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Find video protocols related to scientific articles indexed in Pubmed.
Wave propagation in bianisotropic metamaterials: angular selective transmission.
Opt Express
PUBLISHED: 11-18-2014
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We investigate the basic features of wave propagation in bianisotropic metamaterials characterized by asymmetric magnetoelectric tensors with zero diagonal elements. The wave propagation is described by a biquadratic dispersion relation with two elliptically polarized eigenwaves. In particular, the bianisotropic media may possess a hybrid character of the elliptic and hyperbolic dispersions. For a wave incident from vacuum onto a bianisotropic medium, there exist an ordinary and an inversion critical angle, leading to angular selective transmission. A standard and a complementary type of angular selective transmissions are illustrated with the incidence of Gaussian beams based on Fourier integral formulation.
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Effect of liver cirrhosis on metastasis in colorectal cancer patients: a nationwide population-based cohort study.
Jpn. J. Clin. Oncol.
PUBLISHED: 11-08-2014
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The aim of this study is to evaluate the liver metastasis risk among colorectal cancer patients with liver cirrhosis.
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Antimicrobial resistance of Escherichia coli isolates from canine urinary tract infections.
J. Vet. Med. Sci.
PUBLISHED: 10-31-2014
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This study determined the antimicrobial resistance profiles of Escherichia coli isolates from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs with UTI diagnosed through clinical examination and urinalysis were processed for isolation of Escherichia coli. Colonies from pure cultures were identified by biochemical reactions (n=114) and were tested for susceptibility to 18 antimicrobials. The two most frequent antimicrobials showing resistance in Urinary E. coli isolates were oxytetracycline and ampicillin. Among the resistant isolates, 17 resistance patterns were observed, with 12 patterns involving multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli isolates, tet(B) was the predominant resistance determinant and was detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the tet(A) determinant. Most ampicillin and/or amoxicillin-resistant E. coli isolates carried blaTEM-1 genes. Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes that are implicated primarily in resistance to aminoglycosides and trimethoprim (dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant E. coli isolates, 38 were resistant to nalidixic acid, and 6 were resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene cmlA and the florfenicol resistant gene floR were also identified. This study revealed an alarming rate of antimicrobial resistance among E. coli isolates from dogs with UTIs.
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Complete Genome Sequence of Vibrio vulnificus 93U204, a Bacterium Isolated from Diseased Tilapia in Taiwan.
Genome Announc
PUBLISHED: 10-04-2014
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Vibrio vulnificus 93U204 is a bacterium isolated from a moribund tilapia collected in Kaohsiung, Taiwan. Here, we report the complete genome sequence of this bacterium to facilitate the investigation of its pathogenicity and for comparative analyses with human-pathogenic strains within the same species.
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Targeting delivery of liposomes with conjugated p-aminophenyl-?-d-manno-pyranoside and apolipoprotein E for inhibiting neuronal degeneration insulted with ?-amyloid peptide.
J Drug Target
PUBLISHED: 10-01-2014
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Abstract Liposomes with conjugated p-aminophenyl-?-d-manno-pyranoside (APMP) and apolipoprotein E (ApoE) (APMP-ApoE-liposomes) were employed to carry neuron growth factor (NGF) across the blood-brain barrier (BBB) and enhance the survival of degenerated neurons. APMP-ApoE-liposomes were used to deliver NGF across a monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes (HAs) for rescuing SK-N-MC cells from an insult of ?-amyloid peptide 1-42 (A?1-42). An increase in the APMP concentration enhanced the particle size, HBMEC and HA viability, permeability for propidium iodide (PI), and permeability for NGF, however, reduced the absolute value of zeta potential, APMP conjugation efficiency and transendothelial electrical resistance (TEER). In addition, an increase in the ApoE concentration increased the particle size, absolute value of zeta potential, HBMEC and HA viability, permeability for PI, permeability for NGF and SK-N-MC cell viability, however, decreased the ApoE conjugation efficiency and TEER. APMP and ApoE on liposomes can be promising surface moieties to carry NGF across the BBB, target degenerated neurons and inhibit A?1-42-induced neurotoxicity in Alzheimer's disease.
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Effect of renal function impairment on the mortality of cirrhotic patients with hepatic encephalopathy: a population-based 3-year follow-up study.
Medicine (Baltimore)
PUBLISHED: 09-26-2014
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Kidney is an important organ to clear neurotoxic substance in circulation. However, it is still unknown about the effect of renal function impairment (RFI) on the mortality of cirrhotic patients with hepatic encephalopathy (HE). We used the Taiwan National Health Insurance Database to identify 4932 cirrhotic patients with HE, hospitalized between January 1, 2007 and December 31, 2007. The enrolled patients were followed up individually for 3 years to identify their 3-year mortalities. There were 411 (8.3%) patients with RFI and 4521 (91.7%) patients without RFI. The adjusted hazard ratio (HR) of RFI for 3-year mortality was 2.03 (95% CI, 1.82-2.27). In RFI group, there were 157 (38.2%) patients with acute renal failure (ARF), 61 (14.8%) with hepatorenal syndrome (HRS), 93 (22.6%) with chronic kidney disease (CKD), and 100 (24.3%) with end-stage renal disease (ESRD). Compared with the non-RFI group, the adjusted HR of ARF for 3-year mortality was 2.57 (95% CI, 2.17-3.06), CKD 1.93 (95% CI, 1.55-2.40), ESRD 1.26 (95% CI, 1.01-1.57), and HRS 3.58 (95% CI, 2.78-4.63). Among ESRD patients, there were 99 patients receiving hemodialysis regularly. Compared with the CKD group, the adjusted HR of ESRD with hemodialysis for 3-year mortality was 0.664 (95% CI, 0.466-0.945). RFI increased the 3-year mortality of cirrhotic patients with HE, especially ARF and HRS. HE patients with ESRD receiving hemodialysis had better 3-year survival rate than those with CKD.
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Is an observed non-co-linear RNA product spliced in trans, in cis or just in vitro?
Nucleic Acids Res.
PUBLISHED: 07-22-2014
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Global transcriptome investigations often result in the detection of an enormous number of transcripts composed of non-co-linear sequence fragments. Such 'aberrant' transcript products may arise from post-transcriptional events or genetic rearrangements, or may otherwise be false positives (sequencing/alignment errors or in vitro artifacts). Moreover, post-transcriptionally non-co-linear ('PtNcl') transcripts can arise from trans-splicing or back-splicing in cis (to generate so-called 'circular RNA'). Here, we collected previously-predicted human non-co-linear RNA candidates, and designed a validation procedure integrating in silico filters with multiple experimental validation steps to examine their authenticity. We showed that >50% of the tested candidates were in vitro artifacts, even though some had been previously validated by RT-PCR. After excluding the possibility of genetic rearrangements, we distinguished between trans-spliced and circular RNAs, and confirmed that these two splicing forms can share the same non-co-linear junction. Importantly, the experimentally-confirmed PtNcl RNA events and their corresponding PtNcl splicing types (i.e. trans-splicing, circular RNA, or both sharing the same junction) were all expressed in rhesus macaque, and some were even expressed in mouse. Our study thus describes an essential procedure for confirming PtNcl transcripts, and provides further insight into the evolutionary role of PtNcl RNA events, opening up this important, but understudied, class of post-transcriptional events for comprehensive characterization.
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Ectopic DNMT3L triggers assembly of a repressive complex for retroviral silencing in somatic cells.
J. Virol.
PUBLISHED: 07-02-2014
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Mammalian genomes are replete with retrotransposable elements, including endogenous retroviruses. DNA methyltransferase 3-like (DNMT3L) is an epigenetic regulator expressed in prospermatogonia, growing oocytes, and embryonic stem (ES) cells. Here, we demonstrate that DNMT3L enhances the interaction of repressive epigenetic modifiers, including histone deacetylase 1 (HDAC1), SET domain, bifurcated 1 (SETDB1), DNA methyltransferase 3A (DNMT3A), and tripartite motif-containing protein 28 (TRIM28; also known as TIF1? and KAP1) in ES cells and orchestrates retroviral silencing activity with TRIM28 through mechanisms including, but not limited to, de novo DNA methylation. Ectopic expression of DNMT3L in somatic cells causes methylation-independent retroviral silencing activity by recruitment of the TRIM28/HDAC1/SETDB1/DNMT3A/DNMT3L complex to newly integrated Moloney murine leukemia virus (Mo-MuLV) proviral DNA. Concurrent with this recruitment, we also observed the accumulation of histone H3 lysine 9 trimethylation (H3K9me3) and heterochromatin protein 1 gamma (HP1?), as well as reduced H3K9 and H3K27 acetylation at Mo-MuLV proviral sequences. Ectopic expression of DNMT3L in late-passage mouse embryonic fibroblasts (MEFs) recruited cytoplasmically localized HDAC1 to the nucleus. The formation of this epigenetic modifying complex requires interaction of DNMT3L with DNMT3A as well as with histone H3. In fetal testes at embryonic day 17.5, endogenous DNMT3L also enhanced the binding among TRIM28, DNMT3A, SETDB1, and HDAC1. We propose that DNMT3L may be involved in initiating a cascade of repressive epigenetic modifications by assisting in the preparation of a chromatin context that further attracts DNMT3A-DNMT3L binding and installs longer-term DNA methylation marks at newly integrated retroviruses.
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Investigation of polyvinylidene fluoride (PVDF) films in identifying high-frequency vibration modes of flexible plates.
IEEE Trans Ultrason Ferroelectr Freq Control
PUBLISHED: 05-27-2014
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Compared with piezoelectric ceramics such as lead zirconate titanate (PZT) ceramics, the low density and high compliance of the PVDF films make them a more suitable choice in modal testing, especially for detecting high-frequency modes in flexible or inflatable structures. In this work, dynamic sensing performances of PVDF films for flexible structures in modal testing are examined, with considerations including the repeatability of the impact source, the accuracy of the sensing responses, and the influences of the nodal lines on the frequency spectra of the transient responses. Two flexible plates with different boundary conditions and thickness are considered. Experimental results, compared with FEM computations or theoretical predictions, demonstrate the excellent dynamic sensing performance of the PVDF film in modal testing applications, especially for identification of high-frequency modes on flexible structures.
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Class A dioscorins of various yam species suppress ovalbumin-induced allergic reactions.
Immunopharmacol Immunotoxicol
PUBLISHED: 05-24-2014
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Dioscorins, the primary storage proteins in yam tubers, of different species exhibited varying immunomodulatory activities in mice. We inferred that this might be attributed to the various isoforms in the yam tubers.
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Evaluation of endoscopic salpingectomy for sterilization of female Formosan macaques (Macaca cyclopis).
Am. J. Primatol.
PUBLISHED: 05-16-2014
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We evaluated the safety and postsurgical outcomes of endoscopic salpingectomy for sterilization of female Formosan macaques (Macaca cyclopis) as a method of population control. Nineteen adult female Formosan macaques were included in our study. The fallopian tubes of each anesthetized macaque were cauterized and excised endoscopically using a 2.7-mm rigid endoscope system. We recorded the complications encountered, and objectively scored the amount of hemorrhage throughout the procedure. Postoperative ovarian function was evaluated by monitoring the serum levels of sex hormones in ten of the macaques for two ovarian cycles following the salpingectomy. Two to 13 months later, eight of the 19 macaques underwent laparoscopy for the objective evaluation of inflammation at the surgical sites on the fallopian tubes. No major anesthetic- or surgical-associated complications were observed in any of the macaques. The hormonal evaluation showed cyclic ovarian function after salpingectomy in all of the ten macaques examined, and the parameters were comparable to those of other macaque species. The long-term postoperative level of inflammation at the surgical site was minimal to low, and was lower than that reported for other tubal occlusion techniques used in macaques. The use of a 2.7-mm rigid endoscope for salpingectomy in macaques is safe and efficient, with fewer postoperative complications than comparable sterilization techniques. Am. J. Primatol. © 2014 Wiley Periodicals, Inc.
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Granulosa cells and retinoic acid co-treatment enrich potential germ cells from manually selected Oct4-EGFP expressing human embryonic stem cells.
Reprod. Biomed. Online
PUBLISHED: 05-13-2014
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Differentiation of human embryonic stem (HES) cells to germ cells may become clinically useful in overcoming diseases related to germ-cell development. Niches were used to differentiate HES cell lines, NTU1 and H9 Oct4-enhanced green fluorescence protein (EGFP), including laminin, granulosa cell co-culture or conditioned medium, ovarian stromal cell co-culture or conditioned medium, retinoic acid, stem cell factor (SCF) and BMP4-BMP7-BMP8b treatment. Flow cytometry showed that granulosa cell co-culture (P < 0.001) or conditioned medium (P = 0.007) treatment for 14 days significantly increased the percentages of differentiated H9 Oct4-EGFP cells expressing early germ cell marker stage-specific embryonic antigen 1(SSEA1); sorted SSEA1[+] cells did not express higher levels of germ cell gene VASA and GDF9. Manually collected H9 Oct4-EGFP[+] cells expressed significantly higher levels of VASA (P = 0.005) and GDF9 (P = 0.001). H9 Oct4-EGFP[+] cells developed to ovarian follicle-like structures after culture for 28 days but with low efficiency. Unlike SCF and BMP4, retinoic acid co-treatment enhanced VASA, GDF9 and SCP3 expression. A protocol is recommended to enrich differentiated HES cells with germ-cell potential by culture with granulosa cells, conditioned medium or retinoic acid, manual selection of Oct4-EGFP[+] cells, and analysis of VASA, GDF9 expression, or both.
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Crystal structures of ligand-bound octaprenyl pyrophosphate synthase from Escherichia coli reveal the catalytic and chain-length determining mechanisms.
Proteins
PUBLISHED: 05-12-2014
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Octaprenyl pyrophosphate synthase (OPPs) catalyzes consecutive condensation reactions of one allylic substrate farnesyl pyrophosphate (FPP) and five homoallylic substrate isopentenyl pyrophosphate (IPP) molecules to form a C40 long-chain product OPP, which serves as a side chain of ubiquinone and menaquinone. OPPs belongs to the trans-prenyltransferase class of proteins. The structures of OPPs from Escherichia coli were solved in the apo-form as well as in complexes with IPP and a FPP thio-analog, FsPP, at resolutions of 2.2-2.6 Å, and revealed the detailed interactions between the ligands and enzyme. At the bottom of the active-site tunnel, M123 and M135 act in concert to form a wall which determines the final chain length. These results represent the first ligand-bound crystal structures of a long-chain trans-prenyltransferase and provide new information on the mechanisms of catalysis and product chain elongation. Proteins 2014. © 2014 Wiley Periodicals, Inc.
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Cardiolipin-incorporated liposomes with surface CRM197 for enhancing neuronal survival against neurotoxicity.
Int J Pharm
PUBLISHED: 04-21-2014
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CRM197-grafted liposomes containing cardiolipin (CL) (CRM197/CL-liposomes) were used to enhance the permeability of neuron growth factor (NGF) across the blood-brain barrier (BBB) for promoting the neuroprotective effect of NGF. CRM197/CL-liposoms were incubated with a monolayer of human astrocyte (HA)-regulated human brain-microvascular endothelial cells (HBMECs) and employed to rescue SK-N-MC cells with insult of fibrillar ?-amyloid peptide (1-42) (A?1-42). An increase in the CL mole percentage enhanced the particle size, absolute value of zeta potential, NGF entrapment efficiency, CRM197 grafting efficiency, viability of HBMECs, HAs, and SK-N-MC cells, and BBB permeability of propidium iodide (PI) and NGF, and reduced the transendothelial electrical resistance (TEER). In addition, an increase in the CRM197 weight percentage increased the particle size, absolute value of zeta potential, viability of HBMECs and HAs, and BBB permeability of PI and NGF, and decreased the CRM197 grafting efficiency and TEER. CRM197/CL-liposomes have the ability to target the BBB and to reduce neurotoxicity of A?142 and can be promising formulations for treating Alzheimer's disease in future medicinal application.
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Neuroprotection against degeneration of sk-N-mc cells using neuron growth factor-encapsulated liposomes with surface cereport and transferrin.
J Pharm Sci
PUBLISHED: 04-16-2014
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Liposomes with Cereport (RMP-7) and transferrin (Tf) (RMP-7/Tf/liposomes) were employed to target the blood-brain barrier (BBB) and to inhibit the degeneration of neurons insulted with fibrillar ?-amyloid peptide 1-42 (A?1-42). Neuron growth factor (NGF)-encapsulated RMP-7/Tf/liposomes (RMP-7/Tf/NGF-liposomes) were used to permeate a monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes (HAs) and to treat A?1-42 -attacked SK-N-MC cells. An increase in RMT-7 concentration increased the particle size, zeta potential, propidium iodide (PI) permeability, and NGF permeability, but decreased the cross-linking efficiency of RMT-7, viability of HBMECs and HAs, and transendothelial electrical resistance (TEER). In addition, an increase in Tf concentration enhanced the particle size, viability of HBMECs, HAs, and SK-N-MC cells, PI permeability, and NGF permeability, but reduced the zeta potential, cross-linking efficiency of RMT-7 and Tf, and TEER. RMP-7/Tf/NGF-liposomes can transport NGF across the BBB and improve the neuroprotection for Alzheimer's disease therapy in preclinical trials.
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Removal of endobronchial malignant mass by cryotherapy improved performance status to receive chemotherapy.
ScientificWorldJournal
PUBLISHED: 04-06-2014
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Although malignant endobronchial mass (MEM) has poor prognosis, cryotherapy is reportedly a palliative treatment. Clinical data on postcryotherapy MEM patients in a university-affiliated hospital between 2007 and 2011 were evaluated. Survival curve with or without postcryotherapy chemotherapy and performance status (PS) improvement of these subjects were analyzed using the Kaplan-Meier method. There were 59 patients (42 males), with median age of 64 years (range, 51-76, and median performance status of 2 (interquartile range [IQR], 2-3). Postcryotherapy complications included minor bleeding (n = 12) and need for multiple procedures (n = 10), while outcomes were relief of symptoms (n = 51), improved PS (n = 45), and ability to receive chemotherapy (n = 40). The survival of patients with chemotherapy postcryotherapy was longer than that of patients without such chemotherapy (median, 534 versus 106 days; log-rank test, P = 0.007; hazard ratio, 0.25; 95% confidence interval, 0.10-0.69). The survival of patients with PS improvement postcryotherapy was longer than that of patients without PS improvement (median, 406 versus 106 days; log-rank test, P = 0.02; hazard ratio, 0.28; 95% confidence interval, 0.10-0.81). Cryotherapy is a feasible treatment for MEM. With better PS after cryotherapy, further chemotherapy becomes possible for patients to improve survival when MEM caused dyspnea and poor PS.
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Inhibition of soluble tumor necrosis factor is therapeutic in Huntington's disease.
Hum. Mol. Genet.
PUBLISHED: 04-03-2014
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Neuroinflammation is a common feature of many neurodegenerative diseases, including Huntington's disease (HD). HD is an autosomal dominant genetic disease caused by an expanded CAG repeat in exon 1 of the huntingtin (HTT) gene. Previous studies demonstrated that levels of several proinflammatory cytokines, including tumor necrosis factor (TNF)-?, were higher in the plasma and brain tissues of mice and patients with HD, suggesting that inflammation may contribute to HD progression. To evaluate the pathological role of TNF-? in HD pathogenesis, we blocked TNF-? signaling using a dominant negative inhibitor of soluble TNF-? (XPro1595). XPro1595 effectively suppressed the inflammatory responses of primary astrocytes-enriched culture isolated from a transgenic mouse model (R6/2) and human astrocytes-enriched culture derived from induced pluripotent stem cells (iPSCs) of HD patients evoked by lipopolysaccharide and cytokines, respectively. Moreover, XPro1595 protected the cytokine-induced toxicity of primary R6/2 neurons and human neurons derived from iPSCs of HD patients. To assess the beneficial effect of XPro1595 in vivo, an intracerebroventricular (i.c.v.) infusion was provided with an osmotic minipump. ELISA analyses showed that i.c.v. infusion of XPro1595 decreased elevated levels of TNF? in the cortex and striatum, improved motor function, reduced caspase activation, diminished the amount of mutant HTT aggregates, increased neuronal density and decreased gliosis in brains of R6/2 mice. Moreover, reducing the peripheral inflammatory response by a systemic injection of XPro1595 improved the impaired motor function of R6/2 mice but did not affect caspase activation. Collectively, our findings suggest that an effective and selective anti-inflammatory treatment targeting the abnormal brain inflammatory response is a potential therapeutic strategy for HD.
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A new copepod with transformed body plan and unique phylogenetic position parasitic in the acorn worm Ptychodera flava.
Biol. Bull.
PUBLISHED: 03-21-2014
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Symbiotic copepods compose one-third of the known copepod species and are associated with a wide range of animal groups. Two parasitic copepods endoparasitic in acorn worms (Hemichordata), Ive balanoglossi and Ubius hilli, collected in the Mediterranean Sea and Australian waters, respectively, were described a century ago. Here we report a new parasitic copepod species, Ive ptychoderae sp. nov., found in Ptychodera flava, a widespread acorn worm in the Indo-Pacific Ocean and an emerging organism for developmental and evolutionary studies. The female of I. ptychoderae is characterized by having a reduced maxilliped and five pairs of annular swellings along the body that are morphologically similar but distinguishable from those in the two previously described parasitic copepods in acorn worms. Phylogenetic analysis based on the 18S rDNA sequence shows that I. ptychoderae may belong to Poecilostomatoida but represent a new family, which we name Iveidae fam. nov. Ive ptychoderae is commonly found in the acorn worm population with an average prevalence of 42% during the collecting period. The infection of the parasite induces the formation of cysts and causes localized lesions of the host tissues, suggesting that it may have negative effects on its host. Interestingly, most cysts contain a single female with one or multiple male copepods, suggesting that their sex determination may be controlled by environmental conditions. The relationships between the parasitic copepods and acorn worms thus provide a platform for understanding physiological and ecological influences and coevolution between parasites and hosts.
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Molecular evolution of the actin-like MreB protein gene family in wall-less bacteria.
Biochem. Biophys. Res. Commun.
PUBLISHED: 02-26-2014
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The mreB gene family encodes actin-like proteins that determine cell shape by directing cell wall synthesis and often exists in one to three copies in the genomes of non-spherical bacteria. Intriguingly, while most wall-less bacteria do not have this gene, five to seven mreB homologs are found in Spiroplasma and Haloplasma, which are both characterized by cell contractility. To investigate the molecular evolution of this gene family in wall-less bacteria, we sampled the available genome sequences from these two genera and other related lineages for comparative analysis. The gene phylogenies indicated that the mreB homologs in Haloplasma are more closely related to those in Firmicutes, whereas those in Spiroplasma form a separate clade. This finding suggests that the gene family expansions in these two lineages are the results of independent ancient duplications. Moreover, the Spiroplasma mreB homologs can be classified into five clades, of which the genomic positions are largely conserved. The inference of gene gains and losses suggests that there has been an overall trend to retain only one homolog from each of the five mreB clades in the evolutionary history of Spiroplasma.
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Molecular evolution of the substrate utilization strategies and putative virulence factors in mosquito-associated Spiroplasma species.
Genome Biol Evol
PUBLISHED: 02-19-2014
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Comparative genomics provides a powerful tool to characterize the genetic differences among species that may be linked to their phenotypic variations. In the case of mosquito-associated Spiroplasma species, such approach is useful for the investigation of their differentiations in substrate utilization strategies and putative virulence factors. Among the four species that have been assessed for pathogenicity by artificial infection experiments, Spiroplasma culicicola and S. taiwanense were found to be pathogenic, whereas S. diminutum and S. sabaudiense were not. Intriguingly, based on the species phylogeny, the association with mosquito hosts and the gain or loss of pathogenicity in these species appears to have evolved independently. Through comparison of their complete genome sequences, we identified the genes and pathways that are shared by all or specific to one of these four species. Notably, we found that a glycerol-3-phosphate oxidase gene (glpO) is present in S. culicicola and S. taiwanense but not in S. diminutum or S. sabaudiense. Because this gene is involved in the production of reactive oxygen species and has been demonstrated as a major virulence factor in Mycoplasma, this distribution pattern suggests that it may be linked to the observed differences in pathogenicity among these species as well. Moreover, through comparative analysis with other Spiroplasma, Mycoplasma, and Mesoplasma species, we found that the absence of glpO in S. diminutum and S. sabaudiense is best explained by independent losses. Finally, our phylogenetic analyses revealed possible recombination of glpO between distantly related lineages and local rearrangements of adjacent genes.
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Suppression of the SOX2 neural effector gene by PRDM1 promotes human germ cell fate in embryonic stem cells.
Stem Cell Reports
PUBLISHED: 02-11-2014
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The mechanisms of transcriptional regulation underlying human primordial germ cell (PGC) differentiation are largely unknown. The transcriptional repressor Prdm1/Blimp-1 is known to play a critical role in controlling germ cell specification in mice. Here, we show that PRDM1 is expressed in developing human gonads and contributes to the determination of germline versus neural fate in early development. We show that knockdown of PRDM1 in human embryonic stem cells (hESCs) impairs germline potential and upregulates neural genes. Conversely, ectopic expression of PRDM1 in hESCs promotes the generation of cells that exhibit phenotypic and transcriptomic features of early PGCs. Furthermore, PRDM1 suppresses transcription of SOX2. Overexpression of SOX2 in hESCs under conditions favoring germline differentiation skews cell fate from the germline to the neural lineage. Collectively, our results demonstrate that PRDM1 serves as a molecular switch to modulate the divergence of neural or germline fates through repression of SOX2 during human development.
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Chronic obstructive pulmonary disease in stage I non-small cell lung cancer that underwent anatomic resection: the role of a recurrence promoter.
COPD
PUBLISHED: 01-29-2014
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Despite the use of anatomic resection, the post-surgical recurrence rate remains high in early-stage non-small cell lung cancer (NSCLC). Chronic inflammation plays a role in the mechanism that promotes tumor initiation. This study aimed to investigate the association between recurrence outcome and chronic inflammation-related co-morbidities in early-stage resected NSCLC.
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Radiopacity and cytotoxicity of Portland cement containing zirconia doped bismuth oxide radiopacifiers.
J Endod
PUBLISHED: 01-28-2014
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This study evaluates the radiopacity and cytotoxicity of Portland cements containing a radiopacifier of bismuth oxide (Bi2O3) with yttria-stabilized zirconia (YSZ) dopant.
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Efficacy of entecavir in chronic hepatitis B patients with persistently normal alanine aminotransferase: randomized, double-blind, placebo-controlled study.
Antivir. Ther. (Lond.)
PUBLISHED: 01-27-2014
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It is still inconclusive whether chronic hepatitis B (CHB) patients with persistently normal alanine aminotransferase (PNALT) should receive nucleos(t)ides analogues. This study is to evaluate the efficacy of entecavir in improving liver histology in CHB patients with PNALT.
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Delivering etoposide to the brain using catanionic solid lipid nanoparticles with surface 5-HT-moduline.
Int J Pharm
PUBLISHED: 01-24-2014
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Brain-targeted delivery of etoposide (ETP) is important for treating malignant tumors in the central nervous system. This study presents the transport of ETP across the blood-brain barrier (BBB) using catanionic solid lipid nanoparticles (CASLNs) grafted with 5-HT-moduline. ETP-encapsulated CASLNs (ETP-CASLNs) were prepared in catanionic microemulsion and constructed into solid colloids by rapid cooling. In addition, the uptake of 5-HT-moduline-grafted ETP-CASLNs (5-HT-moduline/ETP-CASLNs) by human brain-microvascular endothelial cells (HBMECs) was visualized by immunochemical staining. We found that a maximal entrapment efficiency of ETP occurred at 0.75 mM of catanionic surfactants. An increase in the concentration of catanionic surfactants reduced the viability of HBMECs. Moreover, an increase in the concentration of 5-HT-moduline reduced the grafting efficiency of 5-HT-moduline, cell viability, and transendothelial electrical resistance of HBMEC monolayer, and enhanced the permeability of propidium iodide and ETP across the BBB. Surface-modified 5-HT-moduline/ETP-CASLNs can be promising drug delivery carriers for anti-brain tumor chemotherapy in preclinical trial.
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Protection of SK-N-MC cells against ?-amyloid peptide-induced degeneration using neuron growth factor-loaded liposomes with surface lactoferrin.
Biomaterials
PUBLISHED: 01-22-2014
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A liposomal system with surface lactoferrin (Lf) was developed for delivering neuron growth factor (NGF) across the blood-brain barrier (BBB) and improving the viability of neuron-like SK-N-MC cells with deposited ?-amyloid peptide (A?). The Lf-grafted liposomes carrying NGF (Lf/NGF-liposomes) were applied to a monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes (HAs) and to fibrillar A?1-42-insulted SK-N-MC cells. An increase in cholesterol mole percentage enhanced the particle size, absolute value of zeta potential, and physical stability, however, reduced the entrapment efficiency and release rate of NGF. In addition, an increase in Lf concentration increased the particle size, surface nitrogen percentage, NGF permeability across the BBB, and viability of HBMECs, HAs, and SK-N-MC cells, however, decreased the absolute value of zeta potential, surface phosphorus percentage, and loading efficiency of Lf. After treating with Lf/NGF-liposomes, a higher A? concentration yielded a lower survival of SK-N-MC cells. The current Lf/NGF-liposomes are efficacious drug carriers to target the BBB and inhibit the A?-induced neurotoxicity as potential pharmacotherapy for Alzheimer's disease.
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Comparisons of terminal densities of cardiovascular function-related projections from the amygdala subnuclei.
Auton Neurosci
PUBLISHED: 01-14-2014
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The amygdala is important in higher-level control of cardiovascular functions. In this study, we compared cardiovascular-related projections among the subnuclei of the amygdala. Biotinylated dextran amine was injected into the central, medial, and basolateral nuclei of the amygdala, and the distributions and densities of anterograde-labeled terminal boutons were analyzed. We found that the medial, basolateral, and central nuclei all had projections into the cardiovascular-related areas of the hypothalamus. However, only the central nucleus had a significant direct projection into the medulla. By contrast, the medial nucleus had limited projections, and the basolateral nucleus had no terminals extending into the medulla. We concluded that the medial, central, and basolateral nuclei of the amygdala may influence cardiovascular-related nuclei through monosynaptic connections with cardiovascular-related nuclei in the hypothalamus and medulla.
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Complete Genome Sequence of Spiroplasma apis B31T (ATCC 33834), a Bacterium Associated with May Disease of Honeybees (Apis mellifera).
Genome Announc
PUBLISHED: 01-11-2014
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Spiroplasma apis B31(T) (ATCC 33834) is a wall-less bacterium in the class Mollicutes that has been linked to May disease of honeybees (Apis mellifera). Here, we report the complete genome sequence of this bacterium to facilitate the investigation of its virulence factors.
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Enterovirus 71 Induces Mitochondrial Reactive Oxygen Species Generation That is Required for Efficient Replication.
PLoS ONE
PUBLISHED: 01-01-2014
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Redox homeostasis is an important host factor determining the outcome of infectious disease. Enterovirus 71 (EV71) infection has become an important endemic disease in Southeast Asia and China. We have previously shown that oxidative stress promotes viral replication, and progeny virus induces oxidative stress in host cells. The detailed mechanism for reactive oxygen species (ROS) generation in infected cells remains elusive. In the current study, we demonstrate that mitochondria were a major ROS source in EV71-infected cells. Mitochondria in productively infected cells underwent morphologic changes and exhibited functional anomalies, such as a decrease in mitochondrial electrochemical potential ??m and an increase in oligomycin-insensitive oxygen consumption. Respiratory control ratio of mitochondria from infected cells was significantly lower than that of normal cells. The total adenine nucleotide pool and ATP content of EV71-infected cells significantly diminished. However, there appeared to be a compensatory increase in mitochondrial mass. Treatment with mito-TEMPO reduced eIF2? phosphorylation and viral replication, suggesting that mitochondrial ROS act to promote viral replication. It is plausible that EV71 infection induces mitochondrial ROS generation, which is essential to viral replication, at the sacrifice of efficient energy production, and that infected cells up-regulate biogenesis of mitochondria to compensate for their functional defect.
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Complete Chloroplast Genome Sequence of Omani Lime (Citrus aurantiifolia) and Comparative Analysis within the Rosids.
PLoS ONE
PUBLISHED: 01-01-2014
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The genus Citrus contains many economically important fruits that are grown worldwide for their high nutritional and medicinal value. Due to frequent hybridizations among species and cultivars, the exact number of natural species and the taxonomic relationships within this genus are unclear. To compare the differences between the Citrus chloroplast genomes and to develop useful genetic markers, we used a reference-assisted approach to assemble the complete chloroplast genome of Omani lime (C. aurantiifolia). The complete C. aurantiifolia chloroplast genome is 159,893 bp in length; the organization and gene content are similar to most of the rosids lineages characterized to date. Through comparison with the sweet orange (C. sinensis) chloroplast genome, we identified three intergenic regions and 94 simple sequence repeats (SSRs) that are potentially informative markers with resolution for interspecific relationships. These markers can be utilized to better understand the origin of cultivated Citrus. A comparison among 72 species belonging to 10 families of representative rosids lineages also provides new insights into their chloroplast genome evolution.
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Self-assembly behaviors of thermal- and pH- sensitive magnetic nanocarriers for stimuli-triggered release.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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In the present work, we prepare thermo- and pH-sensitive polymer-based nanoparticles incorporating with magnetic iron oxide as the remote-controlled, stimuli-response nanocarriers. Well-defined, dual functional tri-block copolymer poly[(acrylic acid)-block-(N-isopropylacrylamide)-block-(acrylic acid)], was synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization with S,S'-bis(?,?'-dimethyl-??-acetic acid)trithiocarbonate (CMP) as a chain transfer agent (CTA). With the aid of using 3-aminopropyltriethoxysilane, the surface-modified iron oxides, Fe3O4-NH2, was then attached on the surface of self-assembled tri-block copolymer micelles via 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinamide (EDC/NHS) crosslinking method in order to furnish not only the magnetic resources for remote control but also the structure maintenance for spherical morphology of our nanocarriers. The nanocarrier was characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV/Vis) spectral analysis. Rhodamine 6G (R6G), as the modeling drugs, was encapsulated into the magnetic nanocarriers by a simple swelling method for fluorescence-labeling and controlled release monitoring. Biocompatibility of the nanocarriers was studied via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed that neither the pristine nanocarrier nor the R6G-loaded nanocarriers were cytotoxic to the normal fibroblast cells (L-929 cells). The in vitro stimuli-triggered release measurement showed that the intelligent nanocarriers were highly sensitive to the change of pH value and temperature rising by the high-frequency magnetic field (HFMF) treatment, which provided the significant potential to apply this technology to biomedical therapy by stimuli-responsive controlled release.
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Magnetic liposomes for colorectal cancer cells therapy by high-frequency magnetic field treatment.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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In this study, we developed the cancer treatment through the combination of chemotherapy and thermotherapy using doxorubicin-loaded magnetic liposomes. The citric acid-coated magnetic nanoparticles (CAMNP, ca. 10 nm) and doxorubicin were encapsulated into the liposome (HSPC/DSPE/cholesterol?=?12.5:1:8.25) by rotary evaporation and ultrasonication process. The resultant magnetic liposomes (ca. 90 to 130 nm) were subject to characterization including transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), zeta potential, Fourier transform infrared (FTIR) spectrophotometer, and fluorescence microscope. In vitro cytotoxicity of the drug carrier platform was investigated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using L-929 cells, as the mammalian cell model. In vitro cytotoxicity and hyperthermia (inductive heating) studies were evaluated against colorectal cancer (CT-26 cells) with high-frequency magnetic field (HFMF) exposure. MTT assay revealed that these drug carriers exhibited no cytotoxicity against L-929 cells, suggesting excellent biocompatibility. When the magnetic liposomes with 1 ?M doxorubicin was used to treat CT-26 cells in combination with HFMF exposure, approximately 56% cells were killed and found to be more effective than either hyperthermia or chemotherapy treatment individually. Therefore, these results show that the synergistic effects between chemotherapy (drug-controlled release) and hyperthermia increase the capability to kill cancer cells.
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Peginterferon alfa-2a is associated with elevations in alanine aminotransferase at the end of treatment in chronic hepatitis C patients with sustained virologic response.
PLoS ONE
PUBLISHED: 01-01-2014
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The purpose of this study was to investigate the incidence and demographic/clinical factors of alanine aminotransferase (ALT) abnormalities at the end of treatment (EOT) in chronic hepatitis C (CHC) patients with sustained virologic response (SVR).
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An association of genotypes and antimicrobial resistance patterns among Salmonella isolates from pigs and humans in Taiwan.
PLoS ONE
PUBLISHED: 01-01-2014
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We collected 110 Salmonella enterica isolates from sick pigs and determined their serotypes, genotypes using pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility to 12 antimicrobials and compared the data with a collection of 18,280 isolates obtained from humans. The pig isolates fell into 12 common serovars for human salmonellosis in Taiwan; S. Typhimurium, S. Choleraesuis, S. Derby, S. Livingstone, and S. Schwarzengrund were the 5 most common serovars and accounted for a total of 84% of the collection. Of the 110 isolates, 106 (96%) were multidrug resistant (MDR) and 48 (44%) had PFGE patterns found in human isolates. S. Typhimurium, S. Choleraesuis, and S. Schwarzengrund were among the most highly resistant serovars. The majority of the 3 serovars were resistant to 8-11 of the tested antimicrobials. The isolates from pigs and humans sharing a common PFGE pattern displayed identical or very similar resistance patterns and Salmonella strains that caused severe infection in pigs were also capable of causing infections in humans. The results indicate that pigs are one of the major reservoirs to human salmonellosis in Taiwan. Almost all of the pig isolates were MDR, which highlights the necessity of strictly regulating the use of antimicrobials in the agriculture sector in Taiwan.
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Distinct phylogenetic relationships and biochemical properties of Arabidopsis ovarian tumor-related deubiquitinases support their functional differentiation.
Front Plant Sci
PUBLISHED: 01-01-2014
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The reverse reaction of ubiquitylation is catalyzed by different classes of deubiquitylation enzymes (DUBs), including ovarian tumor domain (OTU)-containing DUBs; experiments using Homo sapiens proteins have demonstrated that OTU DUBs modulate various cellular processes. With the exception of OTLD1, plant OTU DUBs have not been characterized. We identified 12 Arabidopsis thaliana OTU loci and analyzed 11 of the encoded proteins in vitro to determine their preferences for the ubiquitin (UB) chains of M1, K48, and K63 linkages as well as the UB-/RUB-/SUMO-GST fusions. The A. thaliana OTU DUBs were shown to be cysteine proteases and classified into four groups with distinct linkage preferences: OTU1 (M1 = K48 > K63), OTU3/4/7/10 (K63 > K48 > M1), OTU2/9 (K48 = K63), and OTU5/11/12/OTLD1 (inactive). Five active OTU DUBs (OTU3/4/7/9/10) also cleaved RUB fusion. OTU1/3/4 cleaved M1 UB chains, suggesting a possible role for M1 chains in plant cellular signaling. The different substrate specificities of the various A. thaliana OTU DUBs indicate the involvement of distinct structural elements; for example, the OTU1 oxyanion residue D89 is essential for cleaving isopeptide bond-linked chains but dispensable for M1 chains. UB-binding activities were detected only for OTU2 and OTLD1, with distinct linkage preferences. These differences in biochemical properties support the involvement of A. thaliana OTU DUBs in different functions. Moreover, based on the established phylogenetic tree, plant- and H. sapiens-specific clades exist, which suggests that the proteins within these clades have taxa-specific functions. We also detected five OTU clades that are conserved across species, which suggests that the orthologs in different species within each clade are involved in conserved cellular processes, such as ERAD and DNA damage responses. However, different linkage preferences have been detected among potential cross-species OTU orthologs, indicating functional and mechanistic differentiation.
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Lhx2 regulates a cortex-specific mechanism for barrel formation.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-21-2013
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LIM homeodomain transcription factors are critical regulators of early development in multiple systems but have yet to be examined for a role in circuit formation. The LIM homeobox gene Lhx2 is expressed in cortical progenitors during development and also in the superficial layers of the neocortex in maturity. However, analysis of Lhx2 function at later stages of cortical development has been hampered by severe phenotypes associated with early loss of function. We identified a particular Cre-recombinase line that acts in the cortical primordium after its specification is complete, permitting an analysis of Lhx2 function in neocortical lamination, regionalization, and circuit formation by selective elimination of Lhx2 in the dorsal telencephalon. We report a profound disruption of cortical neuroanatomical and molecular features upon loss of Lhx2 in the cortex from embryonic day 11.5. A unique feature of cortical circuitry, the somatosensory barrels, is undetectable, and molecular patterning of cortical regions appears disrupted. Surprisingly, thalamocortical afferents innervate the mutant cortex with apparently normal regional specificity. Electrophysiological recordings reveal a loss of responses evoked by stimulation of individual whiskers, but responses to simultaneous stimulation of multiple whiskers were present, suggesting that thalamic afferents are unable to organize the neurocircuitry for barrel formation because of a cortex-specific requirement of Lhx2. We report that Lhx2 is required for the expression of transcription factor paired box gene 6, axon guidance molecule Ephrin A5, and the receptor NMDA receptor 1. These genes may mediate Lhx2 function in the formation of specialized neurocircuitry necessary for neocortical function.
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Quantitative proteomics of protein complexes and their implications for cell reprograming and pluripotency.
J. Proteome Res.
PUBLISHED: 11-20-2013
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Pluripotency of embryonic stem cells (ESCs)/induced pluripotent stem cells (iPSCs) and reprograming of somatic cells (SCs) to pluripotency are governed by known and unknown factors. These factors, including protein complexes, are poorly described at the proteome level. Here, we established the quantitative proteomic profiles across three types of cells (iPSCs, ESCs, and SCs) using OFFGEL fractionation coupled with LTQ-Orbitrp analysis. Additionally, we utilized the previously published proteomic profiles of iPSCs, ESCs, and SCs. By integrating these proteomic profiles with protein-protein interaction resources, we identified numerous protein complexes in iPSCs and/or ESCs, which include known and novel chromatin remodeling complexes that facilitate cell reprograming. The identified protein complexes also include the previously unreported ones that are associated with the imperfect aspects of iPSCs or cell reprograming process. Further, we performed a comparison between our study and previously published studies and highlighted a partial conservation of the identified protein complexes across the iPSCs generated by different laboratories and iPS cell-type specific protein complexes. The identified protein complexes were validated by integrated in silico analysis of microarray repository data related to ESCs differentiation into embryoid bodies. A majority of the protein complexes exhibited significant (p < 0.005) co-regulation of their components upon ESC differentiation, suggesting their role in the maintenance of the pluripotent state. Finally, we showed a link between the components of the protein complexes and embryonic development using the existing loss-of-function phenotype data. Together, our integrated approach provides the first comprehensive view of the protein complexes that may have implications for cell reprograming and pluripotency.
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Suppression of allergic reactions in ovalbumin-sensitized mice by yam storage proteins dioscorins.
J. Agric. Food Chem.
PUBLISHED: 11-18-2013
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To study the biomedical functions of dioscorins isolated from various species of Dioscorea , we investigated their antiallergic potential using an OVA-induced allergy mouse model. All the dioscorins suppressed allergic reactions by decreasing the serum IgE and histamine levels. The serum IFN-? and IgG2a levels increased in all the dioscorin-treated mice. The spleen cells from the dioscorin-treated mice also exhibited an up-regulation of IFN-? secretion in response to ConA stimulation. Although dioscorins did not affect the IgG1 levels, the IL-5 levels decreased to basal levels in mice treated with dioscorins of D. alata or D. japonica and in most of the lymphoid cells of the dioscorin-treated mice in response to ConA stimulation. The decrease of IgE and histamine levels was concomitant with an increase in IFN-? and IgG2a levels and with a decrease in IL-5 levels, suggesting that dioscorins suppressed the OVA-induced allergic reactions, possibly through modulating an imbalanced Th1/Th2 immune response.
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A Double-Blind Randomized Controlled Study to Evaluate the Efficacy of Low-Dose Oral Interferon-Alpha in Preventing Hepatitis C Relapse.
J. Interferon Cytokine Res.
PUBLISHED: 11-15-2013
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Low-dose oral interferon could exert immune-modulating effects in human. We conducted a clinical trial to investigate the efficacy of oral interferon-alpha in preventing hepatitis C relapse. Totally 169 genotype 1b chronic hepatitis C patients having achieved end-of-therapy virological clearance were randomized to receive interferon-alpha lozenge 500?IU/day (n=59), 1,500?IU/day (n=53), or placebo (n=57) for 24 weeks. Overall, no significant differences were found for the relapse rates in the 3 groups (P>0.05). However, in patients with fibroindex 1.4-1.7, relapse occurred in 1/12 (8.3%) 500?IU-group patients versus 9/21 (42.9%) patients of the other groups (P=0.05). In 158 patients receiving at least 4 weeks of oral interferon, significantly higher platelet count was found at the end of trial in the 500?IU group (P=0.003). In thrombocytopenic patients, a significantly expedited recovery of platelet count was found in the 500?IU group (P=0.002). No drug-related severe adverse events were reported. In conclusion, at 500?IU/day, oral interferon exerted a borderline suppression effect of virological relapse in chronic hepatitis C patients with mild liver fibrosis. Additionally, it significantly expedited platelet count recovery after the end of peginterferon therapy.
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Integrative transcriptome sequencing identifies trans-splicing events with important roles in human embryonic stem cell pluripotency.
Genome Res.
PUBLISHED: 10-16-2013
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Trans-splicing is a post-transcriptional event that joins exons from separate pre-mRNAs. Detection of trans-splicing is usually severely hampered by experimental artifacts and genetic rearrangements. Here, we develop a new computational pipeline, TSscan, which integrates different types of high-throughput long-/short-read transcriptome sequencing of different human embryonic stem cell (hESC) lines to effectively minimize false positives while detecting trans-splicing. Combining TSscan screening with multiple experimental validation steps revealed that most chimeric RNA products were platform-dependent experimental artifacts of RNA sequencing. We successfully identified and confirmed four trans-spliced RNAs, including the first reported trans-spliced large intergenic noncoding RNA ("tsRMST"). We showed that these trans-spliced RNAs were all highly expressed in human pluripotent stem cells and differentially expressed during hESC differentiation. Our results further indicated that tsRMST can contribute to pluripotency maintenance of hESCs by suppressing lineage-specific gene expression through the recruitment of NANOG and the PRC2 complex factor, SUZ12. Taken together, our findings provide important insights into the role of trans-splicing in pluripotency maintenance of hESCs and help to facilitate future studies into trans-splicing, opening up this important but understudied class of post-transcriptional events for comprehensive characterization.
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Endobronchial ultrasound-guided transbronchial biopsy and brushing: a comparative evaluation for the diagnosis of peripheral pulmonary lesions.
Eur J Cardiothorac Surg
PUBLISHED: 09-27-2013
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The diagnosis of peripheral pulmonary lesions (PPLs) often involves endobronchial ultrasound (EBUS)-guided transbronchial biopsy (TBB), washing and brushing. Certain echoic features of PPL have been associated with biopsy yield. This study compared yields of TBB and bronchial washing (TBBW) with those of TBBW plus bronchial brushing and analysed the associations between clinical and echoic features and yield.
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Chronic cough and obstructive sleep apnoea in a sleep laboratory-based pulmonary practice.
Cough
PUBLISHED: 08-03-2013
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Obstructive sleep apnoea (OSA) has recently been identified as a possible aetiology for chronic cough. The aim of this study was to compare the incidence of chronic cough between patients with and without OSA and the impact of continuous positive airway pressure (CPAP) treatment in resolving chronic cough.
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Donor-Derived Cryptococcus Infection in Liver Transplant: Case Report and Literature Review.
Exp Clin Transplant
PUBLISHED: 07-30-2013
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Cryptococcosis occurring within 30 days after transplant is unusual. We present a case of cryptococcosis diagnosed within 2 weeks of liver transplant and cryptococcal infection transmitted by liver transplant is considered as the cause. A 63-year-old woman with hepatitis C virus-related cirrhosis and hepatocellular carcinoma had an orthotopic liver transplant from a 45-year-old donor. The immediate postoperative course was smooth, although she was confused with a fever, tachycardia, respiratory failure of 1 weeks duration after the orthotopic liver transplant. A liver biopsy was performed for hyperbilirubinemia 2 weeks after the orthotopic liver transplant that showed a Cryptococcus-like yeast. Her blood culture was re-examined, and it was confirmed as Cryptococcus neoformans that had been misinterpreted as candida initially. At the time of the re-examination, her sputum was clear. We checked her preoperative blood sample, retrospectively, for serum cryptococcal antigen with negative result. She was on liposomal amphotericin treatment for 1 month when her blood culture became negative. She was discharged home, with good liver function and a low antigen titer for cryptococcal infection. Cryptococcal disease usually develops at a mean of 5.6 months after transplant. However an early occurrence is rare. Apart from that, its variable clinical presentations make early detection difficult. It might be an early reactivation or a donor-derived infection. The latter usually occurs in unusual sites (eg, the transplanted organ as the sole site of involvement). Our case presented as cryptococcoma and liver involvement was diagnosed by an unintentional liver biopsy.
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Comparison of metabolic capacities and inference of gene content evolution in mosquito-associated Spiroplasma diminutum and S. taiwanense.
Genome Biol Evol
PUBLISHED: 07-23-2013
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Mosquitoes are hosts of several Spiroplasma species that belong to different serogroups. To investigate the genetic mechanisms that may be involved in the utilization of similar hosts in these phylogenetically distinct bacteria, we determined the complete genome sequences of Spiroplasma diminutum and S. taiwanense for comparative analysis. The genome alignment indicates that their chromosomal organization is highly conserved, which is in sharp contrast to the elevated genome instabilities observed in other Spiroplasma lineages. Examination of the substrate utilization strategies revealed that S. diminutum can use a wide range of carbohydrates, suggesting that it is well suited to living in the gut (and possibly the circulatory system) of its mosquito hosts. In comparison, S. taiwanense has lost several carbohydrate utilization genes and acquired additional sets of oligopeptide transporter genes through tandem duplications, suggesting that proteins from digested blood meal or lysed host cells may be an important nutrient source. Moreover, one glycerol-3-phosphate oxidase gene (glpO) was found in S. taiwanense but not S. diminutum. This gene is linked to the production of reactive oxygen species and has been shown to be a major virulence factor in Mycoplasma mycoides. This finding may explain the pathogenicity of S. taiwanense observed in previous artificial infection experiments, while no apparent effect was found for S. diminutum. To infer the gene content evolution at deeper divergence levels, we incorporated other Mollicutes genomes for comparative analyses. The results suggest that the losses of biosynthetic pathways are a recurrent theme in these host-associated bacteria.
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Solid lipid nanoparticles carrying chemotherapeutic drug across the blood-brain barrier through insulin receptor-mediated pathway.
J Drug Target
PUBLISHED: 07-01-2013
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Carmustine (BCNU)-loaded solid lipid nanoparticles (SLNs) were grafted with 83-14 monoclonal antibody (MAb) (83-14 MAb/BCNU-SLNs) and applied to the brain-targeting delivery. Human brain-microvascular endothelial cells (HBMECs) incubated with 83-14 MAb/BCNU-SLNs were stained to demonstrate the interaction between the nanocarriers and expressed insulin receptors (IRs). The results revealed that the particle size of 83-14 MAb/BCNU-SLNs decreased with an increasing weight percentage of Dynasan 114 (DYN). Storage at 4?°C for 6 weeks slightly deformed the colloidal morphology. In addition, poloxamer 407 on 83-14 MAb/BCNU-SLNs induced cytotoxicity to RAW264.7 cells and inhibited phagocytosis by RAW264.7 cells. An increase in the weight percentage of DYN from 0% to 67% slightly reduced the viability of RAW264.7 cells and promoted phagocytosis. Moreover, the transport ability of 83-14 MAb/BCNU-SLNs across the blood-brain barrier (BBB) in vitro enhanced with an increasing weight percentage of Tween 80. 83-14 MAb on MAb/BCNU-SLNs stimulated endocytosis by HBMECs via IRs and enhanced the permeability of BCNU across the BBB. 83-14 MAb/BCNU-SLNs can be a promising antitumor drug delivery system for transporting BCNU to the brain.
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Polybutylcyanoacrylate nanoparticles for delivering hormone response element-conjugated neurotrophin-3 to the brain of intracerebral hemorrhagic rats.
Biomaterials
PUBLISHED: 06-29-2013
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Hypertensive intracerebral hemorrhage (ICH) is a rapidly evolutional pathology, inducing necrotic cell death followed by apoptosis, and alters gene expression levels in surrounding tissue of an injured brain. For ICH therapy by controlled gene release, the development of intravenously administrable delivery vectors to promote the penetration across the blood-brain barrier (BBB) is a critical challenge. To enhance transfer efficiency of genetic materials under hypoxic conditions, polybutylcyanoacrylate (PBCA) nanoparticles (NPs) were used to mediate the intracellular transport of plasmid neurotrophin-3 (NT-3) containing hormone response element (HRE) with a cytomegalovirus (cmv) promoter and to differentiate induced pluripotent stem cells (iPSCs). The differentiation ability of iPSCs to neurons was justified by various immunological stains for protein fluorescence. The effect of PBCA NP/cmvNT-3-HRE complexes on treating ICH rats was studied by immunostaining, western blotting and Nissl staining. We found that the treatments with PBCA NP/cmvNT-3-HRE complexes increased the capability of differentiating iPSCs to express NT-3, TrkC and MAP-2. Moreover, PBCA NPs could protect cmvNT-3-HRE against degradation with EcoRI/PstI and DNase I in vitro and raise the delivery across the BBB in vivo. The administration of PBCA NP/cmvNT-3-HRE complexes increased the expression of NT-3, inhibited the expression of apoptosis-inducing factor, cleaved caspase-3 and DNA fragmentation, and reduced the cell death rate after ICH in vivo. PBCA NPs are demonstrated as an appropriate delivery system for carrying cmvNT-3-HRE to the brain for ICH therapy.
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Viral load and alanine aminotransferase correlate with serologic response in chronic hepatitis B patients treated with entecavir.
J. Gastroenterol. Hepatol.
PUBLISHED: 06-29-2013
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Although entecavir has been shown to have good efficacy and low resistance for the treatment of chronic hepatitis B (CHB), factors associated with a favorable response remain unknown.
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LHX2 regulates the neural differentiation of human embryonic stem cells via transcriptional modulation of PAX6 and CER1.
Nucleic Acids Res.
PUBLISHED: 06-26-2013
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The LIM homeobox 2 transcription factor Lhx2 is known to control crucial aspects of neural development in various species. However, its function in human neural development is still elusive. Here, we demonstrate that LHX2 plays a critical role in human neural differentiation, using human embryonic stem cells (hESCs) as a model. In hESC-derived neural progenitors (hESC-NPs), LHX2 was found to be expressed before PAX6, and co-expressed with early neural markers. Conditional ectopic expression of LHX2 promoted neural differentiation, whereas disruption of LHX2 expression in hESCs significantly impaired neural differentiation. Furthermore, we have demonstrated that LHX2 regulates neural differentiation at two levels: first, it promotes expression of PAX6 by binding to its active enhancers, and second, it attenuates BMP and WNT signaling by promoting expression of the BMP and WNT antagonist Cerberus 1 gene (CER1), to inhibit non-neural differentiation. These findings indicate that LHX2 regulates the transcription of downstream intrinsic and extrinsic molecules that are essential for early neural differentiation in human.
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Horizontal transfer of potential mobile units in phytoplasmas.
Mob Genet Elements
PUBLISHED: 06-19-2013
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Phytoplasmas are uncultivated phytopathogenic bacteria that cause diseases in a wide range of economically important plants. Through secretion of effector proteins, they are able to manipulate their plant hosts to facilitate their multiplication and dispersal by insect vectors. The genome sequences of several phytoplasmas have been characterized to date and a group of putative composite transposons called potential mobile units (PMUs) are found in these highly reduced genomes. Recently, our team reported the genome sequence and comparative analysis of a peanut witches broom (PnWB) phytoplasma, the first representative of the phytoplasma 16SrII group. Comparisons between the species phylogeny and the phylogenies of the PMU genes revealed that the PnWB PMU is likely to have been transferred from the 16SrI group. This indicates that PMUs are not only the DNA unit for transposition within a genome, but also for horizontal transfer among divergent phytoplasma lineages. Given the association of PMUs with effector genes, the mobility of PMUs across genomes has important implications for phytoplasma ecology and evolution.
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MiRNA targets of prostate cancer.
Methods Mol. Biol.
PUBLISHED: 06-15-2013
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Prostate cancer (PC) is the most prevalent strain of cancer in men, but it is often slow-acting or undetected. Common diagnostic tools for PC include prostate biopsy and consequent analysis by the Gleason scoring of the tissue samples, as well as tests for the presence and levels of prostate-specific antigens. Common treatments for androgen-dependent PC include prostatectomy or irradiation, which can be invasive and significantly lower the patients quality of life. Alternative treatments exist, such as androgen ablation therapy, which, though effective, causes relapse into androgen-independent PC, which is far more invasive and likely to metastasize to other parts of the body. MicroRNAs (miRNA) are short nucleotide sequences (between 19 and 25 nucleotides long) that bind to various targeted messenger RNA (mRNA) sequences post-transcriptionally through complementary binding and control gene expression, often through silencing or leading to the degradation of targeted mRNA. Studies have shown that miRNAs are expressed abnormally in various cancers, suggesting that they play a pivotal role in cancer development and progression. Some miRNAs are oncogenes that incite cancerous growth, while others are involved in tumor suppression and cell cycle controls. MiRNA expression also differs in various types of cancers. Studies of PC-specific miRNAs show potential for their utilization in the prevention, diagnosis, and treatment of PC to more effectively target tumor growth and provide patients with better therapeutic options.
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Identify intronic microRNA with bioinformatics.
Methods Mol. Biol.
PUBLISHED: 06-15-2013
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MicroRNAs (miRNAs) are single-strand nonprotein coding RAN with 18 to 25-nucleotides long. With complementary sequence to target messenger RNA (mRNA), miRNA regulates mRNA degradation and protein translation. miRNAs have been identified in various organisms ranging from virus to human. Increasing evidence indicates that mammalian gene regulation has multiple layers and the availability of mRNA is not the sole regulation mechanism. The evolutionally conserved miRNA may be a primary regulation mechanism of gene expression. Its role in directing embryo development and stem cell differentiation should not be underestimated.Due to the small size of miRNA, identifying it with experimental approach (e.g., direct cloning) is difficult. The cell type and developmental-specific expression of miRNA make the experimental approach even more difficult. Consequently, bioinformatics approaches have been developed to identify novel miRNA. In human miRNA study, many studies search for the mostly complete human genomic sequence. Here, we report a rapid bioinformatics approach to mine miRNA from gene specific introns. Intronic miRNA may directly regulate the expression of its target genes during development. The reported bioinformatics approach not only identifies the potential miRNA, but also provides the intron location of these miRNA like sequence. This information is critical for studying the gene-gene interaction via miRNA, and facilitates the study of miRNA in gene expression regulation.
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MicroRNA-mediated somatic cell reprogramming.
J. Cell. Biochem.
PUBLISHED: 06-05-2013
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Since the first report of induced pluripotent stem cells (iPSCs) using somatic cell nuclear transfer (SCNT), much focus has been placed on iPSCs due to their great therapeutic potential for diseases such as abnormal development, degenerative disorders, and even cancers. Subsequently, Takahashi and Yamanaka took a novel approach by using four defined transcription factors to generate iPSCs in mice and human fibroblast cells. Scientists have since been trying to refine or develop better approaches to reprogramming, either by using different combinations of transcription factors or delivery methods. However, recent reports showed that the microRNA expression pattern plays a crucial role in somatic cell reprogramming and ectopic introduction of embryonic stem cell-specific microRNAs revert cells back to an ESC-like state, although, the exact mechanism underlying this effect remains unclear. This review describes recent work that has focused on microRNA-mediated approaches to somatic cell reprogramming as well as some of the pros and cons to these approaches and a possible mechanism of action. Based on the pivotal role of microRNAs in embryogenesis and somatic cell reprogramming, studies in this area must continue in order to gain a better understanding of the role of microRNAs in stem cells regulation and activity.
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HBV-DNA level at 6 months of entecavir treatment predicts HBeAg loss in HBeAg-positive chronic hepatitis B patients.
J. Formos. Med. Assoc.
PUBLISHED: 06-01-2013
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To evaluate whether on-treatment HBV-DNA level could predict the treatment response to entecavir in hepatitis B e antigen (HBe)-positive chronic hepatitis B (CHB) patients.
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Complete genomes of two dipteran-associated spiroplasmas provided insights into the origin, dynamics, and impacts of viral invasion in spiroplasma.
Genome Biol Evol
PUBLISHED: 05-29-2013
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Spiroplasma is a genus of wall-less, low-GC, Gram-positive bacteria with helical morphology. As commensals or pathogens of plants, insects, ticks, or crustaceans, they are closely related with mycoplasmas and form a monophyletic group (Spiroplasma-Entomoplasmataceae-Mycoides) with Mycoplasma mycoides and its relatives. In this study, we report the complete genome sequences of Spiroplasma chrysopicola and S. syrphidicola from the Chrysopicola clade. These species form the sister group to the Citri clade, which includes several well-known pathogenic spiroplasmas. Surprisingly, these two newly available genomes from the Chrysopicola clade contain no plectroviral genes, which were found to be highly repetitive in the previously sequenced genomes from the Citri clade. Based on the genome alignment and patterns of GC-skew, these two Chrysopicola genomes appear to be relatively stable, rather than being highly rearranged as those from the Citri clade. Phylogenetic analyses suggest that the susceptibility to plectroviral invasion probably originated in the common ancestor of the Citri clade or one of its subclades. This susceptibility may be attributed to the absence of antiviral systems found in the Chrysopicola clade. Using the virus-free genomes of the Chrysopicola clade as references, we inferred the putative viral integration sites in the Citri genomes. Comparisons of syntenic regions suggest that the extensive viral invasion in the Citri clade promoted genome rearrangements and expansions. More importantly, the viral invasion may have facilitated horizontal gene transfers that contributed to adaptation in the Citri clade.
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Cationic solid lipid nanoparticles with cholesterol-mediated surface layer for transporting saquinavir to the brain.
Biotechnol. Prog.
PUBLISHED: 05-27-2013
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Cholesterol-mediated cationic solid lipid nanoparticles (CSLNs) were formulated with esterquat 1 (EQ 1) and stearylamine as positively charged external layers on hydrophobic internal cores of cacao butter. These CSLNs were employed to deliver saquinavir (SQV) to the brain. The permeability of SQV across the blood-brain barrier (BBB) using SQV-loaded CSLNs (SQV-CSLNs) was estimated with an in vitro model of a monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes. The results revealed that the average diameter of SQV-CSLNs diminished when the weight percentage of cholesterol and EQ 1 increased. The morphological images indicated a uniform size of SQV-CSLNs with compact lipid structure. In addition, an increasing weight percentage of cholesterol and EQ 1 enhanced the zeta potential of SQV-CSLNs. The fluorescent staining demonstrated that HBMECs could internalize SQV-CSLNs. An increase in the weight percentage of cholesterol and EQ 1 also promoted the uptake of SQV-CSLNs by HBMECs. Moreover, a high content of cholesterol and EQ 1 in SQV-CSLNs increased the BBB permeability of SQV. The cholesterol-mediated SQV-CSLNs can be an efficacious drug delivery system for brain-targeting delivery of antiviral agents. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 2013.
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SOCS-1 promoter methylation and treatment response in chronic hepatitis C patients receiving pegylated-interferon/ribavirin.
J. Clin. Immunol.
PUBLISHED: 05-02-2013
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Suppressor of cytokine signaling-1 (SOCS-1) is a negative regulator of the Janus kinase/signal transducer and activation of transcription pathway. The purpose of this study was to investigate the relationship between methylation of SOCS-1 and sustained virologic response (SVR) in chronic hepatitis C (CHC) patients treated with pegylated interferon (PEG-IFN)-alpha and ribavirin (RBV).
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Complete Genome Sequence of Serratia marcescens WW4.
Genome Announc
PUBLISHED: 04-06-2013
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Serratia marcescens WW4 is a biofilm-forming bacterium isolated from paper machine aggregates. Under conditions of phosphate limitation, this bacterium exhibits intergeneric inhibition of Pseudomonas aeruginosa. Here, the complete genome sequence of S. marcescens WW4, which consists of one circular chromosome (5,241,455 bp) and one plasmid (pSmWW4; 3,248 bp), was determined.
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Polybutylcyanoacrylate nanoparticle-mediated neurotrophin-3 gene delivery for differentiating iPS cells into neurons.
Biomaterials
PUBLISHED: 02-27-2013
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Guided neuronal differentiation of induced pluripotent stem cells (iPSCs) with genetic regulation is an important issue in biomedical research and in clinical practice for nervous regeneration and repair. To enhance the intracellular delivery of plasmid DNA (pDNA), polybutylcyanoacrylate (PBCA) nanoparticles (NPs) were employed to mediate the transport of neurotrophin-3 (NT-3) into iPSCs. The ability of iPSCs to differentiate into neuronal lineages was shown by immunofluorescent staining, western blotting, and flow cytometry. By transmission electron microscopy, we found that PBCA NPs could efficiently grasp pDNA, thereby increasing the particle size and conferring a negative surface charge. In addition, the treatments with PBCA NP/NT-3 complexes enhanced the expression of NT-3, TrkC, NH-H, NSE, and PSD95 by differentiating iPSCs. Neurons produced from iPSCs were incapable of returning to pluripotency, demonstrating with a series of differentiation scheme for adipogenesis and osteogenesis. The pretreatment with PBCA NP/NT-3 complexes can be one of critical biotechnologies and effective delivery systems in gene transfection to accelerate the differentiation of iPSCs into neurons.
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Analysis of the gut microbiota of walking sticks (Phasmatodea).
BMC Res Notes
PUBLISHED: 02-20-2013
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Little is known about the Phasmatodea gut microbial community, including whether phasmids have symbiotic bacteria aiding in their digestion. While symbionts are near ubiquitous in herbivorous insects, the Phasmatodeas distinctively thin body shape precludes the gut enlargements needed for microbial fermentation. High-throughput sequencing was used to characterize the entire microbiota of the fat bodies, salivary glands, and anterior and posterior midguts of two species of walking stick.
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Meperidine as the single sedative agent during esophagogastroduodenoscopy, a double-blind, randomized, controlled study.
J. Gastroenterol. Hepatol.
PUBLISHED: 02-11-2013
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In Taiwan, unsedated esophagogastroduodenoscopy (EGD) is widely used, but it is uncomfortable for some patients. While meperidine has been adopted in colonoscopy, its use in EGD has not received extensive attention. This was a prospective study to investigate the use of meperidine as a single sedative agent during EGD.
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Effect of human leukocyte antigen class I and II alleles on hepatitis C viral load among chronic hepatitis C patients in Southern Taiwan.
Hum. Immunol.
PUBLISHED: 02-03-2013
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The viral load of hepatitis C virus (HCV) in chronic hepatitis C patients affects clinical outcomes and response to interferon treatment. Various factors may be involved in determining the viral load, including host genetic factors. The aim of this study was to investigate the relationship between HCV viral load and human leukocyte antigen (HLA) class I and class II alleles. One hundred and six HCV RNA positive subjects were enrolled, and viral load was measured. HLA-A, -B, -C, -DR, and -DQ loci were determined by sequence-based genotyping. Univariate analysis indicated that HLA-B(*)40 and HLA-C(*)07 alleles had significantly higher HCV RNA levels (P<0.05). Patients with the HLA-C(*)15 allele exhibited a trend toward a lower HCV viral load (P=0.06). After controlling for confounding factors, multivariate analysis revealed that only HLA-C(*)15 allele was identified as a significant determinant for HCV-RNA level (slope=-0.91, 95% CI: -1.58, -0.24; Holms P<0.01). Patients expressing the HLA-C(*)15 allele had significantly lower HCV RNA levels. HCV genotype 1 was significantly associated with high HCV RNA levels (P<0.05 by Mann-Whitney U test). In conclusion, HLA-C(*)15 is an important host immunogenetic factor with an inverse association to HCV viral load in CHC patients in Taiwan. HCV genotype 1 is the viral factor that associated with high viral load.
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Phosphate limitation induces the intergeneric inhibition of Pseudomonas aeruginosa by Serratia marcescens isolated from paper machines.
FEMS Microbiol. Ecol.
PUBLISHED: 01-31-2013
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Phosphate is an essential nutrient for heterotrophic bacteria, affecting bacterioplankton in aquatic ecosystems and bacteria in biofilms. However, the influence of phosphate limitation on bacterial competition and biofilm development in multispecies populations has received limited attention in existing studies. To address this issue, we isolated 13 adhesive bacteria from paper machine aggregates. Intergeneric inhibition of Pseudomonas aeruginosa WW5 by Serratia marcescens WW4 was identified under phosphate-limited conditions, but not in Luria-Bertani medium or M9 minimal medium. The viable numbers of the pure S. marcescens WW4 culture decreased over 3 days in the phosphate-limited medium; however, the mortality of S. marcescens WW4 was significantly reduced when it was co-cultured with P. aeruginosa WW5, which appeared to sustain the S. marcescens WW4 biofilm. In contrast, viable P. aeruginosa WW5 cells immediately declined in the phosphate-limited co-culture. To identify the genetic/inhibitory element(s) involved in this process, we inserted a mini-Tn5 mutant of S. marcescens WW4 that lacked inhibitory effect. The results showed that an endonuclease bacteriocin was involved in this intergeneric inhibition by S. marcescens WW4 under phosphate limitation. In conclusion, this study highlights the importance of nutrient limitation in bacterial interactions and provides a strong candidate gene for future functional characterisation.
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High mortality of pneumonia in cirrhotic patients with ascites.
BMC Gastroenterol
PUBLISHED: 01-28-2013
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Cirrhotic patients with ascites are prone to develop various infectious diseases. This study aimed to evaluate the occurrence and effect of major infectious diseases on the mortality of cirrhotic patients with ascites.
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Algorithmic approach by endobronchial ultrasound-guided transbronchial needle aspiration for isolated intrathoracic lymphadenopathy: A study in a tuberculosis-endemic country.
J. Formos. Med. Assoc.
PUBLISHED: 01-24-2013
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Isolated intrathoracic lymphadenopathy (IT-LAP) is clinically challenging because of the difficult anatomic location and wide range of associated diseases, including tuberculosis (TB). Although sampling via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for histopathology is a major development, there is still room for improvement. This study aimed to investigate an algorithmic approach driven by EBUS-TBNA and conventional bronchoscopy to streamline the management of IT-LAP.
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Role of flexible bronchoscopic cryotechnology in diagnosing endobronchial masses.
Ann. Thorac. Surg.
PUBLISHED: 01-24-2013
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Endobronchial masses obstruct the central airway, and cryotechnology is reportedly a feasible means of managing such masses. However, few reports have explored the role of cryotechnology in diagnosing endobronchial masses.
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The risk for bacterial endocarditis in cirrhotic patients: a population-based 3-year follow-up study.
Int. J. Infect. Dis.
PUBLISHED: 01-23-2013
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We noted only rare reports of cirrhotic patients with bacterial endocarditis (BE). There is insufficient data on the risk of BE in liver cirrhosis. This is the first national population-based study evaluating the risk of BE in cirrhotic patients.
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Comparative genome analysis of Spiroplasma melliferum IPMB4A, a honeybee-associated bacterium.
BMC Genomics
PUBLISHED: 01-16-2013
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The genus Spiroplasma contains a group of helical, motile, and wall-less bacteria in the class Mollicutes. Similar to other members of this class, such as the animal-pathogenic Mycoplasma and the plant-pathogenic Candidatus Phytoplasma, all characterized Spiroplasma species were found to be associated with eukaryotic hosts. While most of the Spiroplasma species appeared to be harmless commensals of insects, a small number of species have evolved pathogenicity toward various arthropods and plants. In this study, we isolated a novel strain of honeybee-associated S. melliferum and investigated its genetic composition and evolutionary history by whole-genome shotgun sequencing and comparative analysis with other Mollicutes genomes.
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Targeting delivery of saquinavir to the brain using 83-14 monoclonal antibody-grafted solid lipid nanoparticles.
Biomaterials
PUBLISHED: 01-09-2013
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83-14 monoclonal antibody (MAb) was modified on solid lipid nanoparticles (SLNs) to improve the brain-targeting delivery of saquinavir (SQV). The endocytosis of 83-14 MAb-grafted SQV-loaded SLNs (83-14 MAb/SQV-SLNs) into human brain-microvasscular endothelial cells (HBMECs) was studied by staining cell nuclei, insulin receptors, and drug carriers. An increase in the weight fraction of palmitic acid in lipid core enhanced the particle size, absolute value of zeta potential, and viability of HBMECs and reduced the entrapment efficiency and release rate of SQV. In addition, an increase in the weight fraction of poloxamer 407 in surfactant layer reduced the particle size, absolute value of zeta potential, phagocytosis by RAW246.7 cells, permeability across the blood-brain barrier (BBB), and uptake by HBMECs and enhanced the viability of HBMECs. Moreover, an increase in the concentration of surface 83-14 MAb enhanced the percentage of surface nitrogen, permeability across the BBB, and uptake by HBMECs and did not significantly vary the viability of HBMECs and phagocytosis by RAW264.7 cells. 83-14 MAb/SQV-SLNs can ameliorate the bioavailability characteristics of SQV, inhibit the lymphatic particle uptake, and promote the transport of SQV into brain endothelia.
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Effects of spike sorting error on the Granger causality index.
Neural Netw
PUBLISHED: 01-08-2013
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Accurately sorting individual neurons is a technical challenge and plays an important role in identifying information flow among neurons. Spike sorting errors are almost unavoidable and can roughly be divided into two types: false positives (FPs) and false negatives (FNs). This study investigates how FPs and FNs affect results of the Granger causality (GC) analysis, a powerful method for detecting causal interactions between time series signals. We derived an explicit formula based on a first order vector autoregressive model to analytically study the effects of FPs and FNs. The proposed formula was able to reveal the intrinsic properties of the GC, and was verified by simulation studies. The effects of FPs and FNs were further evaluated using real experimental data from the ventroposterior medial nucleus of the thalamus. Some practical suggestions for spike sorting are also provided in this paper.
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