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Find video protocols related to scientific articles indexed in Pubmed.
Congenital diseases and semaphorin signaling: Overview to date of the evidence linking them.
Congenit Anom (Kyoto)
PUBLISHED: 10-31-2014
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Semaphorins and their receptors, neuropilins and plexins, were initially characterized as a modulator of axonal guidance during development, but are now recognized as a regulator of a wide range of developmental events including morphogenesis and angiogenesis, and activities of the immune system. Owing to the development of next-generation sequencing technologies together with other useful DNA assays, it has also become clear that semaphorin signaling plays a crucial role in many congenital diseases such as retinal degeneration and congenital heart defects. This review summarizes the recent knowledge about the relationship between a variety of congenital diseases and semaphorin signaling.
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Successful curative resection of gallbladder cancer following S-1 chemotherapy: A case report and review of the literature.
Oncol Lett
PUBLISHED: 08-01-2014
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The symptoms of gallbladder cancer (GBC) are vague and non-specific. Therefore, GBC is often detected at an advanced or metastatic stage. The most effective treatment for GBC is surgical resection, however the majority of GBC cases are unresectable at the time of diagnosis. Therefore, numerous GBC patients undergo chemotherapy. This study reports the case of a 60-year-old female with GBC who underwent successful surgical curative resection following a single dose of the chemotherapeutic agent, S-1, twice daily for 4 weeks followed by a 14-day rest period for 36 months. S-1 is a novel orally administered drug composed of a combination of the 5-fluorouracil (5-FU) prodrug, tegafur, 5-chloro-2,4-dihydroxypyridine (CDHP) and oteracil potassium in a 1:0.4:1 molar concentration ratio. The focus of the present study was the candidate factors that affect the therapeutic efficacy of S-1-based chemotherapy. In particular, the gene expression involved in the S-1 metabolic pathway was investigated by assessing the intratumoral dihydropyrimidine dehydrogenase (DPD), thymidylate synthase (TS) and orotate phosphoribosyltransferase gene expression. The surgical specimen exhibited high intratumoral DPD gene expression levels compared with those observed in previously reported non S-1 responsive cases of biliary tract cancer. Due to the results obtained in the current study, we hypothesize that CDHP enhanced the antitumor efficacy of 5-FU by inhibiting the excess DPD protein produced by the tumor.
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Synergistic antitumor effect of a combination of paclitaxel and carboplatin with nobiletin from Citrus depressa on non-small-cell lung cancer cell lines.
Planta Med.
PUBLISHED: 03-31-2014
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Non-small-cell lung carcinomas do not sufficiently respond to cancer chemotherapeutic drugs. Combination effects of cancer chemotherapy drugs (paclitaxel and carboplatin) with nobiletin or powdered Shiikuwasha extract from Citrus depressa were examined by isobologram and combination index analyses. It was demonstrated that the combination generated a synergistic inhibitory effect against the proliferation of the human non-small-cell lung carcinoma cell lines A549 and H460 and that of the two chemotherapy drugs, paclitaxel was responsible for this synergistic effect. Furthermore, the percentage of apoptotic cells was decreased with increasing rates of nobiletin to paclitaxel and carboplatin. These findings were considered to be attributed to the ability of nobiletin to regulate cells in the G1 phase, which escaped cell death initiated by paclitaxel and carboplatin. An antitumor activity assay showed that this combination significantly suppressed the growth of subcutaneous A549 tumor xenografts in nude mice.
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Cyst infection of intraductal papillary mucinous neoplasms of the pancreas: management of a rare complication: report of 2 cases.
Pancreas
PUBLISHED: 03-14-2014
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The purpose of this study was to describe the cyst infection of intraductal papillary mucinous neoplasm in 2 patients. The patients were 62- and 74-year-old men. The initial symptom was acute febrile abdominal pain. Laboratory tests revealed severe infection (C-reactive protein concentrations were 23.3 µg/mL in patient 1 and 22.3 µg/mL in patient 2) and multilocular cystic masses (the diameters were 70 mm in patient 1 and 50 mm in patient 2) at the pancreatic head that involved peripancreatic vessels were demonstrated by computed tomography. Laboratory and radiographic findings were markedly improved by endoscopic transpapillary drainage. The enteric bacteria were detected in the drainage specimens. Curative resection was achieved, and histological findings indicated a carcinoma in situ in patient 1 and an invasive carcinoma in patient 2. Neither hyperamylasemia nor histological fat necrosis, frequently observed in acute pancreatitis, was evident. Both patients were free from recurrence after surgery (17 months in patient 1, and 18 months in patient 2). Cyst infection is an unknown complication of intraductal papillary mucinous neoplasm. Transpapillary drainage is highly recommended as an initial intervention. It is difficult to distinguish between cyst infection and unresectable invasive carcinoma with imaging modalities; however, surgical intervention after drainage may contribute to long-term survival.
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Brain endothelial cells control fertility through ovarian-steroid-dependent release of semaphorin 3A.
PLoS Biol.
PUBLISHED: 03-01-2014
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Neuropilin-1 (Nrp1) guides the development of the nervous and vascular systems, but its role in the mature brain remains to be explored. Here we report that the expression of the 65 kDa isoform of Sema3A, the ligand of Nrp1, by adult vascular endothelial cells, is regulated during the ovarian cycle and promotes axonal sprouting in hypothalamic neurons secreting gonadotropin-releasing hormone (GnRH), the neuropeptide controlling reproduction. Both the inhibition of Sema3A/Nrp1 signaling and the conditional deletion of Nrp1 in GnRH neurons counteract Sema3A-induced axonal sprouting. Furthermore, the localized intracerebral infusion of Nrp1- or Sema3A-neutralizing antibodies in vivo disrupts the ovarian cycle. Finally, the selective neutralization of endothelial-cell Sema3A signaling in adult Sema3aloxP/loxP mice by the intravenous injection of the recombinant TAT-Cre protein alters the amplitude of the preovulatory luteinizing hormone surge, likely by perturbing GnRH release into the hypothalamo-hypophyseal portal system. Our results identify a previously unknown function for 65 kDa Sema3A-Nrp1 signaling in the induction of axonal growth, and raise the possibility that endothelial cells actively participate in synaptic plasticity in specific functional domains of the adult central nervous system, thus controlling key physiological functions such as reproduction.
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Small-for-size syndrome in living-donor liver transplantation using a left lobe graft.
Surg. Today
PUBLISHED: 02-27-2014
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In living-donor liver transplantation with a left lobe graft, which can reduce the burden on the donor compared to right lobe graft, the main problem is small-for-size (SFS) syndrome. SFS syndrome is a multifactorial disease that includes aspects related to the graft size, graft quality, recipient factors and even technical issues. The main pathophysiology of SFS syndrome is the sinusoidal microcirculatory disturbance induced by shear stress, which is caused by excessive portal inflow into the smaller graft. The donor age, the presence of steatosis of the graft and a poor recipient status are all risk factors for SFS syndrome. To resolve SFS syndrome, portal inflow modulation, splenectomy, splenic artery modulation and outflow modulation have been developed. It is important to establish strict criteria for managing SFS syndrome. Using pharmacological interventions and/or therapeutic approaches that promote liver regeneration could increase the adequate outcomes in SFS liver transplantation. Left lobe liver transplantation could be adopted in Western countries to help resolve the organ shortage.
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[Anchor Fast endotracheal tube securing device for a pediatric patient during therapeutic hypothermia].
Masui
PUBLISHED: 02-25-2014
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A 5-year-old girl was admitted to our hospital after resuscitation from cardiac arrest due to near-drowning accident in a river. On admission, Glasgow Coma Scale score was 7; arterial blood pressure was 113/73 mm Hg; heart rate was 157 beats x min(-1), and percutaneous oxygen saturation was 99% on 10 l x min(-1) of oxygen. The patient was intubated with a 5.0 mm internal diameter endotracheal tube, and therapeutic hypothermia was started for neural protection. Hypothermia in the target temperature of 34 degrees C was maintained for 24 hours using Arctic Sun System. Although the patient had been sedated with fentanyl 0.6-1.2 microg x kg(-1) x hr(-1), midazolam 0.2-0.4 mg x kg(-1) x hr(-1) and dexmedetomidine 0.6-1.0 mirog x kg(-1) x hr(-1), agitation increased during the rewarming period following hypothermia. To avoid accidental extubation, we used Anchor Fast as a device for securing oral endotracheal tube. Anchor Fast kept the tube position properly even though the patient was turned or moved. Seventy-two hours later, she was rewarmed and extubated as scheduled. Ten days after admission, she was discharged without any neurological deficits.
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Versatile design of biohybrid light-harvesting architectures to tune location, density, and spectral coverage of attached synthetic chromophores for enhanced energy capture.
Photosyn. Res.
PUBLISHED: 02-22-2014
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Biohybrid antennas built upon chromophore-polypeptide conjugates show promise for the design of efficient light-capturing modules for specific purposes. Three new designs, each of which employs analogs of the ?-polypeptide from Rhodobacter sphaeroides, have been investigated. In the first design, amino acids at seven different positions on the polypeptide were individually substituted with cysteine, to which a synthetic chromophore (bacteriochlorin or Oregon Green) was covalently attached. The polypeptide positions are at -2, -6, -10, -14, -17, -21, and -34 relative to the 0-position of the histidine that coordinates bacteriochlorophyll a (BChl a). All chromophore-polypeptides readily formed LH1-type complexes upon combination with the ?-polypeptide and BChl a. Efficient energy transfer occurs from the attached chromophore to the circular array of 875 nm absorbing BChl a molecules (denoted B875). In the second design, use of two attachment sites (positions -10 and -21) on the polypeptide affords (1) double the density of chromophores per polypeptide and (2) a highly efficient energy-transfer relay from the chromophore at -21 to that at -10 and on to B875. In the third design, three spectrally distinct bacteriochlorin-polypeptides were prepared (each attached to cysteine at the -14 position) and combined in an ~1:1:1 mixture to form a heterogeneous mixture of LH1-type complexes with increased solar coverage and nearly quantitative energy transfer from each bacteriochlorin to B875. Collectively, the results illustrate the great latitude of the biohybrid approach for the design of diverse light-harvesting systems.
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Plexin-A4-dependent retrograde semaphorin 3A signalling regulates the dendritic localization of GluA2-containing AMPA receptors.
Nat Commun
PUBLISHED: 02-11-2014
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The dendritic targeting of neurotransmitter receptors is vital for dendritic development and function. However, how such localization is established remains unclear. Here we show that semaphorin 3A (Sema3A) signalling at the axonal growth cone is propagated towards the cell body by retrograde axonal transport and drives AMPA receptor GluA2 to the distal dendrites, which regulates dendritic development. Sema3A enhances glutamate receptor interacting protein 1-dependent localization of GluA2 in dendrites, which is blocked by knockdown of cytoplasmic dynein heavy chain. PlexinA (PlexA), a receptor component for Sema3A, interacts with GluA2 at the immunoglobulin-like Plexin-transcription-factor domain (PlexA-IPT) in somatodendritic regions. Overexpression of PlexA-IPT suppresses dendritic localization of GluA2 and induces aproximal bifurcation phenotype in the apical dendrites of CA1 hippocampal neurons. Thus, we propose a control mechanism by which retrograde Sema3A signalling regulates the glutamate receptor localization through trafficking of cis-interacting PlexA with GluA2 along dendrites.
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Photophysical properties and electronic structure of retinylidene-chlorin-chalcones and analogues.
Photochem. Photobiol. Sci.
PUBLISHED: 02-04-2014
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Synthetic chlorins can accommodate diverse substituents about the macrocycle perimeter. Simple auxochromes (e.g., vinyl, acetyl, phenyl) allow systematic tuning of spectral and photophysical features. More extensive spectral tailoring may be achieved by using more potent, highly conjugated substituents that themselves bring new absorption into a target spectral region, if deleterious excited-state quenching processes can be avoided. To explore such an expanded substituent space, herein the spectral and photophysical properties of four chlorin-chalcones are reported. The molecules are free base and zinc chlorins with substituents at the 13-position that include a chalcone and an extended chalcone derived by reaction of the 13-acetylchlorin with benzaldehyde and all-trans-retinal, respectively. Measurements of the spectral and photophysical properties (?f, ?s, kf, kic, kisc) are accompanied by density functional calculations that examine the characteristics of the frontier molecular orbitals. The chlorin-chalcones in nonpolar (toluene) and polar (dimethylsulfoxide) media exhibit bathochromically shifted (and intense) Qy absorption bands. The presence of the retinylidene group adds new absorption in the blue-green region where the chlorins are typically transparent; excitation in this region leads to quantitative formation of the chlorin Qy excited state. The spectral properties generally correlate with substituent effects on the frontier MOs. The four chlorin-chalcones in the solvent toluene have high fluorescence yields (0.24-0.30) and multi-nanosecond singlet excited-state lifetimes (3.7-8.4 ns), in addition to the added absorption imparted by the chalcone moiety. Collectively, the studies reported herein provide insight into the fundamental properties of chlorins and illustrate the utility of chalcones as a means of both tuning and augmenting the spectral properties of these chromophores.
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Sema3A chemorepellant regulates the timing and patterning of dental nerves during development of incisor tooth germ.
Cell Tissue Res.
PUBLISHED: 01-31-2014
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Semaphorin 3A (Sema3A) axon repellant serves multiple developmental functions. Sema3A mRNAs are expressed in epithelial and mesenchymal components of the developing incisor in a dynamic manner. Here, we investigate the functions of Sema3A during development of incisors using Sema3A-deficient mice. We analyze histomorphogenesis and innervation of mandibular incisors using immunohistochemistry as well as computed tomography and thick tissue confocal imaging. Whereas no apparent disturbances in histomorphogenesis or hard tissue formation of Sema3A (-/-) incisors were observed, nerve fibers were prematurely seen in the presumptive dental mesenchyme of the bud stage Sema3A (-/-) tooth germ. Later, nerves were ectopically present in the Sema3A (-/-) dental papilla mesenchyme during the cap and bell stages, whereas in the Sema3A (+/+) mice the first nerve fibers were seen in the pulp after the onset of dental hard tissue formation. However, no apparent topographic differences in innervation pattern or nerve fasciculation were seen inside the pulp between postnatal and adult Sema3A (+/+) or Sema3A (-/-) incisors. In contrast, an abnormally large number of nerves and arborizations were observed in the Sema3A (-/-) developing dental follicle target field and periodontium and, unlike in the wild-type mice, nerve fibers were abundant in the labial periodontium. Of note, the observed defects appeared to be mostly corrected in the adult incisors. The expressions of Ngf and Gdnf neurotrophins and their receptors were not altered in the Sema3A (-/-) postnatal incisor or trigeminal ganglion, respectively. Thus, Sema3A is an essential, locally produced chemorepellant, which by creating mesenchymal exclusion areas, regulates the timing and patterning of the dental nerves during the development of incisor tooth germ.
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Bio-imaging of hydroxyl radicals in plant cells using the fluorescent molecular probe rhodamine B hydrazide, without any pretreatment.
J. Biosci. Bioeng.
PUBLISHED: 01-31-2014
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Rhodamine B hydrazide can be used to detect hydroxyl radicals in plant cells. RBH was easily inserted into plant cells without any pretreatment, and specifically reacted with intracellular hydroxyl radicals produced by antimycin A. RBH will be a powerful tool for detecting hydroxyl radicals in plant cells.
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Statistical considerations on the formation of circular photosynthetic light-harvesting complexes from Rhodopseudomonas palustris.
Photosyn. Res.
PUBLISHED: 01-15-2014
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Depending on growth conditions, some species of purple photosynthetic bacteria contain peripheral light-harvesting (LH2) complexes that are heterogeneous owing to the presence of different protomers (containing different ??-apoproteins). Recent spectroscopic studies of Rhodopseudomonas palustris grown under low-light conditions suggest the presence of a C 3-symmetric LH2 nonamer comprised of two distinct protomers. The software program Cyclaplex, which enables generation and data-mining of virtual libraries of molecular rings formed upon combinatorial reactions, has been used to delineate the possible number and type of distinct nonamers as a function of numbers of distinct protomers. The yield of the C 3-symmetric nonamer from two protomers (A and B in varying ratios) has been studied under the following conditions: (1) statistical, (2) enriched (preclusion of the B-B sequence), and (3) seeded (pre-formation of an A-B-A block). The yield of C 3-symmetric nonamer is at most 0.98 % under statistical conditions versus 5.6 % under enriched conditions, and can be dominant under conditions of pre-seeding with an A-B-A block. In summary, the formation of any one specific nonamer even from only two protomers is unlikely on statistical grounds but must stem from enhanced free energy of formation or a directed assembly process by as-yet unknown factors.
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Central Venous Access via External Jugular Vein with CT-Venography Using a Multidetector Helical 16-Section CT.
J Invest Surg
PUBLISHED: 12-19-2013
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ABSTRACT Objective: To determine the success rate and complications of using the external jugular vein (EJV) for central venous access with a preoperative estimate of the detailed anatomical orientation of the cervical venous plexus using computed tomography venography (CT-V). Design: Prospective, observational human study. Setting: Surgical intensive care unit. Patients: Fifty-two patients who were undergoing EJV cannulations with CT-V using a Multidetector Helical 16-section CT (MDCT). Intervention: The preoperative anatomical estimation of the cervical venous plexus was performed with CT-V using an MDCT. In particular, the angulation between the EJV and the right subclavian vein (SCV) was measured. The anatomical abnormalities and the angulation between the EJV and the anterior jugular vein (AJV), transverse cervical vein (TCV), and suprascapular vein (SSV) were estimated. Measurements and Main Results: The success of CT-V was achieved in 52 of 52 patients (100%). The mean angulation between the right EJV and the right SCV was 144 ± 36 degrees in the obtuse-angle cases (88%) and 72 ± 28 degrees in the sharp-angle cases (12%). A plexus of veins under the clavicle was most commonly responsible for insertion of the central venous catheter (CVC). The EJV approach resulted in a 93% rate of successful cannulations. No complications of pneumothorax or carotid artery puncture occurred during insertion procedures. Conclusions: The EJV route is associated with comparable technical success and lower major procedural complication. The EJV approach with CT-V guidance is an option as the initial method when central venous cannulation must be performed under suboptimal conditions.
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[Long-term survival of a patient with advanced colon cancer and para-aortic lymph node metastases treated with re-administration of high-dose molecular targeted agent bevacizumab].
Gan To Kagaku Ryoho
PUBLISHED: 11-08-2013
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A 49-year-old woman was admitted to our hospital because of epigastralgia and abdominal distension. She was diagnosed as advanced colon cancer with para-aortic and common iliac lymph node metastases, without liver and lung metastasis. Extended right hemicolectomy was performed to remove symptoms of stenosis. Bevacizumab (BV) (5 mg/kg) + mFOLFOX6 was performed as the initial postoperative chemotherapy. The tumor marker CEA, CA19-9 decreased, and reduction in the size of distant lymph node metastasis was confirmed, which obtained PR. In July 2009, computed tomography revealed the right pulmonary hilar lymph node metastases and progressive disease was confirmed; therefore, cetuximab and FOLFIRI combination therapy was initiated. However, in October 2009, bilateral inguinal lymph node metastases was seen; therefore we changed chemotherapy to BV (10 mg/kg) and FOLFIRI. Although the abdominal lymph node was decreased slightly after 2 months, chemotherapy was changed to BV (10 mg/kg) and mFOLFOX6 since the inguinal lymph node had enlarged. Skin metastases appeared, and there was no change in the inguinal lymph node and abdominal lymph node. She was deceased due to peritonitis carcinomatosis; however, her survival time exceeded 30 months. There was a possibility that long-term survival could be obtained by increasing the quantity of BV and re-administering it in second-line chemotherapy after PD in BV + FOLFOX first-line chemotherapy.
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Synthesis and photophysical properties of chlorins bearing 0-4 distinct meso-substituents.
Photochem. Photobiol. Sci.
PUBLISHED: 09-24-2013
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The presence of substituents at designated sites about the chlorin macrocycle can alter the spectral properties, a phenomenon that can be probed through synthesis. Prior syntheses have provided access to chlorins bearing distinct aryl substituents (individually or collectively) at the 5, 10, and 15-positions, but not the 20-position. A new Western half (5-phenyl-2,3,4,5-tetrahydro-1,3,3-trimethyldipyrrin) has been employed in condensation with an Eastern half (9-bromodipyrromethane-1-carboxaldehyde) followed by oxidative cyclization to give (5% yield) the zinc(II) 20-phenylchlorin. Condensation of the same Western half and a diaryl-substituted Eastern half provided (11% yield) the zinc(II) 5,10,20-triarylchlorin; demetalation with TFA followed by 15-bromination and Suzuki coupling gave the free base 5,10,15,20-tetraarylchlorin. Altogether, 10 new synthetic chlorins have been prepared. The near-UV (B) absorption band of the free base chlorins shifts bathochromically from 389 to 429 nm and that for the zinc chlorins from 398 to 420 nm as the number of meso-aryl rings is increased stepwise from 0-4. The long-wavelength (Q(y)) absorption band undergoes a bathochromic and hypochromic shift upon increase in number of meso-aryl groups. Regardless of the number and positions of the meso-aryl substituents (including "walking a phenyl group around the ring"), the respective fluorescence quantum yields (0.17 to 0.27) and singlet excited-state lifetimes (9.4 to 13.1 ns) are comparable among the free base chlorins and the same is true for the zinc chelates (0.057 to 0.080; 1.2 to 1.6 ns). Density functional theory calculations show that of the frontier molecular orbitals of the chlorin, the energy of the HOMO-1 is the most affected by meso-aryl substituents, undergoing progressive destabilization as the number of meso-aryl groups is increased. The availability of chlorins with 0-4 distinct meso-aryl substituents provides the individual stepping-stones to bridge the known unsubstituted chlorin and the meso-tetraarylchlorins.
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[Nasal high-flow therapy in a patient with postanesthetic hypoxia after tracheal extubation].
Masui
PUBLISHED: 08-30-2013
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A 63-year-old female with obesity (body mass index of 32.0 kg x m(-2)) was scheduled for total abdominal hysterectomy under combined epidural general anesthesia. The surgical procedure was completed without any troubles. Immediately after tracheal extubation, however, the patient developed acute respiratory distress, and the percutaneous oxygen saturation (Spo2) decreased from 97 to 44% for 1 minute. When the patient was admitted to our intensive care unit due to hypoxia, arterial blood gas values showed pH 7.37, Paco2 40.4 mmHg, Pao2 67.5 mmHg, and Spo2 94% on 5 l x min(-1) of oxygen via face mask. Her respiratory rate was 23 breaths x min(-1). We used a nasal high-flow humidified oxygen system (Optiflow) to improve oxygenation. We set the initial flow rate at 35 l x min(-1) with 50% oxygen. One hour after initiating the nasal high-flow system, the patients respiratory rate fell to 18 breaths x min(-1), and Spo2 rose up to 98%. Arterial blood gas showed improved Pao2 of 98.0 mmHg. Nasal high-flow therapy was useful to avoid intubation in a patient with postanesthetic respiratory failure.
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Enumeration of virtual libraries of combinatorial modular macrocyclic (bracelet, necklace) architectures and their linear counterparts.
J Chem Inf Model
PUBLISHED: 08-15-2013
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A wide variety of cyclic molecular architectures are built of modular subunits and can be formed combinatorially. The mathematics for enumeration of such objects is well-developed yet lacks key features of importance in chemistry, such as specifying (i) the structures of individual members among a set of isomers, (ii) the distribution (i.e., relative amounts) of products, and (iii) the effect of nonequal ratios of reacting monomers on the product distribution. Here, a software program (Cyclaplex) has been developed to determine the number, identity (including isomers), and relative amounts of linear and cyclic architectures from a given number and ratio of reacting monomers. The program includes both mathematical formulas and generative algorithms for enumeration; the latter go beyond the former to provide desired molecular-relevant information and data-mining features. The program is equipped to enumerate four types of architectures: (i) linear architectures with directionality (macroscopic equivalent = electrical extension cords), (ii) linear architectures without directionality (batons), (iii) cyclic architectures with directionality (necklaces), and (iv) cyclic architectures without directionality (bracelets). The program can be applied to cyclic peptides, cycloveratrylenes, cyclens, calixarenes, cyclodextrins, crown ethers, cucurbiturils, annulenes, expanded meso-substituted porphyrin(ogen)s, and diverse supramolecular (e.g., protein) assemblies. The size of accessible architectures encompasses up to 12 modular subunits derived from 12 reacting monomers or larger architectures (e.g. 13-17 subunits) from fewer types of monomers (e.g. 2-4). A particular application concerns understanding the possible heterogeneity of (natural or biohybrid) photosynthetic light-harvesting oligomers (cyclic, linear) formed from distinct peptide subunits.
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Computed Tomography (CT) Venography Using a Multidetector CT Prior to the Percutaneous External Jugular Vein Approach for an Implantable Venous-Access Port.
Ann. Surg. Oncol.
PUBLISHED: 08-12-2013
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The objective of this study was to determine the success rate and complications of using the percutaneous approach of the external jugular vein (EJV) for placement of a totally implantable venous-access port (TIVAP) with a preoperative estimate of the detailed anatomical orientation of the cervical venous plexus using computed tomography venography (CT-V).
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Sinodielide A exerts thermosensitizing effects and induces apoptosis and G2/M cell cycle arrest in DU145 human prostate cancer cells via the Ras/Raf/MAPK and PI3K/Akt signaling pathways.
Int. J. Mol. Med.
PUBLISHED: 07-27-2013
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Sinodielide A (SA) is a naturally occurring guaianolide, which is isolated from the root of Sinodielsia yunnanensis. This root, commonly found in Yunnan province, is used in traditional Chinese medicine as an antipyretic, analgesic and diaphoretic agent. A number of studies have reported that agents isolated from a species of Umbelliferae (Apiaceae) have antitumor activities. We previously reported, using combined treatments with this medicinal herb and hyperthermia at various temperatures, an enhanced cytotoxicity in the human prostate cancer androgen?independent cell lines, PC3 and DU145, and analyzed the related mechanisms. In the present study, we investigated the effects of treatment with SA prior to hyperthermia on the thermosensitivity of DU145 cells, and the mechanisms related to the induction of apoptosis and G2/M cell cycle arrest via the activation of extracellular-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) signaling pathways, as well as the phosphoinositide 3-kinase (PI3K)/Akt signaling pathways. Cells were exposed to hyperthermia alone (40-44?C) or hyperthermia in combination with SA. Lethal damage to cells treated with mild hyperthermia (40 or 42?C) for up to 6 h was slight; however, hyperthermia in combination with SA synergistically enhanced thermosensivity. Lethal damage to cells treated with acute hyperthermia (43 or 44?C) was more severe, but these effects were also enhanced and were more significant by the combined treatment with SA. The kinetics of apoptosis induction and cell cycle distribution were analyzed by flow cytometry. In addition, the levels of ERK1/2, JNK and Akt were determined by western blot analysis. The incidence of apoptotic cells after treatment with SA (20.0 µM) at 37?C for 4 h, hyperthermia (44?C) alone for 30 min, and the combination in sequence were examined. The sub-G1 division (%) in the diagram obtained by flow cytometry was applied to that assay. The percentage of apoptotic cells (10.53±5.02%) was higher at 48 h as compared to 0, 12 and 24 h after treatment. The distribution of DU145 cells in the G2/M cell cycle phase was markedly increased after 24 h of heating at 44?C and after the combined treatment with heating and SA. The phosphorylation of ERK1/2 was reduced following treatment with heating and SA, while the levels of phosphorylated JNK (p-JNK) were markedly increased immediately after heating at 44?C and when heating was combined with SA. By contrast, the levels of phosphorylated Akt (p-Akt) were immediately increased only after heating at 44?C. Thus, we concluded that SA exerts its thermosensitizing effects on DU145 cells by inhibiting the activation of the MAPK/ERK1/2 and PI3K/Akt signaling pathways.
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Expression of tricellulin in epithelial cells and non-epithelial cells.
Histol. Histopathol.
PUBLISHED: 06-13-2013
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Tricellulin is the first molecular component of tricellular tight junctions at tricellular contacts where three epithelial cells meet, and it is required for the their formation and maintenance of the epithelial barrier. Tricellulin binds other tight junction proteins, and its expression and distribution are affected by the bicellular tight junction protein occludin and lipolysis-stimulated lipoprotein receptor (LSR) which is expressed at tricellular contacts. Tricellulin is also detected in endothelial cells, neurons, microglia and astrocytes. Here, we focused tricellulin expression in various types of epithelial cells, nasal epithelial cells, pancreatic duct epithelial cells cells and hepatocytes, and non-epithelial cells, dendritic cells and Schwann cells, compared to expression of the bicellular tight junction protein occludin and LSR, and discuss the regulation and the role of tricellulin in cellular specificity.
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Structure-activity relationship study of phenylpyrazole derivatives as a novel class of anti-HIV agents.
Bioorg. Med. Chem. Lett.
PUBLISHED: 05-15-2013
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The structure-activity relationship of phenylpyrazole derivative 1 was investigated for the development of novel anti-HIV agents. Initial efforts revealed that the diazenyl group can be replaced by an aminomethylene group. In addition, we synthesized various derivatives by the reductive amination of benzaldehydes with 5-aminopyrazoles and carried out parallel structural optimization on the benzyl group and the pyrazole ring. This optimization led to a six-fold more potent derivative 32j than the lead compound 1, and this derivative has a 3,4-dichloro-(1,1-biphenyl)-3-yl group.
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In vitro and in vivo antiproliferative effect of a combination of ultraviolet-A and alkoxy furocoumarins isolated from Umbelliferae medicinal plants, in melanoma cells.
Photochem. Photobiol.
PUBLISHED: 03-13-2013
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We examined the effects of six furocoumarins with alkoxy groups at the C-5 or C-8 position isolated from Umbelliferae medicinal plants on cell proliferation, and their mechanisms of action against B16F10 melanoma cells or in melanin-possessing hairless mice implanted with B16F10 cells, under UVA irradiation. Three furocoumarins with an alkoxy group at C-5, isoimperatorin (1), oxypeucedanin (2) and oxypeucedanin hydrate (3), showed antiproliferative activity and caused G2/M arrest at concentrations of 0.1-10.0 ?m. Furthermore, three furocoumarins with an alkoxy group at C-8, imperatorin (4), heraclenin (5) and heraclenol (6), inhibited the proliferation of melanoma cells and cell cycle at G2/M at concentrations of 0.1-1.0 ?m. UVA plus 1, 2, 3, 4 and 6 reduced tumor growth and final tumor weight in B16F10-bearing mice at a dose of 0.3, 0.5 or 1.0 mg kg(-1) (intraperitoneal injection). UVA plus 1, 3 and 6 increased Chk1 phosphorylation and reduced cdc2 (Thr 161) phosphorylation in melanoma cells. We suggest that the antitumor actions of UVA plus furocoumarins with an alkoxy group at C-5 or C-8 were due to G2/M arrest of the cell cycle by an increase in phosphor-Chk1 and decrease in phospho-cdc2.
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Development of the dorsal ramus of the spinal nerve in the mouse embryo: involvement of semaphorin 3A in dorsal muscle innervation.
Congenit Anom (Kyoto)
PUBLISHED: 03-10-2013
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The spinal nerve, which is composed of dorsal root ganglion (DRG) sensory axons and spinal motor axons, forms the dorsal ramus projecting to the dorsal musculature. By using the free-floating immunohistochemistry method, we closely examined the spatiotemporal pattern of the formation of the dorsal ramus and the relationship between its projection to the myotome/dorsal musculature and semaphorin 3A (Sema3A), which is an axonal guidance molecule. In embryonic day (E) 10.5-E11.5 wild-type mouse embryos, we clearly showed the existence of a waiting period for the dorsal ramus projection to the myotome. In contrast, in E10.5-E11.5 Sema3A-deficient embryos, the dorsal ramus fibers projected beyond the edge of the myotome without exhibiting the waiting period for projection. These results strongly suggest that the delayed innervation by dorsal ramus fibers may be caused by Sema3A-induced axon repulsion derived from the myotome. Next, by performing culture experiments, we confirmed that E12.5 mouse axons responded to Sema3A-induced repulsion. Together, our results imply that Sema3A may play a key role in the proper development of the dorsal ramus projection.
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Anti-tumor effects of various furocoumarins isolated from the roots, seeds and fruits of Angelica and Cnidium species under ultraviolet A irradiation.
J Nat Med
PUBLISHED: 02-03-2013
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We examined the effects on cell proliferation of 10 methoxyfurocoumarins and 7 dihydrofurocumarins isolated from Umbelliferae medicinal plants, and their mechanisms of action against B16F10 melanoma cells or in melanin-possessing hairless mice implanted with B16F10 melanoma cells, under UVA irradiation. Furocoumarins having a methoxy group, such as bergapten (1), xanthotoxin (2), phellopterin (4), byakangelicin (6), neobyakangelicin (8), isobergapten (9) and sphondin (10), showed anti-proliferative activity and caused G2/M arrest at concentrations of 0.05-15.0 ?M. The 7 dihydrofurocoumarins had no effect. UVA plus 1, 2, 4, 6 and sec-O-acetylbyakagelicin (7), having one methoxy group at the C-5 position and a linear-type conformation, reduced tumor growth and final tumor weight in B16F10-bearing mice at 0.5 or 1.0 mg/kg (intraperitoneal injection). UVA plus 1 and 2 increased Chk1 phosphorylation and decreased cdc2 (Thr 161) phosphorylation in the melanoma cells. The anti-tumor actions of UVA plus furocoumarins having a methoxy group might be due to the arrest of the cell cycle at G2/M through an increase in phospho-Chk1 and reduction in phospho-cdc2.
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Photophysical properties and electronic structure of stable, tunable synthetic bacteriochlorins: extending the features of native photosynthetic pigments.
J Phys Chem B
PUBLISHED: 08-29-2011
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Bacteriochlorins, which are tetrapyrrole macrocycles with two reduced pyrrole rings, are Natures near-infrared (NIR) absorbers (700-900 nm). The strong absorption in the NIR region renders bacteriochlorins excellent candidates for a variety of applications including solar light harvesting, flow cytometry, molecular imaging, and photodynamic therapy. Natural bacteriochlorins are inherently unstable due to oxidative conversion to the chlorin (one reduced pyrrole ring) or the porphyrin. The natural pigments are also only modestly amenable to synthetic manipulation, owing to a nearly full complement of substituents on the macrocycle. Recently, a new synthetic methodology has afforded access to stable synthetic bacteriochlorins wherein a wide variety of substituents can be appended to the macrocycle at preselected locations. Herein, the spectroscopic and photophysical properties of 33 synthetic bacteriochlorins are investigated. The NIR absorption bands of the chromophores range from ?700 to ?820 nm; the lifetimes of the lowest excited singlet state range from ?2 to ?6 ns; the fluorescence quantum yields range from ?0.05 to ?0.25; and the yield of the lowest triplet excited state is ?0.5. The spectroscopic/photophysical studies of the bacteriochlorins are accompanied by density functional theory (DFT) calculations that probe the characteristics of the frontier molecular orbitals. The DFT calculations indicate that the impact of substituents on the spectral properties of the molecules derives primarily from effects on the lowest unoccupied molecular orbital. Collectively, the studies show how the palette of synthetic bacteriochlorins extends the properties of the native photosynthetic pigments (bacteriochlorophylls). The studies have also elucidated design principles for tuning the spectral and photophysical characteristics as required for a wide variety of photochemical applications.
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Rhabdomyolysis associated with fenofibrate monotherapy in a patient with chronic myelogenous leukemia.
Case Rep Gastroenterol
PUBLISHED: 08-27-2011
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Rhabdomyolysis associated with fenofibrate monotherapy is extremely rare. Here, we report a rare case of rhabdomyolysis of the psoas muscle in an 82-year-old man with chronic myelogenous leukemia (CML). He was prescribed fenofibrate because of a hypertriglyceridemia. The patient reported generalized muscle pain and right abdominal pain while receiving fenofibrate monotherapy. An abdominal computed tomography scan and an abdominal ultrasound showed a large and low attenuation and high echogenicity, respectively, in the right middle abdominal area. Laboratory values included a serum creatine concentration of 4.1 mg/dl and a creatinine phosphokinase concentration of 5,882 IU/l. During laparotomy, a large hematoma and necrotic mass was identified in the right psoas muscle. Histological examination revealed that the resected specimens were of the psoas muscle with irregular fiber sizes, degenerating fibers surrounding the inflammatory reaction, and fiber necrosis that is typical for polymyositis. Based on these findings and the clinical history, a diagnosis of fenofibrate-induced rhabdomyolysis was made. To the best of our knowledge, no patient has ever been diagnosed with fulminant psoas rhabdomyolysis due to a fenofibrate monotherapy. This report details the rare case of rhabdomyolysis in a patient with CML associated with fenofibrate monotherapy and offers a review of the literature.
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Virtual libraries of tetrapyrrole macrocycles. Combinatorics, isomers, product distributions, and data mining.
J Chem Inf Model
PUBLISHED: 08-25-2011
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A software program (PorphyrinViLiGe) has been developed to enumerate the type and relative amounts of substituted tetrapyrrole macrocycles in a virtual library formed by one of four different classes of reactions. The classes include (1) 4-fold reaction of n disubstituted heterocycles (e.g., pyrroles or diiminoisoindolines) to form ?-substituted porphyrins, ?-substituted tetraazaporphyrins, or ?- or ?-substituted phthalocyanines; (2) combination of m aminoketones and n diones to form m × n pyrroles, which upon 4-fold reaction give ?-substituted porphyrins; (3) derivatization of an 8-point tetrapyrrole scaffold with n reagents, and (4) 4-fold reaction of n aldehydes and pyrrole to form meso-substituted porphyrins. The program accommodates variable ratios of reactants, reversible or irreversible reaction (reaction classes 1 and 2), and degenerate modes of formation. Po?lyas theorem (for enumeration of cyclic entities) has also been implemented and provides validation for reaction classes 3 and 4. The output includes the number and identity of distinct reaction-accessible substituent combinations, the number and identity of isomers thereof, and the theoretical mass spectrum. Provisions for data mining enable assessment of the number of products having a chosen pattern of substituents. Examples include derivatization of an octa-substituted phthalocyanine with eight reagents to afford a library of 2,099,728 members (yet only 6435 distinct substituent combinations) and reversible reaction of six distinct disubstituted pyrroles to afford 2649 members (yet only 126 distinct substituent combinations). In general, libraries of substituted tetrapyrrole macrocycles occupy a synthetically accessible region of chemical space that is rich in isomers (>99% or 95% for the two examples, respectively).
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Inhibitory effects of furanocoumarin derivatives in Kampo extract medicines on P-glycoprotein at the blood-brain barrier.
Biol. Pharm. Bull.
PUBLISHED: 08-02-2011
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Furanocoumarin derivatives, known as components of grapefruit juice, showing inhibitory effects against P-glycoprotein (P-gp) in the intestine are also contained in the plants of rutaceae and umbelliferae families, which are used as components of Kampo extract medicines. In this study, we investigated the inhibitory effects of byakangelicol and rivulobirin A, known as furanocoumarins showing P-gp inhibitory effect using Caco-2 monolayer, against P-gp at the blood-brain barrier (BBB) under both in vitro and in vivo conditions. First we studied the membrane permeability of furanocoumarins to clarify whether they can be absorbed from the intestine. Both furanocoumarins showed high permeability through the Caco-2 monolayer, suggesting that they can easily reach the systemic circulation after oral administration. Then, we evaluated the effect of these furanocoumarins on the uptake of calcein acetoxymethyl ester (calcein-AM), a P-gp substrate, into bovine brain microvascular endothelial cells (BBMEC). Both furanocoumarins significantly increased the uptake amount of calcein-AM into BBMEC by the inhibition of P-gp at the BBB in vitro. Next we also investigated the P-gp inhibitory effect of these furanocoumarins at the rat BBB in vivo using verapamil as a P-gp substrate. Both furanocoumarins increased the B/P ratio of verapamil compared to the control, even under in vivo conditions; however, the extent of the inhibitory effect was much lower than in vitro condition. In conclusion, byakangelicol and rivulobirin A may inhibit P-gp expressed at the BBB even under in vivo conditions. Further studies using Kampo extract medicines under in vivo condition are necessary for safe drug therapy.
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[Spontaneous disappearance of intracranial arteriovenous malformation after living-donor liver transplantation: a case report].
No Shinkei Geka
PUBLISHED: 06-02-2011
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In this report, the authors describe a 35-year-old male whose intracranial arteriovenous malformation (AVM) spontaneously disappeared about 2 years after successful living-donor liver transplantation for alcohol-induced liver cirrhosis. Preoperative screening MRI revealed intracranial arteriovenous malformation (AVM) around the midbrain. Cerebral angiography demonstrated that the AVM was fed by the paramedian mesencephalic arteries and was drained via the vein of Galen. He successfully underwent living-donor liver transplantation, and his postoperative course was uneventful. Follow-up MRI and MRA revealed spontaneous disappearance of the AVM 27 months after surgery. The authors discuss precisely the underlying mechanism of this rare phenomenon, based on thorough literature review.
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Syntaxin 1B suppresses macropinocytosis and semaphorin 3A-induced growth cone collapse.
J. Neurosci.
PUBLISHED: 05-20-2011
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Growth cone collapse is a crucial process for repulsive axon guidance and is accompanied by a reduction in growth cone surface area. This process of reduction may be regulated by endocytosis; however, its molecular mechanism is unclear. Macropinocytosis is a clathrin-independent form of endocytosis in which large areas of plasma membrane can be engulfed. We have reported previously that macropinocytosis is induced in growth cones of chick dorsal root ganglion neurons by semaphorin 3A (Sema3A), a repulsive axon guidance cue, and that Sema3A-induced reduction in growth cone surface area and macropinocytic vacuole area were correlated, suggesting a positive role for macropinocytosis in Sema3A-induced growth cone collapse. In the present study, we found that syntaxin 1B (Syx1B), a membrane trafficking protein, is a negative regulator of macropinocytosis, and its expression is downregulated by Sema3A signaling. Macropinocytosis inhibitor ethylisopropylamiloride or Syx1B overexpression suppressed Sema3A-induced macropinocytosis and growth cone collapse. These results indicate that Syx1B couples macropinocytosis-mediated massive internalization of the plasma membrane to Sema3A-induced growth cone collapse.
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[A successful case of systemic chemotherapy followed by liver resection for advanced hepatocellular carcinoma with highly vascular invasion and multiple pulmonary metastases].
Gan To Kagaku Ryoho
PUBLISHED: 05-14-2011
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The prognosis for hepatocellular carcinoma with extrahepatic metastasis or vascular invasion is very poor. We treated a case successfully by combining chemotherapy and liver resection for hepatocellular carcinoma with multiple pulmonary metastases and vascular invasion. A 56-year-old man who complained of abdominal pain in his right side was transported to the hospital by ambulance. Because CT scan revealed the rupture of hepatocellular carcinoma, he underwent emergency transcatheter arterial embolization (TAE). A close examination revealed tumor thrombus in the inferior vena cava and posterior segment of the portal vein branch, with multiple pulmonary metastases. We conducted right hepatic lobectomy and removal of the inferior vena cava tumor thrombus. After the operation, pulmonary metastatic lesions gradually grew larger, so the oral administration of S-1 at 120 mg per day was started. At the end of the first course, the CT scan revealed that multiple pulmonary metastases were significantly reduced, and treatment was maintained until the end of 4 courses. A prolongation of survival could be expected by combining systemic chemotherapy and liver resection for advanced hepatocellular carcinoma such as the present case.
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Primary adenocarcinoma of the stomach in von Recklinghausens disease with high serum levels of multiple tumor markers: a case report.
J Med Case Rep
PUBLISHED: 04-28-2011
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Gastric tumors in patients affected by neurofibromatosis type 1 are usually carcinoids or stromal tumors, and rarely adenocarcinomas.
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Gastric Cancer with a Very High Serum CA 19-9 Level.
Case Rep Gastroenterol
PUBLISHED: 04-22-2011
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Carbohydrate antigen 19-9 (CA 19-9) is a sensitive marker for pancreatic and hepatobiliary malignancies. The highest frequency of elevated serum CA 19-9 levels is found among patients with pancreatic cancer. CA 19-9 has recently been demonstrated to be a marker of digestive tract malignancies. We report the case of a patient with a gastric cancer and a very high serum CA 19-9 level. During laparotomy, a large mass was found in the antrum. A distal gastrectomy with D2 dissection of the lymph nodes was performed. Histological examination, including immunohistochemistry, revealed an adenocarcinoma of the stomach producing CA 19-9. To the best of our knowledge, no patient with an extremely high serum CA 19-9 level resulting from a gastric adenocarcinoma has been reported previously.
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Xanthoangelols isolated from Angelica keiskei inhibit inflammatory-induced plasminogen activator inhibitor 1 (PAI-1) production.
Biofactors
PUBLISHED: 04-15-2011
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The folk medicine Angelica keiskei (Ashitaba) exhibits antitumor, antioxidant and antidiabetic activities and it has recently attracted attention as a health food. Ashitaba is thought to have antithrombotic properties, but this has not yet been scientifically proven. The elevation of plasma plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis results in a predisposition to the risk of thrombosis. The present study showed that Ashitaba exudates injected intraperitoneally and orally administered over long-term suppressed the lipopolysaccharide (LPS) induced PAI-1 increase in mouse plasma. We also found that xanthoangelol, xanthoangelols B and D, the components of Ashitaba exudates, significantly inhibited TNF?-induced PAI-1 production from human umbilical vein endothelial cells (HUVECs). These findings suggest that Ashitaba can decrease elevated PAI-1 production, and that daily consumption of Ashitaba product might maintain anticoagulant status by inhibiting elevations in PAI-1 under inflammatory conditions.
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New microtubule polymerization inhibitors comprising a nitrooxymethylphenyl group.
Bioorg. Med. Chem.
PUBLISHED: 04-05-2011
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We have designed cancer antiproliferative compounds, starting from aniline or phenol derivative, which comprise one or two nitrooxymethylphenyl groups as do the hybrid drugs NCX4040 and NCX530. Compound 2a with p-nitrooxymethylbenzoyl-oxy and -amino groups as well as 8a with a p-nitrooxymethylbenzoylamino group showed more promising effects than NCX4040 against human colon and breast cancer cells. Since 2a and 8a, but not NCX4040, arrested human colon carcinoma HCT116 cells in the M phase, the former two compounds may inhibit cell growth differently from NCX4040. Merged images of immunofluorescence-stained ?-tubulin and Hoechst-stained nuclei in human fibrosarcoma HT1080 cells showed that 2a and 8a disrupted microtubule formation just as did vincristine, the tubulin polymerization inhibitor. In experiments in vivo, the intraperitoneal administration of 8a at 80 mg/kg/day reduced the growth of HCT116 xenografts in nude mice to T/C 55%.
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p53 inhibits vascular endothelial growth factor expression in solid tumor.
J. Surg. Res.
PUBLISHED: 01-15-2011
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The p53 tumor-suppressor gene is one of the most frequently mutated genes in cancers, and its mutations affect various biological actions, such as tumor growth, apoptosis, and so on. During hypoxia, p53 is stabilized by interaction with hypoxia-inducible factor-1 (HIF-1). This interaction raised the possibility for regulating HIF-1 activity by p53, which is still to be elucidated.
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Endoscopic naso-pancreatic drainage for the treatment of pancreatic fistula occurring after LDLT.
World J. Gastroenterol.
PUBLISHED: 01-04-2011
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Pancreatic fistula is a quite rare complication in patients who undergo living donor liver transplantation (LDLT). However, in the cases that show pancreatic fistula, the limited volume of the graft and the resultant inadequate liver function may complicate the management of the fistula. As a result, the pancreatic fistula may result in the death of the patient. We present 2 cases in which endoscopic treatment was effective against pancreatic fistulas that developed after LDLT. In case 1, a 61-year-old woman underwent LDLT for primary biliary cirrhosis. Because of a portal venous thrombus caused by a splenorenal shunt, the patient underwent portal vein reconstruction, and a splenorenal shunt was ligated on postoperative day (POD) 7. The main pancreatic duct was injured during the manipulation to achieve hemostasis, thereby necessitating open drainage. However, discharge of pancreatic fluid continued even after POD 300. Endoscopic naso-pancreatic drainage (ENPD) was performed, and this procedure resulted in a remarkable decrease in drain output. The refractory pancreatic fistula healed on day 40 after ENPD. In case 2, a 58-year-old man underwent LDLT for cirrhosis caused by the hepatitis C virus. When the portal vein was exposed during thrombectomy, the pancreatic head was injured, which led to the formation of a pancreatic fistula. Conservative therapy was ineffective; therefore, ENPD was performed. The pancreatic fistula healed on day 38 after ENPD. The findings in these 2 cases show that endoscopic drainage of the main pancreatic duct is a less invasive and effective treatment for pancreatic fistulas that develop after LDLT.
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[A study of cirrhotic patients with hepatocellular carcinoma and huge splenomegaly who received treatment for hepatocellular carcinoma with concomitant splenectomy].
Gan To Kagaku Ryoho
PUBLISHED: 10-15-2010
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Treatment for hepatocellular carcinoma (HCC) with advanced cirrhosis, especially with hypersplenic thrombocytopenia, will be very difficult. Then we evaluated usefulness of concomitant splenectomy with treatment for patients with HCC, severe cirrhosis and huge splenomegaly. The preoperative mean platelet (Plt) count was 4.6 × 10(4)/µL and the mean longest diameter of spleen on CT was 143.0 mm. The mean Plt count on postoperative days 14 and 28 was 23.1 × 10(4)/µL (p=0.005) and 16.1 × 10(4)/µL (p=0.01), respectively and improved significantly compared with preoperative one. A white blood cell count and serum albumin also improved significantly on postoperative days 14 and 28, respectively. Treatment for recurrent HCC after splenectomy was preformed 2.4 times per patient (transarterial chemoembolization 13 times and radiofrequency ablation 4 times/7 patients). Now 5 patients are alive and the mean survival period was 17.3 months (range 8-38 months). It maybe said that concomitant splenectomy for cirrhotic patients with HCC and huge splenomegaly who need to receive a treatment for HCC was useful in our study, because those patients could receive a treatment for recurrent HCC repeatedly, and that probably contributes to the improvement of prognosis.
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Activation energies for oxidation of porphyrin monolayers anchored to Au(111).
Langmuir
PUBLISHED: 09-30-2010
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The activation energy for the oxidation of porphyrin monolayers anchored to gold surfaces is determined via measurement of the temperature dependence of the electron-transfer rates. The activation energy (1) increases with increasing surface concentration of the porphyrin and (2) is significantly lower (8.1-17 versus 37-49 kJ mol(-1)) when smaller, more mobile counterions (Cl(-) versus PF(6)(-)) are used as the supporting electrolyte. Regardless, the lower activation energies do not result in radically different electron-transfer rates for the different types of counterions owing to compensating entropic effects.
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Three-dimensional computed tomography scan analysis of hepatic vasculatures in the donor liver for living donor liver transplantation.
Liver Transpl.
PUBLISHED: 09-07-2010
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Because hepatic vasculatures exhibit variations, a preoperative evaluation of the vascular anatomy and an estimation of the volume of the liver graft are essential for successful adult living donor liver transplantation. Using 3-dimensional (3D) computed tomography (CT), we analyzed the volumetric and anatomical relationship of the hepatic vasculatures of liver grafts. The livers of 223 potential donors were analyzed by 3D CT. Volumetric analysis was performed for each hepatic vein and its tributaries. The anatomy of the portal vein and hepatic artery was assessed along with the biliary system via intraoperative cholangiography in 110 recipients. On the basis of the anatomical presentation of the inferior right hepatic vein (IRHV), the hepatic veins were classified as follows: in type I, the IRHV was absent; in type II, the IRHV was smaller than the right hepatic vein (RHV); and in type III, the IRHV was greater than or equal to the RHV in size. The drainage volume of the middle hepatic vein (MHV) and especially its tributaries in the right lobe increased with the size of the IRHV (P < 0.001). In type III hepatic veins with a large IRHV (17% of the donors), the MHV tributaries had the largest drainage volume in the right lobe (41.2% +/- 11.8%). Furthermore, type III hepatic veins typically exhibited biliary variations in 75% of the donors. No correlation was observed between variations in the hepatic artery and portal vein. In conclusion, a right lobe graft with a large IRHV is accompanied by a large drainage volume via the MHV and by bile duct variations in 17% of livers. Therefore, anatomical and volumetric analysis is important for preoperative evaluations.
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Identification and characterization of a novel zebrafish semaphorin.
Neurosci. Lett.
PUBLISHED: 08-31-2010
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The semaphorin gene family contains numerous secreted and transmembrane proteins. Some of them function as the repulsive and attractive axon guidance molecules during development. Herein, we report the cloning and characterization of a novel member of zebrafish semaphorin gene, semaphorin 6E (sema6E). Sema6E is expressed predominantly in the nervous system during embryogenesis. Results also show that Sema6E binds Plexin-A1, but not other Plexins. Sema6E chemorepels not only dorsal root ganglion axons but also sympathetic axons. Therefore, Sema6E might utilize Plexin-A1 as a receptor to repel axons of the specific types during development.
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Antitumor Agents. 282. 2-(R)-O-acetylglaucarubinone, a quassinoid from Odyendyea gabonensis as a potential anti-breast and anti-ovarian cancer agent.
J. Nat. Prod.
PUBLISHED: 08-27-2010
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A new quassinoid, designated 2-(R)-O-acetylglaucarubinone (1), and seven known quassinoids (2-8) were isolated, using bioactivity-guided separation, from the bark of Odyendyea gabonensis (Pierre) Engler [syn. Quassia gabonensis Pierre]. The structure of 1 was determined by spectroscopic analysis and by semisynthesis from glaucarubolone. Complete (1)H and (13)C NMR assignments of compounds 1-8 were also established from detailed analysis of two-dimensional NMR spectra, and the reported configurations in odyendene (7) and odyendane (8) were corrected. Compound 1 showed potent cytotoxicity against multiple cancer cell lines. Further investigation using various types of breast and ovarian cancer cell lines suggested that 1 does not target the estrogen receptor or progesterone receptor. When tested against mammary epithelial proliferation in vivo using a Brca1/p53-deficient mice model, 1 also caused significant reduction in mammary duct branching.
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Probing the rate of hole transfer in oxidized porphyrin dyads using thallium hyperfine clocks.
J. Am. Chem. Soc.
PUBLISHED: 08-10-2010
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Understanding hole/electron-transfer processes among interacting constituents of multicomponent molecular architectures is central to the fields of artificial photosynthesis and molecular electronics. One strategy for examining ground-state hole/electron transfer in oxidized tetrapyrrolic arrays entails analysis of the hyperfine interactions observed in the electron paramagnetic resonance (EPR) spectrum of the pi-cation radical. Herein, it is demonstrated that (203)Tl/(205)Tl hyperfine "clocks" are greatly superior to those provided by (1)H, (14)N, or (13)C owing to the fact that the (203)Tl/(205)Tl hyperfine couplings are much larger (15-25 G) than those of the (1)H, (14)N, or (13)C nuclei (1-6 G). The large (203)Tl/(205)Tl hyperfine interactions permit accurate simulations of the EPR spectra and the extraction of specific rates of hole/electron transfer. The (203)Tl/(205)Tl hyperfine clock strategy is applied to a series of seven porphyrin dyads. All of the dyads are joined at a meso position of the porphyrin macrocycle via linkers of a range of lengths and composition (diphenylethyne, diphenylbutadiyne, and (p-phenylene)(n), where n = 1-4); substituents such as mesityl at the nonlinking meso positions are employed to provide organic solubility. The hole/electron-transfer time constants are in the hundreds of picoseconds to sub-10 ns regime, depending on the specific porphyrin and/or linker. Density functional theory calculations on the constituents of the dyads are consistent with the view that the relative energies of the porphyrin versus linker highest occupied molecular orbitals strongly influence the hole/electron-transfer rates. Variable-temperature EPR studies further demonstrate that the hole/electron-transfer process is at best weakly activated (12-15 kJ mol(-1)) at room temperature and somewhat below. At lower temperatures, the process is essentially activationless. The weak activation is attributed to restricted torsional motions of the phenyl rings of the linker. Collectively, the studies provide the physical basis for the rational design of multicomponent architectures for efficient hole/electron transfer.
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Five condensed furanocoumarins from the root of Heracleum candicans Wall.
J Nat Med
PUBLISHED: 07-26-2010
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Three new spirotrifuranocoumarins, canditririns C-E (1-3), a new spirotetrafuranocoumarin, canditetrarin A (4), and a new tetrafuranocoumarin, canditetrarin B (5), were isolated from the roots of Heracleum candicans Wall. Their structures were established using spectral methods.
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Four novel furanocoumarin glucosides, candinosides A, B, C and D, from Heracleum candicans Wall.
J Nat Med
PUBLISHED: 06-09-2010
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Four novel furanocoumarin glucosides, candinosides A, B, C and D (1-4), were isolated from the roots of Heracleum candicans Wall. Their structures were established using chemical and spectral methods.
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Furanocoumarin derivatives in Kampo extract medicines inhibit cytochrome P450 3A4 and P-glycoprotein.
Drug Metab. Dispos.
PUBLISHED: 05-12-2010
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Furanocoumarins in grapefruit are known to show inhibitory effects against P-glycoprotein (P-gp) and CYP3A4 in intestinal epithelial cells; however, furanocoumarin derivatives are widely contained in the plants of Rutaceae and Umbelliferae families, which are used as components of Kampo extract medicines. In this study, we investigated the inhibitory effects of 12 furanocoumarins extracted from plants in the Umbelliferae family against P-gp and CYP3A4 activity. Furthermore, we studied their inhibitory effect on P-gp when furanocoumarins are used as Kampo extract medicine rather than as an isolated single compound. From screening of the CYP3A4 inhibitory effect, notopterol and rivulobirin A, the only dimer types of furanocoumarin, were found to be potent inhibitors of CYP3A4. On the other hand, byakangelicol and rivulobirin A showed strong P-gp inhibition from the screening of P-gp inhibitor evaluated by quinidine permeation through the Caco-2 monolayer; however, the chemical structural relationship of furanocoumarins between P-gp and CYP3A4 inhibitory effects could not be obtained. We also investigated the effect of these furanocoumarins on the transport of digoxin through the Caco-2 monolayer. The inhibitory effect of rivulobirin A was more potent than that of byakangelicol. Application of either Senkyu-cha-cho-san or Sokei-kakketsu-to, which are composed of herbal remedies in the Umbelliferae group, significantly decreased the efflux ratio of digoxin. In conclusion, it was found that some furanocoumarins extracted from the plants in the Umbelliferae family strongly inhibited P-gp and CYP3A4. Kampo extract medicines containing herbal remedies belonging to the Umbelliferae family may cause a drug-drug interaction with P-gp or a CYP3A4 substrate drug.
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Probing the rate of hole transfer in oxidized synthetic chlorin dyads via site-specific (13)C-labeling.
J. Org. Chem.
PUBLISHED: 05-01-2010
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Understanding electronic communication among interacting constituents of multicomponent molecular architectures is important for rational design in diverse fields including artificial photosynthesis and molecular electronics. One strategy for examining ground-state hole/electron transfer in an oxidized tetrapyrrolic array relies on analysis of the hyperfine interactions observed in the EPR spectrum of the pi-cation radical. This strategy has been previously employed to probe the hole/electron-transfer process in oxidized multiporphyrin arrays of normal isotopic composition, wherein (1)H and (14)N serve as the hyperfine "clocks", and in arrays containing site-specific (13)C-labels, which serve as additional hyperfine clocks. Herein, the hyperfine-clock strategy is applied to dyads of dihydroporphyrins (chlorins). Chlorins are more closely related structurally to chlorophylls than are porphyrins. A de novo synthetic strategy has been employed to introduce a (13)C label at the 19-position of the chlorin macrocycle, which is a site of large electron/hole density and is accessible synthetically beginning with (13)C-nitromethane. The resulting singly (13)C-labeled chlorin was coupled with an unlabeled chlorin to give a dyad wherein a diphenylethyne linker spans the 10-positions of the two zinc chlorins. EPR studies of the monocations of both the natural abundance and (13)C-labeled zinc chlorin dyads and benchmark zinc chlorin monomers reveal that the time scale for hole/electron transfer is in the 4-7 ns range, which is 5-10-fold longer than that in analogous porphyrin arrays. The slower hole/electron transfer rate observed for the chlorin versus porphyrin dyads is attributed to the fact that the HOMO is a(1u)-like for the chlorins versus a(2u)-like for the porphyrins; the a(1u)-like orbital exhibits little (or no) electron/hole density at the site of linker attachment whereas the a(2u)-like orbital exhibits significant electron/hole density at this site. Collectively, the studies of the chlorin and porphyrin dyads provide insights into the structural features that influence the hole/electron-transfer process.
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New orally bioavailable 2-aminobenzamide-type histone deacetylase inhibitor possessing a (2-hydroxyethyl)(4-(thiophen-2-yl)benzyl)amino group.
Bioorg. Med. Chem.
PUBLISHED: 03-15-2010
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New 2-aminobenzamide-type histone deacetylase (HDAC) inhibitors were synthesized. They feature a sulfur-containing bicyclic arylmethyl moiety-a surface recognition domain introduced to increase in cellular uptake-and a substituted tert-amino group which affects physicochemical properties such as aqueous solubility. Compound 22 with a (2-hydroxyethyl)(4-(thiophen-2-yl)benzyl)amino group reduced the volume of human colon cancer HCT116 xenografts in nude mice to T/C 67% by oral administration at 45mg/kg, which was comparable to the rate (T/C 62%) for a positive control, MS-275. Western blot analyses as well as cell cycle and TUNEL assays by flow cytometry suggested that the two compounds inhibited the growth of cancer cells via similar mechanisms.
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Perioperative management of hepatic resection toward zero mortality and morbidity: analysis of 793 consecutive cases in a single institution.
J. Am. Coll. Surg.
PUBLISHED: 03-03-2010
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The mortality rates associated with hepatectomy are still not zero. Our aim was to define the risk factors for complications and to evaluate our perioperative management.
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Semaphorins guide the entry of dendritic cells into the lymphatics by activating myosin II.
Nat. Immunol.
PUBLISHED: 02-23-2010
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The recirculation of leukocytes is essential for proper immune responses. However, the molecular mechanisms that regulate the entry of leukocytes into the lymphatics remain unclear. Here we show that plexin-A1, a principal receptor component for class III and class VI semaphorins, was crucially involved in the entry of dendritic cells (DCs) into the lymphatics. Additionally, we show that the semaphorin Sema3A, but not Sema6C or Sema6D, was required for DC transmigration and that Sema3A produced by the lymphatics promoted actomyosin contraction at the trailing edge of migrating DCs. Our findings not only demonstrate that semaphorin signals are involved in DC trafficking but also identify a previously unknown mechanism that induces actomyosin contraction as these cells pass through narrow gaps.
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Chemical studies on the root of Heracleum candicans Wall. (Part 3).
J Nat Med
PUBLISHED: 01-14-2010
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Two new ester coumarins, candinols B and C (1 and 2), and three new coumarin dimers, candibirins F-H (3-5), were isolated from the roots of Heracleum candicans Wall. Their structures were established by using chemical and spectral means.
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Determination of flavonoids in licorice using acid hydrolysis and reversed-phase HPLC and evaluation of the chemical quality of cultivated licorice.
Planta Med.
PUBLISHED: 12-14-2009
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Licorice contains flavonoids and triterpenoids as the major bioactive components. Most of the flavonoids are the glycosidic form of liquiritigenin (LIQ), isoliquiritigenin (ISO) and formononetin (FOR). A reversed-phase HPLC method for the quantification of LIQ, ISO and FOR in licorice was developed. This method does not measure each glycoside but measures the aglycones using acid hydrolysis. All calibration curves showed good linear regression (r > 0.9998). The method showed good precision for intraday (RSD < 2.14 %) and interday (RSD < 0.51 %) assays. The limit of detection was 0.031 microg for LIQ, 0.011 microg for ISO and 0.006 microg for FOR. The limit of quantification was 0.31 microg for LIQ, 0.11 microg for ISO and 0.06 microg for FOR. The flavonoid contents along with the glycyrrhizin content of cultivated licorice from seedling plants in Japan and commercial wild licorice were investigated. This new method could be extremely useful for evaluating the quality of licorice.
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[A case of steroid-dependent ulcerative colitis complicated by skin infection of Mycobacterium szulgai].
Nihon Shokakibyo Gakkai Zasshi
PUBLISHED: 09-08-2009
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We describe a case of a 47-year old Japanese man with steroid-dependent, refractory ulcerative colitis complicated by non-tuberculous mycobacterial skin infection. The patient remained in remission by combination therapy of 100mg azathioprine and 27.5mg prednisolone (total dose over 25g for three years), but developed a deep genital ulcer. Mycobacterium szulgai was confirmed by skin culture, and the ulcer became turned into a scar after oral administration of isoniazid, rifampicin, and ethanbutol.
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Increased proximal bifurcation of CA1 pyramidal apical dendrites in sema3A mutant mice.
J. Comp. Neurol.
PUBLISHED: 08-06-2009
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Semaphorin-3A (Sema3A) is an attractive guidance molecule for cortical apical dendrites. To elucidate the role of Sema3A in hippocampal dendritic formation, we examined the Sema3A expression pattern in the perinatal hippocampal formation and analyzed hippocampal dendrites of the brains from young adult sema3A mutant mice. Sema3A protein was predominantly expressed in the hippocampal plate and the inner marginal zone at the initial period of apical dendritic growth. Neuropilin-1 and plexin-A, the receptor components for Sema3A, were also localized in the same regions. The Golgi impregnation method revealed that in wildtype mice more than 90% of hippocampal CA1 pyramidal neurons extended a single trunk or apical trunks bifurcated in stratum radiatum. Seven percent of the pyramidal neurons showed proximal bifurcation of apical trunks in stratum pyramidale or at the border of the stratum pyramidale and stratum radiatum. In sema3A mutant mice, proximally bifurcated apical dendrites were increased to 32%, while the single apical dendritic pyramidal neurons were decreased. We designate this phenotype in sema3A mutant mice as "proximal bifurcation." In the dissociated culture system, approximately half of the hippocampal neurons from wildtype mice resembled pyramidal neurons, which possess a long, thick, and tapered dendrite. In contrast, only 30% of the neurons from sema3A mutants exhibited pyramidal-like morphology. Proximal bifurcation of CA1 pyramidal neurons was also increased in the mutant mice of p35, an activator of cyclin-dependent kinase 5 (Cdk5). Thus, Sema3A may facilitate the initial growth of CA1 apical dendrites via the activation of p35/Cdk5, which may in turn signal hippocampal development.
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Liver transplantation for hepatocellular carcinoma: the Japanese experience.
J Hepatobiliary Pancreat Sci
PUBLISHED: 07-01-2009
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Despite the wide spectrum of selection criteria used by living donor liver transplantation (LDLT) centers in Japan, LDLT for hepatocellular carcinoma (HCC) can achieve an acceptable outcome comparable to the outcome for deceased donor liver transplantation (DDLT) for HCC. One of the most crucial considerations in liver transplantation for HCC is the advent of expanded criteria that allow more patients with HCC to receive the organs and offer similar or even better results compared to the Milan of UCSF criteria. Expanded criteria for HCC are proposed from three single-center and one multicenter study in Japan. These criteria are based on the independent predictors for outcome derived from the analyses of the pretransplant factors and explant pathology. The beneficial effect of those proposed criteria can be predicted by the inclusion rates of the patients compared to the Milan or UCSF criteria in the same cohort and the outcome for those included patients. While application of the UCSF criteria increases the inclusion rate compared to the Milan criteria by 5-10%, these proposed criteria increase the inclusion rates by 5-54% compared to the Milan criteria. The higher inclusion rates compared to the application of the Milan criteria are achieved by criteria including tumor markers, either AFP or PIVKA II or both. Inclusion of tumor markers in addition to parameters of tumor morphology might be the key to establish the best criteria for liver transplantation for HCC.
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Synthesis and photochemical properties of 12-substituted versus 13-substituted chlorins.
J. Org. Chem.
PUBLISHED: 06-13-2009
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Understanding the effects of substituents on natural photosynthetic pigments is essential for the rational design of artificial photosynthetic systems. The long-wavelength absorption of chlorins derives from a transition that encompasses rings A and C, which includes the 2,3- and 12,13-positions, respectively. Chlorophylls bear a 3-vinyl group and a 13-keto group, as well as a full complement of substituents at the other beta-pyrrole sites. Prior studies of sparsely substituted synthetic chlorins to probe the effects of substituents yielded 3,13-substituted chlorins that contain a geminal dimethyl group in the pyrroline ring (for stability) and a mesityl group at the 10-position. Attempts to prepare analogous chlorins lacking the 10-mesityl substituent encountered unexpected difficulties during construction of the Eastern half precursor (8,9-dibromo-1-formyldipyrromethane) to the 13-bromochlorin. Direct bromination of 1-formyldipyrromethane with 2 mol equiv of NBS at -78 degrees C led to an isomeric mixture of the desired 8,9-dibromodipyrromethane (minor) and the unexpected 7,9-dibromodipyrromethane (major). Hence, a new rational route was developed for the synthesis of 8,9-dibromo-1-formyldipyrromethane that entailed (i) InCl(3)-catalyzed condensation of 4-bromo-2-(hydroxymethyl)pyrrole and pyrrole to give the 8-bromodipyrromethane, (ii) 1-formylation, and (iii) 9-bromination. Two new substituted chlorins carrying auxochromes at the 3- and 13-positions were synthesized. The photophysical and redox properties of the 13-substituted chlorins were compared with those of isomeric 12-substituted chlorins, synthesized previously via a 7,9-dibromo-1-formyldipyrromethane. Such studies (static absorption and fluorescence spectroscopy, time-resolved fluorescence spectroscopy, electrochemistry of the zinc chelates, and density functional theoretical calculations) reveal only very slight differences between the isomeric 12- and 13-substituted chlorins.
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Excited-state energy flow in phenylene-linked multiporphyrin arrays.
J Phys Chem B
PUBLISHED: 05-19-2009
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The dynamics and pathways for excited-state energy transfer in three dyads and five triads composed of combinations of zinc, magnesium, and free base porphyrins (denoted Zn, Mg, Fb) connected by p-phenylene linkers have been investigated. The processes in the triads include energy transfer between adjacent nonequivalent porphyrins, between adjacent equivalent porphyrins, and between nonadjacent nonequivalent porphyrins using the intervening porphyrin as a superexchange mediator. In the case of the triad ZnZnFbPhi, excitation of the zinc porphyrin (to yield Zn) ultimately leads to production of the excited free base porphyrin (Fb) via the three processes with the derived rate constants as follows: (2.8 ps)(-1) for ZnZn Fb --> ZnZnFb, (4 ps)(-1) for Zn ZnFb left arrow over right arrow ZnZn Fb, and (14 ps)(-1) for Zn ZnFb --> ZnZnFb. These results and those obtained for the other four triads show that energy transfer between nonadjacent sites is significant and is only 5-7-fold slower than between adjacent sites. This same scaling was found previously for arrays joined via diphenylethyne linkers. Simulations of the energy-transfer properties of fictive dodecameric arrays based on the data reported herein show that nonadjacent transfer steps make a significant contribution to the observed performance of such larger molecular architectures. Collectively, these results indicate that energy transfer between nonadjacent sites has important implications for the design of multichromophore arrays for molecular-photonic and solar-energy applications.
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Regioselective bromination tactics in the de novo synthesis of chlorophyll b analogues.
J. Org. Chem.
PUBLISHED: 04-25-2009
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The ability to introduce substituents at designated sites about the perimeter of the chlorin or 13(1)-oxophorbine macrocycle is essential for fundamental studies related to chlorophylls. A chlorin is a dihydroporphyrin, whereas a 13(1)-oxophorbine is a chlorin containing an annulated oxopentano ring spanning positions 13 and 15. 13(1)-Oxophorbines bearing auxochromes at the 7-position of the macrocycle are valuable targets given their resemblance to chlorophyll a or b, which contains the 13(1)-oxophorbine skeleton and bears a 7-methyl or 7-formyl group, respectively. A rational route to 7-substituted 13(1)-oxophorbines was developed that relies on a new method for regioselective bromination. Under neutral conditions, a 13-acetyl-10-mesitylchlorin (FbC-M(10)A(13)) undergoes bromination (with 1 molar equiv of NBS in THF) both in ring B (7-position) and at the 15-position (42% versus 28% isolated yield), thereby thwarting installation of the isocyclic ring (ring E, spanning the 13-15 positions). Under acidic conditions (10% TFA in CH(2)Cl(2)), ring B is deactivated, and bromination occurs preferentially at the 15-position (87% yield). The capability for preferential 15-bromination is essential to install the isocyclic ring, after which bromination can be directed to the 7-position of ring B (neutral conditions, 86% yield). The ability to suppress bromination in ring B (under acidic media) has been exploited in syntheses of sparsely substituted analogues of chlorophyll b. The analogues contain a 7-substituent (acetyl, formyl, or TIPS-ethynyl), a 10-mesityl group, and the 18,18-dimethyl group as the only substituents in the 13(1)-oxophorbine skeleton. The three analogues exhibit absorption spectral features that closely resemble those of free base analogues of chlorophyll b. Taken together, the facile access to chlorins and 13(1)-oxophorbines bearing substituents at distinct sites should enable fundamental spectroscopic studies and diverse applications.
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Probing ground-state hole transfer between equivalent, electrochemically inaccessible states in multiporphyrin arrays using time-resolved optical spectroscopy.
Photochem. Photobiol.
PUBLISHED: 04-11-2009
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A new strategy is described and implemented for determining the rates of hole-transfer between equivalent porphyrins in multiporphyrin architectures. The approach allows access to these rates between sites that are not the most easily oxidized components of the array. The specific architectures investigated with this new strategy are triads consisting of one zinc porphyrin (Zn) and two free base porphyrins (Fb). The triads employ a diphenylethyne linker (ZnFbFbU) and a phenylene linker (ZnFbFbPhi). The zinc porphyrin is selectively oxidized to produce Zn(+)FbFb, the free base porphyrins are excited to produce the excited-state mixture Zn(+)Fb*Fb and Zn(+)FbFb*, and the subsequent dynamics are monitored by ultrafast absorption spectroscopy. The system evolves by a combination of energy- and hole-transfer processes involving (adjacent and nonadjacent) zinc and free base porphyrin constituents that are complete within 100 ps of excitation; the rate constants of many of these processes are derived from prior studies of the oxidized forms of the benchmark dyads (ZnFbU and ZnFbPhi). One of the excited-state decay channels produces the metastable state ZnFbFb(+) that decays to a second metastable state ZnFb(+)Fb by the target hole-transfer process, followed by rapid hole transfer to produce the Zn(+)FbFb thermodynamic ground state of the system. The rate constant for hole transfer between the free base porphyrins in the oxidized ZnFbFb triads is found to be (0.5 ns)(-1) and (0.6 ns)(-1) across phenylene and diphenylethyne linkers, respectively. These rate constants are comparable to those recently measured, using a related but distinct strategy, for ground-state hole transfer between zinc porphyrins in oxidized ZnZnFb triads. The two complementary strategies provide unique approaches for probing hole transfer between equivalent sites in multiporphyrin arrays, with the choice of method being guided by the particular target process and the ease of synthesis of the necessary architectures.
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Ca2+ induces macropinocytosis via F-actin depolymerization during growth cone collapse.
Mol. Cell. Neurosci.
PUBLISHED: 01-28-2009
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Growth cone collapse occurs in repulsive axon guidance and is accompanied by a reduction in the surface area of the plasma membrane of growth cones. However, the mechanism of this reduction is unclear. Here, we show that during growth cone collapse, caffeine-induced Ca(2+) release from ryanodine-sensitive Ca(2+) stores triggers the formation of large vacuoles in growth cones by macropinocytosis, a clathrin-independent endocytosis for the massive retrieval of the cellular plasma membrane, and subsequent retrograde membrane transport. We observed a significant correlation of the area of caffeine-induced macropinosomes with growth cone collapse. We also detected macropinocytosis induced by semaphorin 3A, a typical repulsive cue, and correlation between the area of semaphorin 3A-induced macropinocytic vacuoles and growth cone collapse. Moreover, jasplakinolide, an inhibitor of F-actin depolymerization, blocked caffeine-induced macropinocytosis. We propose that the coordinated regulation of actin cytoskeletal reorganization and macropinocytosis-mediated retrograde membrane trafficking may contribute to Ca(2+)-induced axon growth inhibition.
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Simple formation of an abiotic porphyrinogen in aqueous solution.
Orig Life Evol Biosph
PUBLISHED: 01-19-2009
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Porphyrins have long been proposed as key ingredients in the emergence of life yet plausible routes for forming their essential pyrrole precursor have heretofore not been identified. Here we show that the anaerobic reaction of ?-aminolevulinic acid (ALA, 1-5 mM) with the ?-ketoester methyl 4-methoxyacetoacetate (2-40 mM) in water (pH5-7) at 70-100°C for >6 h affords the porphyrinogen, which upon chemical oxidation gives the corresponding porphyrin in overall yield of up to 10%. The key intermediate is the ?-methoxymethyl-substituted pyrrole, which undergoes tetramerization and macrocycle formation under kinetic control. The resulting type-I porphyrin bears four propionic acid and four carbomethoxy groups, is distinct from porphyrins (e.g., uroporphyrin or coproporphyrin) derivable from ALA alone via the extant universal biosynthetic path to tetrapyrroles, and is photoactive upon assembly into cationic micelles in aqueous solution. The simple self-organization of eight acyclic molecules into a tetrapyrrole macrocycle, from which a porphyrin is derived that is photoactive in lipid assemblies, augurs well for the spontaneous origin of catalysts and pigments essential for prebiotic metabolism and proto-photosynthesis.
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Cancer preventive agents 9. Betulinic acid derivatives as potent cancer chemopreventive agents.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-16-2009
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C-3 esterifications of betulinic acid (BA, 1) and its A-ring homolog, ceanothic acid (CA, 2), were carried out to provide sixteen terpenoids, 4-19, including nine new compounds (4-12). All synthesized compounds were evaluated in an in vitro antitumor-promoting assay using the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. Among them, compounds 4-6, 11-14, 16, and 17 displayed remarkable inhibitory effects of EBV-EA activation. BA analog 6, which contains a prenyl-like group, showed the most potent inhibitory effect (100%, 76%, 37%, and 11% inhibition of EBA activation at 1000, 500, 100, and 10mol ratio/TPA, respectively, with IC(50) value of 285mol ratio/32pmol TPA). Compound 6 merits further development as a cancer preventive agent.
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[Bacillus cereus bacteremia in Crohns disease with multiple ileal stricture on maintenance azathioprine therapy].
Nihon Shokakibyo Gakkai Zasshi
PUBLISHED: 01-06-2009
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We describe a case of 36-year-old Japanese man with Crohns disease, complicated by Bacillus cereus bacteremia on maintenance azathioprine therapy. Although anti-microbial agents were ineffective, the patient became well immediately after a partial resection of the ileum with multiple severe stenosis.
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Semaphorin 3A controls timing and patterning of the dental pulp innervation.
Differentiation
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Timing and patterning of dental pulp innervation are strictly spatio-temporally regulated but it is still not known how they are controlled at molecular level. We analyzed postnatal innervation of the dental pulp in the mandibular first molar of mice deficient for Semaphorin 3A (Sema3A) axon repellant molecule. Immunohistochemical localization of nerve fibers on serial sections covering the whole tooth germs using anti-peripherin antibody revealed that nerve fibers were prematurely present within the preodontoblast layer next to the inner enamel epithelium already at PN0 in Sema3A(-/-) mice. In contrast, in the wild-type (Sema3A(+/+)) mice nerve fibers were seen in the pulp only after enamel formation at PN3. The nerves in Sema3A(-/-) pulp were notably defasciculated and thinner compared to that of Sema3A(+/+) mice. A premature formation of an abnormal, enlarged nerve plexus with a high number of arborizations was apparent in the pulp-dentin border target area in Sema3A(-/-) already at PN2 whereas in the wild-type mice the first sign of plexus formation was seen at PN7. The expression of mRNAs for Ngf, Gdnf and Ncam neuroregulatory molecules in mandibular molar as well as receptors for neurotrophic factors and class 3 semaphorins including Sema3A (TrkA, p75, TrkB, TrkC, Ret, Npn1, Npn2, PlxA4) in trigeminal ganglia were not altered in the Sema3A(-/-) mice. Collectively, this data show that Sema3A serves an essential role in molar tooth pulp innervation controlling the timing of nerve fiber penetration into the pulp, their patterning and the formation of nerve plexus at pulp-dentin border area, and provide further support for the hypothesis that tooth innervation is regulated by the coordinated activity of locally expressed neuroregulatory molecules exerting positive and negative influences on growing dental nerve fibers.
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Primordial oil slick and the formation of hydrophobic tetrapyrrole macrocycles.
Astrobiology
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The functional end products of the extant biosynthesis of tetrapyrrole macrocycles in photosynthetic organisms are hydrophobic: chlorophylls and bacteriochlorophylls. A model for the possible prebiogenesis of hydrophobic analogues of natures photosynthetic pigments was investigated by reaction of acyclic reactants in five media: aqueous solution (pH 7, 60°C, 24?h); aqueous solution containing 0.1 M decanoic acid (which forms a turbid suspension of vesicles); or aqueous solution accompanied by dodecane, mesitylene, or a five-component organic mixture (each of which forms a phase-separated organic layer). The organic mixture was composed of equimolar quantities of decanoic acid, dodecane, mesitylene, naphthalene, and pentyl acetate. The reaction of 1,5-dimethoxy-3-methylpentan-2,4-dione and 1-aminobutan-2-one to give etioporphyrinogens was enhanced in the presence of decanoic acid, affording (following chemical oxidation) etioporphyrins (tetraethyltetramethylporphyrins) in yields of 1.4-10.8% across the concentration range of 3.75-120?mM. The yield of etioporphyrins was greater in the presence of the five-component organic mixture (6.6% at 120?mM) versus that with dodecane or mesitylene (2.1% or 2.9%, respectively). The reaction in aqueous solution with no added oil-slick constituents resulted in phase separation-where the organic reactants themselves form an upper organic layer-and the yield of etioporphyrins was 0.5-2.6%. Analogous reactions leading to uroporphyrins (hydrophilic, eight carboxylic acids) or coproporphyrins (four carboxylic acids) were unaffected by the presence of decanoic acid or dodecane, and all yields were at most ?2% or ?8%, respectively. Taken together, the results indicate a facile means for the formation of highly hydrophobic constituents of potential value for prebiotic photosynthesis.
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Hepatic schwannoma: imaging findings on CT, MRI and contrast-enhanced ultrasonography.
World J. Gastroenterol.
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A primary benign schwannoma of the liver is extremely rare and is difficult to preoperatively discriminate from a malignant tumor. We compared the imaging and pathological findings, and examined the possibility of preoperatively diagnosing a benign liver schwannoma. A 72-year-old woman was admitted to our hospital because of a 4.6-cm mass in the liver. A malignant tumor was suspected, and a right hepatectomy was performed. After this, the diagnosis of a primary benign schwannoma of the liver was made through pathological examination. Contrast-enhanced ultrasonography (CEUS) with Sonazoid showed minute blood flows into the septum and solid areas of the tumor in the vascular phase; most likely due to increased arterial flow associated with infiltration of chronic inflammatory cells. In the postvascular phase, CEUS showed contrast defect of cystic areas and delayed enhancement of solid areas; most likely due to aggregation of siderophores. Because discriminating between a benign and malignant schwannoma of the liver is difficult, surgery is generally recommended. However, the two key findings from CEUS may be useful in discriminating ancient schwannoma by recognizing the hemorrhage involved in the secondary degeneration and aggregation of siderophores.
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Development of the dorsal ramus of the spinal nerve in the chick embryo: a close relationship between development and expression of guidance cues.
Brain Res.
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The spinal nerve, which is composed of dorsal root ganglion (DRG) axons and spinal motor axons, divides into ventral and dorsal rami. Although the development of the ventral ramus has been examined in considerable detail, that of the dorsal ramus has not. Therefore, we first examined the spatial-temporal pattern of the dorsal ramus formation in the chick embryo, with special reference to the projection to the dermamyotome and its derivatives. Next, we focused on two guidance molecules, chick semaphorin 3A (SEMA3A) and fibroblast growth factor 8 (FGF8), because these are the best candidates as molecules for controlling the dorsal ramus formation. Using in situ hybridization and immunohistochemistry methods, we clearly showed a close relationship between the spatial-temporal expression of SEMA3A/FGF8 and the projection of dorsal ramus fibers to the dorsal muscles. We further examined the axonal response of motor and DRG neurons to SEMA3A and FGF8. We showed that motor axons responded to both SEMA3A-induced repulsion and FGF8-induced attraction. On the other hand, DRG axons responded to SEMA3A-induced repulsion but not to FGF8-induced attraction. These findings suggest that FGF8-induced attraction may guide early motor axons beneath the myotome and that SEMA3A-induced repulsion may prevent these early motor axons from entering the myotome. Our results also imply that the loss of SEMA3A expression in the dorsal muscles may lead to the gross projection of the dorsal ramus fibers into the dorsal muscles. Together, SEMA3A and FGF8 may contribute to the proper formation of the dorsal ramus.
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Synthesis and physicochemical properties of metallobacteriochlorins.
Inorg Chem
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Access to metallobacteriochlorins is essential for investigation of a wide variety of fundamental photochemical processes, yet relatively few synthetic metallobacteriochlorins have been prepared. Members of a set of synthetic bacteriochlorins bearing 0-4 carbonyl groups (1, 2, or 4 carboethoxy substituents, or an annulated imide moiety) were examined under two conditions: (i) standard conditions for zincation of porphyrins [Zn(OAc)(2)·2H(2)O in N,N-dimethylformamide (DMF) at 60-80 °C], and (ii) treatment in tetrahydrofuran (THF) with a strong base [e.g., NaH or lithium diisopropylamide (LDA)] followed by a metal reagent MX(n). Zincation of bacteriochlorins that bear 2-4 carbonyl groups proceeded under the former method whereas those with 0-2 carbonyl groups proceeded with NaH or LDA/THF followed by Zn(OTf)(2). The scope of metalation (via NaH or LDA in THF) is as follows: (a) for bacteriochlorins that bear two electron-releasing aryl groups, M = Cu, Zn, Pd, and InCl (but not Mg, Al, Ni, Sn, or Au); (b) for bacteriochlorins that bear two carboethoxy groups, M = Ni, Cu, Zn, Pd, Cd, InCl, and Sn (but not Mg, Al, or Au); and (c) a bacteriochlorin with four carboethoxy groups was metalated with Mg (other metals were not examined). Altogether, 15 metallobacteriochlorins were isolated and characterized. Single-crystal X-ray analysis of 8,8,18,18-tetramethylbacteriochlorin reveals the core geometry provided by the four nitrogen atoms is rectangular; the difference in length of the two sides is ?0.08 Å. Electronic characteristics of (metal-free) bacteriochlorins were probed through electrochemical measurements along with density functional theory calculation of the energies of the frontier molecular orbitals. The photophysical properties (fluorescence yields, triplet yields, singlet and triplet excited-state lifetimes) of the zinc bacteriochlorins are generally similar to those of the metal-free analogues, and to those of the native chromophores bacteriochlorophyll a and bacteriopheophytin a. The availability of diverse metallobacteriochlorins should prove useful in a variety of fundamental photochemical studies and applications.
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