treatment of tuberculosis. We report 2 possible cases of isoniazid-induced tenosynovitis. Case 1: A 49-year-old man with untreated diabetic mellitus presented with hypesthesia and difficulty grasping with his right hand 1 month after starting treatment of tuberculosis of the lung and pleuritis using isoniazid, rifampicin, ethambutol, and pyrazinamide. His symptoms were due to tenosynovitis, which was detected by magnetic resonance imaging. The clinical course and isoniazid challenge test revealed that the condition was related to isoniazid. After discontinuing isoniazid treatment, his symptoms gradually improved. Case 2: An 78-year-old man operated on for rectal cancer 3 weeks previously presented with edema and arthralgia of both hands 1 month after starting anti-tuberculosis treatment. His tuberculosis was diagnosed at preoperative screening tests for rectal cancer. Owing to a medical history of gout, pyrazinamide was discontinued. However, his symptoms did not improve. Magnetic resonance imaging revealed findings indicative of tenosynovitis. At the end of anti-tuberculosis treatment, his symptoms improved slightly within 6 months. Isoniazid-induced tenosynovitis and arthritis are rare adverse effects. However, they may be underestimated because the severity is variable. We suggest further investigations of the side effects of isoniazid using imaging techniques such as magnetic resonance imaging.
Related JoVE Video
Emerging roles of secreted phospholipase A2 enzymes: The 3rd edition.
Biochimie
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
Within the phospholipase A2 (PLA2) superfamily, secreted PLA2 (sPLA2) enzymes comprise the largest family that contains 11 to 12 mammalian isoforms with a conserved His-Asp catalytic dyad. Individual sPLA2s exhibit unique tissue and cellular localizations and specific enzymatic properties, suggesting distinct biological roles. Individual sPLA2s are involved in diverse biological events through lipid mediator-dependent or -independent processes and act redundantly or non-redundantly in a given microenvironment. In the past few years, new biological aspects of sPLA2s have been clarified using their transgenic and knockout mouse lines in combination with mass spectrometric lipidomics to unveil their target substrates and products in vivo. In the 3rd edition of this review series, we highlight the newest understanding of the in vivo functions of sPLA2s in pathophysiological conditions in the context of immunity and metabolism. We will also describe the latest knowledge on PLA2R1, the best known sPLA2 receptor, which may serve either as a clearance or signaling receptor for sPLA2 or may even act independently of sPLA2 function.
Related JoVE Video
[Obstructive pneumonia and brain abscess due to Nocardia elegans in a patient with systemic lupus erythematosus].
Kansenshogaku Zasshi
PUBLISHED: 07-01-2014
Show Abstract
Hide Abstract
We herein report on a 69-year-old male who developed lung nocardiosis and brain abscessation. In April 2011, he was diagnosed as having systemic lupus erythematosus complicated by peripheral neuropathy. Immunosuppressive therapy with high-dose prednisolone was begun. In November 2011, he developed cryptococcal pneumonia and meningitis, which was treated with liposomal amphotericin and flucytosine for 4 weeks and was maintained with fluconazole. In April 2012, consolidation and peripheral atelectasis in the right middle lobe appeared. Bronchoscopy revealed edematous mucosa in the right middle bronchus and occlusive change of the right B4 and B5, but biopsy and culture results provided no etiological information. In late June, he developed an intermittent fever, and obstructive pneumonia of the right middle lobe was suspected. Nocardia species were detected from the sputum culture and were thought to be the causative pathogen. Brain CT and MRI revealed a contrast-enhanced lesion in the right cerebellar hemisphere. The patient was diagnosed as having lung nocardiosis and brain abscessation. Considering that the nocardiosis had developed under prophylaxis for Pneumocystis jirovecii pneumonia using one tablet per day of a sulfamethoxazole-trimethoprim combination, meropenem and amikacin were administered in addition to the sulfamethoxazole-trimethoprim combination for 6 and 4 weeks, respectively. After N. elegans had been identified from the sputum, antibiotics were switched to a sulfamethoxazole-trimethoprim combination and clarithromycin based on the susceptibility results. The patient's clinical and radiological findings were improved and have been well sustained.
Related JoVE Video
The adipocyte-inducible secreted phospholipases PLA2G5 and PLA2G2E play distinct roles in obesity.
Cell Metab.
PUBLISHED: 02-19-2014
Show Abstract
Hide Abstract
Metabolic disorders, including obesity and insulin resistance, have their basis in dysregulated lipid metabolism and low-grade inflammation. In a microarray search of unique lipase-related genes whose expressions are associated with obesity, we found that two secreted phospholipase A2s (sPLA2s), PLA2G5 and PLA2G2E, were robustly induced in adipocytes of obese mice. Analyses of Pla2g5(-/-) and Pla2g2e(-/-) mice revealed distinct roles of these sPLA2s in diet-induced obesity. PLA2G5 hydrolyzed phosphatidylcholine in fat-overladen low-density lipoprotein to release unsaturated fatty acids, which prevented palmitate-induced M1 macrophage polarization. As such, PLA2G5 tipped the immune balance toward an M2 state, thereby counteracting adipose tissue inflammation, insulin resistance, hyperlipidemia, and obesity. PLA2G2E altered minor lipoprotein phospholipids, phosphatidylserine and phosphatidylethanolamine, and moderately facilitated lipid accumulation in adipose tissue and liver. Collectively, the identification of "metabolic sPLA2s" adds this gene family to a growing list of lipolytic enzymes that act as metabolic coordinators.
Related JoVE Video
Parvimonas micra as a causative organism of spondylodiscitis: a report of two cases and a literature review.
Int. J. Infect. Dis.
PUBLISHED: 02-02-2014
Show Abstract
Hide Abstract
Spondylodiscitis caused by Parvimonas micra, a rarely reported infection, might be under-detected using conventional methods. This report of the detection and treatment of two cases of spondylodiscitis due to P. micra and review of the literature indicates that the use of gene sequencing methods might improve the accuracy of diagnosing this infection.
Related JoVE Video
Cardiovascular and bleeding risk of non-cardiac surgery in patients on antiplatelet therapy.
J Cardiol
PUBLISHED: 01-17-2014
Show Abstract
Hide Abstract
The perioperative risk of non-cardiac surgery (NCS) in the patients on antiplatelet therapy after percutaneous coronary intervention (PCI) remains unclear.
Related JoVE Video
Meningococcemia due to the 2000 Hajj-associated outbreak strain (Serogroup W-135 ST-11) with immunoreactive complications.
Jpn. J. Infect. Dis.
PUBLISHED: 09-20-2013
Show Abstract
Hide Abstract
We present the first reported case of systemic infection with Neisseria meningitidis serogroup W-135 sequence type (ST)-11 in Japan. A 44-year-old woman presented with high fever, sore throat, and fatigue and was diagnosed with N. meningitidis bacteremia. The causative strain was identified as serogroup W-135 ST-11 by polymerase chain reaction and multilocus sequence typing. Approximately 1 month after treatment, she developed high fever, dyspnea, chest pain, and shoulder pain due to pericarditis, polyarthritis, and tenosynovitis, which are all relatively common immunoreactive complications of W-135 ST-11 meningococcal infections. This causative strain was the same as that responsible for an outbreak of meningitis among Hajj pilgrims in 2000. The strain is now found worldwide because it can attain a high carriage rate and has a long duration of carriage. We suspect that our patients infection was acquired from an imported chronic carrier.
Related JoVE Video
Lymphoid tissue phospholipase A2 group IID resolves contact hypersensitivity by driving antiinflammatory lipid mediators.
J. Exp. Med.
PUBLISHED: 05-20-2013
Show Abstract
Hide Abstract
Resolution of inflammation is an active process that is mediated in part by antiinflammatory lipid mediators. Although phospholipase A2 (PLA2) enzymes have been implicated in the promotion of inflammation through mobilizing lipid mediators, the molecular entity of PLA2 subtypes acting upstream of antiinflammatory lipid mediators remains unknown. Herein, we show that secreted PLA2 group IID (PLA2G2D) is preferentially expressed in CD11c(+) dendritic cells (DCs) and macrophages and displays a pro-resolving function. In hapten-induced contact dermatitis, resolution, not propagation, of inflammation was compromised in skin and LNs of PLA2G2D-deficient mice (Pla2g2d(-/-)), in which the immune balance was shifted toward a proinflammatory state over an antiinflammatory state. Bone marrow-derived DCs from Pla2g2d(-/-) mice were hyperactivated and elicited skin inflammation after intravenous transfer into mice. Lipidomics analysis revealed that PLA2G2D in the LNs contributed to mobilization of a pool of polyunsaturated fatty acids that could serve as precursors for antiinflammatory/pro-resolving lipid mediators such as resolvin D1 and 15-deoxy-?(12,14)-prostaglandin J2, which reduced Th1 cytokine production and surface MHC class II expression in LN cells or DCs. Altogether, our results highlight PLA2G2D as a "resolving sPLA2" that ameliorates inflammation through mobilizing pro-resolving lipid mediators and points to a potential use of this enzyme for treatment of inflammatory disorders.
Related JoVE Video
[An 8-year-old boy with anti-NMDA receptor encephalitis, successfully treated with cyclophosphamide].
No To Hattatsu
PUBLISHED: 04-19-2013
Show Abstract
Hide Abstract
We report on an 8-year-old boy with non-paraneoplastic anti-NMDA receptor (NMDAR) encephalitis, who presented with psychotic symptoms and involuntary movement following an intractable seizure. His serum and CSF tested positive for anti-NMDAR antibodies. He received an initial immunotherapy consisting of methylprednisolone pulse therapy (mPSL) and intravenous immunoglobulin therapy (IVIg), without any clinical improvement. He had three cycles of monthly cyclophosphamide pulse therapy (500 mg/m2), and his clinical condition started to improve gradually two weeks after the first cycle, without any side effects. Six months after onset, he tested normal upon standard neurological examination. Cyclophosphamide therapy should be considered for children with anti-NMDAR encephalitis, as well as mPSL and IVIg.
Related JoVE Video
Mast cell maturation is driven via a group III phospholipase A2-prostaglandin D2-DP1 receptor paracrine axis.
Nat. Immunol.
PUBLISHED: 03-11-2013
Show Abstract
Hide Abstract
Microenvironment-based alterations in phenotypes of mast cells influence the susceptibility to anaphylaxis, yet the mechanisms underlying proper maturation of mast cells toward an anaphylaxis-sensitive phenotype are incompletely understood. Here we report that PLA2G3, a mammalian homolog of anaphylactic bee venom phospholipase A2, regulates this process. PLA2G3 secreted from mast cells is coupled with fibroblastic lipocalin-type PGD2 synthase (L-PGDS) to provide PGD2, which facilitates mast-cell maturation via PGD2 receptor DP1. Mice lacking PLA2G3, L-PGDS or DP1, mast cell-deficient mice reconstituted with PLA2G3-null or DP1-null mast cells, or mast cells cultured with L-PGDS-ablated fibroblasts exhibited impaired maturation and anaphylaxis of mast cells. Thus, we describe a lipid-driven PLA2G3-L-PGDS-DP1 loop that drives mast cell maturation.
Related JoVE Video
Comparison of hemostasis using bipolar hemostatic forceps with hemostasis by endoscopic hemoclipping for nonvariceal upper gastrointestinal bleeding in a prospective non-randomized trial.
Surg Endosc
PUBLISHED: 01-30-2013
Show Abstract
Hide Abstract
We previously reported on the safety and efficacy of bipolar hemostatic forceps for treating nonvariceal upper gastrointestinal (UGI) bleeding. However, no prospective or randomized studies have evaluated the efficacy of bipolar hemostatic forceps. The aim of this study was to evaluate the hemostatic efficacy of using bipolar hemostatic forceps compared with the hemostatic efficacy of the commonly used method of endoscopic hemoclipping for treating nonvariceal UGI bleeding.
Related JoVE Video
Group X secreted phospholipase A2 limits the development of atherosclerosis in LDL receptor-null mice.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 01-24-2013
Show Abstract
Hide Abstract
Several secreted phospholipases A2 (sPLA2s), including group IIA, III, V, and X, have been linked to the development of atherosclerosis, which led to the clinical testing of A-002 (varespladib), a broad sPLA2 inhibitor for the treatment of coronary artery disease. Group X sPLA2 (PLA2G10) has the most potent hydrolyzing activity toward phosphatidylcholine and is believed to play a proatherogenic role.
Related JoVE Video
Dopamine inhibits reproduction in female zebrafish (Danio rerio) via three pituitary D2 receptor subtypes.
Endocrinology
PUBLISHED: 01-07-2013
Show Abstract
Hide Abstract
In many teleosts, the stimulatory control of gonadotrope axis by GnRH is opposed by an inhibitory control by dopamine (DA). The functional importance of this inhibitory pathway differs widely from one teleostean species to another. The zebrafish (Danio rerio) is a teleost fish that has become increasingly popular as an experimental vertebrate model. However, the role of DA in the neuroendocrine control of its reproduction has never been studied. Here the authors evaluated in sexually regressed female zebrafish the effects of in vivo treatments with a DA D2 receptor (D2-R) antagonist domperidone, or a GnRH agonist, alone and in combination, on the pituitary level of FSH? and LH? transcripts, the gonadosomatic index, and the ovarian histology. Only the double treatment with GnRH agonist and domperidone could induce an increase in the expression of LH?, in the gonadosomatic index, and a stimulation of ovarian vitellogenesis, indicating that removal of dopaminergic inhibition is required for the stimulatory action of GnRH and reactivation of ovarian function to occur. Using double immunofluorescent staining on pituitary, the authors showed in this species the innervation of LH cells by tyrosine-hydroxylase immunoreactive fibers. Finally, using in situ hybridization and immunofluorescence, the authors showed that the three subtypes of zebrafish DA D2-R (D2a, D2b, and D2c) were expressed in LH-producing cells, suggesting that they all may be involved in mediating this inhibition. These results show for the first time that, in zebrafish, DA has a direct and potent inhibitory action capable of opposing the stimulatory effect of GnRH in the neuroendocrine control of reproduction.
Related JoVE Video
Analysis of two major intracellular phospholipases A(2) (PLA(2)) in mast cells reveals crucial contribution of cytosolic PLA(2)?, not Ca(2+)-independent PLA(2)?, to lipid mobilization in proximal mast cells and distal fibroblasts.
J. Biol. Chem.
PUBLISHED: 08-31-2011
Show Abstract
Hide Abstract
Mast cells release a variety of mediators, including arachidonic acid (AA) metabolites, to regulate allergy, inflammation, and host defense, and their differentiation and maturation within extravascular microenvironments depend on the stromal cytokine stem cell factor. Mouse mast cells express two major intracellular phospholipases A(2) (PLA(2)s), namely group IVA cytosolic PLA(2) (cPLA(2)?) and group VIA Ca(2+)-independent PLA(2) (iPLA(2)?), and the role of cPLA(2)? in eicosanoid synthesis by mast cells has been well documented. Lipidomic analyses of mouse bone marrow-derived mast cells (BMMCs) lacking cPLA(2)? (Pla2g4a(-/-)) or iPLA(2)? (Pla2g6(-/-)) revealed that phospholipids with AA were selectively hydrolyzed by cPLA(2)?, not by iPLA(2)?, during Fc?RI-mediated activation and even during fibroblast-dependent maturation. Neither Fc?RI-dependent effector functions nor maturation-driven phospholipid remodeling was impaired in Pla2g6(-/-) BMMCs. Although BMMCs did not produce prostaglandin E(2) (PGE(2)), the AA released by cPLA(2)? from BMMCs during maturation was converted to PGE(2) by microsomal PGE synthase-1 (mPGES-1) in cocultured fibroblasts, and accordingly, Pla2g4a(-/-) BMMCs promoted microenvironmental PGE(2) synthesis less efficiently than wild-type BMMCs both in vitro and in vivo. Mice deficient in mPGES-1 (Ptges(-/-)) had an augmented local anaphylactic response. These results suggest that cPLA(2)? in mast cells is functionally coupled, through the AA transfer mechanism, with stromal mPGES-1 to provide anti-anaphylactic PGE(2). Although iPLA(2)? is partially responsible for PGE(2) production by macrophages and dendritic cells, it is dispensable for mast cell maturation and function.
Related JoVE Video
Orofacial manifestations in patients with sickle cell anemia.
Quintessence Int
PUBLISHED: 08-16-2011
Show Abstract
Hide Abstract
To compare the prevalence of orofacial manifestations between patients with and without sickle cell anemia and to investigate the distribution of such events in patients with sickle cell anemia by sex and age.
Related JoVE Video
Secreted phospholipase A2 revisited.
J. Biochem.
PUBLISHED: 07-11-2011
Show Abstract
Hide Abstract
Phospholipase A(2) (PLA(2)) catalyses the hydrolysis of the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. So far, more than 30 enzymes that possess PLA(2) or related activity have been identified in mammals. About one third of these enzymes belong to the secreted PLA(2) (sPLA(2)) family, which comprises low molecular weight, Ca(2+) requiring, secreted enzymes with a His/Asp catalytic dyad. Individual sPLA(2)s display distinct localizations and enzymatic properties, suggesting their specialized biological roles. However, in contrast to intracellular PLA(2)s, whose roles in signal transduction and membrane homoeostasis have been well documented, the biological roles of sPLA(2)s in vivo have remained obscure until recently. Over the past decade, information fuelled by studies employing knockout and transgenic mice as well as specific inhibitors, in combination with lipidomics, has clarified when and where the different sPLA(2) isoforms are expressed, which isoforms are involved in what types of pathophysiology, and how they exhibit their specific functions. In this review, we highlight recent advances in PLA(2) research, focusing mainly on the physiological functions of sPLA(2)s and their modes of action on extracellular phospholipid targets versus lipid mediator production.
Related JoVE Video
Severe neutrophil-mediated lung inflammation in myeloperoxidase-deficient mice exposed to zymosan.
Inflamm. Res.
PUBLISHED: 05-17-2011
Show Abstract
Hide Abstract
This study examines the role of myeloperoxidase (MPO), a major constituent of neutrophils that generates hypochlorous acid, in neutrophil recruitment into the zymosan-exposed lung of mice.
Related JoVE Video
Differential expression of dopaminergic cell markers in the adult zebrafish forebrain.
J. Comp. Neurol.
PUBLISHED: 04-13-2011
Show Abstract
Hide Abstract
Although the simultaneous presence of tyrosine hydroxylase (TH), aromatic amino acid decarboxylase (AADC), dopamine transporter (DAT), and vesicular monoamine transporter 2 (VMAT2) is considered as a phenotypic signature of dopamine (DA) neurons, it has been suggested that they are not uniformly expressed in all dopaminergic brain nuclei. Moreover, in nonmammalian vertebrates, two tyrosine hydroxylase genes (TH1 and TH2) are found, and they exhibit different expression patterns in zebrafish brains. Here we present a detailed description of the distribution of TH1, TH2, AADC, DAT, and VMAT2 transcripts, in relation to TH and DA immunoreactivity to better characterize dopaminergic nuclei in the adult zebrafish forebrain. TH2-positive cells in the hypothalamus are strongly DA immunoreactive (DAir), providing direct evidence that they are dopaminergic. DAir cells are also found in most TH1-positive or TH-immunoreactive (THir) nuclei. However, the DAir signal was weaker than THir in the olfactory bulb, telencephalon, ventral thalamus, pretectum, and some posterior tubercular and preoptic nuclei. These cell populations also exhibited low levels of VMAT2 transcripts, suggesting that low DA is due to a lower vesicular DA accumulation. In contrast, cell populations with low levels of AADC did not always have low levels of DA. DAT transcripts were abundantly expressed in most of the TH1- or TH2-positive territories. In addition, DAT and/or VMAT2 transcripts were found in some periventricular cell populations such as in the telencephalon without TH1 or TH2 expression. Thus, expression patterns of dopaminergic cell markers are not homogeneous, suggesting that the gene regulatory logic determining the dopaminergic phenotype is unexpectedly complex.
Related JoVE Video
The evolution of dopamine systems in chordates.
Front Neuroanat
PUBLISHED: 03-15-2011
Show Abstract
Hide Abstract
Dopamine (DA) neurotransmission in the central nervous system (CNS) is found throughout chordates, and its emergence predates the divergence of chordates. Many of the molecular components of DA systems, such as biosynthetic enzymes, transporters, and receptors, are shared with those of other monoamine systems, suggesting the common origin of these systems. In the mammalian CNS, the DA neurotransmitter systems are diversified and serve for visual and olfactory perception, sensory-motor programming, motivation, memory, emotion, and endocrine regulations. Some of the functions are conserved among different vertebrate groups, while others are not, and this is reflected in the anatomical aspects of DA systems in the forebrain and midbrain. Recent findings concerning a second tyrosine hydroxylase gene (TH2) revealed new populations of DA-synthesizing cells, as evidenced in the periventricular hypothalamic zones of teleost fish. It is likely that the ancestor of vertebrates possessed TH2 DA-synthesizing cells, and the TH2 gene has been lost secondarily in placental mammals. All the vertebrates possess DA cells in the olfactory bulb, retina, and in the diencephalon. Midbrain DA cells are abundant in amniotes while absent in some groups, e.g., teleosts. Studies of protochordate DA cells suggest that the diencephalic DA cells were present before the divergence of the chordate lineage. In contrast, the midbrain cell populations have probably emerged in the vertebrate lineage following the development of the midbrain-hindbrain boundary. The functional flexibility of the DA systems, and the evolvability provided by duplication of the corresponding genes permitted a large diversification of these systems. These features were instrumental in the adaptation of brain functions to the very variable way of life of vertebrates.
Related JoVE Video
Image of tumor metastasis and inflammatory lymph node enlargement by contrast-enhanced ultrasonography.
World J Radiol
PUBLISHED: 03-12-2011
Show Abstract
Hide Abstract
To compare the difference between tumor-induced lymph node enlargement and inflammation-induced lymph node enlargement by contrast-enhanced ultrasonography and pathological findings.
Related JoVE Video
Secreted phospholipase A2, lipoprotein hydrolysis, and atherosclerosis: integration with lipidomics.
Anal Bioanal Chem
PUBLISHED: 03-01-2011
Show Abstract
Hide Abstract
Phospholipase A(2) (PLA(2)) is a group of enzymes that hydrolyze the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. Of many PLA(2)s or related enzymes identified to date, secreted PLA(2)s (sPLA(2)s) comprise the largest family that contains 10 catalytically active isozymes. Besides arachidonic acid released from cellular membranes for eicosanoid synthesis, several if not all sPLA(2)s have recently been implicated in hydrolysis of phospholipids in lipoprotein particles. The sPLA(2)-processed low-density lipoprotein (LDL) particles contain a large amount of lysophospholipids and exhibit the property of "small-dense" or "modified" LDL, which facilitates foam cell formation from macrophages. Transgenic overexpression of these sPLA(2)s leads to development of atherosclerosis in mice. More importantly, genetic deletion or pharmacological inhibition of particular sPLA(2)s significantly attenuates atherosclerosis and aneurysm. In this article, we will give an overview of current understanding of the role of sPLA(2)s in atherosclerosis, with recent lipidomics data showing the action of a subset of sPLA(2)s on lipoprotein phospholipids.
Related JoVE Video
Integrated lipidomics in the secreted phospholipase a(2) biology.
Int J Mol Sci
PUBLISHED: 01-30-2011
Show Abstract
Hide Abstract
Mammalian genomes encode genes for more than 30 phospholipase A(2)s (PLA(2)s) or related enzymes, which are subdivided into several subgroups based on their structures, catalytic mechanisms, localizations and evolutionary relationships. More than one third of the PLA(2) enzymes belong to the secreted PLA(2) (sPLA(2)) family, which consists of low-molecular-weight, Ca(2+)-requiring extracellular enzymes, with a His-Asp catalytic dyad. Individual sPLA(2) isoforms exhibit unique tissue and cellular localizations and enzymatic properties, suggesting their distinct pathophysiological roles. Recent studies using transgenic and knockout mice for several sPLA(2) isoforms, in combination with lipidomics approaches, have revealed their distinct contributions to various biological events. Herein, we will describe several examples of sPLA(2)-mediated phospholipid metabolism in vivo, as revealed by integrated analysis of sPLA(2) transgenic/knockout mice and lipid mass spectrometry. Knowledge obtained from this approach greatly contributes to expanding our understanding of the sPLA(2) biology and pathophysiology.
Related JoVE Video
Hair follicular expression and function of group X secreted phospholipase A2 in mouse skin.
J. Biol. Chem.
PUBLISHED: 01-25-2011
Show Abstract
Hide Abstract
Although perturbed lipid metabolism can often lead to skin abnormality, the role of phospholipase A(2) (PLA(2)) in skin homeostasis is poorly understood. In the present study we found that group X-secreted PLA(2) (sPLA(2)-X) was expressed in the outermost epithelium of hair follicles in synchrony with the anagen phase of hair cycling. Transgenic mice overexpressing sPLA(2)-X (PLA2G10-Tg) displayed alopecia, which was accompanied by hair follicle distortion with reduced expression of genes related to hair development, during a postnatal hair cycle. Additionally, the epidermis and sebaceous glands of PLA2G10-Tg skin were hyperplasic. Proteolytic activation of sPLA(2)-X in PLA2G10-Tg skin was accompanied by preferential hydrolysis of phosphatidylethanolamine species with polyunsaturated fatty acids as well as elevated production of some if not all eicosanoids. Importantly, the skin of Pla2g10-deficient mice had abnormal hair follicles with noticeable reduction in a subset of hair genes, a hypoplasic outer root sheath, a reduced number of melanin granules, and unexpected up-regulation of prostanoid synthesis. Collectively, our study highlights the spatiotemporal expression of sPLA(2)-X in hair follicles, the presence of skin-specific machinery leading to sPLA(2)-X activation, a functional link of sPLA(2)-X with hair follicle homeostasis, and compartmentalization of the prostanoid pathway in hair follicles and epidermis.
Related JoVE Video
Physiological roles of group X-secreted phospholipase A2 in reproduction, gastrointestinal phospholipid digestion, and neuronal function.
J. Biol. Chem.
PUBLISHED: 01-25-2011
Show Abstract
Hide Abstract
Although the secreted phospholipase A(2) (sPLA(2)) family has been generally thought to participate in pathologic events such as inflammation and atherosclerosis, relatively high and constitutive expression of group X sPLA(2) (sPLA(2)-X) in restricted sites such as reproductive organs, the gastrointestinal tract, and peripheral neurons raises a question as to the roles played by this enzyme in the physiology of reproduction, digestion, and the nervous system. Herein we used mice with gene disruption or transgenic overexpression of sPLA(2)-X to clarify the homeostatic functions of this enzyme at these locations. Our results suggest that sPLA(2)-X regulates 1) the fertility of spermatozoa, not oocytes, beyond the step of flagellar motility, 2) gastrointestinal phospholipid digestion, perturbation of which is eventually linked to delayed onset of a lean phenotype with reduced adiposity, decreased plasma leptin, and improved muscle insulin tolerance, and 3) neuritogenesis of dorsal root ganglia and the duration of peripheral pain nociception. Thus, besides its inflammatory action proposed previously, sPLA(2)-X participates in physiologic processes including male fertility, gastrointestinal phospholipid digestion linked to adiposity, and neuronal outgrowth and sensing.
Related JoVE Video
Fucoxanthin and its deacetylated product, fucoxanthinol, induce apoptosis of primary effusion lymphomas.
Cancer Lett.
PUBLISHED: 01-07-2011
Show Abstract
Hide Abstract
Primary effusion lymphoma (PEL) is a rare type of non-Hodgkins lymphoma caused by human herpesvirus 8. Conventional chemotherapy has limited effect on PEL, and the prognosis is poor. Carotenoids are a family of natural pigments and have several biological functions. We evaluated the anti-PEL effects of carotenoid, fucoxanthin (FX) and its metabolite, fucoxanthinol (FXOH). Treatment of PEL cells with FX or FXOH induced cell cycle arrest during G? phase and caspase-dependent apoptosis. FX and FXOH treatment silenced NF-?B, AP-1 and Akt activation, in conjunction with down-regulation of anti-apoptotic proteins and cell cycle regulators. Importantly, proteasome degradation was responsible for the low levels of proteins after FXOH treatment. In animal studies, treatment with FX reduced the growth of PEL-cell tumors. The results provide the rationale for future clinical use of FX and FXOH for the treatment of PEL.
Related JoVE Video
Recent progress in phospholipase A? research: from cells to animals to humans.
Prog. Lipid Res.
PUBLISHED: 12-24-2010
Show Abstract
Hide Abstract
Mammalian genomes encode genes for more than 30 phospholipase A?s (PLA?s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA?s (sPLA?s), Ca²+-dependent cytosolic PLA?s (cPLA?s), Ca²+-independent PLA?s (iPLA?s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA?s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA? and iPLA? families and the extracellular sPLA? family are recognized as the "big three". From a general viewpoint, cPLA?? (the prototypic cPLA? plays a major role in the initiation of arachidonic acid metabolism, the iPLA? family contributes to membrane homeostasis and energy metabolism, and the sPLA? family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA? family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA? and sPLA? families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA? enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA? genes. This review focuses on current understanding of the emerging biological functions of PLA?s and related enzymes.
Related JoVE Video
[Ultra-thin transnasal esophagogastroduodenoscopy].
Nippon Rinsho
PUBLISHED: 07-29-2010
Show Abstract
Hide Abstract
It is reported that ultra-thin transnasal esophagogastroduodenoscopy (TN-EGD) reduces pharyngeal discomfort and is more tolerable for the patients. Ultra-thin transnasal endoscopy has been reported as inferior to transoral conventional EGD (TO-EGD) in terms of image quality, suction, air insufflation and lens washing, due to the smaller endoscope caliber. TN-EGD should be conducted slowly, with short distance observation, and also with image-enhanced endoscopy. With reference to image-enhanced endoscopy, chromoendoscopy method (indigocarmine) is suitable for gastric neoplasm, on the other hand optical digital method (NBI) and digital method (i-scan, FICE) is suitable for esophageal neoplasm. TN-EGD is applied in various gastrointestinal (GI) procedures such as percutaneous endoscopic gastrostomy, nasoenteric feeding tube placement, endoscopic retrograde cholangiopancreaticography with nasobiliary drainage, long intestinal tube placement in small bowel obstruction, esophageal manometry.
Related JoVE Video
Helicobacter pylori infection and reflux esophagitis in young and middle-aged Japanese subjects.
J. Gastroenterol. Hepatol.
PUBLISHED: 07-01-2010
Show Abstract
Hide Abstract
Helicobacter pylori infection rates are reported to be high in people over the age of 40 years, but are decreasing in younger age groups. A negative correlation has been reported between H. pylori infection and reflux esophagitis (RE).
Related JoVE Video
Clinical evaluation of emergency endoscopic hemostasis with bipolar forceps in non-variceal upper gastrointestinal bleeding.
Dig Endosc
PUBLISHED: 05-08-2010
Show Abstract
Hide Abstract
The present study was designed to evaluate the usefulness and safety of bipolar hemostatic forceps, known as a less invasive and highly safe means of thermal coagulation used for hemostasis in cases of non-variceal upper gastrointestinal bleeding. This technique of bipolar forceps is simple, safe and unlikely to induce complications, and is therefore promising as a new technique of endoscopic hemostasis. The study involved 39 cases where hemostasis was attempted with bipolar forceps to deal with non-variceal upper gastrointestinal bleeding, including 28 cases of gastric ulcer, six cases of duodenal ulcer, three cases of bleeding after endoscopic submucosal dissection (ESD), one case of Mallory-Weiss syndrome and one case of postoperative bleeding from the anastomosed area. There were 34 males and five females, with a mean age of 63.6 years. Bipolar forceps were the first-line means of hemostasis in cases of oozing bleeding (venous bleeding), pulsatile or spurting bleeding (arterial bleeding) and exposed vessels without active bleeding. The primary hemostasis success rate was 92.3%, and the re-bleeding rate was 0%. In cases where the bleeding site was located along the tangential line or in cases where large respiration-caused motions hampered identification of the bleeding site, hemostasis by means of coagulation was easily effected by application of electricity while the forceps were kept open and compressed the bleeding area. In addition, there were no complications. This technique of bipolar forceps is simple, safe and unlikely to induce complications, and is therefore promising as a new technique of endoscopic hemostasis.
Related JoVE Video
Emerging roles of secreted phospholipase A2 enzymes: Lessons from transgenic and knockout mice.
Biochimie
PUBLISHED: 03-18-2010
Show Abstract
Hide Abstract
Among the emerging phospholipase A(2) (PLA(2)) superfamily, the secreted PLA(2) (sPLA(2)) family consists of low-molecular-mass, Ca(2+)-requiring extracellular enzymes with a His-Asp catalytic dyad. To date, more than 10 sPLA(2) enzymes have been identified in mammals. Individual sPLA(2)s exhibit unique tissue and cellular localizations and enzymatic properties, suggesting their distinct pathophysiological roles. Despite numerous enzymatic and cell biological studies on this enzyme family in the past two decades, their precise in vivo functions still remain largely obscure. Recent studies using transgenic and knockout mice for several sPLA(2) enzymes, in combination with lipidomics approaches, have opened new insights into their distinct contributions to various biological events such as food digestion, host defense, inflammation, asthma and atherosclerosis. In this article, we overview the latest understanding of the pathophysiological functions of individual sPLA(2) isoforms fueled by studies employing transgenic and knockout mice for several sPLA(2)s.
Related JoVE Video
Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice.
J. Clin. Invest.
PUBLISHED: 02-10-2010
Show Abstract
Hide Abstract
Ejaculated mammalian sperm must undergo a maturation process called capacitation before they are able to fertilize an egg. Several studies have suggested a role for members of the secreted phospholipase A2 (sPLA2) family in capacitation, acrosome reaction (AR), and fertilization, but the molecular nature of these enzymes and their specific roles have remained elusive. Here, we have demonstrated that mouse group X sPLA2 (mGX) is the major enzyme present in the acrosome of spermatozoa and that it is released in an active form during capacitation through spontaneous AR. mGX-deficient male mice produced smaller litters than wild-type male siblings when crossed with mGX-deficient females. Further analysis revealed that spermatozoa from mGX-deficient mice exhibited lower rates of spontaneous AR and that this was associated with decreased in vitro fertilization (IVF) efficiency due to a drop in the fertilization potential of the sperm and an increased rate of aborted embryos. Treatment of sperm with sPLA2 inhibitors and antibodies specific for mGX blocked spontaneous AR of wild-type sperm and reduced IVF success. Addition of lysophosphatidylcholine, a catalytic product of mGX, overcame these deficiencies. Finally, recombinant mGX triggered AR and improved IVF outcome. Taken together, our results highlight a paracrine role for mGX during capacitation in which the enzyme primes sperm for efficient fertilization and boosts premature AR of a likely phospholipid-damaged sperm subpopulation to eliminate suboptimal sperm from the pool available for fertilization.
Related JoVE Video
Group III secreted phospholipase A2 regulates epididymal sperm maturation and fertility in mice.
J. Clin. Invest.
PUBLISHED: 02-10-2010
Show Abstract
Hide Abstract
Although lipid metabolism is thought to be important for the proper maturation and function of spermatozoa, the molecular mechanisms that underlie this dynamic process in the gonads remains incompletely understood. Here, we show that group III phospholipase A2 (sPLA2-III), a member of the secreted phospholipase A2 (sPLA2) family, is expressed in the mouse proximal epididymal epithelium and that targeted disruption of the gene encoding this protein (Pla2g3) leads to defects in sperm maturation and fertility. Although testicular spermatogenesis in Pla2g3-/- mice was grossly normal, spermatozoa isolated from the cauda epididymidis displayed hypomotility, and their ability to fertilize intact eggs was markedly impaired. Transmission EM further revealed that epididymal spermatozoa in Pla2g3-/- mice had both flagella with abnormal axonemes and aberrant acrosomal structures. During epididymal transit, phosphatidylcholine in the membrane of Pla2g3+/+ sperm underwent a dramatic shift in its acyl groups from oleic, linoleic, and arachidonic acids to docosapentaenoic and docosahexaenoic acids, whereas this membrane lipid remodeling event was compromised in sperm from Pla2g3-/- mice. Moreover, the gonads of Pla2g3-/- mice contained less 12/15-lipoxygenase metabolites than did those of Pla2g3+/+ mice. Together, our results reveal a role for the atypical sPLA2 family member sPLA2-III in epididymal lipid homeostasis and indicate that its perturbation may lead to sperm dysfunction.
Related JoVE Video
Inhibition of Akt/GSK3beta signalling pathway by Legionella pneumophila is involved in induction of T-cell apoptosis.
Biochem. J.
PUBLISHED: 01-28-2010
Show Abstract
Hide Abstract
Legionella pneumophila is the causative agent of human Legionnaires disease. L. pneumophila has been shown to induce apoptosis of T-cells and this may be important pathologically and clinically. The present study has determined the molecular mechanisms underlying L. pneumophila-induced apoptosis, which were unclear. Wild-type L. pneumophila and flagellin-deficient Legionella, but not L. pneumophila lacking a functional type IV secretion system Dot/Icm, replicated in T-cells. However, apoptosis was efficiently induced in T-cells only by wild-type L. pneumophila, and not flagellin-deficient or Dot/Icm-deficient Legionella. Induction of apoptosis involved activation of the initiator caspase 9 and effector caspase 3. Infection with L. pneumophila inhibited phosphorylation of Akt (also known as protein kinase B) and the Akt substrate GSK3beta (glycogen synthase kinase 3beta), and reduced the levels of beta-catenin, a transcriptional activator regulated by GSK3beta. It also caused the activation of the pro-apoptotic protein Bax and inhibited the expression of the anti-apoptotic protein XIAP (X-linked inhibitor of apoptosis) via inhibition of the Akt pathway. In conclusion, L. pneumophila induces mitochondria-mediated T-cell apoptosis through inhibition of the Akt/GSK3beta signalling pathway.
Related JoVE Video
Two tyrosine hydroxylase genes in vertebrates New dopaminergic territories revealed in the zebrafish brain.
Mol. Cell. Neurosci.
PUBLISHED: 01-15-2010
Show Abstract
Hide Abstract
Tyrosine hydroxylase (TH) is the rate limiting enzyme for dopamine synthesis, catalyzing transformation of l-tyrosine to l-DOPA. Two TH genes (TH1 and TH2) have been reported to exist in the genome of some teleost fishes, TH1 being orthologous to the mammalian TH gene (Candy and Collet, 2005). Here we show that two TH genes are commonly found in genomes of jawed vertebrates. Our analyses of molecular phylogeny and gene synteny strongly suggest that the two TH genes emerged as a consequence of a whole genome duplication before the divergence of jawed vertebrates, and that TH2 was secondarily lost in eutherians (placental mammals). The distribution of TH1 and TH2 transcripts revealed that TH1 and TH2 are differentially expressed in the zebrafish adult brain, as often observed for duplicated genes. In particular we found that TH2 transcripts were much more abundant than TH1 in the hypothalamus, and that the TH2 cells along the periventricular zone are devoid of TH immunoreactivity, due to the lack of affinity of the available anti-TH antibodies. Although these neurons have been considered to be dopamine-uptaking cells in previous studies, the expression of other monoaminergic markers such as aromatic amino acid decarboxylase (AADC), dopamine transporter (DAT), and vesicular monoamine transporter 2 (VMAT2) suggests that these TH2 cells are dopamine-synthesizing neurons.
Related JoVE Video
Distribution of smooth muscle cells and macrophages expressing scavenger receptor BI/II in atherosclerosis.
J. Atheroscler. Thromb.
PUBLISHED: 12-22-2009
Show Abstract
Hide Abstract
Scavenger receptors type I and II (SRBI/II) have dual roles in both atherogenic and antiatherogenic functions through interactions with lipoproteins and their expression in macrophages; how-ever, the distribution and density of SRBI/II-positive macrophages and smooth muscle cells (SMCs) as well as their association with lipid metabolism-related proteins in atherosclerotic intima of the human aorta remain unclear.
Related JoVE Video
Group III secreted phospholipase A2 transgenic mice spontaneously develop inflammation.
Biochem. J.
PUBLISHED: 04-18-2009
Show Abstract
Hide Abstract
PLA2 (phospholipase A2) group III is an atypical sPLA2 (secretory PLA2) that is homologous with bee venom PLA2 rather than with other mammalian sPLA2s. In the present paper, we show that endogenous group III sPLA2 (PLA2G3) is expressed in mouse skin and that Tg (transgenic) mice overexpressing human PLA2G3 spontaneously develop skin inflammation. Pla2g3-Tg mice over 9 months of age frequently developed dermatitis with hyperkeratosis, acanthosis, parakeratosis, erosion, ulcer and sebaceous gland hyperplasia. The dermatitis was accompanied by infiltration of neutrophils and macrophages and by elevated levels of pro-inflammatory cytokines, chemokines and prostaglandin E2. In addition, Pla2g3-Tg mice had increased lymph aggregates and mucus in the airway, lymphocytic sialadenitis, hepatic extramedullary haemopoiesis, splenomegaly with increased populations of granulocytes and monocytes/macrophages, and increased serum IgG1. Collectively, these observations provide the first demonstration of spontaneous development of inflammation in mice with Tg overexpression of mammalian sPLA2.
Related JoVE Video
Oligomeric amyloid beta-protein as a therapeutic target in Alzheimers disease: its significance based on its distinct localization and the occurrence of a familial variant form.
Curr Alzheimer Res
PUBLISHED: 04-10-2009
Show Abstract
Hide Abstract
Oligomer Abeta is the term utilized for multimeric but non-fibrillar forms of amyloid beta-protein (Abeta). The most prominent property of oligomer Abeta is considered to be its solubility and structure. Here, we examined the histochemical localization of oligomer Abeta in AD brains. At present, little information is available on the structure and function of cerebral oligomer Abeta. We therefore studied the molecular localization of oligomer Abeta using a newly generated polyclonal mouse antisera against a variant Abeta with a deletion mutation of the 22(nd) glutamate that we found recently in a patient with familial Alzheimers disease. Intracellular as well as extracellular oligomer Abeta are herein discussed to define their structure and pathological roles in disease.
Related JoVE Video
Mucosal cutting biopsy technique for histological diagnosis of suspected gastrointestinal stromal tumors of the stomach.
Dig Endosc
Show Abstract
Hide Abstract
The Japanese Gastrointestinal Stromal Tumor (GIST) therapeutic guidelines recommend endoscopic ultrasound-guided fine-needle aspiration biopsy for histological diagnosis. However, before 2010, this technique was only carried out at a minority of medical institutions in Japan. In the present study, we investigated the usefulness of mucosal cutting biopsy.
Related JoVE Video
Evolution of dopamine receptor genes of the D1 class in vertebrates.
Mol. Biol. Evol.
Show Abstract
Hide Abstract
The receptors of the dopamine neurotransmitter belong to two unrelated classes named D1 and D2. For the D1 receptor class, only two subtypes are found in mammals, the D1A and D1B, receptors, whereas additional subtypes, named D1C, D1D, and D1X, have been found in other vertebrate species. Here, we analyzed molecular phylogeny, gene synteny, and gene expression pattern of the D1 receptor subtypes in a large range of vertebrate species, which leads us to propose a new view of the evolution of D1 dopamine receptor genes. First, we show that D1C and D1D receptor sequences are encoded by orthologous genes. Second, the previously identified Cypriniform D1X sequence is a teleost-specific paralog of the D1B sequences found in all groups of jawed vertebrates. Third, zebrafish and several sauropsid species possess an additional D1-like gene, which is likely to form another orthology group of vertebrate ancestral genes, which we propose to name D1E. Ancestral jawed vertebrates are thus likely to have possessed four classes of D1 receptor genes-D1A, D1B(X), D1C(D), and D1E-which arose from large-scale gene duplications. The D1C receptor gene would have been secondarily lost in the mammalian lineage, whereas the D1E receptor gene would have been lost independently in several lineages of modern vertebrates. The D1A receptors are well conserved throughout jawed vertebrates, whereas sauropsid D1C receptors have rapidly diverged, to the point that they were misidentified as D1D. The functional significance of the D1C receptor loss is not known. It is possible that the function may have been substituted with D1A or D1B receptors in mammals, following the disappearance of D1C receptors in these species.
Related JoVE Video
Pulmonary embolism caused by intimal sarcoma of the pulmonary artery.
Intern. Med.
Show Abstract
Hide Abstract
We herein report the case of a 39-year-old woman with a pulmonary embolism caused by intimal sarcoma of the pulmonary artery. She presented with shortness of breath and leg edema. Computed tomography showed a low density area that extended from the main pulmonary artery to the bilateral pulmonary arteries. We diagnosed her to have a pulmonary thromboembolism. The thrombosis did not decrease after the administration of anti-coagulant therapy, and she underwent resection of the thrombotic tissue. Histopathologically, the surgical specimen was not found to be thrombotic tissue but rather an intimal sarcoma of the pulmonary artery. After undergoing surgery, she received radiation therapy and chemotherapy; however, she died 31 months after being diagnosed.
Related JoVE Video
[A case of pseudomembranous colitis concomitant with toxic megacolon and paralytic ileus].
Nihon Shokakibyo Gakkai Zasshi
Show Abstract
Hide Abstract
A 60-year-old man was diagnosed as pseudomembranous colitis with chief complaint of fever and abdominal distension after a cerebral operation. It was ineffective although vancomycin hydrochloride (VCM) was given orally. Complications occurred. The patient had toxic megacolon and paralytic ileus. VCM was administrated via an ileus tube. In addition, the bowel was lavaged and VCM was sprayed by colonoscopy. This therapy was very effective. Generally, a patient with pseudomembranous colitis concomitant with toxic megacolon or/and paralytic ileus is considered to have a poor prognosis, however, he completely recovered by a combination of medical treatment.
Related JoVE Video
Narrow-band imaging on screening of esophageal lesions using an ultrathin transnasal endoscopy.
J. Gastroenterol. Hepatol.
Show Abstract
Hide Abstract
Ultrathin transnasal endoscopy, used extensively in Japan, is considered to have inferior image quality and suction performance, and questionable diagnostic performance. So the aim of the present study was to compare the diagnostic performance of white light (WL) examination and non-magnified narrow-band imaging (NBI) examination in screening for esophageal disorders with ultrathin transnasal endoscopy.
Related JoVE Video
Transglutaminase 2: a novel autoantigen in canine idiopathic central nervous system inflammatory diseases.
J. Vet. Med. Sci.
Show Abstract
Hide Abstract
Necrotizing meningoencephalitis (NME), necrotizing leukoencephalitis (NLE) and granulomatous meningoencephalomyelitis (GME) are common idiopathic inflammatory central nervous system (CNS) diseases with unknown etiology in dogs. We previously showed that IgG autoantibodies in the cerebrospinal fluid (CSF) of NME cases reacted to unknown brain proteins as well as to glial fibrillary acidic protein (GFAP). In the present report, we evaluated the autoantibodies against transglutaminase2 (TG2) in the canine CNS diseases. CSF samples obtained from dogs with NME (n=19), NLE (n=7), GME (n=11) and miscellaneous CNS diseases (n=12) were subjected. CSFs from 20 healthy dogs were used as controls. Indirect fluorescent antibody test on the canine cerebrum revealed astrocyte-binding IgG in the CSF of NME. After absorption of the CSF with bovine GFAP, the CSF still possessed the reactivity to astrocytes. Double-color staining showed clear colocalization of the autoantibodies and anti-human TG2 rabbit polyclonal IgG. An immunoblot assay against human recombinant TG2 revealed anti-TG2 IgG in the CSF from dogs with NME, NLE and GME. The CSF of canine idiopathic encephalitis cases, notably of NME, tended to show high ELISA OD values against human recombinant TG2 compared to healthy controls. The presence of anti-TG2 autoantibodies in the CSF may contribute to the elucidation of the etiology of canine NME, NLE and GME.
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.