Control of respiration-driven retrograde flow in the subdiaphragmatic venous return of the Fontan circulation

PubMed Central

Vukicevic, M; Conover, T; Jaeggli, M; Zhou, J; Pennati, G; Hsia, TY; Figliola, RS

2014-01-01

Respiration influences the subdiaphragmatic venous return in the total cavopulmonary connection (TCPC) of the Fontan circulation whereby both the inferior vena cava (IVC) and hepatic vein flows can experience retrograde motion. Controlling retrograde flows could improve patient outcomes. Using a patient-specific model within a Fontan mock circulatory system with respiration, we inserted a valve into the IVC to examine its effects on local hemodynamics while varying retrograde volumes by changing vascular impedances. A bovine valved conduit reduced IVC retrograde flow to within 3% of antegrade flow in all cases. The valve closed only under conditions supporting retrograde flow and its effects on local hemodynamics increased with larger retrograde volume. Liver and TCPC pressures improved only while the valve leaflets were closed while cycle-averaged pressures improved only slightly (italic>1 mm Hg). Increased pulmonary vascular resistance raised mean circulation pressures but the valve functioned and cardiac output improved and stabilized. Power loss across the TCPC improved by 12–15% (pbold>0.05) with a valve. The effectiveness of valve therapy is dependent on patient vascular impedance. PMID:24814833

Effects of low molecular sugars on the retrogradation of tapioca starch gels during storage

PubMed Central

Li, Rongfang; Kang, Huaibin; Luo, Denglin; Fan, Jinling; Zhu, Wenxue; Liu, Xinfang; Tong, Qunyi

2017-01-01

The effects of low molecular sugars (sucrose, glucose and trehalose) on the retrogradation of tapioca starch (TS) gels stored at 4°C for different periods were examined with different methods. Decrease in melting enthalpy (ΔHmelt) were obtained through differential scanning calorimetry analysis. Analysis of decrease in crystallization rate constant (k) and increase in semi-crystallization time (τ1/2) results obtained from retrogradation kinetics indicated that low molecular sugars could retard the retrogradation of TS gels and further revealed trehalose as the best inhibitor among the sugars used in this study. Fourier transform infrared (FTIR) analysis indicated that the intensity ratio of 1047 to 1022 cm−1 was increased with the addition of sugars in the order of trehalose > sucrose > glucose. Decrease in hardness parameters and increase in springiness parameters obtained from texture profile analysis (TPA) analysis also indicated that low molecular sugars could retard the retrogradation of TS gels. The results of FTIR and TPA showed a consistent sugar effect on starch retrogradation with those of DSC and retrogradation kinetics analysis. PMID:29284007

Effects of low molecular sugars on the retrogradation of tapioca starch gels during storage.

PubMed

Zhang, Xiaoyu; Li, Rongfang; Kang, Huaibin; Luo, Denglin; Fan, Jinling; Zhu, Wenxue; Liu, Xinfang; Tong, Qunyi

2017-01-01

The effects of low molecular sugars (sucrose, glucose and trehalose) on the retrogradation of tapioca starch (TS) gels stored at 4°C for different periods were examined with different methods. Decrease in melting enthalpy (ΔHmelt) were obtained through differential scanning calorimetry analysis. Analysis of decrease in crystallization rate constant (k) and increase in semi-crystallization time (τ1/2) results obtained from retrogradation kinetics indicated that low molecular sugars could retard the retrogradation of TS gels and further revealed trehalose as the best inhibitor among the sugars used in this study. Fourier transform infrared (FTIR) analysis indicated that the intensity ratio of 1047 to 1022 cm-1 was increased with the addition of sugars in the order of trehalose > sucrose > glucose. Decrease in hardness parameters and increase in springiness parameters obtained from texture profile analysis (TPA) analysis also indicated that low molecular sugars could retard the retrogradation of TS gels. The results of FTIR and TPA showed a consistent sugar effect on starch retrogradation with those of DSC and retrogradation kinetics analysis.

Modeling electric bicycle's lane-changing and retrograde behaviors

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Luo, Xiao-Feng; Zhang, Jian; Chen, Liang

2018-01-01

Recently, electric bicycle (EB) has been one important traffic tool due to its own merits. However, EB's motion behaviors (especially at a signalized/non-signalized intersection) are more complex than those of vehicle since it always has lane-changing and retrograde behaviors. In this paper, we propose a model to explore EB's lane-changing and retrograde behaviors on a road with a signalized intersection. The numerical results indicate that the proposed model can qualitatively describe each EB's lane-changing and retrograde behaviors near a signalized intersection, and that lane-changing and retrograde behaviors have prominent impacts on the signalized intersection (i.e., prominent jams and congestions occur). The above results show that EB should be controlled as a vehicle, i.e., lane-changing and retrograde behaviors at a signalized intersection should strictly be prohibited to improve the operational efficiency and traffic safety at the signalized intersection.

A retrograde object near Jupiter's orbit

NASA Astrophysics Data System (ADS)

Connors, M.; Wiegert, P.

2018-02-01

Asteroid 2007 VW266 is among the rare objects with a heliocentric retrograde orbit, and its semimajor axis is within a Hill sphere radius of that of Jupiter. This raised the interesting possibility that it could be in co-orbital retrograde resonance with Jupiter, a second "counter-orbital" object in addition to recently discovered 2015 BZ509. We find instead that the object is in 13/14 retrograde mean motion resonance (also referred to as 13/-14). The object is shown to have entered its present orbit about 1700 years ago, and it will leave it in about 8000 years, both through close approach to Jupiter. Entry and exit states both avoid 1:1 retrograde resonance, but the retrograde nature is preserved. The temporary stable state is due to an elliptic orbit with high inclination keeping nodal passages far from the associated planet. We discuss the motion of this unusual object based on modeling and theory, and its observational prospects.

The SAL-PAP Chloroplast Retrograde Pathway Contributes to Plant Immunity by Regulating Glucosinolate Pathway and Phytohormone Signaling.

PubMed

Ishiga, Yasuhiro; Watanabe, Mutsumi; Ishiga, Takako; Tohge, Takayuki; Matsuura, Takakazu; Ikeda, Yoko; Hoefgen, Rainer; Fernie, Alisdair R; Mysore, Kirankumar S

2017-10-01

Chloroplasts have a crucial role in plant immunity against pathogens. Increasing evidence suggests that phytopathogens target chloroplast homeostasis as a pathogenicity mechanism. In order to regulate the performance of chloroplasts under stress conditions, chloroplasts produce retrograde signals to alter nuclear gene expression. Many signals for the chloroplast retrograde pathway have been identified, including chlorophyll intermediates, reactive oxygen species, and metabolic retrograde signals. Although there is a reasonably good understanding of chloroplast retrograde signaling in plant immunity, some signals are not well-understood. In order to understand the role of chloroplast retrograde signaling in plant immunity, we investigated Arabidopsis chloroplast retrograde signaling mutants in response to pathogen inoculation. sal1 mutants (fry1-2 and alx8) responsible for the SAL1-PAP retrograde signaling pathway showed enhanced disease symptoms not only to the hemibiotrophic pathogen Pseudomonas syringae pv. tomato DC3000 but, also, to the necrotrophic pathogen Pectobacterium carotovorum subsp. carotovorum EC1. Glucosinolate profiles demonstrated the reduced accumulation of aliphatic glucosinolates in the fry1-2 and alx8 mutants compared with the wild-type Col-0 in response to DC3000 infection. In addition, quantification of multiple phytohormones and analyses of their gene expression profiles revealed that both the salicylic acid (SA)- and jasmonic acid (JA)-mediated signaling pathways were down-regulated in the fry1-2 and alx8 mutants. These results suggest that the SAL1-PAP chloroplast retrograde pathway is involved in plant immunity by regulating the SA- and JA-mediated signaling pathways.

Routine Use of Surgical Retrograde Transtibial Endovascular Approach for Failed Attempts at Antegrade Recanalization of Chronic Peripheral Artery Total Occlusions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, GangZhu; Zhang, FuXian, E-mail: gangzhuliang@126.com; Luo, XiaoYun

PurposeOur aim was to describe the technical aspects and clinical outcomes of an open surgical approach to retrograde transtibial endovascular therapy for recanalization of chronic total occlusions (CTOs) of peripheral arteries because of inability to acquire antegrade intravascular access across the occlusion.Materials and MethodsBetween January 2011 and May 2014, conventional antegrade revascularization failed in 15 limbs of 15 patients (11 males, 4 females) with complex CTOs. The mean age of the patients was 74 years (range 48–83 years). Five patients had severe claudication (Rutherford Category 3), and 10 patients had critical limb-threatening ischemia (Rutherford Categories 4–5). For each of these cases ofmore » antegrade failure, an open surgical exposure of the tibial or dorsalis pedis artery was used to allow a safe retrograde transtibial endovascular approach to recanalize the CTO.ResultsSurgical retrograde access from the tibial artery was achieved successfully in 14 of the 15 patients. In the 14 successful retrograde endovascular approaches, surgical retrograde transtibial access was achieved from the dorsalis pedis artery in 8 patients and from the posterior tibial artery in 6. The average time to obtain retrograde access was 5 min (range 2–11 min). No stenosis or occlusion occurred in the tibial or dorsalis pedis arteries used for the retrograde access sites during follow-up.ConclusionsRoutine surgical exposure can be a safe and an effective method for retrograde transtibial access to the more proximal occluded arterial segments in selected patients with CTO.« less

The 'SAFARI' Technique Using Retrograde Access Via Peroneal Artery Access

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhuang, Kun Da, E-mail: zkunda@gmail.com; Tan, Seck Guan; Tay, Kiang Hiong

2012-08-15

The 'SAFARI' technique or subintimal arterial flossing with antegrade-retrograde intervention is a method for recanalisation of chronic total occlusions (CTOs) when subintimal angioplasty fails. Retrograde access is usually obtained via the popliteal, distal anterior tibial artery (ATA)/dorsalis pedis (DP), or distal posterior tibial artery (PTA). Distal access via the peroneal artery has not been described and has a risk of continued bleeding, leading to compartment syndrome due to its deep location. We describe our experience in two patients with retrograde access via the peroneal artery and the use of balloon-assisted hemostasis for these retrograde punctures. This approach may potentially givemore » more options for endovascular interventions in lower limb CTOs.« less

Is retrograde drilling really useful for osteochondral lesion of talus with subchondral cyst?: A case report.

PubMed

Jeong, Seong-Yup; Kim, Jong-Kil; Lee, Kwang-Bok

2016-12-01

Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochondral lesion with subchondral cyst and discuss the mechanism involved in the development of subchondral cyst. We report a 53-year-old man who had complained left ankle pain that lasted over 6 months which was exacerbated by walking. We diagnosed it as osteochondral lesion of the talus with subchondral cyst. Plain X-ray, computed tomography, and magnetic resonance imaging (MRI) of the ankle. He undertook retrograde drilling without debridement of cartilage. After the surgery, the pain had been subsided for 1 year, although arthritic change had progressed. However, after 5 years of retrograde drilling, he revisited our hospital due to severe ankle pain. Plain X-ray and MRI showed arthritic change of the ankle and multiple cystic formation of talus. Retrograde drilling has some problem because this procedure is not theoretically correct when the development of a subchondral cyst in osteochondral lesion of the talus is considered. In addition, retrograde drilling may impair uninjured bone marrow of the talus, resulting in the development of multiple cystic formations.

Dynamics of the retrograde 1/1 mean motion resonance

NASA Astrophysics Data System (ADS)

Huang, Yukun; Li, Miao; Li, Junfeng; Gong, Shengping

2018-04-01

Mean motion resonances are very common in the solar system. Asteroids in mean motion resonances with giant planets have been studied for centuries. But it was not until recently that asteroids in retrograde mean motion resonances with Jupiter and Saturn were discovered. The newly discovered asteroid, 2015 BZ509 is confirmed to be the first asteroid in retrograde 1:1 mean motion resonance (or retrograde co-orbital resonance) with Jupiter, which gives rise to our interests in its unique resonant dynamics. In this study, we thoroughly investigate the phase-space structure of the retrograde 1:1 resonance within the framework of the circular restricted three-body problem. We begin by constructing a simple integrable approximation for the planar retrograde resonance with the Hamiltonian approach and show that the variables definition of the retrograde resonance is very different to the prograde one. When it comes to the disturbing function, we abandon the classical series expansion approach, whereas numerically carry out the averaging process on the disturbing function in closed form. The phase portrait of the retrograde 1:1 resonance is depicted with the level curves of the averaged Hamiltonian. We find that the topological structure of phase space for the retrograde 1:1 resonance is very different to other resonances, due to the consistent existence of the collision separatrix. And the surprising bifurcation of equilibrium point around 180° (i.e., the apocentric libration center) has never been found in any other mean motion resonances before. We thoroughly analyze the novel apocentric librations and find that close encounter with the planet does not always lead to the disruption of a stable apocentric libration. Afterwards, we examine the Kozai dynamics inside the mean motion resonance with the similar Hamiltonian approach and explain why the exact resonant point does not exist in the 3D retrograde 1:1 resonance model.

Retrograde motion of a rolling disk

NASA Astrophysics Data System (ADS)

Borisov, A. V.; Kilin, A. A.; Karavaev, Yu L.

2017-12-01

This paper presents results of theoretical and experimental research explaining the retrograde final-stage rolling of a disk under certain relations between its mass and geometric parameters. Modifying the no-slip model of a rolling disk by including viscous rolling friction provides a qualitative explanation for the disk’s retrograde motion. At the same time, the simple experiments described in the paper completely reject the aerodynamical drag torque as a key reason for the retro-grade motion of a disk considered, thus disproving some recent hypotheses.

Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons

PubMed Central

Chen, Xu-Qiao; Wang, Bin; Wu, Chengbiao; Pan, Jin; Yuan, Bo; Su, Yuan-Yuan; Jiang, Xing-Yu; Zhang, Xu; Bao, Lan

2012-01-01

Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals. However, the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood. Here, we report that the signals of the purinergic (P)2X3 receptor, an ATP-gated ion channel, are retrogradely transported in dorsal root ganglion (DRG) neuron axons. We found that Rab5, a small GTPase, controls the early sorting of P2X3 receptors into endosomes, while Rab7 mediates the fast retrograde transport of P2X3 receptors. Intraplantar injection and axonal application into the microfluidic chamber of α, β-methylene-ATP (α, β-MeATP), a P2X selective agonist, enhanced the endocytosis and retrograde transport of P2X3 receptors. The α, β-MeATP-induced Ca2+ influx activated a pathway comprised of protein kinase C, rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK), which associated with endocytic P2X3 receptors to form signaling endosomes. Disruption of the lipid rafts abolished the α, β-MeATP-induced ERK phosphorylation, endocytosis and retrograde transport of P2X3 receptors. Furthermore, treatment of peripheral axons with α, β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability. Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α, β-MeATP-induced retrograde signals. These results indicate that P2X3 receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels. PMID:22157653

Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons.

PubMed

Chen, Xu-Qiao; Wang, Bin; Wu, Chengbiao; Pan, Jin; Yuan, Bo; Su, Yuan-Yuan; Jiang, Xing-Yu; Zhang, Xu; Bao, Lan

2012-04-01

Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals. However, the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood. Here, we report that the signals of the purinergic (P)2X(3) receptor, an ATP-gated ion channel, are retrogradely transported in dorsal root ganglion (DRG) neuron axons. We found that Rab5, a small GTPase, controls the early sorting of P2X(3) receptors into endosomes, while Rab7 mediates the fast retrograde transport of P2X(3) receptors. Intraplantar injection and axonal application into the microfluidic chamber of α, β-methylene-ATP (α, β-MeATP), a P2X selective agonist, enhanced the endocytosis and retrograde transport of P2X(3) receptors. The α, β-MeATP-induced Ca(2+) influx activated a pathway comprised of protein kinase C, rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK), which associated with endocytic P2X(3) receptors to form signaling endosomes. Disruption of the lipid rafts abolished the α, β-MeATP-induced ERK phosphorylation, endocytosis and retrograde transport of P2X(3) receptors. Furthermore, treatment of peripheral axons with α, β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability. Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α, β-MeATP-induced retrograde signals. These results indicate that P2X(3) receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels.

Management of Endovascular Aortic Aneurysm Complications via Retrograde Catheterization Through the Distal Stent-Graft Landing Zone.

PubMed

Zhang, Xicheng; Sun, Yuan; Chen, Zhaolei; Jing, Yuanhu; Xu, Miao

2017-08-01

A retrograde technique through the gap between the distal stent landing zone and the iliac artery wall has been applied to treat type II endoleak after endovascular aortic aneurysm repair (EVAR). In this study, we tried to investigate its efficacy in the management of type III endoleak and intraoperative accidental events. We reported 2 complications of EVAR that were difficult to treat with conventional methods. One patient had a sustained type III endoleak after EVAR, and the right renal artery was accidentally sealed by a graft stent in the other patient during the operation. Both complications were managed by the retrograde technique from the distal stent landing zone. In the first case, the endoleak was easily embolized by the retrograde catheterization technique, and in the second case, a stent was implanted in the right renal artery using the retrograde technique to restore blood flow. In some EVAR cases, the technique of retrograde catheterization through the distal stent-graft landing zone is feasible, safe, and easy to perform.

Investigation of the Usability of Retrograded Flour in Meatball Production as A Structure Enhancer.

PubMed

Dinçer, Elif Aykin; Büyükkurt, Özlem Kiliç; Candal, Cihadiye; Bilgiç, Büşra Fatma; Erbaş, Mustafa

2018-02-01

This study aimed to research the possibilities of using retrograded flour produced in the laboratory environment in meatballs and the characteristics of these meatballs. In the use of retrograded flour to produce meatballs, it was ensured that the meatball properties, with respect to chemical, physical and sensorial aspects, were comparable to those of meatballs produced with bread (traditional) and rusk flour (commercial). The cooking loss of meatballs produced with using retrograded flour was similar to that of commercial meatballs. Doses of retrograded flour from 5% to 20% led to a significant decrease in cooking loss, from 21.95% to 6.19%, and in the diameter of meatballs, from 18.60% to 12.74%, but to an increase in the thickness of meatballs, from 28.82% to 41.39% compared to the control. The increase of a * and b * values was shown in that the meatballs were browned on cooking with increasing retrograded flour doses because of non-enzymatic reactions. The springiness of the traditional meatballs was significantly higher than that of the other meatballs. This might have been due to the bread crumbs having a naturally springy structure. Moreover, the addition of retrograded flour in the meatballs significantly ( p <0.05) affected the hardness, springiness and cohesiveness of the meatballs with respect to textural properties. Accordingly, it is considered that the use of 10% retrograded flour is ideal to improve the sensorial values of meatballs and the properties of their structure.

Investigation of the Usability of Retrograded Flour in Meatball Production as A Structure Enhancer

PubMed Central

2018-01-01

This study aimed to research the possibilities of using retrograded flour produced in the laboratory environment in meatballs and the characteristics of these meatballs. In the use of retrograded flour to produce meatballs, it was ensured that the meatball properties, with respect to chemical, physical and sensorial aspects, were comparable to those of meatballs produced with bread (traditional) and rusk flour (commercial). The cooking loss of meatballs produced with using retrograded flour was similar to that of commercial meatballs. Doses of retrograded flour from 5% to 20% led to a significant decrease in cooking loss, from 21.95% to 6.19%, and in the diameter of meatballs, from 18.60% to 12.74%, but to an increase in the thickness of meatballs, from 28.82% to 41.39% compared to the control. The increase of a* and b* values was shown in that the meatballs were browned on cooking with increasing retrograded flour doses because of non-enzymatic reactions. The springiness of the traditional meatballs was significantly higher than that of the other meatballs. This might have been due to the bread crumbs having a naturally springy structure. Moreover, the addition of retrograded flour in the meatballs significantly (p<0.05) affected the hardness, springiness and cohesiveness of the meatballs with respect to textural properties. Accordingly, it is considered that the use of 10% retrograded flour is ideal to improve the sensorial values of meatballs and the properties of their structure. PMID:29725226

Coronary perforation with tamponade successfully managed by retrograde and antegrade coil embolization

PubMed Central

Boukhris, Marouane; Tomasello, Salvatore Davide; Azzarelli, Salvatore; Elhadj, Zied Ibn; Marzà, Francesco; Galassi, Alfredo Ruggero

2015-01-01

In recent years, retrograde approach for chronic total occlusions has rapidly evolved, enabling a higher rate of revascularization success. Compared to septal channels, epicardial collaterals tend to be more tortuous, more difficult to negotiate, and more prone to rupture. Coronary perforation is a rare but potentially life-threatening complication of coronary angioplasty, often leading to emergency cardiac surgery. We report a case of a retrograde chronic total occlusion revascularization through epicardial collaterals, complicated by both retrograde and antegrade coronary perforation with tamponade, and successfully managed by coil embolization. PMID:26136637

The topology of connections between rat prefrontal and temporal cortices

PubMed Central

Bedwell, Stacey A.; Billett, E. Ellen; Crofts, Jonathan J.; MacDonald, Danielle M.; Tinsley, Chris J.

2015-01-01

Understanding the structural organization of the prefrontal cortex (PFC) is an important step toward determining its functional organization. Here we investigated the organization of PFC using different neuronal tracers. We injected retrograde (Fluoro-Gold, 100 nl) and anterograde [Biotinylated dextran amine (BDA) or Fluoro-Ruby, 100 nl] tracers into sites within PFC subdivisions (prelimbic, ventral orbital, ventrolateral orbital, dorsolateral orbital) along a coronal axis within PFC. At each injection site one injection was made of the anterograde tracer and one injection was made of the retrograde tracer. The projection locations of retrogradely labeled neurons and anterogradely labeled axon terminals were then analyzed in the temporal cortex: area Te, entorhinal and perirhinal cortex. We found evidence for an ordering of both the anterograde (anterior-posterior, dorsal-ventral, and medial-lateral axes: p < 0.001) and retrograde (anterior-posterior, dorsal-ventral, and medial-lateral axes: p < 0.001) connections of PFC. We observed that anterograde and retrograde labeling in ipsilateral temporal cortex (i.e., PFC inputs and outputs) often occurred reciprocally (i.e., the same brain region, such as area 35d in perirhinal cortex, contained anterograde and retrograde labeling). However, often the same specific columnar temporal cortex regions contained only either labeling of retrograde or anterograde tracer, indicating that PFC inputs and outputs are frequently non-matched. PMID:26042005

Periprocedural ischaemia during recanalisation of chronic total coronary occlusions: the influence of the transcollateral retrograde approach.

PubMed

Werner, Gerald S; Coenen, Anja; Tischer, Karl-Heinz

2014-11-01

Percutaneous coronary intervention for chronic total coronary occlusions (CTO) becomes increasingly more complex with the transcollateral retrograde approach. This study assesses the effect of the retrograde approach on markers of ischaemia and clinical events. Four hundred and ninety-two consecutive procedures in 392 patients were prospectively evaluated. Before and within 18-24 hours after the PCI creatine kinase (CK) and cardiac troponin I (cTnI) were obtained. A CK increase of greater than three times the upper limit of normal (ULN) was considered a periprocedural MI. Patients with initially elevated cTnI were excluded. In 106 patients with a retrograde wire passage of the septal collaterals, the incidence of a CK or TnI increase was higher as compared to the antegrade group. Patients with septal dilatation or passage of a dilatation catheter (Corsair) showed the highest cTnI. There was no difference in cardiac death or cerebral complications between the groups with antegrade and retrograde approach within the first 30 days. Complex retrograde recanalisation procedures for CTOs lead to an increased periprocedural ischaemic burden, most likely due to obstruction of the collateral pathway, and to the increased plaque burden of complex lesions treated with the retrograde approach.

Live cell imaging of mitochondrial movement along actin cables in budding yeast.

PubMed

Fehrenbacher, Kammy L; Yang, Hyeong-Cheol; Gay, Anna Card; Huckaba, Thomas M; Pon, Liza A

2004-11-23

Mitochondrial inheritance is essential for cell division. In budding yeast, mitochondrial movement from mother to daughter requires (1) actin cables, F-actin bundles that undergo retrograde movement during elongation from buds into mother cells; (2) the mitochore, a mitochondrial protein complex implicated in linking mitochondria to actin cables; and (3) Arp2/3 complex-mediated force generation on mitochondria. We observed three new classes of mitochondrial motility: anterograde movement at velocities of 0.2-0.33 microm/s, retrograde movement at velocities of 0.26-0.51 microm/s, and no net anterograde or retrograde movement. In all cases, motile mitochondria were associated with actin cables undergoing retrograde flow at velocities of 0.18-0.62 microm/s. Destabilization of actin cables or mutations of the mitochore blocked all mitochondrial movements. In contrast, mutations in the Arp2/3 complex affected anterograde but not retrograde mitochondrial movements. Actin cables are required for movement of mitochondria, secretory vesicles, mRNA, and spindle alignment elements in yeast. We provide the first direct evidence that one of the proposed cargos use actin cables as tracks. In the case of mitochondrial inheritance, anterograde movement drives transfer of the organelle from mothers to buds, while retrograde movement contributes to retention of the organelle in mother cells. Interaction of mitochondria with actin cables is required for anterograde and retrograde movement. In contrast, force generation on mitochondria is required only for anterograde movement. Finally, we propose a novel mechanism in which actin cables serve as "conveyor belts" that drive retrograde organelle movement.

Using Kinesthetic Activities to Teach Ptolemaic and Copernican Retrograde Motion

ERIC Educational Resources Information Center

Richards, Ted

2012-01-01

This paper describes a method for teaching planetary retrograde motion, and the Ptolemaic and Copernican accounts of retrograde motion, by means of a series kinesthetic learning activities (KLAs). In the KLAs described, the students literally walk through the motions of the planets in both systems. A retrospective statistical analysis shows that…

Criteria for retrograde rotation of accreting black holes

NASA Astrophysics Data System (ADS)

Mikhailov, A. G.; Piotrovich, M. Yu; Gnedin, Yu N.; Natsvlishvili, T. M.; Buliga, S. D.

2018-06-01

Rotating supermassive black holes produce jets and their origin is connected to the magnetic field that is generated by accreting matter flow. There is a point of view that electromagnetic fields around rotating black holes are brought to the hole by accretion. In this situation the prograde accreting discs produce weaker large-scale black hole threading magnetic fields, implying weaker jets than in retrograde regimes. The basic goal of this paper is to find the best candidates for retrograde accreting systems in observed active galactic nuclei. We show that active galactic nuclei with low Eddington ratio are really the best candidates for retrograde systems. This conclusion is obtained for kinetically dominated Fanaroff-Riley class II radio galaxies, flat-spectrum radio-loud narrow-line Seyfert I galaxies and a number of nearby galaxies. Our conclusion is that the best candidates for retrograde systems are the noticeable population of active galactic nuclei in the Universe. This result corresponds to the conclusion that in the merging process the interaction of merging black holes with a retrograde circumbinary disc is considerably more effective for shrinking the binary system.

A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots

NASA Astrophysics Data System (ADS)

Zhou, Nan; Hao, Zeyu; Zhao, Xiaohuan; Maharjan, Suraj; Zhu, Shoujun; Song, Yubin; Yang, Bai; Lu, Laijin

2015-09-01

The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers. Electronic supplementary information (ESI) available: PL spectra of CTB; absorption spectra of dialysate; fluorescence signal and immunohistochemical staining of CTB-CDs in L4 DRG. See DOI: 10.1039/c5nr04361a

Using Kinesthetic Activities to Teach Ptolemaic and Copernican Retrograde Motion

NASA Astrophysics Data System (ADS)

Richards, Ted

2012-06-01

This paper describes a method for teaching planetary retrograde motion, and the Ptolemaic and Copernican accounts of retrograde motion, by means of a series kinesthetic learning activities (KLAs). In the KLAs described, the students literally walk through the motions of the planets in both systems. A retrospective statistical analysis shows that students who participated in these activities performed better on examination questions pertaining to retrograde motion than students who did not. Potential explanations for this result, including the breaking of classroom routine, the effect of body movement on conceptual memory, and egocentric spatial proprioception, are considered.

The epithelial cell cytoskeleton and intracellular trafficking. I. Shiga toxin B-subunit system: retrograde transport, intracellular vectorization, and more.

PubMed

Johannes, Ludger

2002-07-01

Many intracellular transport routes are still little explored. This is particularly true for retrograde transport between the plasma membrane and the endoplasmic reticulum. Shiga toxin B subunit has become a powerful tool to study this pathway, and recent advances on the molecular mechanisms of transport in the retrograde route and on its physiological function(s) are summarized. Furthermore, it is discussed how the study of retrograde transport of Shiga toxin B subunit allows one to design new methods for the intracellular delivery of therapeutic compounds.

Real-time visualization and quantification of retrograde cardioplegia delivery using near infrared fluorescent imaging.

PubMed

Rangaraj, Aravind T; Ghanta, Ravi K; Umakanthan, Ramanan; Soltesz, Edward G; Laurence, Rita G; Fox, John; Cohn, Lawrence H; Bolman, R M; Frangioni, John V; Chen, Frederick Y

2008-01-01

Homogeneous delivery of cardioplegia is essential for myocardial protection during cardiac surgery. Presently, there exist no established methods to quantitatively assess cardioplegia distribution intraoperatively and determine when retrograde cardioplegia is required. In this study, we evaluate the feasibility of near infrared (NIR) imaging for real-time visualization of cardioplegia distribution in a porcine model. A portable, intraoperative, real-time NIR imaging system was utilized. NIR fluorescent cardioplegia solution was developed by incorporating indocyanine green (ICG) into crystalloid cardioplegia solution. Real-time NIR imaging was performed while the fluorescent cardioplegia solution was infused via the retrograde route in five ex vivo normal porcine hearts and in five ex vivo porcine hearts status post left anterior descending (LAD) coronary artery ligation. Horizontal cross-sections of the hearts were obtained at proximal, middle, and distal LAD levels. Videodensitometry was performed to quantify distribution of fluorophore content. The progressive distribution of cardioplegia was clearly visualized with NIR imaging. Complete visualization of retrograde distribution occurred within 4 minutes of infusion. Videodensitometry revealed retrograde cardioplegia, primarily distributed to the left ventricle (LV) and anterior septum. In hearts with LAD ligation, antegrade cardioplegia did not distribute to the anterior LV. This deficiency was compensated for with retrograde cardioplegia supplementation. Incorporation of ICG into cardioplegia allows real-time visualization of cardioplegia delivery via NIR imaging. This technology may prove useful in guiding intraoperative decisions pertaining to when retrograde cardioplegia is mandated.

Optimal Timing for Laparoscopic Cholecystectomy After Endoscopic Retrograde Cholangiopancreatography: A Systematic Review.

PubMed

Friis, C; Rothman, J P; Burcharth, J; Rosenberg, J

2018-06-01

Endoscopic retrograde cholangiopancreatography followed by laparoscopic cholecystectomy is often used as definitive treatment for common bile duct stones. The aim of this study was to investigate the optimal time interval between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy. PubMed and Embase were searched for studies comparing different time delays between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy. Observational studies and randomized controlled trials were included. Primary outcome was conversion rate from laparoscopic to open cholecystectomy and secondary outcomes were complications, mortality, operating time, and length of stay. A total of 14 studies with a total of 1930 patients were included. The pooled estimate revealed an increase from a 4.2% conversion rate when laparoscopic cholecystectomy was performed within 24 h of endoscopic retrograde cholangiopancreatography to 7.6% for 24-72 h delay to 12.3% when performed within 2 weeks, to 12.3% for 2-6 weeks, and to a 14% conversion rate when operation was delayed more than 6 weeks. According to this systematic review, it is preferable to perform cholecystectomy within 24 h of endoscopic retrograde cholangiopancreatography to reduce conversion rate. Early laparoscopic cholecystectomy does not increase mortality, perioperative complications, or length of stay and on the contrary it reduces the risk of reoccurrence and progression of disease in the delay between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy.

Magnetic susceptibility of ultrahigh pressure eclogite: The role of retrogression

NASA Astrophysics Data System (ADS)

Xu, Haijun; Jin, Zhenmin; Mason, Roger; Ou, Xingong

2009-09-01

Retrograde metamorphism played the dominant role in changing the low-field rock magnetic properties and density of 198 specimens of variably retrograded eclogites from the main borehole of the Chinese Continental Scientific Drilling Project (CCSD) and from surface outcrops in the Donghai area in the southern part of the Sulu UHP belt, China. Bulk magnetic susceptibility ( κ) of unretrogressed UHP eclogite is controlled by whole-rock chemical composition and ranges from 397 to 2312 μSI with principal magnetic susceptibility carrying minerals paramagnetic garnet, omphacite, rutile and phengite. Partially retrograded eclogites show large variations in magnetic susceptibility between 804 and 24,277 μSI, with high mean magnetic susceptibility values of 4372 ± 4149 μSI caused by appreciable amounts of Fe-Ti oxide minerals such as magnetite, ilmenite and/or titanohematite produced by retrograde metamorphic reactions. Completely retrograded eclogites have lower susceptibilities of 1094 ± 600 μSI and amphibolite facies mineral assemblages lacking high magnetic susceptibility minerals. Jelínek's corrected anisotropy ( Pj) of eclogites ranges from 1.001 to 1.540, and shows a positive correlation with low-field magnetic susceptibility ( κ). Arithmetic mean bulk density ( ρ) shows a steady decrease from 3.54 ± 0.11 g/cm 3 (fresh eclogite) to 2.98 ± 0.06 g/cm 3 (completely retrograded eclogite). Retrograde metamorphic changes in mineral composition during exhumation appear to be the major factor causing variations in low field magnetic susceptibility and anisotropy. Retrograde processes must be taken into account when interpreting magnetic surveys and geophysical well logs in UHP metamorphic terranes, and petrophysical properties such as density and low-field magnetic susceptibility could provide a means for semi-quantifying the degree of retrogression of eclogite during exhumation.

Impact of Retrograde Arch Extension in Acute Type B Aortic Dissection on Management and Outcomes.

PubMed

Nauta, Foeke J H; Tolenaar, Jip L; Patel, Himanshu J; Appoo, Jehangir J; Tsai, Thomas T; Desai, Nimesh D; Montgomery, Daniel G; Mussa, Firas F; Upchurch, Gilbert R; Fattori, Rosella; Hughes, G Chad; Nienaber, Christoph A; Isselbacher, Eric M; Eagle, Kim A; Trimarchi, Santi

2016-12-01

Optimal management of acute type B aortic dissection with retrograde arch extension is controversial. The effect of retrograde arch extension on operative and long-term mortality has not been studied and is not incorporated into clinical treatment pathways. The International Registry of Acute Aortic Dissection was queried for all patients presenting with acute type B dissection and an identifiable primary intimal tear. Outcomes were stratified according to management for patients with and without retrograde arch extension. Kaplan-Meier survival curves were constructed. Between 1996 and 2014, 404 patients (mean age, 63.3 ± 13.9 years) were identified. Retrograde arch extension existed in 67 patients (16.5%). No difference in complicated presentation was noted (36.8% vs 31.7%, p = 0.46), as defined by limb or organ malperfusion, coma, rupture, and shock. Patients with or without retrograde arch extension received similar treatment, with medical management in 53.7% vs 56.5% (p = 0.68), endovascular treatment in 32.8% vs 31.1% (p = 0.78), open operation in 11.9% vs 9.5% (p = 0.54), or hybrid approach in 1.5% vs 3.0% (p = 0.70), respectively. The in-hospital mortality rate was similar for patients with (10.7%) and without (10.4%) retrograde arch extension (p = 0.96), and 5-year survival was also similar at 78.3% and 77.8%, respectively (p = 0.27). The incidence of retrograde arch dissection involves approximately 16% of patients with acute type B dissection. In the International Registry of Acute Aortic Dissection, this entity seems not to affect management strategy or early and late death. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

On remembering and forgetting our autobiographical pasts: retrograde amnesia and Andrew Mayes's contribution to neuropsychological method.

PubMed

Kopelman, M D; Bright, P

2012-11-01

Andrew Mayes's contribution to the neuropsychology of memory has consisted in steadily teasing out the nature of the memory deficit in the amnesic syndrome. This has been done with careful attention to matters of method at all stages. This particularly applies to his investigations of forgetting rates in amnesia and to his studies of retrograde amnesia. Following a brief outline of his work, the main current theories of retrograde amnesia are considered: consolidation theory, episodic-to-semantic shift theory, and multiple trace theory. Findings across the main studies in Alzheimer dementia are reviewed to illustrate what appears to be consistently found, and what is much more inconsistent. A number of problems and issues in current theories are then highlighted--including the nature of the temporal gradient, correlations with the extent of temporal lobe damage, what we would expect 'normal' remote memory curves to look like, how they would appear in focal retrograde amnesia, and whether we can pinpoint retrograde amnesia to hippocampal/medial temporal damage on the basis of existing studies. A recent study of retrograde amnesia is re-analysed to demonstrate temporal gradients on recollected episodic memories in hippocampal/medial temporal patients. It is concluded that there are two requirements for better understanding of the nature of retrograde amnesia: (i) a tighter, Mayesian attention to method in terms of both the neuropsychology and neuroimaging in investigations of retrograde amnesia; and (ii) acknowledging that there may be multiple factors underlying a temporal gradient, and that episodic and semantic memory show important interdependencies at both encoding and retrieval. Such factors may be critical to understanding what is remembered and what is forgotten from our autobiographical pasts. Copyright © 2012 Elsevier Ltd. All rights reserved.

A retrograde apoptotic signal originating in NGF-deprived distal axons of rat sympathetic neurons in compartmented cultures.

PubMed

Mok, Sue-Ann; Lund, Karen; Campenot, Robert B

2009-05-01

Previous investigations of retrograde survival signaling by nerve growth factor (NGF) and other neurotrophins have supported diverse mechanisms, but all proposed mechanisms have in common the generation of survival signals retrogradely transmitted to the neuronal cell bodies. We report the finding of a retrograde apoptotic signal in axons that is suppressed by local NGF signaling. NGF withdrawal from distal axons alone was sufficient to activate the pro-apoptotic transcription factor, c-jun, in the cell bodies. Providing NGF directly to cell bodies, thereby restoring a source of NGF-induced survival signals, could not prevent c-jun activation caused by NGF withdrawal from the distal axons. This is evidence that c-jun is not activated due to loss of survival signals at the cell bodies. Moreover, blocking axonal transport with colchicine inhibited c-jun activation caused by NGF deprivation suggesting that a retrogradely transported pro-apoptotic signal, rather than loss of a retrogradely transported survival signal, caused c-jun activation. Additional experiments showed that activation of c-jun, pro-caspase-3 cleavage, and apoptosis were blocked by the protein kinase C inhibitors, rottlerin and chelerythrine, only when applied to distal axons suggesting that they block the axon-specific pro-apoptotic signal. The rottlerin-sensitive mechanism was found to regulate glycogen synthase kinase 3 (GSK3) activity. The effect of siRNA knockdown, and pharmacological inhibition of GSK3 suggests that GSK3 is required for apoptosis caused by NGF deprivation and may function as a retrograde carrier of the axon apoptotic signal. The existence of a retrograde death signaling system in axons that is suppressed by neurotrophins has broad implications for neurodevelopment and for discovering treatments for neurodegenerative diseases and neurotrauma.

Chronic total occlusion in ostium of right coronary artery – retrograde approach as the first-choice method of revascularization?

PubMed Central

Kameczura, Tomasz; Surowiec, Sławomir; Januś, Bogdan; Derlaga, Bogusław; Dudek, Dariusz; Czarnecka, Danuta

2013-01-01

Recanalization of chronic total occlusion (CTO) located in the ostium may require the operator's ability to use the retrograde approach. We present a case of opening a chronically occluded right coronary artery (RCA) by the retrograde approach after an unsuccessful attempt of recanalization by classic antegrade technique. PMID:24570749

Factors Influencing Cecal Intubation Time during Retrograde Approach Single-Balloon Enteroscopy

PubMed Central

Chen, Peng-Jen; Shih, Yu-Lueng; Huang, Hsin-Hung; Hsieh, Tsai-Yuan

2014-01-01

Background and Aim. The predisposing factors for prolonged cecal intubation time (CIT) during colonoscopy have been well identified. However, the factors influencing CIT during retrograde SBE have not been addressed. The aim of this study was to determine the factors influencing CIT during retrograde SBE. Methods. We investigated patients who underwent retrograde SBE at a medical center from January 2011 to March 2014. The medical charts and SBE reports were reviewed. The patients' characteristics and procedure-associated data were recorded. These data were analyzed with univariate analysis as well as multivariate logistic regression analysis to identify the possible predisposing factors. Results. We enrolled 66 patients into this study. The median CIT was 17.4 minutes. With univariate analysis, there was no statistical difference in age, sex, BMI, or history of abdominal surgery, except for bowel preparation (P = 0.021). Multivariate logistic regression analysis showed that inadequate bowel preparation (odds ratio 30.2, 95% confidence interval 4.63–196.54; P < 0.001) was the independent predisposing factors for prolonged CIT during retrograde SBE. Conclusions. For experienced endoscopist, inadequate bowel preparation was the independent predisposing factor for prolonged CIT during retrograde SBE. PMID:25505904

Scanning electron microscopy (SEM) evaluation of sealing ability of MTA and EndoSequence as root-end filling materials with chitosan and carboxymethyl chitosan (CMC) as retrograde smear layer removing agents.

PubMed

Nagesh, Bolla; Jeevani, Eppala; Sujana, Varri; Damaraju, Bharagavi; Sreeha, Kaluvakolanu; Ramesh, Penumaka

2016-01-01

The purpose of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA) and EndoSequence with chitosan and carboxymethyl chitosan (CMC) as retrograde smear layer removing agents using scanning electron microscopy (SEM). Forty human single rooted teeth were taken. Crowns were decoronated and canals were obturated. Apically roots were resected and retrograde cavities were done. Based on the type of retrograde material placed and the type of smear layer removal agent used for retrograde cavities, they were divided into four groups (N = 10): Group I chitosan with EndoSequence, group II chitosan with MTA, group III CMC with EndoSequence, and Group IV CMC with MTA. All the samples were longitudinally sectioned, and the SEM analysis was done for marginal adaptation. Kruskal-Wallis and Mann-Witney analysis tests. SEM images showed the presence of less gaps in group III, i.e., CMC with EndoSequence when compared to other groups with statistically significant difference. Within the limited scope of this study, it was concluded that EndoSequence as retrograde material showed better marginal sealing ability.

Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate.

PubMed

Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Sahraoui

2016-01-01

High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed.

Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate

PubMed Central

Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Sahraoui

2016-01-01

High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed. PMID:27219066

Refinement of ERCP by using the Olympus V-scope system with a 0.025 in. compatible and complete fixable Visiglide(®) guidewire.

PubMed

Raithel, Martin; Naegel, Andreas; Seidel, Sebastian; Raithel, Sandra; Diebel, Hiwot; Neurath, Markus F; Maiss, Juergen

2011-10-01

Prospective evaluation of the new 0.025 in. Visiglide(®) guidewire to facilitate endoscopic retrograde cholangiopancreaticography using the Olympus V-scope. Interventional endoscopic retrograde cholangiopancreaticography was performed in 9 patients with the Olympus V-scope and the 0.025 in. Visiglide(®) guidewire (VS group), whilst 9 other patients underwent endoscopic retrograde cholangiopancreaticography with a conventional Olympus duodenoscope using 0.035 in. conventional guidewires (controls). Exchange time of accessories, X-ray time, dose and endoscopic retrograde cholangiopancreaticography examination time were investigated. The VS group showed a significantly lower exchange time of endoscopic retrograde cholangiopancreaticography accessories (9; 4-10s, p<0.0001) than controls (29; 19-44s). The Visiglide(®) guidewire was complete fixable by the elevator in 35/36 instrument exchanges (97%) compared to 16/31 exchanges (52%) using conventional guidewires. Single-centre study, small patient numbers, two investigators. Endoscopic retrograde cholangiopancreaticography using the Olympus V-scope with the new 0.025 in. Visiglide(®) guidewire enables a 3-fold faster exchange of accessories due to a nearly complete fixation of the guidewire. Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Physiologic responses to forward and retrograde simulated stair stepping.

PubMed

Ryan, P T; Plowman, S A; Ball, T E; Looney, M A

1994-07-01

This study compared the physiologic responses to forward and retrograde simulated stair stepping on the StairMaster 4000 PT. Twenty male subjects (mean age 23.65 +/- 1.63 years) volunteered for this study. Subjects completed a practice trial of 6 minutes of both forward and retrograde stepping at Level 5. Each experimental trial was divided into four 3-minute stages: Level 3, Level 5, Level 7, and Level 9. Heart rate, blood pressure, and rating of perceived exertion (RPE) were recorded during the second minute of each stage. Expired gases were analyzed and averaged over the last 2 minutes of each stage. Caloric expenditure and delta efficiency were later calculated. Data were analyzed using a 2 x 4 ANOVA (direction by level) and 2 x 3 ANOVA (for delta efficiency). Compared to forward responses, retrograde heart rates were significantly higher at Levels 7 and 9 (p < 0.01). Retrograde responses for RPE, metabolic equivalents (METS), and caloric expenditure were significantly higher at (p < 0.01) Levels 5, 7, and 9 when compared to forward responses. However, the results of this study show that these differences between forward and retrograde stepping are not practically meaningful.

Real-time Visualization and Quantification of Retrograde Cardioplegia Delivery using Near Infrared Fluorescent Imaging

PubMed Central

Rangaraj, Aravind T.; Ghanta, Ravi K.; Umakanthan, Ramanan; Soltesz, Edward G.; Laurence, Rita G.; Fox, John; Cohn, Lawrence H.; Bolman, R. M.; Frangioni, John V.; Chen, Frederick Y.

2009-01-01

Background and Aim of the Study Homogeneous delivery of cardioplegia is essential for myocardial protection during cardiac surgery. Presently, there exist no established methods to quantitatively assess cardioplegia distribution intraoperatively and determine when retrograde cardioplegia is required. In this study, we evaluate the feasibility of near infrared (NIR) imaging for real-time visualization of cardioplegia distribution in a porcine model. Methods A portable, intraoperative, real-time NIR imaging system was utilized. NIR fluorescent cardioplegia solution was developed by incorporating indocyanine green (ICG) into crystalloid cardioplegia solution. Real-time NIR imaging was performed while the fluorescent cardioplegia solution was infused via the retrograde route in 5 ex-vivo normal porcine hearts and in 5 ex-vivo porcine hearts status post left anterior descending (LAD) coronary artery ligation. Horizontal cross-sections of the hearts were obtained at proximal, middle, and distal LAD levels. Videodensitometry was performed to quantify distribution of fluorophore content. Results The progressive distribution of cardioplegia was clearly visualized with NIR imaging. Complete visualization of retrograde distribution occurred within 4 minutes of infusion. Videodensitometry revealed that retrograde cardioplegia primarily distributed to the left ventricle and anterior septum. In hearts with LAD ligation, antegrade cardioplegia did not distribute to the anterior left ventricle. This deficiency was compensated for with retrograde cardioplegia supplementation. Conclusions Incorporation of ICG into cardioplegia allows real-time visualization of cardioplegia delivery via NIR imaging. This technology may prove useful in guiding intraoperative decisions pertaining to when retrograde cardioplegia is mandated. PMID:19016995

The inherent catastrophic traps in retrograde CTO PCI.

PubMed

Wu, Eugene B; Tsuchikane, Etsuo

2018-05-01

When we learn to drive, our driving instructor tells us how to check the side mirror and turn your head to check the blind spot before changing lanes. He tells us how to stop at stop signs, how to drive in slippery conditions, the safe stopping distances, and these all make our driving safe. Similarly, when we learn PCI, our mentors teach us to seat the guiding catheter co-axially, to wire the vessel safely, to deliver balloon and stents over the wire, to watch the pressure of the guiding, in order that we perform PCI safely and evade complications. In retrograde CTO PCI, there is no such published teaching. Also many individual mentors have not had the wide experience to see all the possible complications of retrograde CTO PCI and, therefore, may not be able to warn their apprentice. As the number of retrograde procedures increase worldwide, there is a corresponding increase in catastrophic complications, many of which, we as experts, can see are easily avoidable. To breach this gap in knowledge, this article describes 12 commonly met inherent traps in retrograde CTO PCI. They are inherent because by arranging our equipment in the manner to perform retrograde CTO PCI, these complications are either induced directly or happen easily. We hope this work will enhance safety of retrograde CTO PCI and avoid many catastrophic complications for our readers and operators. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention – a step by step practical approach and an observational study

PubMed Central

Fang, Hsiu-Yu; Lee, Wei-Chieh; Fang, Chih-Yuan; Wu, Chiung-Jen

2016-01-01

Abstract Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the “snare technique.” We retrospectively examined the use of “snare technique” among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015. “Snare technique” was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without “snare technique” were similar. The “snare technique” group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P < 0.001). The contrast volume was significantly lower in the “snare technique” group (285.0 ± 68.5 vs 379.2 ± 144.0, P = 0.04). The incidence of major complications, retrograde success, or final success did not differ between the groups. The “snare technique” is safe and feasible in retrograde CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter. PMID:27741138

Surfing the Sec61 channel: bidirectional protein translocation across the ER membrane.

PubMed

Römisch, K

1999-12-01

Misfolded secretory and transmembrane proteins are retained in the endoplasmic reticulum (ER) and subsequently degraded. Degradation is primarily mediated by cytosolic proteasomes and thus requires retrograde transport out of the ER back to the cytosol. The available evidence suggests that the protein-conducting channel formed by the Sec61 complex is responsible for both forward and retrograde transport of proteins across the ER membrane. For transmembrane proteins, retrograde transport can be viewed as a reversal of integration of membrane proteins into the ER membrane. Retrograde transport of soluble proteins through the Sec61 channel after signal-peptide cleavage, however, must be mechanistically distinct from signal-peptide-mediated import into the ER through the same channel.

TCTEX1D2 mutations underlie Jeune asphyxiating thoracic dystrophy with impaired retrograde intraflagellar transport.

PubMed

Schmidts, Miriam; Hou, Yuqing; Cortés, Claudio R; Mans, Dorus A; Huber, Celine; Boldt, Karsten; Patel, Mitali; van Reeuwijk, Jeroen; Plaza, Jean-Marc; van Beersum, Sylvia E C; Yap, Zhi Min; Letteboer, Stef J F; Taylor, S Paige; Herridge, Warren; Johnson, Colin A; Scambler, Peter J; Ueffing, Marius; Kayserili, Hulya; Krakow, Deborah; King, Stephen M; Beales, Philip L; Al-Gazali, Lihadh; Wicking, Carol; Cormier-Daire, Valerie; Roepman, Ronald; Mitchison, Hannah M; Witman, George B

2015-06-05

The analysis of individuals with ciliary chondrodysplasias can shed light on sensitive mechanisms controlling ciliogenesis and cell signalling that are essential to embryonic development and survival. Here we identify TCTEX1D2 mutations causing Jeune asphyxiating thoracic dystrophy with partially penetrant inheritance. Loss of TCTEX1D2 impairs retrograde intraflagellar transport (IFT) in humans and the protist Chlamydomonas, accompanied by destabilization of the retrograde IFT dynein motor. We thus define TCTEX1D2 as an integral component of the evolutionarily conserved retrograde IFT machinery. In complex with several IFT dynein light chains, it is required for correct vertebrate skeletal formation but may be functionally redundant under certain conditions.

Reducing retrogradation and lipid oxidation of normal and glutinous rice flours by adding mango peel powder.

PubMed

Siriamornpun, Sirithon; Tangkhawanit, Ekkarat; Kaewseejan, Niwat

2016-06-15

Green and ripe mango peel powders (MPP) were added to normal rice flour (NRF) and glutinous rice flour (GRF) at three levels (400, 800 and 1200 ppm) and their effects on physicochemical properties and lipid oxidation inhibition were investigated. Overall, MPP increased the breakdown viscosity and reduced the final viscosity in rice flours when compared to the control. Decreasing in retrogradation was observed in both NRF and GRF with MPP added of all levels. MPP addition also significantly inhibited the lipid oxidation of all flours during storage (30 days). Retrogradation values were strongly negatively correlated with total phenolic and flavonoid contents, but not with fiber content. The hydrogen bonds and hydrophilic interactions between phenolic compounds with amylopectin molecule may be involved the decrease of starch retrogradation, especially GRF. We suggest that the addition of MPP not only reduced the retrogradation but also inhibited the lipid oxidation of rice flour. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quality assessment of noodles made from blends of rice flour and canna starch.

PubMed

Wandee, Yuree; Uttapap, Dudsadee; Puncha-arnon, Santhanee; Puttanlek, Chureerat; Rungsardthong, Vilai; Wetprasit, Nuanchawee

2015-07-15

Canna starch and its derivatives (retrograded, retrograded debranched, and cross-linked) were evaluated for their suitability to be used as prebiotic sources in a rice noodle product. Twenty percent of the rice flour was replaced with these tested starches, and the noodles obtained were analyzed for morphology, cooking qualities, textural properties, and capability of producing short-chain fatty acids (SCFAs). Cross-linked canna starch could increase tensile strength and elongation of rice noodles. Total dietary fiber (TDF) content of noodles made from rice flour was 3.0% and increased to 5.1% and 7.3% when rice flour was replaced with retrograded and retrograded debranched starches, respectively. Cooking qualities and textural properties of noodles containing 20% retrograded debranched starch were mostly comparable, while the capability of producing SCFAs and butyric acid was superior to the control rice noodles; the cooked noodle strips also showed fewer tendencies to stick together. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Viral Receptor Complementation Strategy to Overcome CAV-2 Tropism for Efficient Retrograde Targeting of Neurons.

PubMed

Li, Shu-Jing; Vaughan, Alexander; Sturgill, James Fitzhugh; Kepecs, Adam

2018-06-06

Retrogradely transported neurotropic viruses enable genetic access to neurons based on their long-range projections and have become indispensable tools for linking neural connectivity with function. A major limitation of viral techniques is that they rely on cell-type-specific molecules for uptake and transport. Consequently, viruses fail to infect variable subsets of neurons depending on the complement of surface receptors expressed (viral tropism). We report a receptor complementation strategy to overcome this by potentiating neurons for the infection of the virus of interest-in this case, canine adenovirus type-2 (CAV-2). We designed AAV vectors for expressing the coxsackievirus and adenovirus receptor (CAR) throughout candidate projection neurons. CAR expression greatly increased retrograde-labeling rates, which we demonstrate for several long-range projections, including some resistant to other retrograde-labeling techniques. Our results demonstrate a receptor complementation strategy to abrogate endogenous viral tropism and thereby facilitate efficient retrograde targeting for functional analysis of neural circuits. Copyright © 2018 Elsevier Inc. All rights reserved.

Retrograde Signaling as a Mechanism of Yeast Adaptation to Unfavorable Factors.

PubMed

Trendeleva, T A; Zvyagilskaya, R A

2018-02-01

Mitochondria perform many essential functions in eukaryotic cells. Being the main producers of ATP and the site of many catabolic and anabolic reactions, they participate in intracellular signaling, proliferation, aging, and formation of reactive oxygen species. Mitochondrial dysfunction is the cause of many diseases and even cell death. The functioning of mitochondria in vivo is impossible without interaction with other cellular compartments. Mitochondrial retrograde signaling is a signaling pathway connecting mitochondria and the nucleus. The major signal transducers in the yeast retrograde response are Rtg1p, Rtg2p, and Rtg3p proteins, as well as four additional negative regulatory factors - Mks1p, Lst8p, and two 14-3-3 proteins (Bmh1/2p). In this review, we analyze current information on the retrograde signaling in yeast that is regarded as a stress or homeostatic response mechanism to changes in various metabolic and biosynthetic activities that occur upon mitochondrial dysfunction. We also discuss relations between retrograde signaling and other signaling pathways in the cell.

A versatile nanobody-based toolkit to analyze retrograde transport from the cell surface.

PubMed

Buser, Dominik P; Schleicher, Kai D; Prescianotto-Baschong, Cristina; Spiess, Martin

2018-06-18

Retrograde transport of membranes and proteins from the cell surface to the Golgi and beyond is essential to maintain homeostasis, compartment identity, and physiological functions. To study retrograde traffic biochemically, by live-cell imaging or by electron microscopy, we engineered functionalized anti-GFP nanobodies (camelid VHH antibody domains) to be bacterially expressed and purified. Tyrosine sulfation consensus sequences were fused to the nanobody for biochemical detection of trans -Golgi arrival, fluorophores for fluorescence microscopy and live imaging, and APEX2 (ascorbate peroxidase 2) for electron microscopy and compartment ablation. These functionalized nanobodies are specifically captured by GFP-modified reporter proteins at the cell surface and transported piggyback to the reporters' homing compartments. As an application of this tool, we have used it to determine the contribution of adaptor protein-1/clathrin in retrograde transport kinetics of the mannose-6-phosphate receptors from endosomes back to the trans -Golgi network. Our experiments establish functionalized nanobodies as a powerful tool to demonstrate and quantify retrograde transport pathways.

How long will asteroids on retrograde orbits survive?

NASA Astrophysics Data System (ADS)

Kankiewicz, Paweł; Włodarczyk, Ireneusz

2018-05-01

Generally, a common scenario for the origin of minor planets with high orbital inclinations does not exist. This applies especially to objects whose orbital inclinations are much greater than 90° (retrograde asteroids). Since the discovery of Dioretsa in 1999, approximately 100 small bodies now are classified as retrograde asteroids. A small number of them were reclassified as comets, due to cometary activity. There are only 25 multi-opposition retrograde asteroids, with a relatively large number of observations and well-determined orbits. We studied the orbital evolution of numbered and multi-opposition retrograde asteroids by numerical integration up to 1 Gy forward and backward in time. Additionally, we analyzed the propagation of orbital elements with the observational errors, determined dynamical lifetimes and studied their chaotic properties. Conclusively, we obtained quantitative parameters describing the long-term stability of orbits relating to the past and the future. In turn, we were able to estimate their lifetimes and how long these objects will survive in the Solar System.

Retrograde adsorption isotherms: an impossible fact?

PubMed

Helfferich, Friedrich G

2005-06-24

"Retrograde" adsorption isotherms have been reported, but seem to violate thermodynamics and would cause concentration steps to migrate against the direction of fluid-phase flow. In general, what appears to be retrograde behavior is caused by one or more additional, uncontrolled variables. This is illustrated with adsorption of sulfonate on a weak-acid ion exchanger, where adsorption is accompanied by partial conversion of the ion exchanger to the sodium form.

Rescue percutaneous coronary recanalization of right coronary artery by retrograde approach

PubMed Central

Kameczura, Tomasz; Surowiec, Sławomir; Dudek, Dariusz; Czarnecka, Danuta

2013-01-01

We describe the case of a 62-year-old female patient in whom there was an occlusion of collaterals and acute inferior wall ischemia during the opening procedure of right coronary artery (RCA) chronic total occlusion. Rescue percutaneous coronary intervention (PCI) of RCA by the retrograde approach was performed preventing heart muscle damage. In this article we discuss the issue of PCI by the retrograde technique. PMID:24570712

Loss of Huntingtin stimulates capture of retrograde dense-core vesicles to increase synaptic neuropeptide stores.

PubMed

Bulgari, Dinara; Deitcher, David L; Levitan, Edwin S

2017-08-01

The Huntington's disease protein Huntingtin (Htt) regulates axonal transport of dense-core vesicles (DCVs) containing neurotrophins and neuropeptides. DCVs travel down axons to reach nerve terminals where they are either captured in synaptic boutons to support later release or reverse direction to reenter the axon as part of vesicle circulation. Currently, the impact of Htt on DCV dynamics in the terminal is unknown. Here we report that knockout of Drosophila Htt selectively reduces retrograde DCV flux at proximal boutons of motoneuron terminals. However, initiation of retrograde transport at the most distal bouton and transport velocity are unaffected suggesting that synaptic capture rate of these retrograde DCVs could be altered. In fact, tracking DCVs shows that retrograde synaptic capture efficiency is significantly elevated by Htt knockout or knockdown. Furthermore, synaptic boutons contain more neuropeptide in Htt knockout larvae even though bouton size, single DCV fluorescence intensity, neuropeptide release in response to electrical stimulation and subsequent activity-dependent capture are unaffected. Thus, loss of Htt increases synaptic capture as DCVs travel by retrograde transport through boutons resulting in reduced transport toward the axon and increased neuropeptide in the terminal. These results therefore identify native Htt as a regulator of synaptic capture and neuropeptide storage. Copyright © 2017 Elsevier GmbH. All rights reserved.

Long-term retrograde amnesia...the crucial role of the hippocampus.

PubMed

Cipolotti, L; Shallice, T; Chan, D; Fox, N; Scahill, R; Harrison, G; Stevens, J; Rudge, P

2001-01-01

For patients with hippocampal pathology, disagreement exists in the literature over whether retrograde amnesia is temporally limited or very extensive depending on whether the anatomical damage is restricted to this structure or also involves additional temporal cortex. We report a comprehensive assessment of retrograde and anterograde memory functions of a severely global amnesic patient (VC). We found that he presented with a remarkably extensive and basically ungraded retrograde amnesia. This impairment profoundly affected four decades preceding the onset of his amnesia and encompassed both non personal and personal facts and events. VC also presented with a severe anterograde amnesia and a deficit in the acquisition of new semantic knowledge in the post-morbid period. Detailed MRI volumetric measurements revealed gross abnormalities in both hippocampi which were markedly shrunken. Of relevance to the debate on retrograde amnesia were the observations that the volumes of both entorhinal cortices and the remainder of both temporal lobes were normal. These data suggest that the hippocampus is critical not only for the efficient encoding and hence normal recall of new information but also for the recall of episodic information acquired before the onset of amnesia. Our results are compatible with the view that retrograde amnesia is both extensive and ungraded when the damage is limited to the hippocampus.

"Rendezvous in coronary" technique with the retrograde approach for chronic total occlusion.

PubMed

Muramatsu, Toshiya; Tsukahara, Reiko; Ito, Yoshiaki

2010-09-01

Percutaneous coronary intervention (PCI) was performed for a chronic total occlusion (CTO) of the right coronary artery (RCA) in a 77-year-old male patient. A guidewire could not be passed through the vessel using the antegrade approach, so we tried the retrograde approach via a collateral septal channel. A Fielder FC guidewire (Asahi Intecc Co. Ltd., Aichi, Japan) was passed through the septal channel, and a Corsair catheter (Asahi Intecc) was advanced to the distal side of the CTO in the RCA. However, the guidewire could not be advanced from the false lumen to the true lumen using the kissing-wire technique (KWT) or the reverse controlled antegrade retrograde tracking (CART) technique. Therefore, we retracted the Corsair channel dilator for a #4PD and tried to advance the antegrade Conquest Pro guidewire (Asahi Intecc) from a straight subintimal site into the retrograde channel dilator catheter. After several attempts, the antegrade Conquest guidewire successfully entered the retrograde channel dilator catheter. Subsequently, a Cypher stent (Cordis Corp., Miami Lakes, Florida) was successfully placed. The "rendezvous in coronary" technique was useful for this CTO patient, in whom it was difficult to advance a guidewire into the true lumen by the KWT and CART techniques during the retrograde approach.

Kinesin Khc-73/KIF13B modulates retrograde BMP signaling by influencing endosomal dynamics at the Drosophila neuromuscular junction

PubMed Central

Gray, Lindsay; Tsurudome, Kazuya; El-Mounzer, Wassim; Elazzouzi, Fatima; Baim, Christopher; Calderon, Mario R.; Kauwe, Grant

2018-01-01

Retrograde signaling is essential for neuronal growth, function and survival; however, we know little about how signaling endosomes might be directed from synaptic terminals onto retrograde axonal pathways. We have identified Khc-73, a plus-end directed microtubule motor protein, as a regulator of sorting of endosomes in Drosophila larval motor neurons. The number of synaptic boutons and the amount of neurotransmitter release at the Khc-73 mutant larval neuromuscular junction (NMJ) are normal, but we find a significant decrease in the number of presynaptic release sites. This defect in Khc-73 mutant larvae can be genetically enhanced by a partial genetic loss of Bone Morphogenic Protein (BMP) signaling or suppressed by activation of BMP signaling in motoneurons. Consistently, activation of BMP signaling that normally enhances the accumulation of phosphorylated form of BMP transcription factor Mad in the nuclei, can be suppressed by genetic removal of Khc-73. Using a number of assays including live imaging in larval motor neurons, we show that loss of Khc-73 curbs the ability of retrograde-bound endosomes to leave the synaptic area and join the retrograde axonal pathway. Our findings identify Khc-73 as a regulator of endosomal traffic at the synapse and modulator of retrograde BMP signaling in motoneurons. PMID:29373576

Simultaneous Antegrade-Retrograde Subintimal Revascularization of a Femoropopliteal Chronic Total Occlusion by a Reentry Device-Facilitated Puncture of a Retrogradely Inserted Balloon.

PubMed

Goltz, Jan Peter; Anton, Susanne; Wiedner, Marcus; Barkhausen, Jörg; Stahlberg, Erik

2017-08-01

To report a rendezvous technique for subintimal revascularization of a chronic total occlusion (CTO) of the superficial femoral artery (SFA). This maneuver is appropriate after failure to cross a long SFA CTO via intra- and subintimal approaches from the ipsilateral femoral as well as retrograde posterior tibial artery (PTA) access sites. After predilation of the subintimal space from the femoral access, a reentry device was placed at the level of the first popliteal artery segment. A balloon was delivered via the retrograde PTA access and inflated at the corresponding level of the reentry device. The balloon was punctured with the needle of the reentry device under fluoroscopic control, and a 0.014-inch guidewire was placed within the punctured balloon. The balloon and the antegrade guidewire were retracted from the retrograde access while the guidewire was gently pushed from the femoral site. Conventional balloon angioplasty of the SFA occlusion was performed via the femoral access, followed by overlapping stent-graft implantation. Complete revascularization of the CTO was documented. In selected cases a transfemoral reentry device-assisted puncture of a retrogradely inserted balloon within the subintimal space may facilitate a rendezvous and revascularization if standard techniques to cross long CTOs have failed.

JNK-Interacting Protein 3 Mediates the Retrograde Transport of Activated c-Jun N-Terminal Kinase and Lysosomes

PubMed Central

Drerup, Catherine M.; Nechiporuk, Alex V.

2013-01-01

Retrograde axonal transport requires an intricate interaction between the dynein motor and its cargo. What mediates this interaction is largely unknown. Using forward genetics and a novel in vivo imaging approach, we identified JNK-interacting protein 3 (Jip3) as a direct mediator of dynein-based retrograde transport of activated (phosphorylated) c-Jun N-terminal Kinase (JNK) and lysosomes. Zebrafish jip3 mutants (jip3nl7) displayed large axon terminal swellings that contained high levels of activated JNK and lysosomes, but not other retrograde cargos such as late endosomes and autophagosomes. Using in vivo analysis of axonal transport, we demonstrated that the terminal accumulations of activated JNK and lysosomes were due to a decreased frequency of retrograde movement of these cargos in jip3nl7, whereas anterograde transport was largely unaffected. Through rescue experiments with Jip3 engineered to lack the JNK binding domain and exogenous expression of constitutively active JNK, we further showed that loss of Jip3–JNK interaction underlies deficits in pJNK retrograde transport, which subsequently caused axon terminal swellings but not lysosome accumulation. Lysosome accumulation, rather, resulted from loss of lysosome association with dynein light intermediate chain (dynein accessory protein) in jip3nl7, as demonstrated by our co-transport analyses. Thus, our results demonstrate that Jip3 is necessary for the retrograde transport of two distinct cargos, active JNK and lysosomes. Furthermore, our data provide strong evidence that Jip3 in fact serves as an adapter protein linking these cargos to dynein. PMID:23468645

The neuroinvasive profiles of H129 (herpes simplex virus type 1) recombinants with putative anterograde-only transneuronal spread properties.

PubMed

Wojaczynski, Gregory J; Engel, Esteban A; Steren, Karina E; Enquist, Lynn W; Patrick Card, J

2015-01-01

The use of viruses as transneuronal tracers has become an increasingly powerful technique for defining the synaptic organization of neural networks. Although a number of recombinant alpha herpesviruses are known to spread selectively in the retrograde direction through neural circuits only one strain, the H129 strain of herpes simplex virus type 1, is reported to selectively spread in the anterograde direction. However, it is unclear from the literature whether there is an absolute block or an attenuation of retrograde spread of H129. Here, we demonstrate efficient anterograde spread, and temporally delayed retrograde spread, of H129 and three novel recombinants. In vitro studies revealed no differences in anterograde and retrograde spread of parental H129 and its recombinants through superior cervical ganglion neurons. In vivo injections of rat striatum revealed a clear bias of anterograde spread, although evidence of deficient retrograde transport was also present. Evidence of temporally delayed retrograde transneuronal spread of H129 in the retina was observed following injection of the lateral geniculate nucleus. The data also demonstrated that three novel recombinants efficiently express unique fluorescent reporters and have the capacity to infect the same neurons in dual infection paradigms. From these experiments we conclude that H129 and its recombinants not only efficiently infect neurons through anterograde transneuronal passage, but also are capable of temporally delayed retrograde transneuronal spread. In addition, the capacity to produce dual infection of projection targets following anterograde transneuronal passage provides an important addition to viral transneuronal tracing technology.

Electroconvulsive therapy-induced persistent retrograde amnesia: could it be minimised by ketamine or other pharmacological approaches?

PubMed

Gregory-Roberts, Emily M; Naismith, Sharon L; Cullen, Karen M; Hickie, Ian B

2010-10-01

Certain pharmacological agents administered during electroconvulsive therapy may have the potential to prevent persistent retrograde amnesia induced during electroconvulsive therapy. This review examines mechanisms for electroconvulsive therapy-induced retrograde amnesia, and evaluates the suitability of the anaesthetic ketamine for preventing this amnestic outcome. A review of human studies, animal models and theoretical models in light of memory dysfunction following electroconvulsive therapy was conducted. MEDLINE was searched from 1950 to April 2009 using the MeSH terms "electroconvulsive therapy", "memory", "memory short term", "memory disorders", "excitatory amino acid antagonists", and "ketamine". PREMEDLINE was searched using the terms "electroconvulsive therapy", "amnesia" and "ketamine". Additional keyword and reference list searches were performed. No language, date constraints or article type constraints were used. Disruption of long term potentiation as a mechanism for electroconvulsive therapy-induced retrograde amnesia is well supported. Based on this putative mechanism, an N-methyl-D-aspartate receptor antagonist would appear suitable for preventing the retrograde amnesia. Available evidence in animals and humans supports the prediction that ketamine, an anaesthetic agent and N-methyl-D-aspartate receptor antagonist, could effectively prevent electroconvulsive therapy-induced persistent retrograde amnesia. Whilst there are concerns about the use of ketamine with electroconvulsive therapy, such as possible psychotomimetic effects, on balance this anaesthetic agent may improve or hasten clinical response to electroconvulsive therapy. A clinical trial is warranted to determine if ketamine anaesthesia during electroconvulsive therapy can lessen persistent retrograde amnesia and improve therapeutic response. Electroconvulsive therapy with ketamine anaesthesia may provide effective antidepressant action with minimal side effects. Copyright 2009 Elsevier B.V. All rights reserved.

The Neuroinvasive Profiles of H129 (Herpes Simplex Virus Type 1) Recombinants with Putative Anterograde-Only Transneuronal Spread Properties

PubMed Central

Wojaczynski, Gregory J.; Engel, Esteban A.; Steren, Karina E.; Enquist, Lynn W.; Card, J. Patrick

2014-01-01

The use of viruses as transneuronal tracers has become an increasingly powerful technique for defining the synaptic organization of neural networks. Although a number of recombinant alpha herpesviruses are known to spread selectively in the retrograde direction through neural circuits only one strain, the H129 strain of herpes simplex virus type 1, is reported to selectively spread in the anterograde direction. However, it is unclear from the literature whether there is an absolute block or an attenuation of retrograde spread of H129. Here we demonstrate efficient anterograde spread, and temporally delayed retrograde spread, of H129 and three novel recombinants. In vitro studies revealed no differences in anterograde and retrograde spread of parental H129 and its recombinants through superior cervical ganglion neurons. In vivo injections of rat striatum revealed a clear bias of anterograde spread, although evidence of deficient retrograde transport was also present. Evidence of temporally delayed retrograde transneuronal spread of H129 in the retina was observed following injection of the lateral geniculate nucleus. The data also demonstrated that three novel recombinants efficiently express unique fluorescent reporters and have the capacity to infect the same neurons in dual infection paradigms. From these experiments we conclude that H129 and its recombinants efficiently infect neurons through anterograde transneuronal passage, but also are capable of temporally delayed retrograde transneuronal spread. In addition, the capacity to produce dual infection of projection targets following anterograde transneuronal passage provides an important addition to viral transneuronal tracing technology. PMID:24585022

DOD Needs to Improve Management and Oversight of Operations at the Theater Retrograde- Camp Arifjan, Kuwait

DTIC Science & Technology

2010-09-30

only at the TRC (includes Retro Sort), Warehouse, and Bulk Yard. 2 Theater Retrograde The Theater Retrograde consists of the TRC (includes Retro Sort...through Kuwait. Figure 1. Proper Flow of Materiel from Iraq through Kuwait Note 1: We reviewed operations at the TRC, Retro Sort, Warehouse...Materiel Processing Instructions CIIC Definition 1 Highest Sensitivity - Non-nuclear missiles and rockets , launcher tube and explosive rounds 2 Highest

Healthy live birth using theophylline in a case of retrograde ejaculation and absolute asthenozoospermia.

PubMed

Ebner, Thomas; Shebl, Omar; Mayer, Richard Bernhard; Moser, Marianne; Costamoling, Walter; Oppelt, Peter

2014-02-01

To analyze whether the use of ready-to-use theophylline is a feasible option in a case of retrograde ejaculation and absolute asthenozoospermia. Case report. In vitro fertilization unit of a public hospital. Thirty-one-year-old nulliparous woman, and 39-year-old male with retrograde ejaculation and absolute asthenozoospermia. Retrieval of postejaculatory urine, restoration of motility using a methylxanthine, intracytoplasmic sperm injection, single-embryo transfer. Sperm motility, fertilization, embryo quality, live birth. Successful fertilization and a single-embryo transfer resulted in a healthy live birth. Theophylline turned out to be a safe, efficient agent for stimulating immotile spermatozoa in patients with retrograde ejaculation. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Post-Golgi anterograde transport requires GARP-dependent endosome-to-TGN retrograde transport.

PubMed

Hirata, Tetsuya; Fujita, Morihisa; Nakamura, Shota; Gotoh, Kazuyoshi; Motooka, Daisuke; Murakami, Yoshiko; Maeda, Yusuke; Kinoshita, Taroh

2015-09-01

The importance of endosome-to-trans-Golgi network (TGN) retrograde transport in the anterograde transport of proteins is unclear. In this study, genome-wide screening of the factors necessary for efficient anterograde protein transport in human haploid cells identified subunits of the Golgi-associated retrograde protein (GARP) complex, a tethering factor involved in endosome-to-TGN transport. Knockout (KO) of each of the four GARP subunits, VPS51-VPS54, in HEK293 cells caused severely defective anterograde transport of both glycosylphosphatidylinositol (GPI)-anchored and transmembrane proteins from the TGN. Overexpression of VAMP4, v-SNARE, in VPS54-KO cells partially restored not only endosome-to-TGN retrograde transport, but also anterograde transport of both GPI-anchored and transmembrane proteins. Further screening for genes whose overexpression normalized the VPS54-KO phenotype identified TMEM87A, encoding an uncharacterized Golgi-resident membrane protein. Overexpression of TMEM87A or its close homologue TMEM87B in VPS54-KO cells partially restored endosome-to-TGN retrograde transport and anterograde transport. Therefore GARP- and VAMP4-dependent endosome-to-TGN retrograde transport is required for recycling of molecules critical for efficient post-Golgi anterograde transport of cell-surface integral membrane proteins. In addition, TMEM87A and TMEM87B are involved in endosome-to-TGN retrograde transport. © 2015 Hirata, Fujita, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Acute inhibition of diacylglycerol lipase blocks endocannabinoid-mediated retrograde signalling: evidence for on-demand biosynthesis of 2-arachidonoylglycerol

PubMed Central

Hashimotodani, Yuki; Ohno-Shosaku, Takako; Tanimura, Asami; Kita, Yoshihiro; Sano, Yoshikazu; Shimizu, Takao; Di Marzo, Vincenzo; Kano, Masanobu

2013-01-01

The endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) produced by diacylglycerol lipase α (DGLα) is one of the best-characterized retrograde messengers at central synapses. It has been thought that 2-AG is produced ‘on demand’ upon activation of postsynaptic neurons. However, recent studies propose that 2-AG is pre-synthesized by DGLα and stored in neurons, and that 2-AG is released from such ‘pre-formed pools’ without the participation of DGLα. To address whether the 2-AG source for retrograde signalling is the on-demand biosynthesis by DGLα or the mobilization from pre-formed pools, we examined the effects of acute pharmacological inhibition of DGL by a novel potent DGL inhibitor, OMDM-188, on retrograde eCB signalling triggered by Ca2+ elevation, Gq/11 protein-coupled receptor activation or synergy of these two stimuli in postsynaptic neurons. We found that pretreatment for 1 h with OMDM-188 effectively blocked depolarization-induced suppression of inhibition (DSI), a purely Ca2+-dependent form of eCB signalling, in slices from the hippocampus, striatum and cerebellum. We also found that at parallel fibre–Purkinje cell synapses in the cerebellum OMDM-188 abolished synaptically induced retrograde eCB signalling, which is known to be caused by the synergy of postsynaptic Ca2+ elevation and group I metabotropic glutamate receptor (I-mGluR) activation. Moreover, brief OMDM-188 treatments for several minutes were sufficient to suppress both DSI and the I-mGluR-induced retrograde eCB signalling in cultured hippocampal neurons. These results are consistent with the hypothesis that 2-AG for synaptic retrograde signalling is supplied as a result of on-demand biosynthesis by DGLα rather than mobilization from presumptive pre-formed pools. PMID:23858009

Golgi-to-Endoplasmic Reticulum (ER) Retrograde Traffic in Yeast Requires Dsl1p, a Component of the ER Target Site that Interacts with a COPI Coat Subunit

PubMed Central

Reilly, Barbara A.; Kraynack, Bryan A.; VanRheenen, Susan M.; Waters, M. Gerard

2001-01-01

DSL1 was identified through its genetic interaction with SLY1, which encodes a t-SNARE-interacting protein that functions in endoplasmic reticulum (ER)-to-Golgi traffic. Conditional dsl1 mutants exhibit a block in ER-to-Golgi traffic at the restrictive temperature. Here, we show that dsl1 mutants are defective for retrograde Golgi-to-ER traffic, even under conditions where no anterograde transport block is evident. These results suggest that the primary function of Dsl1p may be in retrograde traffic, and that retrograde defects can lead to secondary defects in anterograde traffic. Dsl1p is an ER-localized peripheral membrane protein that can be extracted from the membrane in a multiprotein complex. Immunoisolation of the complex yielded Dsl1p and proteins of ∼80 and ∼55 kDa. The ∼80-kDa protein has been identified as Tip20p, a protein that others have shown to exist in a tight complex with Sec20p, which is ∼50 kDa. Both Sec20p and Tip20p function in retrograde Golgi-to-ER traffic, are ER-localized, and bind to the ER t-SNARE Ufe1p. These findings suggest that an ER-localized complex of Dsl1p, Sec20p, and Tip20p functions in retrograde traffic, perhaps upstream of a Sly1p/Ufe1p complex. Last, we show that Dsl1p interacts with the δ-subunit of the retrograde COPI coat, Ret2p, and discuss possible roles for this interaction. PMID:11739780

An innovative approach for rubber dam isolation of root end tip: A case report.

PubMed

Mittal, Sunandan; Kumar, Tarun; Mittal, Shifali; Sharma, Jyotika

2015-01-01

The success of an apicoectomy with a retrofilling is dependent upon obtaining an acceptable apical seal. The placement of the variously approved retrograde materials requires adequate access, visibility, lighting, and a sterile dry environment. There are instances, however, in which it is difficult to use the rubber dam. One such instance is during retrograde filling. This case report highlights an innovative technique for rubber dam isolation of root end retrograde filling.

Successful Treatment of Mesenteric Varices After Living Donor Liver Transplantation with Retrograde Transvenous Obliteration Via an Abdominal Wall Vein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikeda, Osamu, E-mail: osamu-3643ik@do9.enjoy.ne.jp; Tamura, Yoshitaka; Nakasone, Yutaka

2010-06-15

Balloon-occluded retrograde transvenous obliteration is an established treatment for gastric varices; it has been used more rarely to treat mesenteric varices. We report a 12-year-old girl who had received a living donor liver transplant and suffered melena due to ruptured mesenteric varices. We addressed treatment of the mesenteric varices by retrograde transvenous obliteration of an abdominal wall collateral vein detected by superior mesenteric arteriography.

Experimental comparison of manually inflatable versus autoinflatable retrograde cardioplegia catheters.

PubMed

Menasché, P

1994-08-01

A pig model of cardiopulmonary bypass and cardioplegic arrest was used to compare leakage around manually inflatable and autoinflatable retrograde coronary sinus cardioplegia catheters. Warm and cold blood cardioplegia were alternately delivered through the catheter under study at both low (16 to 24 mm Hg) and high (30 to 40 mm Hg) perfusion pressures. During each experiment, the coronary sinus ostium was sealed around the shaft of the retrograde cannula so that all backflow occurring during cardioplegia delivery could be collected by a separate drainage catheter inserted directly into the coronary sinus approximately midway between the right atrium and the distal end of the balloon. Only two of the 52 manually inflatable cannulas leaked. The leakage in both cases was negligible (< 1% of the total retrograde cardioplegia flow). In contrast, leakage occurred with 57 of the 73 autoinflatable devices tested (p < 0.0001) and averaged 22% +/- 3% (mean +/- the standard error of the mean) of the total retrograde flow. The temperature of the cardioplegia solution had no effect on leakage. These results suggest that autoinflatable balloons inconsistently seal the coronary sinus during cardioplegia infusion, thereby decreasing the amount of flow that effectively reaches the myocardium. This should make surgeons cautious about using them with warm blood cardioplegia, which largely relies upon the delivery of sufficiently high retrograde nutritive flows for preventing cardioprotective aerobic arrest from becoming a life-threatening ischemic arrest.

Rate of Subtalar Joint Arthrodesis After Retrograde Tibiotalocalcaneal Arthrodesis With Intramedullary Nail Fixation: Evaluation of the RAIN Database.

PubMed

Dujela, Michael; Hyer, Christopher F; Berlet, Gregory C

2017-11-01

Hindfoot arthritis or significant deformity involving the ankle and subtalar joint (STJ) is a disabling condition with few salvage options. Many surgeons note a decreased STJ fusion rate compared with ankle union when a retrograde nail construct is used. The purpose of this study was to report the STJ fusion rate of tibiotalocalcaneal (TTC) arthrodesis with retrograde nail. A chart and radiographic review was performed. TTC fusions performed in patients with osteoarthritis, posttraumatic arthritis, or deformity correction with retrograde nail fixation were included. Exclusion criteria included neuropathy, Charcot arthropathy, and failed total ankle replacement. Ultimately, 66 retrograde TTC fusions (in 63 patients) met inclusion criteria. The average age was 57.0 years. There were 29 female and 34 male patients. Radiographic fusion of the ankle and STJ was demonstrated in 68.2% of the patients. There were 11 cases (16.7%) of ankle arthrodesis with STJ nonunion, 6 cases (9.1%) of STJ fusion but ankle nonunion, and 4 cases (6.1%) of stable radiographic nonunion of both joints. The mean time to subtalar fusion was 112.1 days. One patient required revision surgery and conversion to below-knee amputation. One patient required a CROW walker for assistance with gait. A 22.8% radiographic nonunion rate of the STJ was noted in retrograde TTC fusion. Despite this, patients were stable and pain free. Level IV: Retrospective Case series.

Apical/Retrograde Periimplantitis/Implant Periapical Lesion: Etiology, Risk Factors, and Treatment Options: A Systematic Review.

PubMed

Ramanauskaite, Ausra; Juodzbalys, Gintaras; Tözüm, Tolga F

2016-10-01

To review the literature on retrograde periimplantitis symptoms, risk factors, and treatment methods and to propose a decision-making tree of retrograde periimplantitis management. An electronic literature search was conducted on the MEDLINE and EMBASE databases for articles published between 1990 and 2015. Clinical human studies in the English language were included. The search resulted in 44 case reports published by 27 authors. The average time of the diagnosis of the pathology was found to be 26.07 weeks after implant placement (SD ± 39.7). Fistula formation was found to be the most common clinical symptom, statistically significantly more often occurring in the maxilla (P = 0.04). A negative correlation was found between pain and the adjacent tooth with incomplete endodontic treatment/endodontic pathology (r = -0.4; P = 0.009) and a positive correlation between the later risk factor and implant removal (r = 0.3; P = 0.028). Regenerative treatment (45.2% of the cases) or implant removal (35.7% of the cases) was the most common treatment techniques used. A decision-making tree of retrograde periimplantitis management is suggested. The etiology of retrograde periimplantitis is most often infectious. A decision-making tree aimed at managing patients with retrograde periimplantitis according to the possible etiology and symptoms of the disease can be a useful tool in the treatment of the pathology.

Integrating bio-prosthetic valves in the Fontan operation - Novel treatment to control retrograde flow in caval veins

NASA Astrophysics Data System (ADS)

Vukicevic, Marija; Conover, Timothy; Zhou, Jian; Hsia, Tain-Yen; Figliola, Richard

2012-11-01

For a child born with only one functional heart ventricle, the sequence of palliative surgeries typically culminates in the Fontan operation. This procedure is usually successful initially, but leads to later complications, for reasons not fully understood. Examples are respiratory-dependent retrograde flows in the caval and hepatic veins, and increased pulmonary vascular resistance (PVR), hypothesized to be responsible for elevated pressure in the liver and disease of the liver and intestines. Here we study the parameters responsible for retrograde flows in the inferior vena cava (IVC) and hepatic vein (HV), and investigate two novel interventions to control retrograde flow: implanting either a Medtronic Contegra valved conduit or an Edwards lifescience pericardial aortic valve in the IVC or HV. We performed the experiments in a multi-scale, patient specific mock circuit, with normal and elevated PVR, towards the optimization of the Fontan circulation. The results show that both valves can significantly reduce retrograde flows in the veins, suggesting potential advantages in the treatment of the patients with congenital heart diseases. Fondation Leducq

The postsynaptic t-SNARE Syntaxin 4 controls traffic of Neuroligin 1 and Synaptotagmin 4 to regulate retrograde signaling.

PubMed

Harris, Kathryn P; Zhang, Yao V; Piccioli, Zachary D; Perrimon, Norbert; Littleton, J Troy

2016-05-25

Postsynaptic cells can induce synaptic plasticity through the release of activity-dependent retrograde signals. We previously described a Ca(2+)-dependent retrograde signaling pathway mediated by postsynaptic Synaptotagmin 4 (Syt4). To identify proteins involved in postsynaptic exocytosis, we conducted a screen for candidates that disrupted trafficking of a pHluorin-tagged Syt4 at Drosophila neuromuscular junctions (NMJs). Here we characterize one candidate, the postsynaptic t-SNARE Syntaxin 4 (Syx4). Analysis of Syx4 mutants reveals that Syx4 mediates retrograde signaling, modulating the membrane levels of Syt4 and the transsynaptic adhesion protein Neuroligin 1 (Nlg1). Syx4-dependent trafficking regulates synaptic development, including controlling synaptic bouton number and the ability to bud new varicosities in response to acute neuronal stimulation. Genetic interaction experiments demonstrate Syx4, Syt4, and Nlg1 regulate synaptic growth and plasticity through both shared and parallel signaling pathways. Our findings suggest a conserved postsynaptic SNARE machinery controls multiple aspects of retrograde signaling and cargo trafficking within the postsynaptic compartment.

Laparoscopic diagnosis of retrograde peristalsis and intussusception in Roux-en-Y limb after laparoscopic gastrectomy: A case report.

PubMed

Yoshiyama, Shigeyuki; Toiyama, Yuji; Ichikawa, Takashi; Shimura, Tadanobu; Yasuda, Hiromi; Hiro, Jun-Ichiro; Ohi, Masaki; Araki, Toshimitsu; Kusunoki, Masato

2018-06-05

The cause of jejunojejunal intussusception, a rare complication after Roux-en-Y gastric surgery, remains unclear. Here, we present a case of retrograde jejunojejunal intussusception that occurred after laparoscopic distal gastrectomy with Roux-en-Y reconstruction. A 51-year-old woman who had undergone laparoscopic distal gastrectomy and Roux-en-Y reconstruction for early gastric cancer 6 years previously was admitted to our hospital with abdominal pain. Abdominal CT revealed the "target sign," and she was diagnosed as having small bowel intussusception. Laparoscopic surgery resulted in a diagnosis of retrograde intussusception of the distal jejunum of the Roux-en-Y anastomosis with retrograde peristalsis in the same area. The Roux-en-Y anastomosis site and intussuscepted segment were resected laparoscopically. To the best of our knowledge, this is the first report of laparoscopic diagnosis of retrograde peristalsis in the distal jejunum of a Roux-en-Y anastomosis. Additionally, relevant published reports concerning this unusual condition are discussed. © 2018 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Transport According to GARP: Receiving Retrograde Cargo at the Trans-Golgi Network

PubMed Central

Bonifacino, Juan S.; Hierro, Aitor

2010-01-01

Tethering factors are large protein complexes that capture transport vesicles and enable their fusion with acceptor organelles at different stages of the endomembrane system. Recent studies have shed new light on the structure and function of a heterotetrameric tethering factor named Golgi-associated retrograde protein (GARP), which promotes fusion of endosome-derived, retrograde transport carriers to the trans-Golgi network (TGN). X-ray crystallography of the Vps53 and Vps54 subunits of GARP has revealed that this complex is structurally related to other tethering factors such as the exocyst, COG and Dsl1, indicating that they all might work by a similar mechanism. Loss of GARP function compromises the growth, fertility and/or viability of the defective organisms, underscoring the essential nature of GARP-mediated retrograde transport. PMID:21183348

A Novel, Modified Reverse Controlled Antegrade and Retrograde Subintimal Tracking Technique for Bypassing the Calcified Proximal Cap of Coronary Total Occlusions

PubMed Central

Ochiai, Masahiko; Munehisa, Masato; Ootomo, Tatsushi

2017-01-01

Antegrade crossing is the most common approach to chronic total occlusions (CTOs). However, it is sometimes difficult to penetrate the proximal hard cap with guidewires, especially in the case of CTOs of anomalous coronary arteries because of a lack of support. Herein, we describe a novel, modified reverse controlled antegrade and retrograde subintimal tracking (CART) technique in which the dissection reentry was intentionally created in the proximal segment of the vessel, not within the occluded segment, using retrograde guidewire and the aid of an antegrade balloon. This technique facilitated retrograde crossing of CTOs by avoiding the proximal hard cap and may provide a viable option for patients in which conventional reverse CART is not possible. PMID:28529807

Neurocognitive and Biomarker Evaluation of Combination mTBI from Blast Overpressure and Traumatic Stress

DTIC Science & Technology

2014-11-01

that the BOP produced a retrograde amnesia . In this regard, it is notable that the BOP exposures took place beginning at ~22 hours after the IES. It is...followed a passive avoidance task (Ahlers et al., 2012). Typically, more severe injuries are required to produce a retrograde amnesia for events already...although to a lesser degree than the sham-BOP treatment group. Thus, the retrograde amnesia would have to be characterized as partial. While a

Interventricular Septal Hematoma and Coronary-Ventricular Fistula: A Complication of Retrograde Chronic Total Occlusion Intervention

PubMed Central

Abdel-karim, Abdul-rahman R.; Main, Michael L.

2016-01-01

Interventricular septal hematoma is a rare complication of retrograde chronic total occlusion (CTO) percutaneous coronary interventions (PCI) with a typically benign course. Here we report two cases of interventricular septal hematoma and coronary-cameral fistula development after right coronary artery (RCA) CTO-PCI using a retrograde approach. Both were complicated by development of ST-segment elevation and chest pain. One case was managed actively and the other conservatively, both with a favorable outcome. PMID:27668097

Antegrade rewiring of the retrograde Corsair catheter during revascularization of chronic total coronary occlusions: a simple alternative to guidewire exteriorization.

PubMed

Haworth, P A J; Hildick-Smith, D

2014-08-01

Chronic total occlusions prevent a significant challenge to interventional cardiologists. Successful opening of chronically occluded vessels has been shown to be associated with decreased mortality and morbidity. Recently, the retrograde approach to chronic total occlusion intervention has been developed. In this case series, we present a novel technique to assist with this procedure involving antegrade wiring of a retrograde microcatheter. © 2011 Wiley Periodicals, Inc., a Wiley company.

EARTH, MOON, SUN, AND CV ACCRETION DISKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montgomery, M. M.

2009-11-01

Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths'more » equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if accretion disks are present or not. Our results suggest that the accretion disk's geometric shape directly affects the disk's precession rate.« less

Retrograde resonance in the planar three-body problem

NASA Astrophysics Data System (ADS)

Morais, M. H. M.; Namouni, F.

2013-12-01

We continue the investigation of the dynamics of retrograde resonances initiated in Morais and Giuppone (Mon Notices R Astron Soc 424:52-64, doi:10.1111/j.1365-2966.2012.21151.x, 2012). After deriving a procedure to deduce the retrograde resonance terms from the standard expansion of the three-dimensional disturbing function, we concentrate on the planar problem and construct surfaces of section that explore phase-space in the vicinity of the main retrograde resonances (2/1, 1/1 and 1/2). In the case of the 1/1 resonance for which the standard expansion is not adequate to describe the dynamics, we develop a semi-analytic model based on numerical averaging of the unexpanded disturbing function, and show that the predicted libration modes are in agreement with the behavior seen in the surfaces of section.

Focal retrograde amnesia and the episodic-semantic distinction.

PubMed

Wheeler, M A; McMillan, C T

2001-03-01

This article reports a review of focal retrograde amnesia (FRA), or the phenomenon of organically based severe memory loss restricted to retrograde, or pretraumatic, memory. Cases of FRA are classified according to the type of memory loss: episodic, semantic, or both. A few different clusters of the disorder were identified. Lesions to either the anterior temporal lobes or the posterior/visual cortex can result in an FRA that devastates retrograde episodic memory, while having smaller effects on semantic memory. A number of left-hemisphere patients have FRA confined to semantic memory. There are several additional examples of FRA following minor cerebral trauma that disrupts either episodic memory alone or both episodic and semantic memory that are not accompanied by evidence of structural brain lesions. We discuss these different profiles of FRA and their implications for the understanding of memory retrieval.

A prospective, randomized, comparative clinical study of resin composite and glass ionomer cement for retrograde root filling.

PubMed

Jensen, S S; Nattestad, A; Egdø, P; Sewerin, I; Munksgaard, E C; Schou, S

2002-12-01

To compare the clinical and radiographic treatment outcome of retrograde root filling with either dentin-bonded resin composite (Retroplast, RP) or glass ionomer cement (Chelon-Silver, CS). A prospective, randomized clinical study of 134 consecutive patients with indication of retrograde root filling of an incisor, canine, premolar, or first molar. Either RP or CS was chosen at random as retrograde filling material. Either material was applied onto the entire resection surface after prepared slightly concave. This preparation technique makes a sealing of the entire resection surface possible and prevents marginal contraction gaps during polymerization. A total of 122 patients were available for 1-year follow-up. After 1 year the proportion of successful cases was significantly higher in the RP group (73%) than in the CS group (31%) (p<0.001). Doubtful healing with a need for a longer observation period was seen in 17% of the RP cases and 19% of the CS cases. The proportion of failures in the RP group (10%) was significantly lower than that in the CS group (50%) (p<0.001). Most of the unsuccessful CS cases failed due to loosening of the retrograde filling. Dentin-bonded RP applied onto the entire, slightly concave resection surface is a predictable apical sealant characterized by a high success rate. In contrast, retrograde root filling with CS results in an unacceptably high failure rate due to insufficient bonding strength to the concave resection surface.

Retrograde transfer RNA nuclear import provides a new level of tRNA quality control in Saccharomyces cerevisiae.

PubMed

Kramer, Emily B; Hopper, Anita K

2013-12-24

In eukaryotes, transfer RNAs (tRNAs) are transcribed in the nucleus yet function in the cytoplasm; thus, tRNA movement within the cell was believed to be unidirectional--from the nucleus to the cytoplasm. It is now known that mature tRNAs also move in a retrograde direction from the cytoplasm to the nucleus via retrograde tRNA nuclear import, a process that is conserved from yeast to vertebrates. The biological significance of this tRNA nuclear import is not entirely clear. We hypothesized that retrograde tRNA nuclear import might function in proofreading tRNAs to ensure that only proper tRNAs reside in the cytoplasm and interact with the translational machinery. Here we identify two major types of aberrant tRNAs in yeast: a 5', 3' end-extended, spliced tRNA and hypomodified tRNAs. We show that both types of aberrant tRNAs accumulate in mutant cells that are defective in tRNA nuclear traffic, suggesting that they are normally imported into the nucleus and are repaired or degraded. The retrograde pathway functions in parallel with the cytoplasmic rapid tRNA decay pathway previously demonstrated to monitor tRNA quality, and cells are not viable if they lack both pathways. Our data support the hypothesis that the retrograde process provides a newly discovered level of tRNA quality control as a pathway that monitors both end processing of pre-tRNAs and the modification state of mature tRNAs.

Retrograde transfer RNA nuclear import provides a new level of tRNA quality control in Saccharomyces cerevisiae

PubMed Central

Kramer, Emily B.; Hopper, Anita K.

2013-01-01

In eukaryotes, transfer RNAs (tRNAs) are transcribed in the nucleus yet function in the cytoplasm; thus, tRNA movement within the cell was believed to be unidirectional—from the nucleus to the cytoplasm. It is now known that mature tRNAs also move in a retrograde direction from the cytoplasm to the nucleus via retrograde tRNA nuclear import, a process that is conserved from yeast to vertebrates. The biological significance of this tRNA nuclear import is not entirely clear. We hypothesized that retrograde tRNA nuclear import might function in proofreading tRNAs to ensure that only proper tRNAs reside in the cytoplasm and interact with the translational machinery. Here we identify two major types of aberrant tRNAs in yeast: a 5′, 3′ end-extended, spliced tRNA and hypomodified tRNAs. We show that both types of aberrant tRNAs accumulate in mutant cells that are defective in tRNA nuclear traffic, suggesting that they are normally imported into the nucleus and are repaired or degraded. The retrograde pathway functions in parallel with the cytoplasmic rapid tRNA decay pathway previously demonstrated to monitor tRNA quality, and cells are not viable if they lack both pathways. Our data support the hypothesis that the retrograde process provides a newly discovered level of tRNA quality control as a pathway that monitors both end processing of pre-tRNAs and the modification state of mature tRNAs. PMID:24297920

Retrograde Transpedal Access for Revascularization of Below-the-Knee Arteries in Patients with Critical Limb Ischemia after an Unsuccessful Antegrade Transfemoral Approach.

PubMed

Goltz, J P; Planert, M; Horn, M; Wiedner, M; Kleemann, M; Barkhausen, J; Stahlberg, E

2016-10-01

To evaluate the safety and technical and clinical success of endovascular below-the-knee (BTK) artery revascularization by a retrograde transpedal access. We retrospectively identified 16/172 patients (9.3 %) with endovascular BTK revascularization in whom a transfemoral approach had failed and transpedal access had been attempted. The dorsal pedal (n = 13) or posterior tibial (n = 3) artery was accessed using a dedicated access set and ultrasound guidance. The procedure was finished in antegrade fashion by plain old balloon angioplasty (POBA). Comorbidities, vessel diameter and calcification at the access site were recorded. The analyzed outcomes were technical success, procedural complications, procedure time, crossing (guidewire beyond lesion and intra-luminal) and procedural (residual stenosis < 30 % after POBA) success, and limb salvage. Diabetes, coronary artery disease and hypertension were present in 15 patients (93.8 %), and both renal impairment and previous amputations in 7 (43.8 %). Pedal access vessel calcification was present in 5/16 patients (31.3 %). The mean diameter was 1.75 +/-0.24 mm. The procedure time was 92.4 +/-23 min. The success rate for achieving retrograde access was 100 %. Retrograde crossing was successful in 12/16 patients (75.0 %). Procedural success was observed in 10/16 patients (68.8 %). Minor complications occurred in 2/16 patients (12.5 %). The rate of limb salvage was 72.9 %, and the overall survival was 100 % at 12 months. Major amputations after revascularization occurred in 2/16 patients (12.5 %). If an antegrade transfemoral approach to BTK lesions fails, a retrograde transpedal approach may nevertheless facilitate treatment. This approach appears to be safe and offers high technical and acceptable clinical success rates. • Retrograde approaches via transpedal or transtibial vessels are safe and offer high technical success.• One problem after technically successful puncture might be the re-entry following subintimal retrograde lesion crossing.• After a failed attempt at antegrade revascularization of a BTK occlusion, a retrograde approach should be performed. Citation Format: • Goltz JP, Planert M, Horn M et al. Retrograde Transpedal Access for Revascularization of Below-the-Knee Arteries in Patients with Critical Limb Ischemia after an Unsuccessful Antegrade Transfemoral Approach. Fortschr Röntgenstr 2016; 188: 940 - 948. © Georg Thieme Verlag KG Stuttgart · New York.

The planetary increase of brightness during retrograde motion: An explanandum constructed ad explanantem.

PubMed

Carman, Christián Carlos

2015-12-01

In Ancient Greek two models were proposed for explaining the planetary motion: the homocentric spheres of Eudoxus and the Epicycle and Deferent System. At least in a qualitative way, both models could explain the retrograde motion, the most challenging phenomenon to be explained using circular motions. Nevertheless, there is another explanandum: during retrograde motion the planets increase their brightness. It is natural to interpret a change of brightness, i.e., of apparent size, as a change in distance. Now, while according to the Eudoxian model the planet is always equidistant from the earth, according to the epicycle and deferent system, the planet changes its distance from the earth, approaching to it during retrograde motion, just as observed. So, it is usually affirmed that the main reason for the rejection of Eudoxus' homocentric spheres in favor of the epicycle and deferent system was that the first cannot explain the manifest planetary increase of brightness during retrograde motion, while the second can. In this paper I will show that this historical hypothesis is not as firmly founded as it is usually believed to be. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pre-operative intra-articular deep tissue sampling with novel retrograde forceps improves the diagnostics in periprosthetic joint infection.

PubMed

Wimmer, Matthias D; Ploeger, Milena M; Friedrich, Max J; Hügle, Thomas; Gravius, Sascha; Randau, Thomas M

2017-07-01

Histopathological tissue analysis is a key parameter within the diagnostic algorithm for suspected periprosthetic joint infections (PJIs), conventionally acquired in open surgery. In 2014, Hügle and co-workers introduced novel retrograde forceps for retrograde synovial biopsy with simultaneous fluid aspiration of the knee joint. We hypothesised that tissue samples acquired by retrograde synovial biopsy are equal to intra-operatively acquired deep representative tissue samples regarding bacterial detection and differentiation of periprosthetic infectious membranes. Thirty patients (male n = 15, 50%; female n = 15, 50%) with 30 suspected PJIs in painful total hip arthroplasties (THAs) were included in this prospective, controlled, non-blinded trial. The results were compared with intra-operatively obtained representative deep tissue samples. In summary, 27 out of 30 patients were diagnosed correctly as infected (17/17) or non-infected (10/13). The sensitivity to predict a PJI using the Retroforce® sampling forceps in addition to standard diagnostics was 85%, the specificity 100%. Retrograde synovial biopsy is a new and rapid diagnostic procedure under local anaesthesia in patients with painful THAs with similar histological results compared to deep tissue sampling.

Directed Retrograde Cerebral Protection during Moderate Hypothermic Circulatory Arrest

PubMed Central

Yacoubian, Vahe; Jyrala, Aarne; Kay, Gregory L.

2006-01-01

There are many choices for neurologic protection for aortic arch surgery. Although numerous investigators have challenged the efficacy of retrograde cerebral perfusion, we have had good results with our application of this technique. We performed a retrospective review of 8 consecutive patients who underwent surgery from 1 June 2001 through 31 March 2003; the age range was 33 to 97 years. All patients required circulatory arrest and underwent retrograde cerebral perfusion with use of a tourniquet on the patients' left and right arms above the elbow to direct retrograde flow to the brain. Moderate hypothermia (around 24 °C nasopharyngeal) was used; circulatory arrest time ranged from 27 to 63 minutes. There was 1 late hospital death due to multiple-organ system failure. There were no neurologic complications (stroke or temporary neurologic dysfunction). There was no substantive neurologic or renal dysfunction in this cohort, in which moderate hypothermia was used. These results are comparable to those reported in the literature for similar patients. We conclude that, for patients who require circulatory arrest, directed retrograde cerebral perfusion at moderate nasopharyngeal hypothermia gives results comparable to those reported with other techniques. PMID:17215968

[Surgical treatment for liver haematoma following endoscopic retrograde cholangiopancreatography; An unusual case].

PubMed

González-López, Rogelio; García-Cano, Eugenio; Espinosa-González, Omar; Cruz-Salgado, Ángel; Montiel-Jarquin, Álvaro-José; Hernández-Zamora, Valeria

2015-01-01

Even in expert hands, there can be serious complications when performing an endoscopic retrograde cholangiopancreatography. The most frequent complications are pancreatitis, cholangitis, bleeding, perforation, and acute cholecystitis. The hepatic subcapsular haematoma is a rare complication, with few cases described worldwide. A case is presented of an extremely rare complication of endoscopic retrograde cholangiopancreatography, which required surgical treatment for its resolution without success. This is second case of mortality reported in the literature. Female patient of 30 years old, with indication for endoscopic retrograde cholangiopancreatography due to benign strictures. A hydro-pneumatic dilation and stent placement of 2 gauge 10 fr was performed. She presented abdominal pain after the procedure and significant decline in haemoglobin with no evidence of haemodynamic instability so an abdominal tomography scan was performed, showing no evidence of liver injury. The patient was haemodynamic unstable within 72 h. A laparotomy was required for damage control, with fatal outcome in the intensive care unit due to multiple organ failure. Subcapsular hepatic haematoma after endoscopic retrograde cholangiopancreatography is a rare complication, with few cases reported in the literature. Treatment described in the literature is conservative, resulting in a satisfactory resolution. Copyright © 2015. Published by Masson Doyma México S.A.

Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach.

PubMed

van der Meer, Rutger W; Weltings, Saskia; van Erkel, Arian R; Roshani, Hossain; Elzevier, Henk W; van Dijk, Lukas C; van Overhagen, Hans

2017-07-01

Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion.

Fully Burdened Cost of Retrograde, Redeployment, Reconstitution, and Reset and Analysis of Alternatives (FBCR4 & AoA): New Model to Formulate Strategic Decisions for Deployed Ground Vehicle Equipment

DTIC Science & Technology

2012-11-05

key leadership of critical R4 cost analysis. The second objective is to equip DoD planners with the framework for solving retrograde dilemmas in...informing key leadership of critical R4 cost analysis. The second objective is to equip DoD planners with the framework for solving retrograde...replicate the same dedication to individuals in similar situations in years to come.  To Captains Aaron Burciaga, Mario Solano, and Maro Enoka, as well

Peritonitis following percutaneous gastrostomy tube insertions in children.

PubMed

Dookhoo, Leema; Mahant, Sanjay; Parra, Dimitri A; John, Philip R; Amaral, Joao G; Connolly, Bairbre L

2016-09-01

Percutaneous retrograde gastrostomy has a high success rate, low morbidity, and can be performed under different levels of sedation or local anesthesia in children. Despite its favourable safety profile, major complications can occur. Few studies have examined peritonitis following percutaneous retrograde gastrostomy in children. To identify potential risk factors and variables influencing the development and early diagnosis of peritonitis following percutaneous retrograde gastrostomy. We conducted a retrospective case-control study of children who developed peritonitis within 7 days of percutaneous retrograde gastrostomy between 2003 and 2012. From the 1,504 patients who underwent percutaneous retrograde gastrostomy, patients who developed peritonitis (group 1) were matched by closest date of procedure to those without peritonitis (group 2). Peritonitis was defined according to recognized clinical criteria. Demographic, clinical, procedural, management and outcomes data were collected. Thirty-eight of 1,504 children (2.5%; 95% confidence interval, 1.8-3.5) who underwent percutaneous retrograde gastrostomy developed peritonitis ≤7 days post procedure (group 1). Fever (89%), irritability (63%) and abdominal pain (55%) occurred on presentation of peritonitis. Group 1 patients were all treated with antibiotics; 41% underwent additional interventions: tube readjustments (8%), aspiration of pneumoperitoneum (23%), laparotomy (10%) and intensive care unit admission (10%). In group 1, enteral feeds started on average 3 days later and patients were discharged 5 days later than patients in group 2. There were two deaths not directly related to peritonitis. Neither age, gender, weight, underlying diagnoses nor operator was identified as a risk factor. Peritonitis following percutaneous retrograde gastrostomy in children occurs in approximately 2.5% of cases. No risk factors for its development were identified. Medical management is usually sufficient for a good outcome. Patients with peritonitis are delayed starting feeds and have a hospital stay that is an average of 5 days longer than those without.

Retrograde Signals: Integrators of Interorganellar Communication and Orchestrators of Plant Development.

PubMed

de Souza, Amancio; Wang, Jin-Zheng; Dehesh, Katayoon

2017-04-28

Interorganellar cooperation maintained via exquisitely controlled retrograde-signaling pathways is an evolutionary necessity for maintenance of cellular homeostasis. This signaling feature has therefore attracted much research attention aimed at improving understanding of the nature of these communication signals, how the signals are sensed, and ultimately the mechanism by which they integrate targeted processes that collectively culminate in organellar cooperativity. The answers to these questions will provide insight into how retrograde-signal-mediated regulatory mechanisms are recruited and which biological processes are targeted, and will advance our understanding of how organisms balance metabolic investments in growth against adaptation to environmental stress. This review summarizes the present understanding of the nature and the functional complexity of retrograde signals as integrators of interorganellar communication and orchestrators of plant development, and offers a perspective on the future of this critical and dynamic area of research.

Telescopic Corsair in 5F Guidion for Retrograde Recanalization of Complex Chronic Total Occlusions (CTOs).

PubMed

Palmers, Pieter-Jan; Maeremans, Joren; Meyer-Gessner, Markus; Bataille, Yoann; Dens, Joseph

2017-04-30

BACKGROUND Retrograde advancement of microcatheters through septal/epicardial connectors can be challenging. Although several tricks might help to do so (e.g., balloon trap of retro wire in second guiding, balloon trap of retro wire in native coronary artery, and use of antegrade extension to approximate the antegrade conduit to the retrograde gear), these tricks cannot always be applied, especially in patients with poor access. Also, puncturing, knuckling, and crossing of the distal CTO cap (or the aorta as described in 1 of the cases) sometimes needs a lot of backup of the microcatheter. CASE REPORT We describe 3 cases in which we used a novel telescopic technique with 5F Guidion (IMDS®) supported retrograde Corsair (Asahi®) advancement in complex CTO lesions. CONCLUSIONS The telescopic Corsair in 5F Guidion may offer the support needed to end successfully in these situations.

Endoscopic retrograde JJ-stenting of the ureter without fluoroscopy guidance--an appraisal of outcome.

PubMed

Shuaibu, S I; Gidado, S; Oseni-Momodu, E

2013-01-01

JJ- ureteral stenting is a means of relieving ureteric obstruction. It is done as a retrograde or antegrade procedure, usually under fluoroscopy guidance. We reviewed our results in 2 independent tertiary health centers in Nigeria which lack fluoroscopy units. A 2 year retrospective review of data of patients who had retrograde JJ- ureteric stenting was done. Data relating to age, indication and outcome of procedure were retrieved and analysed. 22 (71%) patients had successful retrograde JJ- ureteric stenting out of 31 patients who were taken for the procedure. These 22 patients had stenting of 27 ureteric units. Mean age was 48.5 years. Commonest indication was carcinoma of the cervix (31.8%). Commonest complication was irritative lower urinary tract symptoms (43.5%). In spite of inherent complications, JJ-stenting is a simple and safe technique. Therefore, the decision to attempt JJ -stenting in carefully selected patients in the absence of fluoroscopy is acceptable.

The microRNA miR-1 regulates a MEF-2 dependent retrograde signal at neuromuscular junctions

PubMed Central

Simon, David J.; Madison, Jon M.; Conery, Annie L.; Thompson-Peer, Katherine L.; Soskis, Michael; Ruvkun, Gary B.; Kaplan, Joshua M.; Kim, John K.

2008-01-01

Summary We show that miR-1, a conserved muscle specific microRNA, regulates aspects of both pre- and post-synaptic function at C. elegans neuromuscular junctions. miR-1 regulates the expression level of two nicotinic acetylcholine receptor (nAChR) subunits (UNC-29 and UNC-63), thereby altering muscle sensitivity to acetylcholine (ACh). miR-1 also regulates the muscle transcription factor MEF-2, which results in altered pre-synaptic ACh secretion, suggesting that MEF-2 activity in muscles controls a retrograde signal. The effect of the MEF-2-dependent retrograde signal on secretion is mediated by the synaptic vesicle protein RAB-3. Finally, acute activation of levamisole-sensitive nAChRs stimulates MEF-2-dependent transcriptional responses, and induces the MEF-2-dependent retrograde signal. We propose that miR-1 refines synaptic function by coupling changes in muscle activity to changes in pre-synaptic function. PMID:18510933

Continuous butanol fermentation and feed starch retrogradation: butanol fermentation sustainability using Clostridium beijerinckii BA101.

PubMed

Ezeji, T C; Qureshi, N; Blaschek, H P

2005-01-26

Use of starch solution as feed for butanol bioconversion processes employing Clostridium beijerinckii BA101 may have added economic advantage over the use of glucose. Acetone butanol ethanol (ABE) was produced from 30 gL(-1) starch solution using a continuous process. The bioreactor was fed at a dilution rate of 0.02 h(-1) and starch solution/feed volume (3 L) was replaced every 72 h. The continuous reactor fed with cornstarch solution (feed temperature 19 degrees C) produced approximately 6.0 gL(-1) total ABE. Increasing the feed storage temperature to 37 degrees C improved ABE production to 7.2 gL(-1) suggesting that retrogradation was occurring more rapidly at 19 degrees C. In both these cases the fermentation drifted toward acid production after approximately 260 h, consistent with the retrogradation of starch overtime. The use of soluble starch, which is less prone to retrogradation, resulted in the production of 9.9 gL(-1) ABE at 37 degrees C feed storage temperature, as compared to 7.2 gL(-1) ABE when cornstarch was used. It should be noted that gelatinized starch retrogradation takes place after sterilization and prior to use of the feed medium, and does not occur during long-term storage of the raw corn material in the months leading up to processing. The degree of hydrolysis of gelatinized starch decreased from 68.8 to 56.2% in 3 days when stored at 37 degrees C. Soluble starch which does not retrograde demonstrated no change in the degree of hydrolysis.

Impact of local hydrothermal treatment during bread baking on soluble amylose, firmness, amylopectin retrogradation and water mobility during bread staling.

PubMed

Besbes, Emna; Le Bail, Alain; Seetharaman, Koushik

2016-01-01

The impact of hydrothermal processing undergone by bread dough during baking on the degree of starch granule disruption, on leaching of soluble amylose, on water mobility, on firmness and on amylopectin retrogradation during staling has been investigated. Two heating rates during baking have been considered (4.67 and 6.31 °C/min) corresponding respectively to baking temperature of 220 and 240 °C. An increase in firmness and in the amount of retrogradated amylopectin accompanied by a decrease in freezable water has been observed during staling. Although a lower heating rate yielded in larger amount of retrogradated amylopectin retrogradation, it resulted in a lower firmness. Additionally, the amount of soluble amylose and the relaxation times of water measured by Nuclear Magnetic Resonance NMR (T20, T21 and T22) decreased during staling. It was demonstrated that the amount of soluble amylose was higher for bread crumb baked at lower heating rate, indicating that an increasing amount of amylose is leached outside the starch granules. This was corresponding to a greater amount of retrograded amylopectin during staling. Moreover, it was found that the degree of gelatinization differs locally in a same bread slice between the top, the centre and the bottom locations in the crumb. This was attributed to the differences in kinetics of heating, the availability of water during baking and the degree of starch granule disruption during baking. Based on first order kinetic model, it was found that staling kinetics were faster for samples baked at higher heating rate.

Subclavian steal: Endovascular treatment of total occlusions of the subclavian artery using a retrograde transradial subintimal approach

PubMed Central

Golwala, Sohil N; Vance, Ansar Z; Tuerff, Sonya N

2016-01-01

Introduction In symptomatic subclavian steal syndrome, endovascular treatment is the first line of therapy prior to extra-anatomic surgical bypass procedures. Subintimal recanalization has been well described in the literature for the coronary arteries, and more recently, in the lower extremities. By modifying this approach, we present a unique retrograde technique using a heavy tip microwire to perform controlled subintimal dissection. Methods We present two cases of symptomatic subclavian steal related to chronic total occlusion of the left subclavian artery and right innominate artery, respectively. Standard crossing techniques were unsuccessful. Commonly at this point, the procedures would be aborted and open surgical intervention would have to be pursued. In our cases, retrograde access was easily achieved via an ipsilateral retrograde radial artery, using controlled subintimal dissection and a heavy-tipped wire. Results We were able to easily achieve recanalization in both attempted cases of chronic total occlusion of the subclavian and innominate artery, using a retrograde radial subintimal approach. Subsequent stent-supported angioplasty resulted in complete revascularization. No major complications were encountered during the procedures; however, one patient did develop thromboembolic stroke secondary to platelet aggregation to the stent graft, 9 days post-procedure. Conclusions Endovascular treatment is considered the first-line intervention in medically refractory patients with symptomatic subclavian steal syndrome. In the setting of chronic total occlusions, a retrograde radial subintimal approach using a heavy tip wire for controlled subintimal dissection is a novel technique that may be considered when standard approaches and wires have failed. PMID:26861024

Retrograde recanalization of chronic total occlusions from the transradial approach; early Canadian experience.

PubMed

Rinfret, Stéphane; Joyal, Dominique; Nguyen, Can Manh; Bagur, Rodrigo; Hui, William; Leung, Raymond; Larose, Eric; Love, Michael P; Mansour, Samer

2011-09-01

Retrograde approach for chronic total occlusions (CTO) improves recanalization success rates. Eight French (Fr) catheters and the femoral approach are advocated. Evaluate whether transradial operators can achieve similar success rates using smaller catheters. This is a single-operator series of 42 consecutive cases performed between January and December 2010, including 13 while demonstrating CTO recanalization. Patients were referred because of complexity of the CTO or after failed attempt. Most frequent indications for recanalization were CCS 3-4 angina (52%) and CCS 1-2 in 21%. Eighteen (43%) patients underwent previous failed attempts. CTO was in the right coronary in 74%, left anterior descending in 24%, and a left main in 1. Most lesions (88%) were ≥20 mm long and 52% were calcified. We used septal collateral channels (CC) in 33 (79%), epicardial CC in 8 (20%), and a saphenous vein graft in one case. Radial access was used in all patients and was bilateral in 37 (88%). Five cases required one radial and one femoral access. Six French guides were used in 91% for the retrograde side and 71% for the antegrade side. Otherwise, 7 Fr guides were used. The Corsair(®) was used in 38 (90%). Procedural success was achieved in 37 (88%), mostly using reverse controlled antegrade-retrograde tracking (60%) or retrograde crossing (29%). The average <24-h Hb drop was 0.75 ± 0.84 g/dl. No in-hospital major cardiac events occurred. Transradial retrograde CTO recanalization is feasible, safe, and still associated with high success rates despite the use of smaller guide catheters. Copyright © 2011 Wiley-Liss, Inc.

Influence of chronic endurance exercise training on conduit artery retrograde and oscillatory shear in older adults.

PubMed

Casey, Darren P; Schneider, Aaron C; Ueda, Kenichi

2016-10-01

With aging, there tends to be an increase in retrograde and oscillatory shear in peripheral conduit arteries of humans. Whether the increase in shear rate is due to the aging process or an effect of a less active lifestyle that often accompanies aging is unknown. Therefore, we examined whether chronic endurance exercise training attenuates conduit artery retrograde and oscillatory shear in older adults. Brachial and common femoral artery mean blood velocities and diameter were determined via Doppler ultrasound under resting conditions, and shear rate was calculated in 13 young (24 ± 2 years), 17 older untrained (66 ± 3 years), and 16 older endurance exercise-trained adults (66 ± 7 years). Brachial artery retrograde (-9.1 ± 6.4 vs. -12.6 ± 9.4 s(-1); P = 0.35) and oscillatory (0.14 ± 0.08 vs. 0.14 ± 0.08 arbitrary units; P = 0.99) shear were similar between the older trained and untrained groups, whereas brachial artery retrograde and oscillatory shear were greater in older untrained compared to young adults (-5.0 ± 3.4, 0.08 ± 0.05 s(-1) arbitrary units, P = 0.017 and 0.048, respectively). There was no difference between the young and older trained brachial retrograde (P = 0.29) and oscillatory (P = 0.07) shear. Common femoral artery retrograde (-6.3 ± 2.9 s(-1)) and oscillatory (0.21 ± 0.08 arbitrary units) shear were reduced in older trained compared to the older untrained group (-10.4 ± 4.1 and 0.30 ± 0.09 s(-1) arbitrary units, both P = 0.005 and 0.006, respectively), yet similar to young adults (-7.1 ± 3.5 and 0.19 ± 0.06 s(-1) arbitrary units, P = 0.81 and 0.87, respectively). Our results suggest that chronic endurance exercise training in older adults ameliorates retrograde and oscillatory shear rate patterns, particularly in the common femoral artery.

Process for forming retrograde profiles in silicon

DOEpatents

Weiner, K.H.; Sigmon, T.W.

1996-10-15

A process is disclosed for forming retrograde and oscillatory profiles in crystalline and polycrystalline silicon. The process consisting of introducing an n- or p-type dopant into the silicon, or using prior doped silicon, then exposing the silicon to multiple pulses of a high-intensity laser or other appropriate energy source that melts the silicon for short time duration. Depending on the number of laser pulses directed at the silicon, retrograde profiles with peak/surface dopant concentrations which vary are produced. The laser treatment can be performed in air or in vacuum, with the silicon at room temperature or heated to a selected temperature.

[RESEARCH PROGRESS IN COMPLICATIONS OF RETROGRADE INTRAMEDULLARY NAIL FIXATION FOR TIBIOTALOCALCANEAL ARTHRODESIS].

PubMed

Feng, Jun; Yu, Guangrong

2015-09-01

To review the cause, treatment, and prevention of complications of retrograde intramedullary nail fixation for tibiotalocalcaneal arthrodesis and enhance the recognition on the complications of tibiotalocalcaneal arthrodesis. The recent literature concerning intramedullary nail fixation for tibiotalocalcaneal arthrodesis was consulted and reviewed. There are intraoperative and postoperative complications of intramedullary nail fixation for tibiotalocalcaneal arthrodesis, and the causes, treatment, and prevention of complications are various. Progress of retrograde intramedullary nail fixation increases the successful rate of tibiotalocalcaneal arthrodesis. However, there is still a high complication rate, so strict preoperative assessment and skilled surgical technique are necessary to prevent complications.

Chloroplast-to-nucleus communication

PubMed Central

Chan, Kai Xun; Crisp, Peter Alexander; Estavillo, Gonzalo Martin

2010-01-01

In order for plant cells to function efficiently under different environmental conditions, chloroplastic processes have to be tightly regulated by the nucleus. It is widely believed that there is inter-organelle communication from the chloroplast to the nucleus, called retrograde signaling. Although some pathways of communication have been identified, the actual signals that move between the two cellular compartments are largely unknown. This review provides an overview of retrograde signaling including its importance to the cell, candidate signals, recent advances and current experimental systems. In addition, we highlight the potential of using drought stress as a model for studying retrograde signaling. PMID:21512326

[Results of the percutaneous retrograde embolization as the first choice in the treatment of varicocele].

PubMed

Piñera, J Gonzálvez; Fernández-Córdoba, M S; Anselmi, E Hernández; Mollá, E Juliá; Jiménez, M J Pedrosa; Cabañero, A G Blanco; Baró, A Palma

2009-07-01

There is evidence that early varicocele treatment decreases testicular damage. The minimally invasive techniques such as laparoscopic varicocelectomy, antegrade sclerotherapy and percutaneous retrograde embolisation, are acquiring greater significance in the treatment of this disease. Since 1994, a series of 51 children, aged 7-16 years (mean, 12.9 years), with left-sided varicocele grades 2 (47%) and 3 (53%) were treated in our institution by percutaneous retrograde embolisation using coils. The right basilica vein was the most widely used (70%) followed by the right femoral vein. Seven children (13.7%) had complications: perforation of internal spermatic vein was the most frequent and treated conservatively. No child presented hydrocele after radiological procedures. Embolisation was accomplished succesfully at the first attempt in 35 (68.6%) of the 51 children and in 45 (88.2%) after a second embolisation. The follow-up ranges from 7 months to 5 ? years (mean, 1.8 years). The patients were monitored with clinical and doppler ultrasound examination 3, 6 and 12 months after the treatment. Retrograde embolisation is a safe and efficient minimally invasive treatment for correcting varicoceles in children. We performed retrograde embolisation as first choice of varicocele treatment in children; a second embolisation or conventional surgery for primary failure or late recurrence should be considered.

The golgin protein Coy1 functions in intra-Golgi retrograde transport and interacts with the COG complex and Golgi SNAREs

PubMed Central

Anderson, Nadine S.; Mukherjee, Indrani; Bentivoglio, Christine M.; Barlowe, Charles

2017-01-01

Extended coiled-coil proteins of the golgin family play prominent roles in maintaining the structure and function of the Golgi complex. Here we further investigate the golgin protein Coy1 and document its function in retrograde transport between early Golgi compartments. Cells that lack Coy1 displayed a reduced half-life of the Och1 mannosyltransferase, an established cargo of intra-Golgi retrograde transport. Combining the coy1Δ mutation with deletions in other putative retrograde golgins (sgm1Δ and rud3Δ) caused strong glycosylation and growth defects and reduced membrane association of the conserved oligomeric Golgi (COG) complex. In contrast, overexpression of COY1 inhibited the growth of mutant strains deficient in fusion activity at the Golgi (sed5-1 and sly1-ts). To map Coy1 protein interactions, coimmunoprecipitation experiments revealed an association with the COG complex and with intra-Golgi SNARE proteins. These physical interactions are direct, as Coy1 was efficiently captured in vitro by Lobe A of the COG complex and the purified SNARE proteins Gos1, Sed5, and Sft1. Thus our genetic, in vivo, and biochemical data indicate a role for Coy1 in regulating COG complex-dependent fusion of retrograde-directed COPI vesicles. PMID:28794270

Water dynamics and retrogradation of ultrahigh pressurized wheat starch.

PubMed

Doona, Christopher J; Feeherry, Florence E; Baik, Moo-Yeol

2006-09-06

The water dynamics and retrogradation kinetics behavior of gelatinized wheat starch by either ultrahigh pressure (UHP) processing or heat are investigated. Wheat starch completely gelatinized in the condition of 90, 000 psi at 25 degrees C for 30 min (pressurized gel) or 100 degrees C for 30 min (heated gel). The physical properties of the wheat starches were characterized in terms of proton relaxation times (T2 times) measured using time-domain nuclear magnetic resonance spectroscopy and evaluated using commercially available continuous distribution modeling software. Different T2 distributions in both micro- and millisecond ranges between pressurized and heated wheat starch gels suggest distinctively different water dynamics between pressurized and heated wheat starch gels. Smaller water self-diffusion coefficients were observed for pressurized wheat starch gels and are indicative of more restricted translational proton mobility than is observed with heated wheat starch gels. The physical characteristics associated with changes taking place during retrogradation were evaluated using melting curves obtained with differential scanning calorimetry. Less retrogradation was observed in pressurized wheat starch, and it may be related to a smaller quantity of freezable water in pressurized wheat starch. Starches comprise a major constituent of many foods proposed for commercial potential using UHP, and the present results furnish insight into the effect of UHP on starch gelatinization and the mechanism of retrogradation during storage.

Structure of Waxy Maize Starch Hydrolyzed by Maltogenic α-Amylase in Relation to Its Retrogradation.

PubMed

Grewal, Navneet; Faubion, Jon; Feng, Guohua; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

2015-04-29

Maltogenic α-amylase is widely used as an antistaling agent in bakery foods. The objective of this study was to determine the degree of hydrolysis (DH) and starch structure after maltogenic amylase treatments in relation to its retrogradation. Waxy maize starch was cooked and hydrolyzed to different degrees by a maltogenic amylase. High-performance anion-exchange chromatography and size exclusion chromatography were used to determine saccharides formed and the molecular weight (Mw) distributions of the residual starch structure, respectively. Chain length (CL) distributions of debranched starch samples were further related to amylopectin (AP) retrogradation. Differential scanning calorimetry (DSC) results showed the complete inhibition of retrogradation when starches were hydrolyzed to >20% DH. Mw and CL distributions of residual AP structure indicated that with an increase in %DH, a higher proportion of unit chains with degree of polymerization (DP) ≤9 and a lower proportion of unit chains with DP ≥17 were formed. A higher proportion of short outer AP chains that cannot participate in the formation of double helices supports the decrease in and eventual inhibition of retrogradation observed with the increase in %DH. These results suggest that the maltogenic amylase could play a powerful role in inhibiting the staling of baked products even at limited starch hydrolysis.

The immune impact of mimic endoscopic retrograde appendicitis therapy and appendectomy on rabbits of acute appendicitis.

PubMed

Liu, Suqin; Pei, Fenghua; Wang, Xinhong; Li, Deliang; Zhao, Lixia; Song, Yanyan; Chen, Zhendong; Liu, Bingrong

2017-09-12

This study was conducted to evaluate the immune impact of mimic endoscopic retrograde appendicitis therapy and appendectomy on rabbits of acute suppurative appendicitis and to determine whether TLR4/MYD88/NF-κB signaling pathway was activated in this process. 48 rabbits were assigned into 4 groups: group I, the mimic endoscopic retrograde appendicitis therapy group; group II, the appendectomy group; group III, the model group; and group IV, the blank group. White blood cells decreased, while levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, interleukin-4, and interleukin-10 increased on the 2 nd day in group I and II. IgA in feces decreased at 2 weeks, while fecal microbiota changed at 2 and 4 weeks after appendectomy. CD8 + cells in appendix of group I increased within 8 weeks. Upregulated expression of TLR4, MYD88, and nuclear NF-κB were detected on the 2 nd day in group I and II. Mimic endoscopic retrograde appendicitis therapy and appendectomy are effective ways for acute suppurative appendicitis. Mimic endoscopic retrograde appendicitis therapy was more preferable due to its advantage in maintaining intestinal immune function. TLR4/MYD88/NF-κB signaling pathway was activated in acute phase of appendicitis.

Wave propagation reversal for wavy vortices in wide-gap counter-rotating cylindrical Couette flow.

PubMed

Altmeyer, S; Lueptow, Richard M

2017-05-01

We present a numerical study of wavy supercritical cylindrical Couette flow between counter-rotating cylinders in which the wavy pattern propagates either prograde with the inner cylinder or retrograde opposite the rotation of the inner cylinder. The wave propagation reversals from prograde to retrograde and vice versa occur at distinct values of the inner cylinder Reynolds number when the associated frequency of the wavy instability vanishes. The reversal occurs for both twofold and threefold symmetric wavy vortices. Moreover, the wave propagation reversal only occurs for sufficiently strong counter-rotation. The flow pattern reversal appears to be intrinsic in the system as either periodic boundary conditions or fixed end wall boundary conditions for different system sizes always result in the wave propagation reversal. We present a detailed bifurcation sequence and parameter space diagram with respect to retrograde behavior of wavy flows. The retrograde propagation of the instability occurs when the inner Reynolds number is about two times the outer Reynolds number. The mechanism for the retrograde propagation is associated with the inviscidly unstable region near the inner cylinder and the direction of the global average azimuthal velocity. Flow dynamics, spatio-temporal behavior, global mean angular velocity, and torque of the flow with the wavy pattern are explored.

Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach

PubMed Central

van der Meer, Rutger W.; Weltings, Saskia; van Erkel, Arian R.; Roshani, Hossain; Elzevier, Henk W.; van Dijk, Lukas C.; van Overhagen, Hans

2017-01-01

Background/Aims Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Methods Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Results Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Conclusion Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion. PMID:28785193

Recrystallization characteristics of high hydrostatic pressure gelatinized normal and waxy corn starch.

PubMed

Li, Wenhao; Tian, Xiaoling; Wang, Peng; Saleh, Ahmed S M; Luo, Qingui; Zheng, Jianmei; Ouyang, Shaohui; Zhang, Guoquan

2016-02-01

High hydrostatic pressure (HHP) can lead to starch gelatinization at room temperature, while the retrogradation mechanism of HHP gelatinized starch is not well known. HHP gelatinized normal and waxy corn starches were stored at room temperature for 192 h in order to investigate the retrogradation characteristics. The scanning electron microscopy (SEM), polarised light microscopy and differential scanning calorimetric (DSC) analysis showed that the pressurization of normal and waxy corn starch suspensions with concentration of 30% (w/v) at 600 MPa for 15 min resulted in a complete gelatinization. In addition, the pressure-gelatinized normal and waxy corn starch gels were stored and subjected to X-ray diffraction (XRD) analysis, resistant starch content determination, swelling power and pasting behavior. The retrograded normal maize and waxy maize starch showed a substantial loss of A-type crystallinity. Both pressure-gelatinized normal and waxy corn starches showed an increase in resistant starch content and relative crystallinity degree with the increase of storage time. In addition, restricted starch swelling power and lower pasting viscosities were observed for these two retrograded starches. The amylose molecule within starch granules has been regarded as the main factor to affect the structural and physicochemical properties during the retrogradation process of HHP-gelatinized starch granules. Copyright © 2015 Elsevier B.V. All rights reserved.

Balloon-Occluded Retrograde Transvenous Embolization of a Pelvic Arteriovenous Malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitsuzaki, Katsuhiko; Yamashita, Yasuyuki; Utsunomiya, Daisuke

1999-11-15

We successfully performed embolization therapy for a pelvic arteriovenous malformation by the retrograde transvenous approach using a liquid embolic material. This malformation was unique in that it had a single draining vein, which allowed this technique employing an occlusion balloon.

Percutaneous nephrostomy versus ureteroscopic management of sepsis associated with ureteral stone impaction: a randomized controlled trial.

PubMed

Wang, Chung-Jing; Hsu, Chi-Sen; Chen, Hung-Wen; Chang, Chien-Hsing; Tsai, Po-Chao

2016-10-01

A randomized trial was conducted prospectively to evaluate the efficacy, related complications, and convalescence of emergent retrograde ureteroscopic management, instead of percutaneous nephrostomy for decompression of the collecting system in cases of sepsis associated with ureteral stone obstruction. A total of 107 patients undergoing ureteroscopic stone manipulation for ureteral stones completed the study protocol, 53 patients in the percutaneous nephrostomy group, and 54 patients in the emergent retrograde ureteroscopic management group. The primary end point was the time to normalization of WBC of 10,000/mm or less and temperature of 37.4 °C or less. The second end point was the comparison analgesic consumption, length of stay, and related complications. Statistical analysis was performed using SPSS(®) version 14.0.1. The Mann-Whitney U test, Chi square test, and fisher's exact test was used as appropriate. The length of hospital stay (days) was 10.25 ± 3.53 and 8.24 ± 2.77 in the percutaneous nephrostomy group and emergent retrograde ureteroscopic management group, respectively, with significant difference (Table 2). However, patients in the emergent retrograde ureteroscopic management group had a significantly higher rate of s body temperature (°C). Meanwhile, the analgesic consumptions are 31.51 ± 11.16 and 40.00 ± 14.54 in the percutaneous nephrostomy group and emergent retrograde ureteroscopic management group, respectively, with significant difference. Our results show that it can be effectively and safely managed by retrograde ureteroscopic management combined with strong antibiotics in select clinical situations. Ureteroscopic management should no longer be considered a contraindication for the treatment of patients with sepsis associated with obstructing ureteral stones.

The Retrograde Transvenous Push-Through Method: A Novel Treatment of Peripheral Arteriovenous Malformations with Dominant Venous Outflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohlgemuth, Walter A., E-mail: walter.wohlgemuth@ukr.de; Müller-Wille, René, E-mail: Rene.Mueller-Wille@ukr.de; Teusch, Veronika I., E-mail: Veronika.Teusch@gmx.de

2015-06-15

PurposeTo evaluate the efficacy and safety of a novel retrograde transvenous embolization technique of peripheral arteriovenous malformations (AVMs) using Onyx.Materials and MethodsWe conducted a retrospective analysis of all patients who underwent transvenous retrograde Onyx embolization of peripheral AVMs with dominant venous outflow over a 29-month period. The embolization is aimed at retrograde filling of the nidus after building a solid plug in the dominant venous outflow (push-through). Classification, clinical signs, technical aspects, clinical and technical success rates, and complications were recorded. Short-term outcome was assessed.Results11 Symptomatic patients (8 female; mean age 31.4 years) were treated at our Vascular Anomalies Center withmore » this method between January 2012 and May 2014. The AVMs were located on the upper extremity (n = 3), pelvis (n = 2), buttock (n = 2), and lower extremity (n = 4). Retrograde embolization was successfully carried out after preparatory transarterial-flow reduction in eight cases (73 %) and venous-flow reduction with Amplatzer Vascular Plugs in four cases (36 %). Complete devascularization (n = 10; 91 %) or 95 % devascularization (n = 1; 9 %) led to complete resolution (n = 8; 73 %) or improvement of clinical symptoms (n = 3; 27 %). One minor complication occurred (pain and swelling). During a mean follow-up time of 8 months, one clinically asymptomatic recurrence of AVM was detected.ConclusionInitial results suggest that retrograde transvenous Onyx embolization of peripheral AVMs with dominant venous outflow is a safe and effective novel technique with a low complication rate.« less

Use of the retrograde limb of the internal mammary vein to avoid venous congestion in DIEP flap breast reconstruction: Further evidences of a reliable and time-sparing procedure.

PubMed

La Padula, Simone; Hersant, Barbara; Noel, Warren; Niddam, Jeremy; Hermeziu, Oana; Bouhassira, Jonathan; Bosc, Romain; Meningaud, Jean Paul

2016-09-01

Venous congestion is a common cause of DIEP flap failure. When identified intraoperatively, an additional venous anastomosis can improve the venous outflow and prevent flap failure. The aim of this study was to assess if the retrograde limb of the internal mammary vein (IMV) could be considered a good recipient vessel to be used when persistent flap congestion is present, and a second venous anastomosis is required. A retrospective study was conducted in 74 patients who had undergone DIEP flap breast reconstruction. Patients were classified into two groups: SVA (single venous anastomosis) and DVA (dual venous anastomosis). In the SVA group (n = 38), the IMV antegrade limb was used for venous drainage. A single DIEV (Deep Inferior Epigastric Vein) was anastomosed to the superior arm of the IMV. In the DVA group (n = 36), both the antegrade (superior) and retrograde (inferior) stumps of the IMV were used, connecting the larger DIEV to the antegrade IMV and the other DIEV or the SIEV (Superficial Inferior Epigastric Vein) to the IMV retrograde limb. No venous congestion or flap loss was observed when two venous anastomoses were performed using both the IMV antegrade and retrograde limbs (P = 0.3271). In the DVA group, no major complication occurred (P = 0.0453). Operative explorations were significantly reduced in the DVA group (P = 0.0242). These findings suggest that when an additional venous outflow is required, the use of the IMV retrograde limb may help to avoid flap venous congestion. © 2016 Wiley Periodicals, Inc. Microsurgery 36:447-452, 2016. © 2016 Wiley Periodicals, Inc.

Contraction of the Ventral Abdomen Potentiates Extracardiac Retrograde Hemolymph Propulsion in the Mosquito Hemocoel

PubMed Central

Andereck, Jonathan W.; King, Jonas G.; Hillyer, Julián F.

2010-01-01

Background Hemolymph circulation in mosquitoes is primarily controlled by the contractile action of a dorsal vessel that runs underneath the dorsal midline and is subdivided into a thoracic aorta and an abdominal heart. Wave-like peristaltic contractions of the heart alternate in propelling hemolymph in anterograde and retrograde directions, where it empties into the hemocoel at the terminal ends of the insect. During our analyses of hemolymph propulsion in Anopheles gambiae, we observed periodic ventral abdominal contractions and hypothesized that they promote extracardiac hemolymph circulation in the abdominal hemocoel. Methodology/Principal Findings We devised methods to simultaneously analyze both heart and abdominal contractions, as well as to measure hemolymph flow in the abdominal hemocoel. Qualitative and quantitative analyses revealed that ventral abdominal contractions occur as series of bursts that propagate in the retrograde direction. Periods of ventral abdominal contraction begin only during periods of anterograde heart contraction and end immediately following a heartbeat directional reversal, suggesting that ventral abdominal contractions function to propel extracardiac hemolymph in the retrograde direction. To test this functional role, fluorescent microspheres were intrathoracically injected and their trajectory tracked throughout the hemocoel. Quantitative measurements of microsphere movement in extracardiac regions of the abdominal cavity showed that during periods of abdominal contractions hemolymph flows in dorsal and retrograde directions at a higher velocity and with greater acceleration than during periods of abdominal rest. Histochemical staining of the abdominal musculature then revealed that ventral abdominal contractions result from the contraction of intrasegmental lateral muscle fibers, intersegmental ventral muscle bands, and the ventral transverse muscles that form the ventral diaphragm. Conclusions/Significance These data show that abdominal contractions potentiate extracardiac retrograde hemolymph propulsion in the abdominal hemocoel during periods of anterograde heart flow. PMID:20886066

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

PubMed

Tanaka, Y; Miyazawa, Y; Hashimoto, R; Nakano, I; Obayashi, T

1999-07-22

Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. To search for new anatomic substrates for focal retrograde amnesia. We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

D-(/sup 3/H)aspartate retrograde labelling of callosal and association neurons of somatosensory areas I and II of cats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbaresi, P.; Fabri, M.; Conti, F.

Experiments were carried out on cats to ascertain whether corticocortical neurons of somatosensory areas I (SI) and II (SII) could be labelled by retrograde axonal transport of D-(/sup 3/H)aspartate (D-(/sup 3/H)Asp). This tritiated enantiomer of the amino acid aspartate is (1) taken up selectively by axon terminals of neurons releasing aspartate and/or glutamate as excitatory neurotransmitter, (2) retrogradely transported and accumulated in perikarya, (3) not metabolized, and (4) visualized by autoradiography. A solution of D-(/sup 3/H)Asp was injected in eight cats in the trunk and forelimb zones of SI (two cats) or in the forelimb zone of SII (six cats).more » In order to compare the labelling patterns obtained with D-(/sup 3/H)Asp with those resulting after injection of a nonselective neuronal tracer, horseradish peroxidase (HRP) was delivered mixed with the radioactive tracer in seven of the eight cats. Furthermore, six additional animals received HRP injections in SI (three cats; trunk and forelimb zones) or SII (three cats; forelimb zone). D-(/sup 3/H)Asp retrograde labelling of perikarya was absent from the ipsilateral thalamus of all cats injected with the radioactive tracer but a dense terminal plexus of anterogradely labelled corticothalamic fibers from SI and SII was observed, overlapping the distribution area of thalamocortical neurons retrogradely labelled with HRP from the same areas. D-(/sup 3/H)Asp-labelled neurones were present in ipsilateral SII (SII-SI association neurones) in cats injected in SI. In these animals a bundle of radioactive fibres was observed in the rostral portion of the corpus callosum entering the contralateral hemisphere. There, neurones retrogradely labelled with silver grains were present in SI (SI-SI callosal neurons).« less

Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions.

PubMed

van der Laan, Michelle E; Mebius, Mirthe J; Roofthooft, Marcus T R; Bos, Arend F; Berger, Rolf M F; Kooi, Elisabeth M W

2017-01-01

In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. Our aim was to compare cerebral and renal tissue oxygen saturation (rSO2) between infants with LSOL with antegrade and retrograde blood flow in the ascending aorta and with and without diastolic backflow in the descending aorta. Based on 2 echocardiograms, the study group was categorized according to the direction of blood flow in the ascending and descending aorta. We measured cerebral and renal rSO2 using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days after birth, were included. Infants with antegrade blood flow (n = 12) and infants with retrograde blood flow in the ascending aorta (n = 7) had similar cerebral rSO2 and FTOE during both echocardiograms. Only during the first echocardiogram, infants with retrograde blood flow in the ascending aorta had lower renal FTOE (0.14 vs. 0.32, p = 0.04) and tended to have higher renal rSO2 (80 vs. 65%, p = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO2 and FTOE during the first (n = 8) as well as the second echocardiogram (n = 10). Retrograde blood flow in the ascending aorta was not associated with cerebral oxygenation, while diastolic backflow in the descending aorta was not associated with renal oxygenation in infants with LSOL. © 2017 S. Karger AG, Basel.

Feasibility of Retrograde Ureteral Contrast Injection to Guide Ultrasonographic Percutaneous Renal Access in the Nondilated Collecting System.

PubMed

Usawachintachit, Manint; Tzou, David T; Mongan, John; Taguchi, Kazumi; Weinstein, Stefanie; Chi, Thomas

2017-02-01

Ultrasound-guided percutaneous nephrolithotomy (PCNL) has become increasingly utilized. Patients with nondilated collecting systems represent a challenge: the target calix is often difficult to visualize. Here we report pilot study results for retrograde ultrasound contrast injection to aid in percutaneous renal access during ultrasound-guided PCNL. From April to July 2016, consecutive patients over the age of 18 years with nondilated collecting systems on preoperative imaging who presented for PCNL were enrolled. B-mode ultrasound imaging was compared with contrast-enhanced mode with simultaneous retrograde injection of Optison™ via an ipsilateral ureteral catheter. Five patients (four males and one female) with renal stones underwent PCNL with retrograde ultrasound contrast injection during the study period. Mean body mass index was 28.3 ± 5.6 kg/m 2 and mean stone size was 24.5 ± 12.0 mm. Under B-mode ultrasound, all patients demonstrated nondilated renal collecting systems that appeared as hyperechoic areas, where it was difficult to identify a target calix for puncture. Retrograde contrast injection facilitated delineation of all renal calices initially difficult to visualize under B-mode ultrasound. Renal puncture was then performed effectively in all cases with a mean puncture time of 55.4 ± 44.8 seconds. All PCNL procedures were completed without intraoperative complications and no adverse events related to ultrasound contrast injection occurred. Retrograde ultrasound contrast injection as an aide for renal puncture during PCNL is a feasible technique. By improving visualization of the collecting system, it facilitates needle placement in challenging patients without hydronephrosis. Future larger scale studies comparing its use to standard ultrasound-guided technique will be required to validate this concept.

Comparison of knee function after antegrade and retrograde intramedullary nailing for diaphyseal femoral fractures: results of isokinetic evaluation.

PubMed

Daglar, Bulent; Gungor, Ertugrul; Delialioglu, Onder M; Karakus, Dilek; Ersoz, Murat; Tasbas, Bulent Adil; Bayrakci, Kenan; Gunel, Ugur

2009-10-01

To evaluate knee function in patients having femoral diaphyseal fractures treated with antegrade or retrograde intramedullary nail insertion. Prospective. Level I referral center. Seventy patients having 71 OTA 32 fractures were randomly allocated into 2 groups to be treated with either antegrade or retrograde intramedullary nails inserted with reaming. Antegrade nail in 41 fractures and retrograde femoral intramedullary nails in 30 fractures. Postoperative knee range of motion, Lysholm Knee Score, and isokinetic knee muscle function testing at least 6 months after documented fracture healing, minimum 1 year postoperatively. Groups had similar data with regard to demographics and injury patterns. Mean follow-up time was 44 (range: 25-80) months. Mean knee flexion angle was 132 and 134 degrees, and mean Lysholm Score was 84 and 83.1 in antegrade and retrograde groups, respectively (P = 0.893 and P = 0.701). Isokinetic evaluation revealed similar results for peak torque deficiencies at 30 and 180 degrees per second and total work deficiencies at 180 degrees per second (P > 0.05). Age affected the knee functioning as the higher the age of the patient is, the lower the Lysholm Score and knee flexion angle (r = -0.449, P = 0.0321 and r = -0.568, P = 0.001, respectively). Knee function seems to have similar clinical results after either antegrade or retrograde nail insertion for femoral diaphyseal fractures when knee range of motion, Lysholm Scores, and isokinetic knee evaluation are considered as outcome measures. With increasing patient age, a decrease in knee functioning should be anticipated in patients with femoral fractures treated with intramedullary nails regardless of technique.

NEXT GENERATION OF TELESCOPES OR DYNAMICS REQUIRED TO DETERMINE IF EXO-MOONS HAVE PROGRADE OR RETROGRADE ORBITS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Karen M.; Fujii, Yuka

2014-08-20

We survey the methods proposed in the literature for detecting moons of extrasolar planets in terms of their ability to distinguish between prograde and retrograde moon orbits, an important tracer of the moon formation channel. We find that most moon detection methods, in particular, sensitive methods for detecting moons of transiting planets, cannot observationally distinguishing prograde and retrograde moon orbits. The prograde and retrograde cases can only be distinguished where the dynamical evolution of the orbit due to, e.g., three body effects is detectable, where one of the two cases is dynamically unstable, or where new observational facilities, which canmore » implement a technique capable of differentiating the two cases, come online. In particular, directly imaged planets are promising targets because repeated spectral and photometric measurements, which are required to determine moon orbit direction, could also be conducted with the primary interest of characterizing the planet itself.« less

Acetylated adipate of retrograded starch as RS 3/4 type resistant starch.

PubMed

Kapelko-Żeberska, M; Zięba, T; Spychaj, R; Gryszkin, A

2015-12-01

This study was aimed at producing acetylated adipate of retrograded starch (ADA-R) with various degrees of substitution with functional groups and at determining the effect of esterification degree on resistance and pasting characteristics of the produced preparations. Paste was prepared from native potato starch, and afterwards frozen and defrosted. After drying and disintegration, the paste was acetylated and crosslinked using various doses of reagents. An increase in the total degree of esterification of the produced ADA-R-preparation caused an increase in its resistance to the action of amyloglucosidase. Viscosity of the paste produced from ADA-R-preparation in a wide range of acetylation degrees was increasing along with increasing crosslinking of starch. The study demonstrated that acetylated adipate of retrograded starch may be classified as a preparation of RS 3/4 type resistant starch (retrograded starch/chemically-modified starch) with good texture-forming properties. The conducted modification offers the possibility of modeling the level of resistance of the produced preparation. Copyright © 2015 Elsevier Ltd. All rights reserved.

A mechanistic approach to studies of the possible digestion of retrograded starch by α-amylase revealed using a log of slope (LOS) plot

PubMed Central

Patel, Hamung; Day, Richard; Butterworth, Peter J.; Ellis, Peter R.

2014-01-01

The rate and extent of digestibility of starch were analysed using the logarithm of the slope (LOS) method. Digestibility curves with α-amylase were obtained for starches in their native, gelatinised and 24 h retrograded form. A LOS plot of the digestibility curves was then constructed, which allowed the rate constant (k) and the concentration of the product at the end of the reaction (C∞) to be calculated. It also allowed the identification of rapid and slow phases in starch digestion. Upon gelatinisation, both k and C∞ increased with dramatic changes notably in C∞; however after starch samples had been stored for 24 h at room temperature, k was not affected but C∞ decreased. This suggests that retrograded starch is virtually inert to amylase action. Both k and C∞ were strongly related to the increase in degree of order of the α-glucan chains, monitored by FTIR-ATR spectroscopy, in retrograded starch. PMID:25256473

The Proteome of the Isolated Chlamydia trachomatis Containing Vacuole Reveals a Complex Trafficking Platform Enriched for Retromer Components

PubMed Central

Fischer, Martina; Jehmlich, Nico; Rose, Laura; Koch, Sophia; Laue, Michael; Renard, Bernhard Y.; Schmidt, Frank; Heuer, Dagmar

2015-01-01

Chlamydia trachomatis is an important human pathogen that replicates inside the infected host cell in a unique vacuole, the inclusion. The formation of this intracellular bacterial niche is essential for productive Chlamydia infections. Despite its importance for Chlamydia biology, a holistic view on the protein composition of the inclusion, including its membrane, is currently missing. Here we describe the host cell-derived proteome of isolated C. trachomatis inclusions by quantitative proteomics. Computational analysis indicated that the inclusion is a complex intracellular trafficking platform that interacts with host cells’ antero- and retrograde trafficking pathways. Furthermore, the inclusion is highly enriched for sorting nexins of the SNX-BAR retromer, a complex essential for retrograde trafficking. Functional studies showed that in particular, SNX5 controls the C. trachomatis infection and that retrograde trafficking is essential for infectious progeny formation. In summary, these findings suggest that C. trachomatis hijacks retrograde pathways for effective infection. PMID:26042774

Worsening cholestasis and possible cefuroxime-induced liver injury following "successful" therapeutic endoscopic retrograde cholangiopancreatography for a distal common bile duct stone: a case report.

PubMed

Niriella, Madunil Anuk; Kumarasena, Ravindu Sujeewa; Dassanayake, Anuradha Supun; Pathirana, Aloka; de Silva Hewavisenthi, Janaki; de Silva, Hithanadura Janaka

2016-12-21

Cefuroxime very rarely causes drug-induced liver injury. We present a case of a patient with paradoxical worsening of jaundice caused by cefuroxime-induced cholestasis following therapeutic endoscopic retrograde cholangiopancreatography for a distal common bile duct stone. A 51-year-old, previously healthy Sri Lankan man presented to our hospital with obstructive jaundice caused by a distal common bile duct stone. Endoscopic retrograde cholangiopancreatography with stone extraction, common bile duct clearance, and stenting failed to improve the cholestasis, with paradoxical worsening of his jaundice. A liver biopsy revealed features of drug-induced intrahepatic cholestasis. Although his case was complicated by an episode of cholangitis, the patient made a complete recovery in 4 months with supportive treatment and withdrawal of the offending drug. This case highlights a very rare drug-induced liver injury caused by cefuroxime as well as our approach to treating a patient with paradoxical worsening of jaundice after therapeutic endoscopic retrograde cholangiopancreatography.

Geldanamycin Enhances Retrograde Transport of Shiga Toxin in HEp-2 Cells

PubMed Central

Simm, Roger; Torgersen, Maria Lyngaas; Sandvig, Kirsten

2015-01-01

The heat shock protein 90 (Hsp90) inhibitor geldanamycin (GA) has been shown to alter endosomal sorting, diverting cargo destined for the recycling pathway into the lysosomal pathway. Here we investigated whether GA also affects the sorting of cargo into the retrograde pathway from endosomes to the Golgi apparatus. As a model cargo we used the bacterial toxin Shiga toxin, which exploits the retrograde pathway as an entry route to the cytosol. Indeed, GA treatment of HEp-2 cells strongly increased the Shiga toxin transport to the Golgi apparatus. The enhanced Golgi transport was not due to increased endocytic uptake of the toxin or perturbed recycling, suggesting that GA selectively enhances endosomal sorting into the retrograde pathway. Moreover, GA activated p38 and both inhibitors of p38 or its substrate MK2 partially counteracted the GA-induced increase in Shiga toxin transport. Thus, our data suggest that GA-induced p38 and MK2 activation participate in the increased Shiga toxin transport to the Golgi apparatus. PMID:26017782

Monitoring the crystallization of starch and lipid components of the cake crumb during staling.

PubMed

Hesso, N; Le-Bail, A; Loisel, C; Chevallier, S; Pontoire, B; Queveau, D; Le-Bail, P

2015-11-20

Cake staling is a complex problem which has still not been fully understood. Starch polymers retrogradation, which is linked to biopolymers recrystallisation, is the most important factor affecting cake firmness in addition to water migration and fat crystallization. In this study, the effect of storage temperatures of 4°C and 20°C on starch retrogradation and fat recrystallization was investigated. Starch retrogradation can be tracked through changes in crystalline structure via X-rays diffraction as well as through melting of crystals via calorimetry. These techniques have been coupled to study the different phenomena occurring during staling. The results revealed that the storage of cakes at 20°C for 25 days showed more starch polymer retrogradation and more intense fat recrystallization in the β form than at 4°C. Consequently, the staling was delayed when a low storage temperature like 4°C was used, which is recommended to retain high quality cakes during storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Protein Kinase A Activity Is Necessary for Fission and Fusion of Golgi to Endoplasmic Reticulum Retrograde Tubules

PubMed Central

Tenorio, María J.; Luchsinger, Charlotte; Mardones, Gonzalo A.

2015-01-01

It is becoming increasingly accepted that together with vesicles, tubules play a major role in the transfer of cargo between different cellular compartments. In contrast to our understanding of the molecular mechanisms of vesicular transport, little is known about tubular transport. How signal transduction molecules regulate these two modes of membrane transport processes is also poorly understood. In this study we investigated whether protein kinase A (PKA) activity regulates the retrograde, tubular transport of Golgi matrix proteins from the Golgi to the endoplasmic reticulum (ER). We found that Golgi-to-ER retrograde transport of the Golgi matrix proteins giantin, GM130, GRASP55, GRASP65, and p115 was impaired in the presence of PKA inhibitors. In addition, we unexpectedly found accumulation of tubules containing both Golgi matrix proteins and resident Golgi transmembrane proteins. These tubules were still attached to the Golgi and were highly dynamic. Our data suggest that both fission and fusion of retrograde tubules are mechanisms regulated by PKA activity. PMID:26258546

Regulation of mitochondria-dynactin interaction and mitochondrial retrograde transport in axons.

PubMed

Drerup, Catherine M; Herbert, Amy L; Monk, Kelly R; Nechiporuk, Alex V

2017-04-17

Mitochondrial transport in axons is critical for neural circuit health and function. While several proteins have been found that modulate bidirectional mitochondrial motility, factors that regulate unidirectional mitochondrial transport have been harder to identify. In a genetic screen, we found a zebrafish strain in which mitochondria fail to attach to the dynein retrograde motor. This strain carries a loss-of-function mutation in actr10 , a member of the dynein-associated complex dynactin. The abnormal axon morphology and mitochondrial retrograde transport defects observed in actr10 mutants are distinct from dynein and dynactin mutant axonal phenotypes. In addition, Actr10 lacking the dynactin binding domain maintains its ability to bind mitochondria, arguing for a role for Actr10 in dynactin-mitochondria interaction. Finally, genetic interaction studies implicated Drp1 as a partner in Actr10-dependent mitochondrial retrograde transport. Together, this work identifies Actr10 as a factor necessary for dynactin-mitochondria interaction, enhancing our understanding of how mitochondria properly localize in axons.

Axonal autophagosomes recruit dynein for retrograde transport through fusion with late endosomes

PubMed Central

Cheng, Xiu-Tang; Zhou, Bing; Lin, Mei-Yao; Cai, Qian

2015-01-01

Efficient degradation of autophagic vacuoles (AVs) via lysosomes is an important cellular homeostatic process. This is particularly challenging for neurons because mature acidic lysosomes are relatively enriched in the soma. Although dynein-driven retrograde transport of AVs was suggested, a fundamental question remains how autophagosomes generated at distal axons acquire dynein motors for retrograde transport toward the soma. In this paper, we demonstrate that late endosome (LE)–loaded dynein–snapin complexes drive AV retrograde transport in axons upon fusion of autophagosomes with LEs into amphisomes. Blocking the fusion with syntaxin17 knockdown reduced recruitment of dynein motors to AVs, thus immobilizing them in axons. Deficiency in dynein–snapin coupling impaired AV transport, resulting in AV accumulation in neurites and synaptic terminals. Altogether, our study provides the first evidence that autophagosomes recruit dynein through fusion with LEs and reveals a new motor–adaptor sharing mechanism by which neurons may remove distal AVs engulfing aggregated proteins and dysfunctional organelles for efficient degradation in the soma. PMID:25940348

A new link between the retrograde actin flow and focal adhesions.

PubMed

Yamashiro, Sawako; Watanabe, Naoki

2014-11-01

The retrograde actin flow, continuous centripetal movement of the cell peripheral actin networks, is widely observed in adherent cells. The retrograde flow is believed to facilitate cell migration when linked to cell adhesion molecules. In this review, we summarize our current knowledge regarding the functional relationship between the retrograde actin flow and focal adhesions (FAs). We also introduce our recent study in which single-molecule speckle (SiMS) microscopy dissected the complex interactions between FAs and the local actin flow. FAs do not simply impede the actin flow, but actively attract and remodel the local actin network. Our findings provide a new insight into the mechanisms for protrusion and traction force generation at the cell leading edge. Furthermore, we discuss possible roles of the actin flow-FA interaction based on the accumulated knowledge and our SiMS study. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

A retrograde co-orbital asteroid of Jupiter.

PubMed

Wiegert, Paul; Connors, Martin; Veillet, Christian

2017-03-29

Recent theoretical work in celestial mechanics has revealed that an asteroid may orbit stably in the same region as a planet, despite revolving around the Sun in the sense opposite to that of the planet itself. Asteroid 2015 BZ 509 was discovered in 2015, but with too much uncertainty in its measured orbit to establish whether it was such a retrograde co-orbital body. Here we report observations and analysis that demonstrates that asteroid 2015 BZ 509 is indeed a retrograde co-orbital asteroid of the planet Jupiter. We find that 2015 BZ 509 has long-term stability, having been in its current, resonant state for around a million years. This is long enough to preclude precise calculation of the time or mechanism of its injection to its present state, but it may be a Halley-family comet that entered the resonance through an interaction with Saturn. Retrograde co-orbital asteroids of Jupiter and other planets may be more common than previously expected.

Doppler-guided retrograde catheterization system

NASA Astrophysics Data System (ADS)

Frazin, Leon J.; Vonesh, Michael J.; Chandran, Krishnan B.; Khasho, Fouad; Lanza, George M.; Talano, James V.; McPherson, David D.

1991-05-01

The purpose of this study was to investigate a Doppler guided catheterization system as an adjunctive or alternative methodology to overcome the disadvantages of left heart catheterization and angiography. These disadvantages include the biological effects of radiation and the toxic and volume effects of iodine contrast. Doppler retrograde guidance uses a 20 MHz circular pulsed Doppler crystal incorporated into the tip of a triple lumen multipurpose catheter and is advanced retrogradely using the directional flow information provided by the Doppler waveform. The velocity detection limits are either 1 m/second or 4 m/second depending upon the instrumentation. In a physiologic flow model of the human aortic arch, multiple data points revealed a positive wave form when flow was traveling toward the catheter tip indicating proper alignment for retrograde advancement. There was a negative wave form when flow was traveling away from the catheter tip if the catheter was in a branch or bent upon itself indicating improper catheter tip position for retrograde advancement. In a series of six dogs, the catheter was able to be accurately advanced from the femoral artery to the left ventricular chamber under Doppler signal guidance without the use of x-ray. The potential applications of a Doppler guided retrograde catheterization system include decreasing time requirements and allowing safer catheter guidance in patients with atherosclerotic vascular disease and suspected aortic dissection. The Doppler system may allow left ventricular pressure monitoring in the intensive care unit without the need for x-ray and it may allow left sided contrast echocardiography. With pulse velocity detection limits of 4 m/second, this system may allow catheter direction and passage into the aortic root and left ventricle in patients with aortic stenosis. A modification of the Doppler catheter may include transponder technology which would allow precise catheter tip localization once the catheter tip is placed in the aortic root. Such technology may conceivably assist in allowing selective coronary catheterization. These studies have demonstrated that Doppler guided retrograde catheterization provides an accurate method to catheterization the aortic root and left ventricular chamber without x-ray. In humans, it may prove useful in a variety of settings including the development of invasive ultrasonic diagnostic and therapeutic technology.

Phosphatidylinositol 3-kinase activity in murine motoneuron disease: the progressive motor neuropathy mouse.

PubMed

Wagey, R; Lurot, S; Perrelet, D; Pelech, S L; Sagot, Y; Krieger, C

2001-01-01

A murine model of motoneuron disease, the pmn/pmn mouse, shows a reduction in the retrograde transport of fluorescent probes applied directly onto the cut end of sciatic nerve. Brain-derived neurotrophic factor (BDNF), when co-applied with fluorescent tracers, increases the number of retrograde labelled motoneurons. We demonstrate here that spinal cord tissue from pmn/pmn mice had significantly reduced phosphatidylinositol 3-kinase activity and expression in the particulate fraction compared to controls, without changes in the activities or expression of the downstream kinases, protein kinase B/Akt or Erk1. Systemic administration of BDNF augmented phosphatidylinositol 3-kinase specific activity in spinal cord tissue from pmn/pmn and control mice, with a greater elevation in the particulate fractions of pmn/pmn mice than in controls. We examined the effect of inhibitors of phosphatidylinositol 3-kinase and mitogen-activated protein kinase kinase on the retrograde labelling of motoneurons, 24h following the direct application of inhibitors and Fluorogold to the cut end of sciatic nerve in control and pmn/pmn mice (labelling index). The mitogen-activated protein kinase kinase inhibitor PD 98059 had no effect on the labelling index in control or pmn/pmn mice. In the absence of exogenous BDNF, phosphatidylinositol 3-kinase inhibitors reduced the number of labelled motoneurons in control mice, without changing the labelling index in pmn/pmn. Co-application of phosphatidylinositol 3-kinase inhibitors with BDNF to the cut end of sciatic nerve blocked the action of BDNF on retrograde labelling in pmn/pmn mice. These results indicate that the retrograde labelling of motoneurons is mediated by phosphatidylinositol 3-kinase-dependent and -independent pathways. In pmn/pmn mice, phosphatidylinositol 3-kinase activity in spinal neurons is below the level required for optimal retrograde labelling of motoneurons and labelling can be augmented by the administration of growth factors stimulating phosphatidylinositol 3-kinase activity. The data indicate that phosphatidylinositol 3-kinase activity is important in the uptake and/or retrograde transport of substances by motoneurons and is altered in this model of motoneuron diseases.

Comparison Between Retrograde and Antegrade Peripheral Venous Cannulation in Intensive Care Unit Patients: Assessment of Thrombus Formation.

PubMed

Abdelaal Ahmed Mahmoud, Ahmed; El-Shafei, Hassan Ismail; Yassin, Hany Mahmoud; Elramely, Mohamed Adly; Abdelhaq, Mohamed Mohamed; El Kady, Hany Wafiq; Awada, Wael Nabil Fahemy

2017-06-01

Antegrade cannulation of peripheral veins is the usual practice. Blood stasis between a catheter and the wall of the vein or at its tip in addition to catheter-induced phlebitis may initiate a thrombosis. The use of retrograde ventriculojugular shunts against the direction of the blood flow with resultant decrease in the incidence of venous thrombosis encouraged us to compare retrograde versus conventional antegrade peripheral venous cannulation. Monocentric, nonblinded, prospective observational cohort of 40 intensive care unit patients receiving 2 peripheral venous catheters in upper limbs, 1 inserted in the direction of blood flow (antegrade cannula) and the other inserted in an opposite direction to blood flow (retrograde cannula). Daily ultrasound assessment of the angle between the catheter and the vascular wall was done to detect onset and progression of thrombus formation. The study included 40 patients, aged 46.7 ± 10.132 years. The incidence of thrombus formation was 100% in both techniques. The onset time of thrombus formation between the catheter and the wall of a vein was significantly longer with the retrograde catheters than with the antegrade catheters with median time (interquartile range [range]) 6 days (5-6.75 [4-8]) with 95% confidence interval (CI), 5.58-6.42 vs 3 days (3-4 [2-5]) with 95% CI (2.76-3.24), respectively, with a P value <.001. The time needed by the recently detected thrombus to reach the catheter tip determined by ultrasound with or without catheter failure was significantly longer in the retrograde catheters than in the antegrade catheter with median time (interquartile range [range]) 9 days (8-9 [7-10]) with 95% CI, 8.76-9.24 vs 4 days (4-5 [3-6]) with 95% CI, 3.76-4.24, respectively, with a P value <.001. Retrograde cannulation did not decrease the incidence of thrombus formation, but significantly increased the onset time until thrombus formation and prolonged the time needed by the newly formed thrombus to reach the catheter tip compared with conventional antegrade cannulation.

Comparison of knee function in patients with a healed fracture of the femoral shaft fixed with retrograde and antegrade intramedullary nailing.

PubMed

Andrzejewski, Krzysztof; Panasiuk, Michał; Grzegorzewski, Andrzej; Synder, Marek

2013-10-31

BACKGROUND. Despite extensive current knowledge about fractures of the femoral shaft, the choice between antegrade and retrograde intramedullary (IM) nailing with respect to the future function of the joint serving to introduce the nail continues to raise controversy. To compare knee function in patients with a healed fracture of the femoral shaft fixed by antegrade vs. retrograde IM nailing. MATERIAL AND METHODS. The study involved a group of 65 individuals with traumatic fractures of the femoral shaft who underwent stabilisation with IM nails in the years 2001-2010. Thirty-two cases were retrograde nails (Group R) and 33 antegrade nails (Group A). Patient age at trauma ranged from 19 to 91 years (mean: 47). Knee function was assessed in both groups with the KOOS, KSS1 and KSS2 scoring systems. RESULTS. Knee function as assessed with KOOS differed significantly between retrograde and antegrade nailing, with a greater incidence of poor and fair results in the former and more excellent outcomes in the latter group (p=0.0133). As regards KSS1 and KSS2, there were no significant differences between the groups (p=0.1947, p=0.4038). The range of motion was 86-125 degrees in Group R and 121-125 degrees in Group A. Knee pain was reported by 37.5% of the patients treated with retrograde nailing and 39.4% of those who had the IM nail inserted via the antegrade approach (p=0.22). The mean time to bone union was 180 days in Group R and 219 days in Group A (p=0.25). Age and presence of osteoarthritis at trauma significantly lowered the KOOS (p=0.0027, p= 0.005) and KSS (p=0.0002, p=0.002) scores, as well as the knee range of motion (p=0.0014, p=0.004) CONCLUSIONS. 1. Knee function following retrograde and antegrade IM nailing to stabilise femoral shaft fractures was comparable. 2. The choice of IM nailing method should not be based solely on orthopaedic indications, but also on the severity of osteoarthritis present at trauma.

Functional retrograde amnesia: a quantitative case study.

PubMed

Schacter, D L; Wang, P L; Tulving, E; Freedman, M

1982-01-01

The memory impairment of a patient suffering from functional retrograde amnesia was assessed both during the amnesic episode and after its termination. The patient's performance on a task tapping semantic memory was nearly identical on the two test occasions, but his performance on a task tapping episodic memory substantially changed across test sessions. Cueing procedures revealed that in spite of the patient's restricted access to episodic memory during the amnesic period, a relatively intact "island" of episodic memories could be uncovered. The distinction between episodic and semantic memory, as well as the relation between organic and functional retrograde amnesia, are discussed in light of the case study.

An Innovative Approach to the Repair of Distal Tibia Nonunion Using a Retrograde Buried Tibio-Talar-Calcaneal Nail: A Case Report.

PubMed

Van Steyn, Peter; Romash, Michael

We report a case using retrograde tibial nailing as treatment of nonunion of a distal tibial osteotomy, which was performed as part of a complex reconstruction of distal tibial malunion with ankle arthritis. Although retrograde nailing has classically been used for tibial-talar-calcaneal arthrodesis, this method spares the subtalar joint. Preservation of some hindfoot motion by subtalar mobility allows for a decrease in the loss of function typically seen with tibial-talar-calcaneal arthrodesis. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Chloroplast-to-nucleus communication: current knowledge, experimental strategies and relationship to drought stress signaling.

PubMed

Chan, Kai Xun; Crisp, Peter Alexander; Estavillo, Gonzalo Martin; Pogson, Barry James

2010-12-01

In order for plant cells to function efficiently under different environmental conditions, chloroplastic processes have to be tightly regulated by the nucleus. It is widely believed that there is inter-organelle communication from the chloroplast to the nucleus, called retrograde signaling. Although some pathways of communication have been identified, the actual signals that move between the two cellular compartments are largely unknown. This review provides an overview of retrograde signaling including its importance to the cell, candidate signals, recent advances, and current experimental systems. In addition, we highlight the potential of using drought stress as a model for studying retrograde signaling.

Retrograde Coronary Chronic Total Occlusion Intervention

PubMed Central

Dash, Debabrata

2015-01-01

Coronary chronic total occlusion (CTO) is a frequent finding in patients with coronary artery disease. It remains one of the most challenging subsets, accounting for 10-20% of all percutaneous coronary interventions (PCI). Although remarkable progress in PCI has been made, it is reasonable to state that successful recanalization of CTO represents the “last frontier” of PCI. PCI of CTOs has been limited historically by technical success rates of 50-70%. The introduction of enhanced guidewires, microcatheter, channel dilatator with increasing operator experience, and innovative techniques such as the retrograde approach have raised hopes for better outcomes. This article goes into depth into various strategies of retrograde approach in CTO.

The Many Faces of Amnesia

ERIC Educational Resources Information Center

Gold, Paul E.

2006-01-01

Results from studies of retrograde amnesia provide much of the evidence for theories of memory consolidation. Retrograde amnesia gradients are often interpreted as revealing the time needed for the formation of long-term memories. The rapid forgetting observed after many amnestic treatments, including protein synthesis inhibitors, and the parallel…

The chloroplast division mutant caa33 of Arabidopsis thaliana reveals a crucial impact of chloroplast homeostasis on stress acclimation and retrograde plastid-to-nucleus signaling

PubMed Central

Šimková, Klára; Kim, Chanhong; Gacek, Katarzyna; Baruah, Aiswarya; Laloi, Christophe; Apel, Klaus

2011-01-01

SUMMARY Retrograde plastid-to-nucleus signaling tightly controls and coordinates nuclear and plastid gene expression that is required for plastid biogenesis and chloroplast activities. As chloroplasts act as sensors of environmental changes, plastid-derived signaling also modulates stress responses of plants by transferring stress-related signals and altering nuclear gene expression. Various mutant screens have been undertaken to identify constituents of plastid signaling pathways. Almost all mutations identified in these screens have in common that they target plastid-specific but not extra-plastidic functions. They have been suggested to define either genuine constituents of retrograde signaling pathways or components required for the synthesis of plastid signals. Here we report the characterization of the caa33 (constitutive activator of AAA-ATPase) mutant, which reveals another way of how mutations that affect plastid functions may modulate retrograde plastid signaling. caa33 disturbs a plastid-specific function by impeding plastid division thereby perturbing plastid homeostasis. This results in pre-conditioning plants by activating the expression of stress genes, enhancing pathogen resistance and attenuating the plant’s capacity to respond to plastid signals. Our study reveals an intimate link between chloroplast activity and the plant’s susceptibility to stress and emphasizes the need to consider the possible impact of pre-conditioning on retrograde plastid-to-nucleus signaling. PMID:22014227

Complications of retrograde balloon cautery endopyelotomy.

PubMed

Schwartz, B F; Stoller, M L

1999-11-01

Adult ureteropelvic junction obstruction is increasingly managed with endoscopic techniques. Retrograde balloon cautery endopyelotomy is quick, requires minimal hospital stay and allows most patients a rapid return to work. The complication rate of retrograde balloon cautery endopyelotomy ranges from 13 to 34%, with vascular injury in 0 to 16% of patients. We report 5 uncommon complications, including 4 vascular injuries, that clinicians should be familiar with when using this technique. We reviewed 52 retrograde endoscopic endopyelotomy procedures performed during a 5-year period. There were 5 uncommon complications. Accessory lower pole renal artery injuries occurred in 3 patients, 1 of whom presented 12 days after endopyelotomy. Embolization was successfully performed in all 3 cases and none had subsequent hypertension. In 1 case a right ovarian vein laceration was not evident on preoperative or postoperative angiography. Emergency post-embolization abdominal exploration revealed a 2 mm. injury to the right ovarian vein before entering the right renal vein close to the ureteropelvic junction incision. Nephrectomy and ovarian vein ligature were curative. In 1 case the electrocautery wire broke intracorporeally after firing, resulting in a bobby pin-like configuration. Successful removal was accomplished by twisting the catheter and wrapping the wire around the tip, enabling atraumatic removal. Retrograde balloon cautery endopyelotomy is an emerging technology with potential adverse outcomes. The complications we noted are complex and potentially life threatening. Awareness of these complications may help avoid poor outcomes and expedite appropriate treatment.

The role of the dynein light intermediate chain in retrograde IFT and flagellar function in Chlamydomonas

PubMed Central

Reck, Jaimee; Schauer, Alexandria M.; VanderWaal Mills, Kristyn; Bower, Raqual; Tritschler, Douglas; Perrone, Catherine A.; Porter, Mary E.

2016-01-01

The assembly of cilia and flagella depends on the activity of two microtubule motor complexes, kinesin-2 and dynein-2/1b, but the specific functions of the different subunits are poorly defined. Here we analyze Chlamydomonas strains expressing different amounts of the dynein 1b light intermediate chain (D1bLIC). Disruption of D1bLIC alters the stability of the dynein 1b complex and reduces both the frequency and velocity of retrograde intraflagellar transport (IFT), but it does not eliminate retrograde IFT. Flagellar assembly, motility, gliding, and mating are altered in a dose-dependent manner. iTRAQ-based proteomics identifies a small subset of proteins that are significantly reduced or elevated in d1blic flagella. Transformation with D1bLIC-GFP rescues the mutant phenotypes, and D1bLIC-GFP assembles into the dynein 1b complex at wild-type levels. D1bLIC-GFP is transported with anterograde IFT particles to the flagellar tip, dissociates into smaller particles, and begins processive retrograde IFT in <2 s. These studies demonstrate the role of D1bLIC in facilitating the recycling of IFT subunits and other proteins, identify new components potentially involved in the regulation of IFT, flagellar assembly, and flagellar signaling, and provide insight into the role of D1bLIC and retrograde IFT in other organisms. PMID:27251063

Malingering and retrograde amnesia: the historic case of the Collegno amnesic.

PubMed

Zago, Stefano; Sartori, Giuseppe; Scarlato, Guglielmo

2004-06-01

Assessment of feigned cognitive disorders is an important field of neuropsychology because of its applications to forensic settings. Strategies for detecting malingering in amnesia are available for anterograde amnesia. Less attention has been given to malingering in retrograde amnesia. The case of the 'Smemorato di Collegno' (The Collegno Amnesic) is probably the most famous case of malingered retrograde amnesia ever known in Italy. In 1926, a man who appeared to have lost all his autobiographical memories and identity spent nearly a year in the Collegno asylum of Turin without a name. He was later initially identified as Giulio Canella, Director of the 'Scuola Normale di Verona' who had disappeared during the war in 1916. He was suspected of later identified as being Mario Bruneri, a petty crook from Turin who played the part of an amnesic whose retrograde memory gradually returned. A lengthy investigation was required before this conclusion was reached. Several clinicians and renowned academics evaluated the case, but only Alfredo Coppola, diagnosed "malingered retrograde amnesia" using a method that was extremely innovative for the times. The aim of the present paper is to review the original cognitive evaluation and the strategies used for malingering detection in the "Collegno case". The outcome of the case is then discussed in the light of present-day forensic neuropsychology and the level of advancement of mental examination achieved in the 1920s in Europe is highlighted.

Hippocampal contributions to recollection in retrograde and anterograde amnesia.

PubMed

Gilboa, Asaf; Winocur, Gordon; Rosenbaum, R Shayna; Poreh, Amir; Gao, Fuqiang; Black, Sandra E; Westmacott, Robyn; Moscovitch, Morris

2006-01-01

Lesions restricted to the hippocampal formation and/or extended hippocampal system (hippocampal formation, fornix, mammillary bodies, and anterior thalamic nuclei) can disrupt conscious recollection in anterograde amnesia, while leaving familiarity-based memory relatively intact. Familiarity may be supported by extra-hippocampal medial temporal lobe (MTL) structures. Within-task dissociations in recognition memory best exemplify this distinction in anterograde amnesia. The authors report for the first time comparable dissociations within recognition memory in retrograde amnesia. An amnesic patient (A.D.) with bilateral fornix and septal nuclei lesions failed to recognize details pertaining to personal past events only when recollection was required, during recognition of episodic details. His intact recognition of generic and semantic details pertaining to the same events was ascribed to intact familiarity processes. Recollective processes in the controls were reflected by asymmetrical Receiver's Operating Characteristic curves, whereas the patient's Receiver's Operating Characteristic was symmetrical, suggesting that his inferior recognition performance on episodic details was reliant on familiarity processes. Anterograde and retrograde memories were equally affected, with no temporal gradient for retrograde memories. By comparison, another amnesic person (K.C.) with extensive MTL damage (involving extra-hippocampal MTL structures in addition to hippocampal and fornix lesions) had very poor recognition and no recollection of either episodic or generic/semantic details. These data suggest that the extended hippocampal system is required to support recollection for both anterograde and retrograde memories, regardless of their age.

Deficiency in the Lipid Exporter ABCA1 Impairs Retrograde Sterol Movement and Disrupts Sterol Sensing at the Endoplasmic Reticulum*♦

PubMed Central

Yamauchi, Yoshio; Iwamoto, Noriyuki; Rogers, Maximillian A.; Abe-Dohmae, Sumiko; Fujimoto, Toyoshi; Chang, Catherine C. Y.; Ishigami, Masato; Kishimoto, Takuma; Kobayashi, Toshihide; Ueda, Kazumitsu; Furukawa, Koichi; Chang, Ta-Yuan; Yokoyama, Shinji

2015-01-01

Cellular cholesterol homeostasis involves sterol sensing at the endoplasmic reticulum (ER) and sterol export from the plasma membrane (PM). Sterol sensing at the ER requires efficient sterol delivery from the PM; however, the macromolecules that facilitate retrograde sterol transport at the PM have not been identified. ATP-binding cassette transporter A1 (ABCA1) mediates cholesterol and phospholipid export to apolipoprotein A-I for the assembly of high density lipoprotein (HDL). Mutations in ABCA1 cause Tangier disease, a familial HDL deficiency. Several lines of clinical and experimental evidence suggest a second function of ABCA1 in cellular cholesterol homeostasis in addition to mediating cholesterol efflux. Here, we report the unexpected finding that ABCA1 also plays a key role in facilitating retrograde sterol transport from the PM to the ER for sterol sensing. Deficiency in ABCA1 delays sterol esterification at the ER and activates the SREBP-2 cleavage pathway. The intrinsic ATPase activity in ABCA1 is required to facilitate retrograde sterol transport. ABCA1 deficiency causes alternation of PM composition and hampers a clathrin-independent endocytic activity that is required for ER sterol sensing. Our finding identifies ABCA1 as a key macromolecule facilitating bidirectional sterol movement at the PM and shows that ABCA1 controls retrograde sterol transport by modulating a certain clathrin-independent endocytic process. PMID:26198636

Effect of cooling step on starch digestibility and other properties of parboiled rice.

USDA-ARS?s Scientific Manuscript database

Retrogradation and the formation of amylose-lipid complex have been reported to contribute to reduced digestibility of starch in parboiled rice. This study looked at the prospect of including a low-temperature holding step in the parboiling process to enhance retrogradation, and subsequently reduce ...

Retrograde pyelogram using the flexible cystoscope.

PubMed

Reddy, P K; Hulbert, J C

1986-12-01

A retrograde pyelogram was performed on 2 men with the flexible choledochonephroscope and a 5F whistle-tip ureteral catheter. The procedure was done on an outpatient basis with topical anesthesia and patient tolerance was good. The technique is simple and is a useful alternative to the classical rigid cystoscopic technique.

Features of cues and processes during chloroplast-mediated retrograde signaling in the alga Chlamydomonas

USDA-ARS?s Scientific Manuscript database

Retrograde signalling is a selective process defined by cues generated in chloroplast/mitochondria which traverse membranes and end up regulating nuclear gene expression and protein synthesis. The coding and encoding of organellar message(s) that alter nuclear gene expression and/or cellular metabo...

Retrograde Ascending Aortic Dissection after Stent Grafting for Stanford Type B Aortic Dissection with Severe Limb Ischemia.

PubMed

Higuchi, Yoshiro; Tochii, Masato; Takami, Yoshiyuki; Kobayashi, Akihiro; Yanagisawa, Tsutomu; Amano, Kentaro; Sakurai, Yusuke; Ishida, Michiko; Ishikawa, Hiroshi; Hattori, Koji; Takagi, Yasushi

2017-03-24

We report a rare case of retrograde Stanford type A aortic dissection after endovascular repair for complicated Stanford type B aortic dissection. A 45-year-old man presented with a sudden onset of back pain and was transferred to our hospital. Computed tomography demonstrated acute Stanford type B aortic dissection with lower limb ischemia. Emergency endovascular surgery was planned for repair of the Stanford type B aortic dissection. The patient suddenly developed recurrent chest pain 10 days after the initial procedure. Computed tomography revealed retrograde Stanford type A aortic dissection involving the ascending aorta and aortic arch. The patient underwent a successful emergency total aortic arch replacement.

Structure of waxy maize starch hydrolyzed by maltogenic alpha-amylase in relation to its retrogradation

USDA-ARS?s Scientific Manuscript database

Maltogenic a-amylase is widely used as an antistaling agent in bakery foods. The objective of this study was to determine the degree of hydrolysis (DH) and starch structure after maltogenic amylase treatments in relation to its retrogradation. Waxy maize starch was cooked and hydrolyzed to different...

External-to-Internal Iliac Stent-Graft: Medium-Term Patency Following Exclusion of a Retrogradely Perfused Common Iliac Aneurysm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholls, Marcus John, E-mail: marcusnicholls@hotmail.co; McPherson, Simon

2010-08-15

Following complicated aortic aneurysm surgery a complete left iliac occlusion resulted in buttock claudication. A retrogradely perfused right common iliac aneurysm expanded. Exclusion was by external-to-internal iliac stent-graft. No deterioration in claudication occurred with medium-term stent-graft patency.

Osteochondritis Dissecans Involving the Trochlear Groove Treated With Retrograde Drilling

PubMed Central

Kaji, Yoshio; Nakamura, Osamu; Yamaguchi, Konosuke; Yamamoto, Tetsuji

2015-01-01

Abstract Osteochondritis dissecans (OCD) occurs frequently in the humeral capitellum of the upper extremity, whereas OCD involving the trochlear groove (trochlear groove OCD) is rarely reported. A standard treatment for trochlear groove OCD has therefore not been determined, although several methods have been tried. The case of a 14-year-old male gymnast with bilateral trochlear groove OCD is presented. Retrograde drilling from the lateral condyle of the humerus was applied for the OCD lesion of the left elbow, since it was larger in size than that in the right elbow and was symptomatic. Conversely, since the right lesion was small and asymptomatic, it was managed conservatively. After treatment, consolidation of the OCD lesions was observed in both elbows. However, the time to healing was shorter in the left elbow treated surgically than in the right elbow managed conservatively. In conclusion, retrograde drilling is a very simple and minimally invasive treatment. This case suggests that retrograde drilling for trochlear groove OCD may be a useful procedure that may accelerate the healing process for OCD lesions. PMID:26356703

A chloroplast retrograde signal, 3'-phosphoadenosine 5'-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination.

PubMed

Pornsiriwong, Wannarat; Estavillo, Gonzalo M; Chan, Kai Xun; Tee, Estee E; Ganguly, Diep; Crisp, Peter A; Phua, Su Yin; Zhao, Chenchen; Qiu, Jiaen; Park, Jiyoung; Yong, Miing Tiem; Nisar, Nazia; Yadav, Arun Kumar; Schwessinger, Benjamin; Rathjen, John; Cazzonelli, Christopher I; Wilson, Philippa B; Gilliham, Matthew; Chen, Zhong-Hua; Pogson, Barry J

2017-03-21

Organelle-nuclear retrograde signaling regulates gene expression, but its roles in specialized cells and integration with hormonal signaling remain enigmatic. Here we show that the SAL1-PAP (3'-phosphoadenosine 5'- phosphate) retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis . Genetically or exogenously manipulating PAP bypasses the canonical signaling components ABA Insensitive 1 (ABI1) and Open Stomata 1 (OST1); priming an alternative pathway that restores ABA-responsive gene expression, ROS bursts, ion channel function, stomatal closure and drought tolerance in ost1 -2. PAP also inhibits wild type and abi1 -1 seed germination by enhancing ABA sensitivity. PAP-XRN signaling interacts with ABA, ROS and Ca 2+ ; up-regulating multiple ABA signaling components, including lowly-expressed Calcium Dependent Protein Kinases (CDPKs) capable of activating the anion channel SLAC1. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses.

LC3 binding to the scaffolding protein JIP1 regulates processive dynein-driven transport of autophagosomes.

PubMed

Fu, Meng-Meng; Nirschl, Jeffrey J; Holzbaur, Erika L F

2014-06-09

Autophagy is essential for maintaining cellular homeostasis in neurons, where autophagosomes undergo robust unidirectional retrograde transport along axons. We find that the motor scaffolding protein JIP1 binds directly to the autophagosome adaptor LC3 via a conserved LIR motif. This interaction is required for the initial exit of autophagosomes from the distal axon, for sustained retrograde transport along the midaxon, and for autophagosomal maturation in the proximal axon. JIP1 binds directly to the dynein activator dynactin but also binds to and activates kinesin-1 in a phosphorylation-dependent manner. Following JIP1 depletion, phosphodeficient JIP1-S421A rescues retrograde transport, while phosphomimetic JIP1-S421D aberrantly activates anterograde transport. During normal autophagosome transport, residue S421 of JIP1 may be maintained in a dephosphorylated state by autophagosome-associated MKP1 phosphatase. Moreover, binding of LC3 to JIP1 competitively disrupts JIP1-mediated activation of kinesin. Thus, dual mechanisms prevent aberrant activation of kinesin to ensure robust retrograde transport of autophagosomes along the axon. Copyright © 2014 Elsevier Inc. All rights reserved.

Telescopic Corsair in 5F Guidion for Retrograde Recanalization of Complex Chronic Total Occlusions (CTOs)

PubMed Central

Palmers, Pieter-Jan; Maeremans, Joren; Meyer-Gessner, Markus; Bataille, Yoann; Dens, Joseph

2017-01-01

Case series Patient: Male, 81 • Female, 72 • Male, 58 Final Diagnosis: CTO Symptoms: Angina pectoris Medication: — Clinical Procedure: PCI Specialty: Cardiology Objective: Unusual setting of medical care Background: Retrograde advancement of microcatheters through septal/epicardial connectors can be challenging. Although several tricks might help to do so (e.g., balloon trap of retro wire in second guiding, balloon trap of retro wire in native coronary artery, and use of antegrade extension to approximate the antegrade conduit to the retrograde gear), these tricks cannot always be applied, especially in patients with poor access. Also, puncturing, knuckling, and crossing of the distal CTO cap (or the aorta as described in 1 of the cases) sometimes needs a lot of backup of the microcatheter. Case Report: We describe 3 cases in which we used a novel telescopic technique with 5F Guidion (IMDS®) supported retrograde Corsair (Asahi®) advancement in complex CTO lesions. Conclusions: The telescopic Corsair in 5F Guidion may offer the support needed to end successfully in these situations. PMID:28456814

Retrograde signals arise from reciprocal crosstalk within plastids.

PubMed

Enami, Kazuhiko; Tanaka, Kan; Hanaoka, Mitsumasa

2012-01-01

In addition to the cell nucleus, plant cells also possess genomic DNA and gene expression machineries within mitochondria and plastids. In higher plants, retrograde transcriptional regulation of several nuclear genes encoding plastid-located proteins has been observed in response to changes in a wide variety of physiological properties in plastids, including organelle gene expression (OGE) and tetrapyrrole metabolism. This regulation is postulated to be accomplished by plastid-to-nucleus signaling, (1,2) although the overall signal transduction pathway(s) are not well characterized. By applying a specific differentiation system in tobacco Bright Yellow-2 (BY-2) cultured cells, (3,4) we recently reported that the regulatory system of nuclear gene expressions modulated by a plastid signal was also observed during differentiation of plastids into amyloplasts. (5) While retrograde signaling from plastids was previously speculated to consist of several independent pathways, we found inhibition of OGE and perturbation in the cellular content of one tetrapyrrole intermediate, heme, seemed to interact to regulate amyloplast differentiation. Our results thus highlight the possibility that several sources of retrograde signaling in plastids could be integrated in an intraorganellar manner.

Arp2/3 complex–dependent actin networks constrain myosin II function in driving retrograde actin flow

PubMed Central

Yang, Qing; Zhang, Xiao-Feng; Pollard, Thomas D.

2012-01-01

The Arp2/3 complex nucleates actin filaments to generate networks at the leading edge of motile cells. Nonmuscle myosin II produces contractile forces involved in driving actin network translocation. We inhibited the Arp2/3 complex and/or myosin II with small molecules to investigate their respective functions in neuronal growth cone actin dynamics. Inhibition of the Arp2/3 complex with CK666 reduced barbed end actin assembly site density at the leading edge, disrupted actin veils, and resulted in veil retraction. Strikingly, retrograde actin flow rates increased with Arp2/3 complex inhibition; however, when myosin II activity was blocked, Arp2/3 complex inhibition now resulted in slowing of retrograde actin flow and veils no longer retracted. Retrograde flow rate increases induced by Arp2/3 complex inhibition were independent of Rho kinase activity. These results provide evidence that, although the Arp2/3 complex and myosin II are spatially segregated, actin networks assembled by the Arp2/3 complex can restrict myosin II–dependent contractility with consequent effects on growth cone motility. PMID:22711700

Sphincterotomy in patients with gallstones, elevated LFTs and a normal CBD on ERCP.

PubMed

Siddique, Iqbal; Mohan, Krishna; Khajah, Abdulkareem; Hasan, Fuad; Memon, Anjum; Kalaoui, Maher; al-Shamali, Mohammad; Patty, Istvan; al-Nakib, Basil

2003-01-01

To determine whether an endoscopic sphincterotomy affects outcome in patients with symptomatic gallstones, elevated liver function tests and a normal common bile duct on endoscopic retrograde cholangiopancreatogram. A total of 163 patients with symptomatic gallstones and elevated liver function tests, and found to have a normal common bile duct on endoscopic retrograde cholangiopancreatogram were included in the study. Endoscopic sphincterotomy was performed in 78 (47.8%) patients, while 85 (52.1%) patients did not have an endoscopic sphincterotomy. The two groups were compared for detection of small unseen common bile duct stones/debris, endoscopic retrograde cholangiopancreatogram related complications, and biliary complications after cholecystectomy. Small common bile duct stones/debris were recovered in 11/43 (25.5%) patients who had instrumentation of the common bile duct performed after endoscopic sphincterotomy. Common bile duct instrumentation was not performed in any of the patients without endoscopic sphincterotomy. No patient had any biliary complication after cholecystectomy, both in the immediate postoperative period and on a follow-up of 37.5 +/- 13.6 months (range 17-66). Endoscopic retrograde cholangiopancreatogram related complications occurred in 8 patients who had an endoscopic sphincterotomy and in 2 without endoscopic sphincterotomy (p < 0.05). Performing an endoscopic sphincterotomy in these patients increases the detection of small unseen common bile duct stones/debris without changing the clinical outcome after cholecystectomy. It also increases the endoscopic retrograde cholangiopancreatogram related complication rate, and therefore may not be necessary.

Nonserotonergic projection neurons in the midbrain raphe nuclei contain the vesicular glutamate transporter VGLUT3.

PubMed

Jackson, Jesse; Bland, Brian H; Antle, Michael C

2009-01-01

The brainstem raphe nuclei are typically assigned a role in serotonergic brain function. However, numerous studies have reported that a large proportion of raphe projection cells are nonserotonergic. The identity of these projection cells is unknown. Recent studies have reported that the vesicular glutamate transporter VGLUT3 is found in both serotonergic and nonserotonergic neurons in both the median raphe (MR) and dorsal raphe (DR) nuclei. We injected the retrograde tracer cholera toxin subunit B into either the dorsal hippocampus or the medial septum (MS) and used triple labeled immunofluorescence to determine if nonserotonergic raphe cells projecting to these structures contained VGLUT3. Consistent with previous studies, only about half of retrogradely labeled MR neurons projecting to the hippocampus contained serotonin, whereas a majority of the retrogradely labeled nonserotonergic cells contained VGLUT3. Similar patterns were observed for MR cells projecting to the MS. About half of retrogradely labeled nonserotonergic neurons in the DR contained VGLUT3. Additionally, a large number of retrogradely labeled cells in the caudal linear and interpeduncular nuclei projecting to the MS were found to contain VGLUT3. These data suggest the enigmatic nonserotonergic projection from the MR to forebrain regions may be glutamatergic. In addition, these results demonstrate a dissociation between glutamatergic and serotonergic MR afferent inputs to the MS and hippocampus suggesting divergent and/or complementary roles of these pathways in modulating cellular activity within the septohippocampal network.

Hippocampus and Retrograde Amnesia in the Rat Model: A Modest Proposal for the Situation of Systems Consolidation

PubMed Central

Sutherland, Robert J.; Sparks, Fraser; Lehmann, Hugo

2010-01-01

The properties of retrograde amnesia after damage to the hippocampus have been explicated with some success using a rat model of human medial temporal lobe amnesia. We review the results of this experimental work with rats focusing on several areas of consensus in this growing literature. We evaluate the theoretically significant hypothesis that hippocampal retrograde amnesia normally exhibits a temporal gradient, affecting recent, but sparing remote memories. Surprisingly, the evidence does not provide much support for the idea that there is a lengthy process of systems consolidation following a learning episode. Instead, recent and remote memories tend to be equally affected. The extent of damage to the hippocampus is a significant factor in this work since it is likely that spared hippocampal tissue can support at least partial memory retrieval. With extensive hippocampal damage gradients are flat or, in the case of memory tasks with flavour/odour retrieval cues, the retrograde amnesia covers a period of about 1 – 3 days. There is consistent evidence that at the time of learning the hippocampus interferes with or overshadows memory acquisition by other systems. This contributes to the breadth and severity of retrograde amnesia relative to anterograde amnesia in the rat. The fact that multiple, distributed learning episodes can overcome this overshadowing is consistent with a parallel dual-store theory or a Distributed Reinstatement Theory in which each learning episode triggers a short period of memory replay that provides a brief hippocampal-dependent systems consolidation. PMID:20430043

Actin retrograde flow and actomyosin II arc contraction drive receptor cluster dynamics at the immunological synapse in Jurkat T cells

PubMed Central

Yi, Jason; Wu, Xufeng S.; Crites, Travis; Hammer, John A.

2012-01-01

Actin retrograde flow and actomyosin II contraction have both been implicated in the inward movement of T cell receptor (TCR) microclusters and immunological synapse formation, but no study has integrated and quantified their relative contributions. Using Jurkat T cells expressing fluorescent myosin IIA heavy chain and F-tractin—a novel reporter for F-actin—we now provide direct evidence that the distal supramolecular activation cluster (dSMAC) and peripheral supramolecular activation cluster (pSMAC) correspond to lamellipodial (LP) and lamellar (LM) actin networks, respectively, as hypothesized previously. Our images reveal concentric and contracting actomyosin II arcs/rings at the LM/pSMAC. Moreover, the speeds of centripetally moving TCR microclusters correspond very closely to the rates of actin retrograde flow in the LP/dSMAC and actomyosin II arc contraction in the LM/pSMAC. Using cytochalasin D and jasplakinolide to selectively inhibit actin retrograde flow in the LP/dSMAC and blebbistatin to selectively inhibit actomyosin II arc contraction in the LM/pSMAC, we demonstrate that both forces are required for centripetal TCR microcluster transport. Finally, we show that leukocyte function–associated antigen 1 clusters accumulate over time at the inner aspect of the LM/pSMAC and that this accumulation depends on actomyosin II contraction. Thus actin retrograde flow and actomyosin II arc contraction coordinately drive receptor cluster dynamics at the immunological synapse. PMID:22219382

REVIVE Trial: Retrograde Delivery of Autologous Bone Marrow in Patients With Heart Failure.

PubMed

Patel, Amit N; Mittal, Sanjay; Turan, Goekmen; Winters, Amalia A; Henry, Timothy D; Ince, Hueseyin; Trehan, Naresh

2015-09-01

Cell therapy is an evolving option for patients with end-stage heart failure and ongoing symptoms despite optimal medical therapy. Our goal was to evaluate retrograde bone marrow cell delivery in patients with either ischemic heart failure (IHF) or nonischemic heart failure (NIHF). This was a prospective randomized, multicenter, open-label study of the safety and feasibility of bone marrow aspirate concentrate (BMAC) infused retrograde into the coronary sinus. Sixty patients were stratified by IHF and NIHF and randomized to receive either BMAC infusion or control (standard heart failure care) in a 4:1 ratio. Accordingly, 24 subjects were randomized to the ischemic BMAC group and 6 to the ischemic control group. Similarly, 24 subjects were randomized to the nonischemic BMAC group and 6 to the nonischemic control group. All 60 patients were successfully enrolled in the study. The treatment groups received BMAC infusion without complications. The left ventricular ejection fraction in the patients receiving BMAC demonstrated significant improvement compared with baseline, from 25.1% at screening to 31.1% at 12 months (p=.007) in the NIHF group and from 26.3% to 31.1% in the IHF group (p=.035). The end-systolic diameter decreased significantly in the nonischemic BMAC group from 55.6 to 50.9 mm (p=.020). Retrograde BMAC delivery is safe. All patients receiving BMAC experienced improvements in left ventricular ejection fraction, but only those with NIHF showed improvements in left ventricular end-systolic diameter and B-type natriuretic peptide. These results provide the basis for a larger clinical trial in HF patients. This work is the first prospective randomized clinical trial using high-dose cell therapy delivered via a retrograde coronary sinus infusion in patients with heart failure. This was a multinational, multicenter study, and it is novel, translatable, and scalable. On the basis of this trial and the safety of retrograde coronary sinus infusion, there are three other trials under way using this route of delivery. ©AlphaMed Press.

Using Digital Computer Field Mapping of Outcrops to Examine the Preservation of High-P Rocks During Pervasive, Retrograde Greenschist Fluid Infiltration, Tinos, Cyclades Archipelago, Greece

NASA Astrophysics Data System (ADS)

Breeding, C. M.; Ague, J. J.; Broecker, M.

2001-12-01

Digital field mapping of outcrops on the island of Tinos, Greece, was undertaken to investigate the nature of retrograde fluid infiltration during exhumation of high-P metamorphic rocks of the Attic-Cycladic blueschist belt. High-resolution digital photographs of outcrops were taken and loaded into graphics editing software on a portable, belt-mounted computer in the field. Geologic features from outcrops were drawn and labeled on the digital images using the software in real-time. The ability to simultaneously identify geologic features in outcrops and digitize those features onto digital photographs in the field allows the creation of detailed, field-verified, outcrop-scale maps that aid in geologic interpretation. During Cretaceous-Eocene subduction in the Cyclades, downgoing crustal material was metamorphosed to eclogite and blueschist facies. Subsequent Oligocene-Miocene exhumation of the high-P rocks was accompanied by pervasive, retrograde fluid infiltration resulting in nearly complete greenschist facies overprinting. On Tinos, most high-P rocks have undergone intense retrogression; however, adjacent to thick marble horizons with completely retrograded contact zones, small (sub km-scale) enclaves of high-P rocks (blueschist and minor eclogite facies) were preserved. Field observations suggest that the remnant high-P zones consist mostly of massive metabasic rocks and minor adjacent metasediments. Within the enclaves, detailed digital outcrop maps reveal that greenschist retrogression increases in intensity outward from the center, implying interaction with a fluid flowing along enclave perimeters. Permeability contrasts could not have been solely responsible for preservation of the high-P rocks, as similar rock suites distal to marble contacts were completely overprinted. We conclude that the retrograded contacts of the marble units served as high-permeability conduits for regional retrograde fluid flow. Pervasive, layer-parallel flow through metasediments would have been drawn into these more permeable flow channels. Deflections in fluid flow paths toward the high flux contacts likely caused retrograde fluids to flow around the enclaves, preserving the zones of "dry," unretrograded high-P rocks near marble horizons. Digital mapping of outcrops is a unique method for direct examination of the relationships between geologic structure, lithology, and mineral assemblage variation in the field. Outcrop mapping in the Attic-Cycladic blueschist belt has revealed that regional fluid flow along contacts can have important implications for the large-scale distribution of mineral assemblages in metamorphic terranes.

Direct visualization of minimal cerebral capillary flow during retrograde cerebral perfusion: an intravital fluorescence microscopy study in pigs.

PubMed

Duebener, Lennart F; Hagino, Ikuo; Schmitt, Katharina; Sakamoto, Takahiko; Stamm, Christof; Zurakowski, David; Schäfers, Hans-Joachim; Jonas, Richard A

2003-04-01

Retrograde cerebral perfusion (RCP) is used in some centers during aortic arch surgery for brain protection during hypothermic circulatory arrest. It is still unclear however whether RCP provides adequate microcirculatory blood flow at a capillary level. We used intravital microscopy to directly visualize the cerebral capillary blood flow in a piglet model of RCP. Twelve pigs (weight 9.7 +/- 0.9 kg) were divided into two groups (n = 6 each): deep hypothermic circulatory arrest (DHCA) and RCP. After the creation of a window over the parietal cerebral cortex, pigs underwent 10 minutes of normothermic bypass and 40 minutes of cooling to 15 degrees C on cardiopulmonary bypass ([CPB] pH-stat, hemocrit 30%, pump flow 100 mL x kg(-1) x min(-1)). This was followed by 45 minutes of DHCA and rewarming on CPB to 37 degrees C. In the RCP group the brain was retrogradely perfused (pump flow 30 mL x kg(-1) x min(-1)) during DHCA through the superior vena cava after inferior vena cava occlusion. Plasma was labeled with fluorescein-isothiocyanate-dextran for assessing microvascular diameter and functional capillary density (FCD), defined as total length of erythrocyte-perfused capillaries per observation area. Cerebral tissue oxygenation was determined by nicotinamide adenine dinucleotide hydrogen (NADH) autofluorescence, which increases during tissue ischemia. During normothermic and hypothermic antegrade cerebral perfusion the FCD did not significantly change from base line (97% +/- 14% and 96% +/- 12%, respectively). During retrograde cerebral perfusion the FCD decreased highly significantly to 2% +/- 2% of base line values (p < 0.001). Thus there was no evidence of significant capillary blood flow during retrograde cerebral perfusion. The microvascular diameter of cerebral arterioles that were slowly perfused significantly decreased to 27% +/- 6% of base line levels during RCP. NADH fluorescence progressively and significantly increased during RCP, indicating poorer tissue oxygenation. At the end of retrograde cerebral perfusion there was macroscopic evidence of significant brain edema. RCP does not provide adequate cerebral capillary blood flow and does not prevent cerebral ischemia. Prolonged RCP induces brain edema. However, there might be a role for a short period of RCP to remove air and debris from the cerebral circulation after DHCA because retrograde flow could be detected in cerebral arterioles.

MAGNETOMETER - TRI-AXIS SENSOR UNIT - GEMINI-TITAN (GT)-12 EXPERIMENT MSC-3 (M405) - MSC

NASA Image and Video Library

1966-10-01

S66-09379 (1 Oct. 1966) --- Tri-Axis Magnetometer-Sensor Unit mounted on telescoping boom. Cable connects Sensor Unit with Electronics Unit mounted on retrograde beam in retrograde adapter section. Objective of experiment is to monitor the direction and amplitude of Earth's magnetic field (Gemini-12). Photo credit: NASA

Advances in Retrograde Technique for Coronary Chronic Total Occlusions

PubMed Central

DeMartini, Tony J.

2014-01-01

Despite a short lag period since its development the retrograde approach has been increasingly integrated within the treatment strategies for the percutaneous treatment of coronary chronic total occlusions. This review article discuss which anatomical features argue most powerfully for its use, the specific skills required for its uptake and the technology which has facilitated these developments. PMID:25311005

Reexposure to the Amnestic Agent Alleviates Cycloheximide-Induced Retrograde Amnesia for Reactivated and Extinction Memories

ERIC Educational Resources Information Center

Briggs, James F.; Olson, Brian P.

2013-01-01

We investigated whether reexposure to an amnestic agent would reverse amnesia for extinction of learned fear similar to that of a reactivated memory. When cycloheximide (CHX) was administered immediately after a brief cue-induced memory reactivation (15 sec) and an extended extinction session (12 min) rats showed retrograde amnesia for both…

Ruptured Pseudoaneurysm of the Lateral Plantar Artery After Tibiotalocalcaneal Fusion With Retrograde Nail-A Rare Complication.

PubMed

Sundararajan, Silvampatti Ramaswamy; Rajagopalakrishnan, Ramakanth; Rajasekaran, Shanmuganathan

We report a rare presentation of a ruptured pseudoaneurysm of the lateral plantar artery following tibiotalocalcaneal fusion with a retrograde nail at 1 month after the index surgery. Although case reports of pseudoaneurysms of larger arteries such as the anterior tibial artery and posterior tibial artery after ankle surgery (e.g., ankle arthroscopy, implant removal, Ilizarov application) have been reported, we report a rare complication of a pseudoaneurysm of the lateral plantar artery. We discuss the anatomic considerations of the lateral plantar artery in the foot and the entry point of the retrograde nail to avoid this unusual complication. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Which is best method for instillation of topical therapy to the upper urinary tract? An in vivo porcine study to evaluate three delivery methods.

PubMed

Liu, Zhenbang; Ng, Junxiang; Yuwono, Arianto; Lu, Yadong; Tan, Yung Khan

2017-01-01

To compare the staining intensity of the upper urinary tract (UUT) urothelium among three UUT delivery methods in an in vivo porcine model. A fluorescent dye solution (indigo carmine) was delivered to the UUT via three different methods: antegrade perfusion, vesico-ureteral reflux via indwelling ureteric stent and retrograde perfusion via a 5F open-ended ureteral catheter. Twelve renal units were tested with 4 in each method. After a 2-hour delivery time, the renal-ureter units were harvested en bloc. Time from harvesting to analysis was also standardised to be 2 hours in each arm. Three urothelium samples of the same weight and size were taken from each of the 6 pre-defined points (upper pole, mid pole, lower pole, renal pelvis, mid ureter and distal ureter) and the amount of fluorescence was measured with a spectrometer. The mean fluorescence detected at all 6 predefined points of the UUT urothelium was the highest for the retrograde method. This was statistically significant with p-value less than <0.05 at all 6 points. Retrograde infusion of UUT by an open ended ureteral catheter resulted in highest mean fluorescence detected at all 6 pre-defined points of the UUT urothelium compared to antegrade infusion and vesico-ureteral reflux via indwelling ureteric stents indicating retrograde method ideal for topical therapy throughout the UUT urothelium. More clinical studies are needed to demonstrate if retrograde method could lead to better clinical outcomes compared to the other two methods. Copyright® by the International Brazilian Journal of Urology.

Which is best method for instillation of topical therapy to the upper urinary tract? An in vivo porcine study to evaluate three delivery methods

PubMed Central

Liu, Zhenbang; Ng, Junxiang; Yuwono, Arianto; Lu, Yadong; Tan, Yung Khan

2017-01-01

ABSTRACT Purpose: To compare the staining intensity of the upper urinary tract (UUT) urothelium among three UUT delivery methods in an in vivo porcine model. Materials and methods: A fluorescent dye solution (indigo carmine) was delivered to the UUT via three different methods: antegrade perfusion, vesico-ureteral reflux via in-dwelling ureteric stent and retrograde perfusion via a 5F open-ended ureteral catheter. Twelve renal units were tested with 4 in each method. After a 2-hour delivery time, the renal-ureter units were harvested en bloc. Time from harvesting to analysis was also standardised to be 2 hours in each arm. Three urothelium samples of the same weight and size were taken from each of the 6 pre-defined points (upper pole, mid pole, lower pole, renal pelvis, mid ureter and distal ureter) and the amount of fluorescence was measured with a spectrometer. Results: The mean fluorescence detected at all 6 predefined points of the UUT urothelium was the highest for the retrograde method. This was statistically significant with p-value less than <0.05 at all 6 points. Conclusions: Retrograde infusion of UUT by an open ended ureteral catheter resulted in highest mean fluorescence detected at all 6 pre-defined points of the UUT urothelium compared to antegrade infusion and vesico-ureteral reflux via indwelling ureteric stents indicating retrograde method ideal for topical therapy throughout the UUT urothelium. More clinical studies are needed to demonstrate if retrograde method could lead to better clinical outcomes compared to the other two methods. PMID:29039888

Transgene expression in target-defined neuron populations mediated by retrograde infection with adeno-associated viral vectors.

PubMed

Rothermel, Markus; Brunert, Daniela; Zabawa, Christine; Díaz-Quesada, Marta; Wachowiak, Matt

2013-09-18

Tools enabling the manipulation of well defined neuronal subpopulations are critical for probing complex neuronal networks. Cre recombinase (Cre) mouse driver lines in combination with the Cre-dependent expression of proteins using viral vectors--in particular, recombinant adeno-associated viral vectors (rAAVs)--have emerged as a widely used platform for achieving transgene expression in specified neural populations. However, the ability of rAAVs to further specify neuronal subsets on the basis of their anatomical connectivity has been reported as limited or inconsistent. Here, we systematically tested a variety of widely used neurotropic rAAVs for their ability to mediate retrograde gene transduction in the mouse brain. We tested pseudotyped rAAVs of several common serotypes (rAAV 2/1, 2/5, and 2/9) as well as constructs both with and without Cre-dependent expression switches. Many of the rAAVs tested--in particular, though not exclusively, Cre-dependent vectors--showed a robust capacity for retrograde infection and transgene expression. Retrograde expression was successful over distances as large as 6 mm and in multiple neuron types, including olfactory projection neurons, neocortical pyramidal cells projecting to distinct targets, and corticofugal and modulatory projection neurons. Retrograde infection using transgenes such as ChR2 allowed for optical control or optically assisted electrophysiological identification of neurons defined genetically as well as by their projection target. These results establish a widely accessible tool for achieving combinatorial specificity and stable, long-term transgene expression to isolate precisely defined neuron populations in the intact animal.

Transgene Expression in Target-Defined Neuron Populations Mediated by Retrograde Infection with Adeno-Associated Viral Vectors

PubMed Central

Rothermel, Markus; Brunert, Daniela; Zabawa, Christine; Díaz-Quesada, Marta

2013-01-01

Tools enabling the manipulation of well defined neuronal subpopulations are critical for probing complex neuronal networks. Cre recombinase (Cre) mouse driver lines in combination with the Cre-dependent expression of proteins using viral vectors—in particular, recombinant adeno-associated viral vectors (rAAVs)—have emerged as a widely used platform for achieving transgene expression in specified neural populations. However, the ability of rAAVs to further specify neuronal subsets on the basis of their anatomical connectivity has been reported as limited or inconsistent. Here, we systematically tested a variety of widely used neurotropic rAAVs for their ability to mediate retrograde gene transduction in the mouse brain. We tested pseudotyped rAAVs of several common serotypes (rAAV 2/1, 2/5, and 2/9) as well as constructs both with and without Cre-dependent expression switches. Many of the rAAVs tested—in particular, though not exclusively, Cre-dependent vectors—showed a robust capacity for retrograde infection and transgene expression. Retrograde expression was successful over distances as large as 6 mm and in multiple neuron types, including olfactory projection neurons, neocortical pyramidal cells projecting to distinct targets, and corticofugal and modulatory projection neurons. Retrograde infection using transgenes such as ChR2 allowed for optical control or optically assisted electrophysiological identification of neurons defined genetically as well as by their projection target. These results establish a widely accessible tool for achieving combinatorial specificity and stable, long-term transgene expression to isolate precisely defined neuron populations in the intact animal. PMID:24048849

Pre-pyloric neural electrical stimulation produces cholinergically-mediated reverse peristalsis in the acute canine model of microprocessor-invoked gastric motility for the treatment of obesity.

PubMed

Neshev, Emil; Onen, Denis; Jalilian, Ehsan; Mintchev, Martin P

2006-04-01

Gastric Electrical Stimulation (GES) has been suggested as a new tool for the treatment of obesity. Among the known methods for GES, only Neural Gastric Electrical Stimulation (NGES) provides direct control of contractility without utilizing the spontaneously existing gastric electrical activity as an intermediary. However, only one of the established GES techniques, gastric pacing, has been described to produce retrograde peristalsis for delaying gastric emptying. The aim of this study was to explore the possibility of producing retrograde peristalsis using either single electrode set or dual electrode set NGES. 8 anesthetized dogs underwent laparotomy and implantation of 2 circumferential electrode sets approximately 3 cm and 7 cm proximal to the pylorus, respectively. Single-set and dual-set NGES sessions were repeatedly administered using a custom-designed implantable neurostimulator. Gastric motility patterns were captured using 3 force transducers implanted on the anterior gastric wall along the gastric axis. Motility indices and velocities were employed to quantify the produced contractile patterns. Both single-set and dual-set NGES produced circumferential lumen-occluding contractions in the vicinity of the electrode sets. The invoked contractions propagated proximally in a retrograde fashion. The propagation scope was different depending on the number of electrode sets used. Different velocities of the invoked retrograde contractions associated with single- and dual-set NGES were observed and quantified. Contractility patterns reflected by the normalized motility indices were very similar regardless of the electrode stimulation technique. Pre-pyloric NGES can produce controlled retrograde peristalsis and serve as another avenue for the treatment of obesity.

Retrograde renal hilar dissection and segmental arterial clamping: a simple modification to achieve super-selective robotic partial nephrectomy.

PubMed

Greene, Richard N; Sutherland, Douglas E; Tausch, Timothy J; Perez, Deo S

2014-03-01

Super-selective vascular control prior to robotic partial nephrectomy (also known as 'zero-ischemia') is a novel surgical technique that promises to reduce warm ischemia time. The technique has been shown to be feasible but adds substantial technical complexity and cost to the procedure. We present a simplified retrograde dissection of the renal hilum to achieve selective vascular control during robotic partial nephrectomy. Consecutive patients with stage 1 solid and complex cystic renal masses underwent robotic partial nephrectomies with selective vascular control using a modification to previously described super-selective robotic partial nephrectomy. In each case, the renal arterial branch supplying the mass and surrounding parenchyma was dissected in a retrograde fashion from the tumor. Intra-renal dissection of the interlobular artery was not performed. Intra-operative immunofluorescence was not utilized as assessment of parenchymal ischemia was documented before partial nephrectomy. Data was prospectively collected in an IRB-approved partial nephrectomy database. Operative variables between patients undergoing super-selective versus standard robotic partial nephrectomy were compared. Super-selective partial nephrectomy with retrograde hilar dissection was successfully completed in five consecutive patients. There were no complications or conversions to traditional partial nephrectomy. All were diagnosed with renal cell carcinoma and surgical margins were all negative. Estimated blood loss, warm ischemia time, operative time and length of stay were all comparable between patients undergoing super-selective and standard robotic partial nephrectomy. Retrograde hilar dissection appears to be a feasible and safe approach to super-selective partial nephrectomy without adding complex renovascular surgical techniques or cost to the procedure.

Biomechanical Strength of Retrograde Fixation in Proximal Third Scaphoid Fractures.

PubMed

Daly, Charles A; Boden, Allison L; Hutton, William C; Gottschalk, Michael B

2018-04-01

Current techniques for fixation of proximal pole scaphoid fractures utilize antegrade fixation via a dorsal approach endangering the delicate vascular supply of the dorsal scaphoid. Volar and dorsal approaches demonstrate equivalent clinical outcomes in scaphoid wrist fractures, but no study has evaluated the biomechanical strength for fractures of the proximal pole. This study compares biomechanical strength of antegrade and retrograde fixation for fractures of the proximal pole of the scaphoid. A simulated proximal pole scaphoid fracture was produced in 22 matched cadaveric scaphoids, which were then assigned randomly to either antegrade or retrograde fixation with a cannulated headless compression screw. Cyclic loading and load to failure testing were performed and screw length, number of cycles, and maximum load sustained were recorded. There were no significant differences in average screw length (25.5 mm vs 25.6 mm, P = .934), average number of cyclic loading cycles (3738 vs 3847, P = .552), average load to failure (348 N vs 371 N, P = .357), and number of catastrophic failures observed between the antegrade and retrograde fixation groups (3 in each). Practical equivalence between the 2 groups was calculated and the 2 groups were demonstrated to be practically equivalent (upper threshold P = .010). For this model of proximal pole scaphoid wrist fractures, antegrade and retrograde screw configuration have been proven to be equivalent in terms of biomechanical strength. With further clinical study, we hope surgeons will be able to make their decision for fixation technique based on approaches to bone grafting, concern for tenuous blood supply, and surgeon preference without fear of poor biomechanical properties.

Hippocampus and Retrograde Amnesia in the Rat Model: A Modest Proposal for the Situation of Systems Consolidation

ERIC Educational Resources Information Center

Sutherland, Robert J.; Sparks, Fraser T.; Lehmann, Hugo

2010-01-01

The properties of retrograde amnesia after damage to the hippocampus have been explicated with some success using a rat model of human medial temporal lobe amnesia. We review the results of this experimental work with rats focusing on several areas of consensus in this growing literature. We evaluate the theoretically significant hypothesis that…

[Tibio-talo-calcaneal arthrodesis by retrograde intramedullary nail--a case report].

PubMed

Lipiński, Łukasz; Synder, Marek; Sibiński, Marcin

2011-01-01

We described a case of 64 year old overweight women, who was treated with revision tibio-talo-calcaneal artrodesis with the use of retrograde intramedullary nail. The procedure was performed after failed primary arthrodesis with the use of lateral approach and fibula osteotomy. Stabilization with intramedullary nail gave good clinical and functional result with a good bone healing.

Retrograde Ascending Dissection After Thoracic Endovascular Aortic Repair Combined With the Chimney Technique and Successful Open Repair Using the Frozen Elephant Trunk Technique.

PubMed

Hirano, Koji; Tokui, Toshiya; Nakamura, Bun; Inoue, Ryosai; Inagaki, Masahiro; Maze, Yasumi; Kato, Noriyuki

2018-01-01

The chimney technique can be combined with thoracic endovascular aortic repair (TEVAR) to both obtain an appropriate landing zone and maintain blood flow of the arch vessels. However, surgical repair becomes more complicated if retrograde type A aortic dissection occurs after TEVAR with the chimney technique. We herein report a case involving a 73-year-old woman who developed a retrograde ascending dissection 3 months after TEVAR for acute type B aortic dissection. To ensure an adequate proximal sealing distance, the proximal edge of the stent graft was located at the zone 2 level and an additional bare stent was placed at the left subclavian artery (the chimney technique) at the time of TEVAR. Enhanced computed tomography revealed an aortic dissection involving the ascending aorta and aortic arch. Surgical aortic repair using the frozen elephant trunk technique was urgently performed. The patient survived without stroke, paraplegia, renal failure, or other major complications. Retrograde ascending dissection can occur after TEVAR combined with the chimney technique. The frozen elephant trunk technique is useful for surgical repair in such complicated cases.

Transcutaneous pleural biopsy with a retrograde forceps: a novel approach.

PubMed

Wiewiorski, Martin; Hiebinger, Andreas; Hoechel, Sebastian; Müller-Gerbl, Magdalena; Barg, Alexej; Valderrabano, Victor; Hügle, Thomas

2016-01-01

Pleural biopsies are commonly performed to investigate the cause of exudative pleural effusion. Biopsy needles (e.g. Abrams needle, Cope needle) are traditionally used to perform the biopsy. However, certain complications such as pneumothorax and haemothorax have been described. We present a technique utilizing a novel retrograde forceps, which could improve the simplicity and lower the complication rate of performing closed pleural biopsies. A retrograde forceps (Retroforceps, Karl Storz, Tuttlingen, Germany) was used to perform 20 transcutaneous pleural biopsies in a cadaver thorax under thoracoscopical control. Video documentation of the procedure from outside and inside the thorax was performed. The surgeon performing the biopsy was blinded to the thoracoscopical view. After the removal of the forceps, it was checked whether biopsy material was retrieved. The video material was retrospectively used to confirm whether the biopsy was taken from the pleura parietalis. Biopsy material was retrieved in 19 out of 20 biopsy attempts. Video material confirmed that the biopsy was taken from the pleura parietalis in all cases. Using a retrograde biopsy forceps is a simple and practicable procedure suitable for clinical application. This technique could potentially reduce the incidence of pneumothorax.

A chloroplast retrograde signal, 3’-phosphoadenosine 5’-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination

PubMed Central

Pornsiriwong, Wannarat; Estavillo, Gonzalo M; Chan, Kai Xun; Tee, Estee E; Ganguly, Diep; Crisp, Peter A; Phua, Su Yin; Zhao, Chenchen; Qiu, Jiaen; Park, Jiyoung; Yong, Miing Tiem; Nisar, Nazia; Yadav, Arun Kumar; Schwessinger, Benjamin; Rathjen, John; Cazzonelli, Christopher I; Wilson, Philippa B; Gilliham, Matthew; Chen, Zhong-Hua; Pogson, Barry J

2017-01-01

Organelle-nuclear retrograde signaling regulates gene expression, but its roles in specialized cells and integration with hormonal signaling remain enigmatic. Here we show that the SAL1-PAP (3′-phosphoadenosine 5′- phosphate) retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis. Genetically or exogenously manipulating PAP bypasses the canonical signaling components ABA Insensitive 1 (ABI1) and Open Stomata 1 (OST1); priming an alternative pathway that restores ABA-responsive gene expression, ROS bursts, ion channel function, stomatal closure and drought tolerance in ost1-2. PAP also inhibits wild type and abi1-1 seed germination by enhancing ABA sensitivity. PAP-XRN signaling interacts with ABA, ROS and Ca2+; up-regulating multiple ABA signaling components, including lowly-expressed Calcium Dependent Protein Kinases (CDPKs) capable of activating the anion channel SLAC1. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses. DOI: http://dx.doi.org/10.7554/eLife.23361.001 PMID:28323614

TorsinA controls TAN line assembly and the retrograde flow of dorsal perinuclear actin cables during rearward nuclear movement

PubMed Central

Saunders, Cosmo A.; Harris, Nathan J.; Willey, Patrick T.; Woolums, Brian M.; Wang, Yuexia; McQuown, Alex J.; Schoenhofen, Amy; Dauer, William T.

2017-01-01

The nucleus is positioned toward the rear of most migratory cells. In fibroblasts and myoblasts polarizing for migration, retrograde actin flow moves the nucleus rearward, resulting in the orientation of the centrosome in the direction of migration. In this study, we report that the nuclear envelope–localized AAA+ (ATPase associated with various cellular activities) torsinA (TA) and its activator, the inner nuclear membrane protein lamina-associated polypeptide 1 (LAP1), are required for rearward nuclear movement during centrosome orientation in migrating fibroblasts. Both TA and LAP1 contributed to the assembly of transmembrane actin-associated nuclear (TAN) lines, which couple the nucleus to dorsal perinuclear actin cables undergoing retrograde flow. In addition, TA localized to TAN lines and was necessary for the proper mobility of EGFP-mini–nesprin-2G, a functional TAN line reporter construct, within the nuclear envelope. Furthermore, TA and LAP1 were indispensable for the retrograde flow of dorsal perinuclear actin cables, supporting the recently proposed function for the nucleus in spatially organizing actin flow and cytoplasmic polarity. Collectively, these results identify TA as a key regulator of actin-dependent rearward nuclear movement during centrosome orientation. PMID:28242745

WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia

PubMed Central

Patel-King, Ramila S.; Gilberti, Renée M.; Hom, Erik F. Y.; King, Stephen M.

2013-01-01

Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle–like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly. PMID:23864713

Retrograde and anterograde memory following selective damage to the dorsolateral entorhinal cortex.

PubMed

Gervais, Nicole J; Barrett-Bernstein, Meagan; Sutherland, Robert J; Mumby, Dave G

2014-12-01

Anatomical and electrophysiological evidence suggest the dorsolateral entorhinal cortex (DLEC) is involved in processing spatial information, but there is currently no consensus on whether its functions are necessary for normal spatial learning and memory. The present study examined the effects of excitotoxic lesions of the DLEC on retrograde and anterograde memory on two tests of allocentric spatial learning: a hidden fixed-platform watermaze task, and a novelty-preference-based dry-maze test. Deficits were observed on both tests when training occurred prior to but not following n-methyl d-aspartate (NMDA) lesions of DLEC, suggesting retrograde memory impairment in the absence of anterograde impairments for the same information. The retrograde memory impairments were temporally-graded; rats that received DLEC lesions 1-3 days following training displayed deficits, while those that received lesions 7-10 days following training performed like a control group that received sham surgery. The deficits were not attenuated by co-infusion of tetrodotoxin, suggesting they are not due to disruption of neural processing in structures efferent to the DLEC, such as the hippocampus. The present findings provide evidence that the DLEC is involved in the consolidation of allocentric spatial information. Copyright © 2014 Elsevier Inc. All rights reserved.

Tibiotalocalcaneal arthrodesis using a dynamically locked retrograde intramedullary nail.

PubMed

Pelton, Kevin; Hofer, Jason K; Thordarson, David B

2006-10-01

Tibiotalocalcaneal arthrodesis is an important salvage method for patients with complex hindfoot problems, including Charcot arthropathy, osteonecrosis of the talus, combined arthritis of the ankle and subtalar joint, and failed total ankle arthroplasty. This study evaluated the results of a dynamic retrograde intramedullary nail for fixation with posterior to anterior distal interlocking screws placed through the calcaneus for tibiotalocalcaneal fusion. Thirty-three consecutive tibiotalocalcaneal fusions were done by a single surgeon (DBT) and were stabilized with a dynamic retrograde intramedullary nail. Time to fusion, impaction of the nail relative to the intramedullary canal, nail-tibial angle, and complications were noted. Average followup was 14 months. Twenty-nine of 33 feet (88%) fused at an average of 3.7 months after surgery. Average impaction of the nail was 2.3 (0.5 to 5.0) mm. Cortical hypertrophy at the tip of the rod or at the proximal interlocking screw was noted in 13 of 27 patients. A trend toward a higher nonunion rate was noted in patients with an increased nail-tibial angle. Dynamic retrograde intramedullary nailing for fixation of the tibiotalocalcaneal fusions is a good method of stabilizing this complex fusion construct.

Extracorporeal shock wave lithotripsy for obstructing pancreatic duct calculi.

PubMed

Matthews, K; Correa, R J; Gibbons, R P; Weissman, R M; Kozarek, R A

1997-08-01

A review was done to determine the effectiveness of extracorporeal shock wave lithotripsy (ESWL) in the treatment of impacted pancreatic duct calculi. A total of 19 patients, who were potential candidates for radical pancreatic surgery after unsuccessful endoscopic retrograde cholangiopancreatography, sphincterotomy and attempted stone extraction from the pancreatic ducts, underwent ESWL of the calculi. Followup ranged from 6 months to 6 years. Of the 19 patients 14 avoided a major operation and 6 have remained pain-free for the long term. Two patients died of causes not related to ESWL or endoscopic retrograde cholangiopancreatography. Five patients eventually underwent a Whipple or Puestow procedure for relief of symptoms or persistent obstruction. Complications were minimal. ESWL is a valuable adjunct in patients with impacted pancreatic duct calculi unretrievable by primary endoscopic retrograde cholangiopancreatography.

Tibial tunnel aperture irregularity after drilling with 5 reamer designs: a qualitative micro-computed tomography analysis.

PubMed

Geeslin, Andrew G; Jansson, Kyle S; Wijdicks, Coen A; Chapman, Mark A; Fok, Alex S; LaPrade, Robert F

2011-04-01

There is limited information in the literature on comparisons of antegrade versus retrograde reaming techniques and the effect on the creation of anterior cruciate ligament (ACL) tibial tunnel entry and exit apertures. Proximal and distal apertures of ACL tibial tunnels, as created with different reamers, will be affected by type of reamer design. Controlled laboratory study. Forty skeletally mature porcine tibias with bone mineral density values comparable with a young athletic population were included in this study. Five 9-mm reamer models were used (3 antegrade: A1, smooth-bore reamer; A2, acorn-head reamer; A3, flat-head reamer; 2 retrograde: R1, retrograde acorn reamer; R2, single-blade retrograde reamer), and a new reamer was used for each tibia (8 reamer-tibia pairs per reamer model). All specimens underwent micro-computed tomography scanning, and images were reconstructed and analyzed using 3-dimensional image analysis software. Aperture rim fractures were graded on a 0-IV scale that described the proportion of the fractured aperture circumference. Specimens with incomplete apertures were also recorded. Because of the unique characteristics of various tunnels, intratunnel characteristics were observed and recorded. In sum, 1 proximal and 7 distal aperture rim fractures were found; 3, 0, and 4 distal aperture rim fractures were found with groups A1, A2, and A3, respectively. Incomplete apertures were more commonly found at the distal aperture (n = 15) than the proximal aperture (n = 8); there were no tibias with this finding at both apertures. All incomplete distal apertures occurred with the retrograde technique, and all incomplete proximal apertures occurred with the antegrade technique, most commonly with reamer design A3. An added finding of tunnel curvature at the distal aspect of the tunnel was observed in all 8 tibias with R1 reamers and 5 tibias with R2 reamers. This phenomenon was not observed in any of the tibias reamed with the antegrade technique. Anterior cruciate ligament tibial tunnel aperture characteristics were highly dependent on reamer design. Optimal proximal aperture characteristics were produced by the retrograde reamers, whereas optimal distal aperture characteristics were obtained with the antegrade reamers. In addition, a phenomenon of tunnel curvature in retrograde-type reamers was found, which may have effects on ACL graft or screw fixation. Differences in tunnel aperture shapes and fractures depend on reamer design. This information is important for the creation of ACL reconstruction tunnels with different reamer designs.

Septic Complication After Balloon-Occluded Retrograde Transvenous Obliteration of Duodenal Variceal Bleeding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akasaka, Thai; Shibata, Toshiya, E-mail: ksj@kuhp.kyoto-u.ac.jp; Isoda, Hiroyoshi

2010-12-15

We report a 64-year-old woman with duodenal varices who underwent balloon-occluded retrograde transvenous obliteration (B-RTO) complicated by intraprocedural variceal rupture. The patient developed shivering and a fever higher than 40{sup o}C 3 days after the B-RTO procedure. A blood culture grew Entereobacter cloacoe. This case represents a rare septic complication of B-RTO for duodenal varices.

A Hands-on Exploration of the Retrograde Motion of Mars as Seen from the Earth

ERIC Educational Resources Information Center

Pincelli, M. M.; Otranto, S.

2013-01-01

In this paper, we propose a set of activities based on the use of a celestial simulator to gain insights into the retrograde motion of Mars as seen from the Earth. These activities provide a useful link between the heliocentric concepts taught in schools and those tackled in typical introductory physics courses based on classical mechanics for…

Behavioral and Functional Neuroanatomical Correlates of Anterograde Autobiographical Memory in Isolated Retrograde Amnesic Patient M. L.

ERIC Educational Resources Information Center

Levine, Brian; Svoboda, Eva; Turner, Gary R.; Mandic, Marina; Mackey, Allison

2009-01-01

Patient M. L. [Levine, B., Black, S. E., Cabeza, R., Sinden, M., Mcintosh, A. R., Toth, J. P., et al. (1998). "Episodic memory and the self in a case of isolated retrograde amnesia." "Brain", "121", 1951-1973], lost memory for events occurring before his severe traumatic brain injury, yet his anterograde (post-injury) learning and memory appeared…

On Common Ground: Jost's (1897) Law of Forgetting and Ribot's (1881) Law of Retrograde Amnesia

ERIC Educational Resources Information Center

Wixted, John T.

2004-01-01

T. Ribot's (1881) law of retrograde amnesia states that brain damage impairs recently formed memories to a greater extent than older memories, which is generally taken to imply that memories need time to consolidate. A. Jost's (1897) law of forgetting states that if 2 memories are of the same strength but different ages, the older will decay more…

Retrograde Endourological Management of Upper Urinary Tract Abnormalities in Patients with Ileal Conduit Urinary Diversion: A Dual-Center Experience.

PubMed

Olson, Louise; Satherley, Hywel; Cleaveland, Paul; Zelhof, Bachar; Mokete, Max; Neilson, Donald; Srirangam, Shalom

2017-09-01

Patients with ileal conduit urinary diversions are at an increased risk of long-term upper urinary tract (UUT) complications, including anastomotic strictures, infections, and urolithiasis. The reconstructed urinary system poses challenges for endoscopic manipulation. We present and describe our dual-center experience in performing retrograde ureteroscopy to treat or diagnose UUT abnormalities in patients with ileal conduit incontinent diversion. We performed a retrospective analysis of medical records for all patients with previous urinary diversion who underwent retrograde ureteroscopic procedures via the ileal loop in our institutions over a 9 year period (between June 2007 and August 2016). Fifty-four procedures were performed in 36 patients. Mean age was 61 (28-90) years. Average time from diversion to ureteroscopic procedure was 13.0 (0.08-53) years. Stone disease was the most common indication for intervention in 35.2% (19/54) of cases, with a stone-free rate of 78.9% (15/19). Other indications included surveillance of transitional-cell carcinoma in 22.2% (12/54), diagnostic flexible ureteroscopy (fURS) in 20.4% (11/54), stricture management in 11.1% (6/54), removal of encrusted stent/nephrostomy in 7.4% (4/54), urine leak after diversion in 1.9% (1/54), and miscellaneous in 1.9% (1/54). Successful retrograde access was possible in 74% (40/54) of cases. A long and tortuous ileal segment, too difficult to negotiate, was the most common cause of failure to access the UUT. In 13 out of 54 (24.1%) cases, retrograde fURS was combined with simultaneous percutaneous antegrade access. Six patients (11.1%) developed postprocedural pyrexia requiring additional antibiotic therapy, and one (1.9%) patient required embolization of the renal artery for ongoing bleeding. Median length of stay was 1 day (0-55), with 13 (24%) being performed as day-case procedures. Retrograde ureteroscopy in patients with ileal conduits can be technically challenging due to distorted anatomy. This procedure can be safely performed in experienced hands with standard endourological equipment. An antegrade approach can be carried out simultaneously, which may be required in a small number of patients.

Transpedal access after failed anterograde recanalization of complex below-the-knee and femoropoliteal occlusions in critical limb ischemia.

PubMed

Ruzsa, Zoltán; Nemes, Balázs; Bánsághi, Zoltán; Tóth, Károly; Kuti, Ferenc; Kudrnova, Slavka; Berta, Balázs; Hüttl, Kálmán; Merkely, Béla

2014-05-01

Successful angioplasty is one of the main factor of limb salvage during critical limb ischemia. In complex femoropopliteal to infrapopliteal occlusions, an anterograde recanalization attempt can fail in up to 20% of the cases. The purpose of this dual center pilot study was to evaluate the acute success and clinical impact of retrograde transpedal access for retrograde below-the-knee and femoropopliteal chronic total occlusions after failed anterograde attempt and to access the late complications at the puncture site. The clinical and angiographic data of 51 consecutive patients with CLI treated by retrograde transpedal recanalization between 2010 and 2011 were evaluated in a pilot study. We have examined the 2-month and 1 year major adverse events (MAEs) and clinical success. In all cases after failure of the anterograde recanalization of occluded below-the-knee segments due to unsuccessful penetration or failed re-entry, the anterior tibial or posterior tibial artery was punctured under fluoroscopic guidance and retrograde recanalization was performed. Direct revascularization was tried firstly following the angiographic zones, but in failed cases indirect revascularization was carried out with increasing the collateral flow to the wound. Successful direct retrograde revascularization was achieved successfully in 40 patients (78.4%) and indirect revascularization was done in 10 patients (19.6%). Revascularization was failed in one patient (2%). MAE at 2 and 12 months follow-up was 6 (11.7%) and 11 (24%). Limb salvage at 2 and 12 months was 93% and 82.3%, respectively. Balloon angioplasty was performed in all interventions and provisional stenting was done in 34 patients (66.7%). One major and three minor vascular complications occurred after the procedure. The mean basal and control creatinine level was 120.9 ± 133.4 and 123.8 ± 131.3 μmol/L (P = 0.83) after the procedure. Failed antegrade attempts to recanalize CTO-s of femoropopliteal and infrapopliteal vessels can be salvaged using a retrograde transpedal access, with a low acute and late complication rate. This technique could be valuable for patients with critical limb ischemia due to femoropopliteal and infrapopliteal occlusions. Copyright © 2013 Wiley Periodicals, Inc.

High-resolution anatomic correlation of cyclic motor patterns in the human colon: Evidence of a rectosigmoid brake

PubMed Central

Lin, Anthony Y.; Du, Peng; Dinning, Philip G.; Arkwright, John W.; Kamp, Jozef P.; Cheng, Leo K.; Bissett, Ian P.

2017-01-01

Colonic cyclic motor patterns (CMPs) have been hypothesized to act as a brake to limit rectal filling. However, the spatiotemporal profile of CMPs, including anatomic origins and distributions, remains unclear. This study characterized colonic CMPs using high-resolution (HR) manometry (72 sensors, 1-cm resolution) and their relationship with proximal antegrade propagating events. Nine healthy volunteers were recruited. Recordings were performed over 4 h, with a 700-kcal meal given after 2 h. Propagating events were visually identified and analyzed by pattern, origin, amplitude, extent of propagation, velocity, and duration. Manometric data were normalized using anatomic landmarks identified on abdominal radiographs. These were mapped over a three-dimensional anatomic model. CMPs comprised a majority of detected propagating events. Most occurred postprandially and were retrograde propagating events (84.9 ± 26.0 retrograde vs. 14.3 ± 11.8 antegrade events/2 h, P = 0.004). The dominant sites of initiation for retrograde CMPs were in the rectosigmoid region, with patterns proximally propagating by a mean distance of 12.4 ± 0.3 cm. There were significant differences in the characteristics of CMPs depending on the direction of travel and site of initiation. Association analysis showed that proximal antegrade propagating events occurred independently of CMPs. This study accurately characterized CMPs with anatomic correlation. CMPs were unlikely to be triggered by proximal antegrade propagating events in our study context. However, the distal origin and prominence of retrograde CMPs could still act as a mechanism to limit rectal filling and support the theory of a “rectosigmoid brake.” NEW & NOTEWORTHY Retrograde cyclic motor patterns (CMPs) are the dominant motor patterns in a healthy prepared human colon. The major sites of initiation are in the rectosigmoid region, with retrograde propagation, supporting the idea of a “rectosigmoid brake.” A significant increase in the number of CMPs is seen after a meal. In our study context, the majority of CMPs occurred independent of proximal propagating events, suggesting that CMPs are primarily controlled by external innervation. PMID:28336544

The pUL37 tegument protein guides alpha-herpesvirus retrograde axonal transport to promote neuroinvasion

PubMed Central

Richards, Alexsia L.; Sollars, Patricia J.; Stults, Austin M.; Pickard, Gary E.

2017-01-01

A hallmark property of the neurotropic alpha-herpesvirinae is the dissemination of infection to sensory and autonomic ganglia of the peripheral nervous system following an initial exposure at mucosal surfaces. The peripheral ganglia serve as the latent virus reservoir and the source of recurrent infections such as cold sores (herpes simplex virus type I) and shingles (varicella zoster virus). However, the means by which these viruses routinely invade the nervous system is not fully understood. We report that an internal virion component, the pUL37 tegument protein, has a surface region that is an essential neuroinvasion effector. Mutation of this region rendered herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PRV) incapable of spreading by retrograde axonal transport to peripheral ganglia both in culture and animals. By monitoring the axonal transport of individual viral particles by time-lapse fluorescence microscopy, the mutant viruses were determined to lack the characteristic sustained intracellular capsid motion along microtubules that normally traffics capsids to the neural soma. Consistent with the axonal transport deficit, the mutant viruses did not reach sites of latency in peripheral ganglia, and were avirulent. Despite this, viral propagation in peripheral tissues and in cultured epithelial cell lines remained robust. Selective elimination of retrograde delivery to the nervous system has long been sought after as a means to develop vaccines against these ubiquitous, and sometimes devastating viruses. In support of this potential, we find that HSV-1 and PRV mutated in the effector region of pUL37 evoked effective vaccination against subsequent nervous system challenges and encephalitic disease. These findings demonstrate that retrograde axonal transport of the herpesviruses occurs by a virus-directed mechanism that operates by coordinating opposing microtubule motors to favor sustained retrograde delivery of the virus to the peripheral ganglia. The ability to selectively eliminate the retrograde axonal transport mechanism from these viruses will be useful in trans-synaptic mapping studies of the mammalian nervous system, and affords a new vaccination paradigm for human and veterinary neurotropic herpesviruses. PMID:29216315

Lissencephaly-1 dependent axonal retrograde transport of L1-type CAM Neuroglian in the adult drosophila central nervous system

PubMed Central

Börner, Jana; Slipchuk, Olesya; Kakad, Priyanka; Lee, LaTasha H.; Qureshi, Aater; Pielage, Jan

2017-01-01

Here, we established the Drosophila Giant Fiber neurons (GF) as a novel model to study axonal trafficking of L1-type Cell Adhesion Molecules (CAM) Neuroglian (Nrg) in the adult CNS using live imaging. L1-type CAMs are well known for their importance in nervous system development and we previously demonstrated a role for Nrg in GF synapse formation. However, in the adult they have also been implicated in synaptic plasticity and regeneration. In addition, to its canonical role in organizing cytoskeletal elements at the plasma membrane, vertebrate L1CAM has also been shown to regulate transcription indirectly as well as directly via its import to the nucleus. Here, we intend to determine if the sole L1CAM homolog Nrg is retrogradley transported and thus has the potential to relay signals from the synapse to the soma. Live imaging of c-terminally tagged Nrg in the GF revealed that there are at least two populations of retrograde vesicles that differ in speed, and either move with consistent or varying velocity. To determine if endogenous Nrg is retrogradely transported, we inhibited two key regulators, Lissencephaly-1 (Lis1) and Dynactin, of the retrograde motor protein Dynein. Similar to previously described phenotypes for expression of poisonous subunits of Dynactin, we found that developmental knock down of Lis1 disrupted GF synaptic terminal growth and that Nrg vesicles accumulated inside the stunted terminals in both mutant backgrounds. Moreover, post mitotic Lis1 knock down in mature GFs by either RNAi or Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) induced mutations, resulted in normal length terminals with fully functional GF synapses which also exhibited severe accumulation of endogenous Nrg vesicles. Thus, our data suggests that accumulation of Nrg vesicles is due to failure of retrograde transport rather than a failure of terminal development. Together with the finding that post mitotic knock down of Lis1 also disrupted retrograde transport of tagged Nrg vesicles in GF axons, it demonstrates that endogenous Nrg protein is transported from the synapse to the soma in the adult central nervous system in a Lis1-dependent manner. PMID:28837701

Lissencephaly-1 dependent axonal retrograde transport of L1-type CAM Neuroglian in the adult drosophila central nervous system.

PubMed

Kudumala, Sirisha R; Penserga, Tyrone; Börner, Jana; Slipchuk, Olesya; Kakad, Priyanka; Lee, LaTasha H; Qureshi, Aater; Pielage, Jan; Godenschwege, Tanja A

2017-01-01

Here, we established the Drosophila Giant Fiber neurons (GF) as a novel model to study axonal trafficking of L1-type Cell Adhesion Molecules (CAM) Neuroglian (Nrg) in the adult CNS using live imaging. L1-type CAMs are well known for their importance in nervous system development and we previously demonstrated a role for Nrg in GF synapse formation. However, in the adult they have also been implicated in synaptic plasticity and regeneration. In addition, to its canonical role in organizing cytoskeletal elements at the plasma membrane, vertebrate L1CAM has also been shown to regulate transcription indirectly as well as directly via its import to the nucleus. Here, we intend to determine if the sole L1CAM homolog Nrg is retrogradley transported and thus has the potential to relay signals from the synapse to the soma. Live imaging of c-terminally tagged Nrg in the GF revealed that there are at least two populations of retrograde vesicles that differ in speed, and either move with consistent or varying velocity. To determine if endogenous Nrg is retrogradely transported, we inhibited two key regulators, Lissencephaly-1 (Lis1) and Dynactin, of the retrograde motor protein Dynein. Similar to previously described phenotypes for expression of poisonous subunits of Dynactin, we found that developmental knock down of Lis1 disrupted GF synaptic terminal growth and that Nrg vesicles accumulated inside the stunted terminals in both mutant backgrounds. Moreover, post mitotic Lis1 knock down in mature GFs by either RNAi or Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) induced mutations, resulted in normal length terminals with fully functional GF synapses which also exhibited severe accumulation of endogenous Nrg vesicles. Thus, our data suggests that accumulation of Nrg vesicles is due to failure of retrograde transport rather than a failure of terminal development. Together with the finding that post mitotic knock down of Lis1 also disrupted retrograde transport of tagged Nrg vesicles in GF axons, it demonstrates that endogenous Nrg protein is transported from the synapse to the soma in the adult central nervous system in a Lis1-dependent manner.

COPI-mediated retrograde trafficking from the Golgi to the ER regulates EGFR nuclear transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ying-Nai; Wang, Hongmei; Yamaguchi, Hirohito

2010-09-03

Research highlights: {yields} ARF1 activation is involved in the EGFR transport to the ER and the nucleus. {yields} Assembly of {gamma}-COP coatomer mediates EGFR transport to the ER and the nucleus. {yields} Golgi-to-ER retrograde trafficking regulates nuclear transport of EGFR. -- Abstract: Emerging evidence indicates that cell surface receptors, such as the entire epidermal growth factor receptor (EGFR) family, have been shown to localize in the nucleus. A retrograde route from the Golgi to the endoplasmic reticulum (ER) is postulated to be involved in the EGFR trafficking to the nucleus; however, the molecular mechanism in this proposed model remains unexplored.more » Here, we demonstrate that membrane-embedded vesicular trafficking is involved in the nuclear transport of EGFR. Confocal immunofluorescence reveals that in response to EGF, a portion of EGFR redistributes to the Golgi and the ER, where its NH{sub 2}-terminus resides within the lumen of Golgi/ER and COOH-terminus is exposed to the cytoplasm. Blockage of the Golgi-to-ER retrograde trafficking by brefeldin A or dominant mutants of the small GTPase ADP-ribosylation factor, which both resulted in the disassembly of the coat protein complex I (COPI) coat to the Golgi, inhibit EGFR transport to the ER and the nucleus. We further find that EGF-dependent nuclear transport of EGFR is regulated by retrograde trafficking from the Golgi to the ER involving an association of EGFR with {gamma}-COP, one of the subunits of the COPI coatomer. Our findings experimentally provide a comprehensive pathway that nuclear transport of EGFR is regulated by COPI-mediated vesicular trafficking from the Golgi to the ER, and may serve as a general mechanism in regulating the nuclear transport of other cell surface receptors.« less

Penile fracture and its treatment: is retrograde urethrograghy necessary for management of penile fracture?

PubMed

Ahmadnia, Hassan; Younesi Rostami, Mehdi; Kamalati, Ali; Imani, Mohammad Mehdi

2014-01-01

Penile fracture, being defined as rupture of the tunica albuginea of the corpus cavernosum, is uncommon. Here, we analyze findings on our patients during a 10-year period and evaluate the role of retrograde urethrography. From February 2002 to April 2012, 116 patients were admitted with penile fracture at Ghaem Medical Center. Patient history and physical examination were taken at their admittance to detect probable urethral injury. Before surgery, retrograde urethrography was performed in all patients. The size and site of the tunical rupture were recorded. Then the rupture of tunica albuginea was sutured with nonabsorbable (3-0 nylon) sutures and the ties were placed on the internal surface (continuous method). All patients were followed up for 12 months. Patients' mean age was (32.78 ± 10.61) years and ranged (16-62) years. The mechanism of trauma was sexual intercourse in 103 patients (89%) and masturbation in 13 patients (11%). The most common site of injury found after exploration was right (55%) and lateral (74%) of the corpus cavernosum. The size of the tunical rupture was from 0.5 to 3.0 cm (mean 1.88 ± 0.72). Three of the patients had Marphan's syndrome. Urethral injury was detected by retrograde urethrography in 4 patients (3%) who had macroscopic hematuria and urethrorrhagia. During 12 months follow-up, no complication was seen. There is no need to perform retrograde urethrography unless the patients have gross hematuria or urethrorrhagia. The key to success in treatment of penile fracture is to achieve a rapid diagnosis based on history and a physical examination, avoid unnecessary imaging tests and perform immediate surgery to reconstruct the site of injury.

Mid-term follow-up of patients with hindfoot arthrodesis with retrograde compression intramedullary nail in Charcot neuroarthropathy of the hindfoot.

PubMed

Chraim, M; Krenn, S; Alrabai, H M; Trnka, H-J; Bock, P

2018-02-01

Hindfoot arthrodesis with retrograde intramedullary nailing has been described as a surgical strategy to reconstruct deformities of the ankle and hindfoot in patients with Charcot arthropathy. This study presents case series of Charcot arthropathy patients treated with two different retrograde intramedullary straight compression nails in order to reconstruct the hindfoot and assess the results over a mid-term follow-up. We performed a retrospective analysis of 18 consecutive patients and 19 operated feet with Charcot arthropathy who underwent a hindfoot arthrodesis using a retrograde intramedullary compression nail. Patients were ten men and eight women with a mean age of 63.43 years (38.5 to 79.8). We report the rate of limb salvage, complications requiring additional surgery, and fusion rate in both groups. The mean duration of follow-up was 46.36 months (37 to 70). The limb salvage rate was 16 of 19 limbs. Three patients had to undergo below-knee amputation due to persistent infection followed by osteomyelitis resistant to parenteral antibiotic therapy and repeated debridement. Complications including infection, hardware removal, nonunion, and persistent ulcers requiring further intervention were also observed. Postoperative functional scores revealed significant improvement compared with preoperative scores on American Orthopaedic Foot and Ankle Society (AOFAS) - Hindfoot scale, Foot Function Index (FFI), visual analogue scale (VAS), and Foot and Ankle Outcome Score (FAOS). The use of retrograde intramedullary compression nail results in good rates of limb salvage when used for hindfoot reconstruction in patients with Charcot arthropathy. Cite this article: Bone Joint J 2018;100-B:190-6. ©2018 The British Editorial Society of Bone & Joint Surgery.

Blueschist preservation in a retrograded, high-pressure, low-temperature metamorphic terrane, Tinos, Greece: Implications for fluid flow paths in subduction zones

NASA Astrophysics Data System (ADS)

Breeding, Christopher M.; Ague, Jay J.; BröCker, Michael; Bolton, Edward W.

2003-01-01

The preservation of high-pressure, low-temperature (HP-LT) mineral assemblages adjacent to marble unit contacts on the Cycladic island of Tinos in Greece was investigated using a new type of digital outcrop mapping and numerical modeling of metamorphic fluid infiltration. Mineral assemblage distributions in a large blueschist outcrop, adjacent to the basal contact of a 150-meter thick marble horizon, were mapped at centimeter-scale resolution onto digital photographs using a belt-worn computer and graphics editing software. Digital mapping reveals that while most HP-LT rocks in the outcrop were pervasively retrograded to greenschist facies, the marble-blueschist contact zone underwent an even more intense retrogression. Preservation of HP-LT mineral assemblages was mainly restricted to a 10-15 meter zone (or enclave) adjacent to the intensely retrograded lithologic contact. The degree and distribution of the retrograde overprint suggests that pervasively infiltrating fluids were channelized into the marble-blueschist contact and associated veins and flowed around the preserved HP-LT enclave. Numerical modeling of Darcian flow, based on the field observations, suggests that near the marble horizon, deflections in fluid flow paths caused by flow channelization along the high-permeability marble-blueschist contact zone likely resulted in very large fluid fluxes along the lithologic contact and significantly smaller fluxes (as much as 8 times smaller than the input flux) within the narrow, low-flux regions where HP-LT minerals were preserved adjacent to the contact. Our results indicate that lithologic contacts are important conduits for metamorphic fluid flow in subduction zones. Channelization of retrograde fluids into these discrete flow conduits played a critical role in the preservation of HP-LT assemblages.

Comparison of Balloon-Occluded Retrograde Transvenous Obliteration (BRTO) Using Ethanolamine Oleate (EO), BRTO Using Sodium Tetradecyl Sulfate (STS) Foam and Vascular Plug-Assisted Retrograde Transvenous Obliteration (PARTO)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Young Hwan; Kim, Young Hwan, E-mail: yhkim68@dsmc.or.kr; Kim, Chan Sun

PurposeTo compare the clinical outcomes of balloon-occluded retrograde transvenous obliteration (BRTO) using ethanolamine oleate (EO), BRTO using sodium tetradecyl sulfate (STS) foam, and vascular plug-assisted retrograde transvenous obliteration (PARTO).Materials and MethodsFrom April 2004 to February 2015, ninety-five patients underwent retrograde transvenous obliteration for gastric varices were analyzed retrospectively. BRTO with EO was performed in 49 patients, BRTO with STS foam in 25, and PARTO in 21. Among them, we obtained follow-up data in 70 patients. Recurrence of gastric varices was evaluated by follow-up endoscopy or CT. Medical records were reviewed for the clinical efficacy. Statistical analyses were performed by Kaplan–Meiermore » method, Chi-square, Fisher’s, and Kruskal–Wallis tests.ResultsTechnical and clinical success was 94.7 %. As major complications, a hemoglobinuria and a death due to disseminated intravascular coagulation (DIC) were occurred in two patients with BRTO using EO. Recurrence occurred more frequently in PARTO group (P < 0.05). Recurrence occurred in three patients in BRTO using EO group and four patients in PARTO group with 3.2 and 32.8 % of each expected 1-year recurrence rates. There was no recurrence in BRTO using STS group. Abdominal pain occurred more frequently in BRTO using EO than BRTO using STS foam and PARTO (P < 0.05). Procedure time of PARTO was shorter than two conventional BRTOs (P < 0.05).ConclusionsBRTO using STS foam or PARTO is better than BRTO using EO for treatment of gastric varices in terms of complication or procedure time. However, PARTO showed frequent recurrence of gastric varices during the long-term follow-up rather than BRTO.« less

Prevention of Retrograde Blood Flow Into Large or Giant Internal Carotid Artery Aneurysms by Endovascular Coil Embolization with High-Flow Bypass: Surgical Technique and Long-Term Results.

PubMed

Nakajima, Norio; Nagahiro, Shinji; Satomi, Junichiro; Tada, Yoshiteru; Nakajima, Kohei; Sogabe, Shu; Hanaoka, Mami; Matsubara, Shunji; Uno, Masaaki; Satoh, Koichi

2015-06-01

Recanalization has been reported in large or giant aneurysms of the internal carotid artery (ICA) addressed by high-flow bypass and endovascular treatment. Aneurysmal recanalization may be attributable to retrograde blood flow into the aneurysm through the ICA branches, such as the ophthalmic artery or the meningohypophyseal trunk, or through the surgically created bypass. We modified the endovascular treatment of aneurysms to prevent retrograde flow and evaluated the long-term efficacy of our method. We used a hybrid operative/endovascular technique to treat 5 patients with large or giant aneurysms arising from the C2-C4 segment of the ICA who presented with visual symptoms due to the mass effect of the aneurysm. To prevent retrograde flow into the aneurysm our modified endovascular treatment involves coil embolization of the aneurysmal orifice and the ICA, including the origin of the ophthalmic artery and meningohypophyseal trunk, and placement of a high-flow bypass using a radial artery graft. During the 5- to 12-year follow-up period, 4 aneurysms disappeared, and the other decreased in size. There were no subarachnoid hemorrhages. All bypass grafts remained patent. Visual preservation was achieved in 2 patients; 1 patient manifested visual improvement. Although 2 patients experienced transient neurological deficits we encountered no permanent complications in this series. The final modified Rankin scale of the 5 patients was 0 or 1. Prevention of retrograde flow into the aneurysm by coil embolization with high-flow bypass is a safe and effective method. It prevents the recanalization of large or giant ICA aneurysms. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Prospective analysis of a complete retrograde ureteroscopic technique with holmium laser stent cutting for management of encrusted ureteral stents.

PubMed

Thomas, Alexandre; Cloutier, Jonathan; Villa, Luca; Letendre, Julien; Ploumidis, Achilles; Traxer, Olivier

2017-03-14

To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The Holmium-YAG laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intra-renal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery or a combination of these techniques. The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Holmium-YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly non-obstructive pyelonephritis (10%). The most significant predictor of this life threatened complication was the presence of struvite stones with the encrusted stent (p=0,018). Contrariwise, operative time, BMI, gender and encrustation rate were not associated with postoperative pyelonephritis. Cystine stone disease or pregnancy both led to faster stent encrustation. Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Holmium-YAG laser is essential to perform the encrustation removal and sectioning of the stent.

Junctional bradycardia is a potential risk factor of stroke.

PubMed

Kim, Gwang Sil; Uhm, Jae-Sun; Kim, Tae-Hoon; Lee, Hancheol; Park, Junbeom; Park, Jin-Kyu; Joung, Boyoung; Pak, Hui-Nam; Lee, Moon-Hyoung

2016-07-25

This study aimed to determine the risk of thromboembolic events in patients with junctional bradycardia(JB). We retrospectively reviewed electrocardiograms(ECGs) for 380,682 patients. Those with JB on an ECG at least twice over a ≥3-month interval were included for analysis. We additionally included 138 CHADS2 score-matched patients(age, 68.4 ± 15.7 years; male, 52.2%) in sinus rhythm as a control group. Between the JB patients(with or without retrograde P wave) and controls, we compared incidences of ischemic stroke and a composite of ischemic stroke, renal infarction, ischemic colitis, acute limb ischemia, and pulmonary embolism. Among 380,682 patients (age, 47.6 ± 19.9 years; male, 49.3%), 69 patients (age, 68.5 ± 16.5 years; male, 50.7%) exhibited JB on an ECG at least twice over a ≥3-month interval; the overall prevalence of JB was 0.02%. The mean follow-up period was 27.2 ± 26.2 months. Forty-five patients (65.2%) in the JB group had no retrograde P wave. Ischemic stroke incidence was significantly higher in JB patients without a retrograde P wave than in controls (6/45 patients [13.3%] and 3/138 patients [2.2%], respectively; P = 0.007). The incidence of composite thromboembolic events was also significantly higher in JB patients without a retrograde P wave than in controls (8/45 patients [17.8%] and 4/138 patients [2.9%], respectively; P = 0.011). In a Cox proportional hazards model, JB patients without a P wave showed a greater incidence of stroke (hazard ratio, 8.89 [2.20-33.01], P = 0.007) than controls and JB patients with a P wave. Junctional bradycardia is potentially associated with ischemic stroke, particularly in the absence of an identifiable retrograde P wave.

Evaluation of the percentage of ganglion cells in the ganglion cell layer of the rodent retina

PubMed Central

Schlamp, Cassandra L.; Montgomery, Angela D.; Mac Nair, Caitlin E.; Schuart, Claudia; Willmer, Daniel J.

2013-01-01

Purpose Retinal ganglion cells comprise a percentage of the neurons actually residing in the ganglion cell layer (GCL) of the rodent retina. This estimate is useful to extrapolate ganglion cell loss in models of optic nerve disease, but the values reported in the literature are highly variable depending on the methods used to obtain them. Methods We tested three retrograde labeling methods and two immunostaining methods to calculate ganglion cell number in the mouse retina (C57BL/6). Additionally, a double-stain retrograde staining method was used to label rats (Long-Evans). The number of total neurons was estimated using a nuclear stain and selecting for nuclei that met specific criteria. Cholinergic amacrine cells were identified using transgenic mice expressing Tomato fluorescent protein. Total neurons and total ganglion cell numbers were measured in microscopic fields of 104 µm2 to determine the percentage of neurons comprising ganglion cells in each field. Results Historical estimates of the percentage of ganglion cells in the mouse GCL range from 36.1% to 67.5% depending on the method used. Experimentally, retrograde labeling methods yielded a combined estimate of 50.3% in mice. A retrograde method also yielded a value of 50.21% for rat retinas. Immunolabeling estimates were higher at 64.8%. Immunolabeling may introduce overestimates, however, with non-specific labeling effects, or ectopic expression of antigens in neurons other than ganglion cells. Conclusions Since immunolabeling methods may overestimate ganglion cell numbers, we conclude that 50%, which is consistently derived from retrograde labeling methods, is a reliable estimate of the ganglion cells in the neuronal population of the GCL. PMID:23825918

Endogenous cannabinoids mediate retrograde signals from depolarized postsynaptic neurons to presynaptic terminals.

PubMed

Ohno-Shosaku, T; Maejima, T; Kano, M

2001-03-01

Endogenous cannabinoids are considered to function as diffusible and short-lived modulators that may transmit signals retrogradely from postsynaptic to presynaptic neurons. To evaluate this possibility, we have made a paired whole-cell recording from cultured hippocampal neurons with inhibitory synaptic connections. In about 60% of pairs, a cannabinoid agonist greatly reduced the release of the inhibitory neurotransmitter GABA from presynaptic terminals. In most of such pairs but not in those insensitive to the agonist, depolarization of postsynaptic neurons and the resultant elevation of intracellular Ca2+ concentration caused transient suppression of inhibitory synaptic currents, which is mainly due to reduction of GABA release. This depolarization-induced suppression was completely blocked by selective cannabinoid antagonists. Our results reveal that endogenous cannabinoids mediate retrograde signals from depolarized postsynaptic neurons to presynaptic terminals to cause the reduction of transmitter release.

Villous adenoma of the common hepatic duct: the importance of contrast-enhanced ultrasound and endoscopic retrograde cholangiopancreatography for relevant diagnosis. A case report and review of the literature.

PubMed

Tefas, Cristian; Tanţău, Marcel; Szenftleben, Alexandru; Chiorean, Liliana; Badea, Radu

2015-12-01

Adenomas are frequently encountered in the lower digestive tract but are rarely diagnosed in the biliary tree. We report a case of villous adenoma of the common hepatic duct. A 58-year old male was admitted with a four week history of intermittent upper right quadrant pain. Gray scale and contrast-enhanced abdominal ultrasound showed a mass inside the common hepatic duct with arterial enhancement and slow wash-out during the late venous phase. Subsequent endoscopic retrograde cholangiopancreatography and intraductal ultrasound confirmed the presence of the lesion. The final histopathological examination showed villous adenoma of the common hepatic duct with high-grade dysplasia. Contrast enhanced ultrasonography used in conjecture with endoscopic retrograde cholangiopancreatography can help in differentiating biliary tumors.

Synaptic sprouting increases the uptake capacities of motoneurons in amyotrophic lateral sclerosis mice

PubMed Central

Millecamps, Stéphanie; Nicolle, Delphine; Ceballos-Picot, Irène; Mallet, Jacques; Barkats, Martine

2001-01-01

Using adenoviruses encoding reporter genes as retrograde tracers, we assessed the capacity of motoneurons to take up and retrogradely transport adenoviral particles injected into the muscles of transgenic mice expressing the G93A human superoxide dismutase mutation, a model of amyotrophic lateral sclerosis. Surprisingly, transgene expression in the motoneurons was significantly higher in symptomatic mice than in control or presymptomatic mice. Using botulinum toxin to induce nerve sprouting at neuromuscular junctions, we showed that the unexpectedly high level of motoneurons retrograde transduction results, at least in part, from newly acquired uptake properties of the sprouts. These findings demonstrate the remarkable uptake properties of amyotrophic lateral sclerosis motoneurons in response to denervation and the rationale of using intramuscular injections of adenoviruses to overexpress therapeutic proteins in motor neuron diseases. PMID:11404466

Thermal behavior of potato starch and water-vaporization behavior of its paste controlled with amino acid and peptide-rich food materials.

PubMed

Sakauchi, Satoshi; Hattori, Makoto; Yoshida, Tadashi; Yagishita, Takahiro; Ito, Koichi; Akemitsu, Shin-Ichi; Takahashi, Koji

2010-03-01

The particular effect of 4 kinds of amino acid and peptide-rich food material (APRM) containing different charged amino acid contents on the gelatinization and retrogradation behavior of potato starch granules and on the water-vaporization behavior was analyzed by differential scanning calorimetry, rapid viscoanalysis, x-ray diffractometry, thermal gravimetry-differential thermal analysis, and pulsed NMR. APRM with a high-charged amino acid content produced unique gelatinization and retrogradation behavior in terms of an elevated gelatinization temperature, reduced viscosity, higher setback, and lower retrograded starch melting enthalpy. The recovered x-ray diffraction intensity decreased with increasing charged amino acid content. APRM with high-charged amino acid content could provide an improved paste having easy vaporization of external water in the swollen starch granules due to the reduced swelling.

Percutaneous Retrograde Sclerotherapy for Refractory Bleeding of Jejunal Varices: Direct Injection via Superficial Epigastric Vein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakata, Manabu, E-mail: nktmnbohsu@jichi.ac.jp; Nakata, Waka, E-mail: waka-s@jichi.ac.jp; Isoda, Norio, E-mail: isodano1@jichi.ac.jp

2012-02-15

Small-bowel varices are rare and almost always occur in cases with portal hypertension. We encountered a patient with bleeding jejunal varices due to liver cirrhosis. Percutaneous retrograde sclerotherapy was performed via the superficial epigastric vein. Melena disappeared immediately after treatment. Disappearance of jejunal varices was confirmed by contrast-enhanced computed tomography. After 24 months of follow-up, no recurrent melena was observed.

Procedure Planning: Anatomical Determinants of Strategy

PubMed Central

Hanratty, Colm; Walsh, Simon

2014-01-01

In contemporary practice there are three main methods that can be employed when attempting to open a chronic total occlusion (CTO) of a coronary artery; antegrade or retrograde wire escalation, antegrade dissection re-entry and retrograde dissection re-entry. This editorial will attempt to clarify the anatomical features that can be identified to help when deciding which of these strategies to employ initially and help understand the reasons for this decision. PMID:24694102

Magnetic Resonance Imaging (MRI) with retrograde intralumen contrast enhancement of the rectum in diagnostics of rectovaginal fistulas after combination therapy of rectal cancer. Experience of application

NASA Astrophysics Data System (ADS)

Usova, A.; Frolova, I.; Afanasev, S.; Tarasova, A.; Molchanov, S.

2016-02-01

Experiment of use of MRI in diagnostics of rectovaginal fistulas after combination therapy of rectal cancer is shown on clinical examples. We used retrograde contrasting of a rectum with 150ml ultrasonic gel to make MRI more informative in case of low diagnostic efficiency of ultrasound, colonoscopy and gynecological examination.

Evolution of cranial telescoping in echolocating whales (Cetacea: Odontoceti).

PubMed

Churchill, Morgan; Geisler, Jonathan H; Beatty, Brian L; Goswami, Anjali

2018-05-01

Odontocete (echolocating whale) skulls exhibit extreme posterior displacement and overlapping of facial bones, here referred to as retrograde cranial telescoping. To examine retrograde cranial telescoping across 40 million years of whale evolution, we collected 3D scans of whale skulls spanning odontocete evolution. We used a sliding semilandmark morphometric approach with Procrustes superimposition and PCA to capture and describe the morphological variation present in the facial region, followed by Ancestral Character State Reconstruction (ACSR) and evolutionary model fitting on significant components to determine how retrograde cranial telescoping evolved. The first PC score explains the majority of variation associated with telescoping and reflects the posterior migration of the external nares and premaxilla alongside expansion of the maxilla and frontal. The earliest diverging fossil odontocetes were found to exhibit a lesser degree of cranial telescoping than later diverging but contemporary whale taxa. Major shifts in PC scores and centroid size are identified at the base of Odontoceti, and early burst and punctuated equilibrium models best fit the evolution of retrograde telescoping. This indicates that the Oligocene was a period of unusually high diversity and evolution in whale skull morphology, with little subsequent evolution in telescoping. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

Live-cell imaging of retrograde transport initiation in primary neurons.

PubMed

Nirschl, Jeffrey J; Holzbaur, Erika L F

2016-01-01

Axonal transport is an essential function in neurons, as mutations in either motor proteins or their adaptors cause neurodegeneration. While some mutations cause a complete block in axonal transport, other mutations affect transport more subtly. This is especially true of mutations identified in human patients, many of which impair but do not block motor function in the cell. Dissecting the pathogenic mechanisms of these more subtle mutations requires assays that can tease apart the distinct phases of axonal transport, including transport initiation, sustained/regulated motility, and cargo-specific sorting or delivery. Here, we describe a live-cell photobleaching assay to assess retrograde flux from the distal axon tip, a measure for distal transport initiation. We have previously used this method to show that the CAP-Gly domain of DCTN1 is required for efficient retrograde transport initiation in the distal axon, but it is not required to maintain retrograde flux along the mid-axon (Moughamian & Holzbaur, 2012). This approach has allowed us to examine the effects of disease-causing mutations in the axonal transport machinery, and in combination with other assays, will be useful in determining the mechanisms and regulation of axonal transport in normal and diseased conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Temporary Vascular Occlusion by Rapid Reverse Phase Polymer: A Preliminary In Vitro Study of Retrograde Injection

PubMed Central

Dregelid, Einar

2012-01-01

During vascular surgical operations, there is a need for a simpler and more reliable method of temporary arterial occlusion than those currently employed, especially of heavily calcified arteries. A thermosensitive polymer, LeGoo (LG) (Pluromed, Woburn, MA), has been used successfully for temporary vascular occlusion. It has hitherto been injected by a cannula that has been introduced into the artery to be occluded, here henceforth called the “cannulation method.” Injection into arterial ostia without cannulation, using an injection device that arrests blood flow during the injection, here henceforth called “a retrograde method” may enable temporary hemostasis when ostial stenoses render it impossible to inject LG using the cannulation method. The objective of the present study was to study the feasibility of a retrograde method and to compare it with the cannulation method in an in vitro model, incorporating a narrow orifice to simulate ostial stenosis, using tap water at 37°C instead of blood. The retrograde method of LG injection, using a modified paediatric Foley catheter, turned out to be feasible to produce a durable LG plug more reliably, at higher water pressure and with less deep LG injection than with the cannulation method. PMID:22888352

Predicting the failure of retrograde ureteral stent insertion for managing malignant ureteral obstruction in outpatients

PubMed Central

WANG, JIN-YOU; ZHANG, HAI-LIANG; ZHU, YAO; QIN, XIAO-JIAN; DAI, BO; YE, DING-WEI

2016-01-01

Malignant ureteral obstruction (MUO) is an unpropitious sign that is commonly observed in patients with advanced incurable cancer. The present study aimed to evaluate predictive factors for the failure of retrograde ureteral stent insertion in the management of MUO in outpatients. A total of 164 patients with MUO were retrospectively assessed in this study. Clinical factors, including age, gender, type of malignancy, level of obstruction, cause of obstruction, pre-operative creatinine level, degree of hydronephrosis, condition of the contralateral ureter, prior radiotherapy, Eastern Cooperative Oncology Group performance status (ECOG PS), bladder wall invasion and technical failure, were recorded for each case. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for predicting the failure of retrograde ureteral stent insertion. In total, 38 out of 164 patients experienced bilateral obstruction, therefore, a total of 202 ureteral units were available for data analysis. The rate of insertion failure in MUO was 34.65%. Multivariate analyses identified ECOG PS, degree of hydronephrosis and bladder wall invasion as independent predictors for insertion failure. Overall, the present study found that rate of retrograde ureteral stent insertion failure is high in outpatients with MUO, and that ECOG PS, degree of hydronephrosis and bladder invasion are potential independent predictors of insertion failure. PMID:26870299

Functional involvement of TMF/ARA160 in Rab6-dependent retrograde membrane traffic.

PubMed

Yamane, Junko; Kubo, Akiharu; Nakayama, Kazuhisa; Yuba-Kubo, Akiko; Katsuno, Tatsuya; Tsukita, Shoichiro; Tsukita, Sachiko

2007-10-01

The small GTPase Rab6 regulates retrograde membrane traffic from endosomes to the Golgi apparatus and from the Golgi to the endoplasmic reticulum (ER). We examined the role of a Rab6-binding protein, TMF/ARA160 (TATA element modulatory factor/androgen receptor-coactivator of 160 kDa), in this process. High-resolution immunofluorescence imaging revealed that TMF signal surrounded Rab6-positive Golgi structures and immunoelectron microscopy revealed that TMF is concentrated at the budding structures localized at the tips of cisternae. The knockdown of either TMF or Rab6 by RNA interference blocked retrograde transport of endocytosed Shiga toxin from early/recycling endosomes to the trans-Golgi network, causing missorting of the toxin to late endosomes/lysosomes. However, the TMF knockdown caused Rab6-dependent displacement of N-acetylgalactosaminyltransferase-2 (GalNAc-T2), but not beta1,4-galactosyltransferase (GalT), from the Golgi. Analyses using chimeric proteins, in which the cytoplasmic regions of GalNAc-T2 and GalT were exchanged, revealed that the cytoplasmic region of GalNAc-T2 plays a crucial role in its TMF-dependent Golgi retention. These observations suggest critical roles for TMF in two Rab6-dependent retrograde transport processes: one from endosomes to the Golgi and the other from the Golgi to the ER.

Novel class of potential therapeutics that target ricin retrograde translocation.

PubMed

Redmann, Veronika; Gardner, Thomas; Lau, Zerlina; Morohashi, Keita; Felsenfeld, Dan; Tortorella, Domenico

2013-12-23

Ricin toxin, an A-B toxin from Ricinus communis, induces cell death through the inhibition of protein synthesis. The toxin binds to the cell surface via its B chain (RTB) followed by its retrograde trafficking through intracellular compartments to the ER where the A chain (RTA) is transported across the membrane and into the cytosol. Ricin A chain is transported across the ER membrane utilizing cellular proteins involved in the disposal of aberrant ER proteins by a process referred to as retrograde translocation. Given the current lack of therapeutics against ricin intoxication, we developed a high-content screen using an enzymatically attenuated RTA chimera engineered with a carboxy-terminal enhanced green fluorescent protein (RTA(E177Q)egfp) to identify compounds that target RTA retrograde translocation. Stabilizing RTA(E177Q)egfp through the inclusion of proteasome inhibitor produced fluorescent peri-nuclear granules. Quantitative analysis of the fluorescent granules provided the basis to discover compounds from a small chemical library (2080 compounds) with known bioactive properties. Strikingly, the screen found compounds that stabilized RTA molecules within the cell and several compounds limited the ability of wild type RTA to suppress protein synthesis. Collectively, a robust high-content screen was developed to discover novel compounds that stabilize intracellular ricin and limit ricin intoxication.

Retrograde amnesia: a study of its relation to anterograde amnesia and semantic memory deficits.

PubMed

Schmidtke, K; Vollmer, H

1997-04-01

This group study of 24 amnesic patients and 40 control subjects examined the hypothesis that retrograde memory deficits result from a combination of two impairment mechanisms: (1) a deficit in the retrieval of contents that is related to dysfunctioning of the hippocampal anterograde memory system, and (2) a deficit in the storage and/or retrieval of contents that is related to concomitant neocortical lesions. Retrograde amnesia was evaluated with the use of new Famous Persons and Autobiographical Memory Tests. The postulated components of retrograde memory impairment were assessed using the Wechsler Memory Scale and a new Semantic Memory Test, respectively. Regression analyses showed that recent episodic autobiography was exclusively related to the hippocampal component, while memory for famous persons and childhood autobiography was related to the neocortical component. In the case of details concerning people of recent fame, both components were identified as independent determinants. The temporal gradient of patients' impairment at the Famous Persons Test was marked for detailed knowledge, but small for overlearned knowledge. The present results thus support the combination hypothesis. They conform to the view that the transition from a hippocampus-dependent to a neocortex-dependent mnemonic representation of new contents is mediated by reiteration, and occurs within 5-10 years.

Tibio-talocalcaneal arthrodesis as a primary procedure using a retrograde intramedullary nail: a retrospective study of 26 patients with rheumatoid arthritis.

PubMed

Anderson, Thomas; Linder, Lars; Rydholm, Urban; Montgomery, Fredrik; Besjakov, Jack; Carlsson, Ake

2005-08-01

Arthrodesis of the ankle joint using screws or external fixation is often a demanding procedure, notably in patients with rheumatoid arthritis. We investigated whether tibio-talocalcaneal arthrodesis with the use of an intramedullary nail is a safe and simple procedure. We retrospectively reviewed 25 ankles (25 patients) at median 3 (1-7) years after tibio-talocalcaneal arthrodesis because of rheumatoid arthritis. All had been operated on by retrograde insertion of a retrograde nail. 5 types of nail had been used. Complications, functional outcome scores, and patient satisfaction were determined and the radiographs evaluated for healing. All but 1 ankle had a radiographically healed arthrodesis. We recorded 3 deep infections, all healed--in 2 cases after extraction of the nail--and the arthrodesis healed in all 3 patients. The average functional scores at follow-up were high, considering that the patients suffered from rheumatoid arthritis. 23 patients were satisfied with the outcome. We found a correlation between the functional scores and the general activity of the disease expressed as a Health Assessment Questionnaire score. In patients with rheumatoid arthritis, tibio-talocalcaneal arthrodesis with a retrograde intra-medullary nail results in a high rate of healing, a high rate of patient satisfaction, and relatively few complications.

Par3 and aPKC regulate BACE1 endosome-to-TGN trafficking through PACS1.

PubMed

Sun, Miao; Zhang, Huaye

2017-12-01

The cleavage of amyloid precursor protein (APP) by β-site APP cleaving enzyme 1 (BACE1) is the rate-limiting step in beta amyloid generation during Alzheimer's disease (AD) pathogenesis. In AD brains, BACE1 is abnormally accumulated in endocytic compartments, where the acidic pH is optimal for its activity. However, mechanisms regulating the endosome-to-trans-Golgi network (TGN) retrieval of BACE1 remain unclear. Here, we show that partitioning defective 3 (Par3) facilitates BACE1 retrograde trafficking from endosomes to the TGN. Par3 functions through aPKC-mediated phosphorylation of BACE1 on Ser498, which in turn promotes the interaction between BACE1 and phosphofurin acidic cluster sorting protein 1 and facilitates the retrograde trafficking of BACE1 to the TGN. In human AD brains, there is a significant decrease in Ser498 phosphorylation of BACE1 suggesting that defective phosphorylation-dependent retrograde transport of BACE1 is important in AD pathogenesis. Together, our studies provide mechanistic insight into a novel role for Par3 and aPKC in regulating the retrograde endosome-to-TGN trafficking of BACE1 and shed light on the mechanisms of AD pathogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Stem-cell therapy for dilated cardiomyopathy: a pilot study evaluating retrograde coronary venous delivery.

PubMed

Pogue, B; Estrada, A H; Sosa-Samper, I; Maisenbacher, H W; Lamb, K E; Mincey, B D; Erger, K E; Conlon, T J

2013-07-01

To evaluate retrograde coronary venous stem-cell delivery for Dobermanns with dilated cardiomyopathy. Retrograde coronary venous delivery of adipose-derived mesenchymal stem cells transduced with tyrosine mutant adeno-associated virus 2 to express stromal-derived factor-1 was performed in Dobermanns with dilated cardiomyopathy. Cases were followed for 2 years and electrocardiograms (ECG), echocardiograms and Holter monitoring were performed. Delivery of cells was feasible in 15 of 15 dogs. One dog died following the development of ventricular fibrillation 24 hours after cell delivery. The remaining 14 dogs were discharged the following day without complications. Echocardiographic measurements of left ventricular size and function showed continued progression of disease. On the basis of Kaplan-Meier product limit estimates, median survival for dogs following stem-cell delivery was 620 days (range of 1-799 days). When including only the occult-dilated cardiomyopathy population and excluding those dogs already in congestive heart failure, median survival was 652 days (range of 46-799 days). Retrograde venous delivery of tyrosine mutant adeno-associated virus 2-stromal-derived factor-1 adipose-derived mesenchymal stem cells appears safe. Stem-cell therapy in dogs with occult-dilated cardiomyopathy does not appear to offer advantage compared to recently published survival data in similarly affected Dobermanns. © 2013 British Small Animal Veterinary Association.

Complications of bladder distension during retrograde urethrography.

PubMed

Barsanti, J A; Crowell, W; Losonsky, J; Talkington, F D

1981-05-01

A severe, ulcerative cystitis that resulted in macroscopic hematuria occurred in 8 of 20 healthy dogs undergoing a series of diagnostic tests. Four of the remaining 12 dogs had mild bladder lesions consisting of submucosal edema and hemorrhage. Nine of the 20 dogs developed urinary tract infection after the procedures. These complications seemed associated with the radiographic technique of retrograde urethrography performed when the urinary bladder was distended. To test this hypothesis, retrograde urethrography was performed on 5 additional dogs. With the bladder undistended, no complications occurred. However, distention of these same dogs' bladders for 1 minute or less with sterile lactated Ringer's solution administered through a Foley catheter in the penile urethra resulted in a macroscopic hematuria in all 5 dogs which persisted for 24 hours. A microscopic hematuria continued for 5 days. One dog developed a bacterial urinary tract infection. A severe fibrinopurulent cystitis was present at necropsy of 2 dogs 2 days after distention. The morphologic changes in the bladder gradually diminished over 7 days, but mild submucosal edema and hemorrhage were still present when 2 dogs were necropsied, 7 days after distention. These studies indicated that retrograde urethrography in dogs may be complicated by hemorrhagic cystitis and urinary tract infection if performed with urinary bladder distention.

The retrograde delivery of adenovirus vector carrying the gene for brain-derived neurotrophic factor protects neurons and oligodendrocytes from apoptosis in the chronically compressed spinal cord of twy/twy mice.

PubMed

Uchida, Kenzo; Nakajima, Hideaki; Hirai, Takayuki; Yayama, Takafumi; Chen, Kebing; Guerrero, Alexander Rodriguez; Johnson, William Eustace; Baba, Hisatoshi

2012-12-15

The twy/twy mouse undergoes spontaneous chronic mechanical compression of the spinal cord; this in vivo model system was used to examine the effects of retrograde adenovirus (adenoviral vector [AdV])-mediated brain-derived neurotrophic factor (BDNF) gene delivery to spinal neural cells. To investigate the targeting and potential neuroprotective effect of retrograde AdV-mediated BDNF gene transfection in the chronically compressed spinal cord in terms of prevention of apoptosis of neurons and oligodendrocytes. Several studies have investigated the neuroprotective effects of neurotrophins, including BDNF, in spinal cord injury. However, no report has described the effects of retrograde neurotrophic factor gene delivery in compressed spinal cords, including gene targeting and the potential to prevent neural cell apoptosis. AdV-BDNF or AdV-LacZ (as a control gene) was injected into the bilateral sternomastoid muscles of 18-week old twy/twy mice for retrograde gene delivery via the spinal accessory motor neurons. Heterozygous Institute of Cancer Research mice (+/twy), which do not undergo spontaneous spinal compression, were used as a control for the effects of such compression on gene delivery. The localization and cell specificity of β-galactosidase expression (produced by LacZ gene transfection) and BDNF expression in the spinal cord were examined by coimmunofluorescence staining for neural cell markers (NeuN, neurons; reactive immunology protein, oligodendrocytes; glial fibrillary acidic protein, astrocytes; OX-42, microglia) 4 weeks after gene injection. The possible neuroprotection afforded by retrograde AdV-BDNF gene delivery versus AdV-LacZ-transfected control mice was assessed by scoring the prevalence of apoptotic cells (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells) and immunoreactivity to active caspases -3, -8, and -9, p75, neurofilament 200 kD (NF), and for the oligodendroglial progenitor marker, NG2. RESULTS.: Four weeks after injection, the retrograde delivery of the LacZ marker gene was identified in cervical spinal neurons and some glial cells, including oligodendrocytes in the white matter of the spinal cord, in both the twy/twy mouse and the heterozygous Institute of Cancer Research mouse (+/twy). In the compressed spinal cord of twy/twy mouse, AdV-BDNF gene transfection resulted in a significant decrease in the number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells present in the spinal cord and a downregulation in the caspase apoptotic pathway compared with AdV-LacZ (control) gene transfection. There was a marked and significant increase in the areas of the spinal cord of AdV-BDNF-injected mice that were NF- and NG2-immunopositive compared with AdV-LacZ-injected mice, indicating the increased presence of neurons and oligodendrocytes in response to BDNF transfection. Our results demonstrate that targeted retrograde BDNF gene delivery suppresses apoptosis in neurons and oligodendrocytes in the chronically compressed spinal cord of twy/twy mouse. Further work is required to establish whether this method of gene delivery may provide neuroprotective effects in other situations of compressive spinal cord injury.

Formation Flying in Earth, Libration, and Distant Retrograde Orbits

NASA Technical Reports Server (NTRS)

Folta, David C.

2004-01-01

This slide presentation examines the current and future state of formation flying, LEO formations, control strategies for flight in the vicinity of the libration points, and distant retrograde orbit formations. This discussion of LEO formations includes background on perturbation theory/accelerations and LEO formation flying. The discussion of strategies for formation flight in the vicinity of the libration points includes libration missions and natural and controlled libration orbit formations. A reference list is included.

Post-metamorphic fluid infiltration into granulites from the Adirondack Mountains, USA

NASA Technical Reports Server (NTRS)

Morrison, J.; Valley, John W.

1988-01-01

Post-metamorphic effects in the anorthosites of the Adirondacks, New York were described. Calcite-chlorite-sericite assemblages occur as veins, in disseminated form and as clots, and document retrograde fluid infiltration. These features are associated with late-state CO2-rich fluid inclusions. Stable isotope analyses of calcites indicates that the retrograde fluids interacted with meta-igneous and supracrustal lithologies, but the precise timing of the retrogression is as yet unknown.

Recovery from anterograde and retrograde amnesia after percutaneous drainage of a cystic craniopharyngioma.

PubMed Central

Ignelzi, R J; Squire, L R

1976-01-01

A case is reported of a cystic craniopharyngioma involving the floor and walls of the third ventricle. Pronounced anterograde and retrograde amnesia were documented preoperatively by formal testing. Rapid improvement in both new learning capacity and remote memory occurred after percutaneous twist drill drainage of the cystic portion of the tumour. The relevance of these observations to the amnesic syndrome and its neuropathological basis is discussed. Images PMID:1011035

Military Readiness: DOD Needs to Incorporate Elements of a Strategic Management Planning Framework into Retrograde and Reset Guidance

DTIC Science & Technology

2016-05-01

purpose of the memo is to provide additional guidance to the DOD components for submission of data and justification material supporting their estimates...and Reset Guidance Report to Congressional Committees May 2016 GAO-16-414 United States Government Accountability Office United States...Incorporate Elements of a Strategic Management Planning Framework into Retrograde and Reset Guidance Why GAO Did This Study Following the end of major

Ileal Varices Treated with Balloon-Occluded Retrograde Transvenous Obliteration

PubMed Central

Sato, Takahiro; Yamazaki, Katsu; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi; Akaike, Jun

2009-01-01

A 55-year-old man with hepatitis B virus antigen-positive liver cirrhosis was admitted to our hospital with anal bleeding. Colonoscopy revealed blood retention in the entire colon, but no bleeding lesion was found. Computed tomography images showed that vessels in the ileum were connected to the right testicular vein, and we suspected ileal varices to be the most probable cause of bleeding. We immediately performed double balloon enteroscopy, but failed to find any site of bleeding owing to the difficulty of fiberscope insertion with sever adhesion. Using a balloon catheter during retrograde transvenous venography, we found ileal varices communicating with the right testicular vein (efferent vein) with the superior mesenteric vein branch as the afferent vein of these varices. We performed balloon occluded retrograde transvenous obliteration by way of the efferent vein of the varices and have detected no further bleeding in this patient one year after treatment. PMID:27956966

Ileal Varices Treated with Balloon-Occluded Retrograde Transvenous Obliteration.

PubMed

Sato, Takahiro; Yamazaki, Katsu; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi; Akaike, Jun

2009-04-01

A 55-year-old man with hepatitis B virus antigen-positive liver cirrhosis was admitted to our hospital with anal bleeding. Colonoscopy revealed blood retention in the entire colon, but no bleeding lesion was found. Computed tomography images showed that vessels in the ileum were connected to the right testicular vein, and we suspected ileal varices to be the most probable cause of bleeding. We immediately performed double balloon enteroscopy, but failed to find any site of bleeding owing to the difficulty of fiberscope insertion with sever adhesion. Using a balloon catheter during retrograde transvenous venography, we found ileal varices communicating with the right testicular vein (efferent vein) with the superior mesenteric vein branch as the afferent vein of these varices. We performed balloon occluded retrograde transvenous obliteration by way of the efferent vein of the varices and have detected no further bleeding in this patient one year after treatment.

Comparison between the use of an ultrasonic tip and a microhead handpiece in periradicular surgery: a prospective randomised trial.

PubMed

Shearer, Jane; McManners, Joseph

2009-07-01

Innovations in periradicular surgery for failed treatment of orthograde root canal disease have been well-documented. We know of no prospective studies that have compared success rates of conventional methods with these presumed advances. In this prospective randomised trial we compare the use of an ultrasonic retrotip with a microhead bur in the preparation of a retrograde cavity. Outcome was estimated clinically by estimation of pain, swelling, and sinus, and radiographically by looking at infill of bone and retrograde root filling 2 weeks and 6 months postoperatively. Both methods used other surgical techniques including microinstruments to place the retrograde root filling. The success rate of the ultrasonic method was higher (all patients, n=26) than that of the microhead method (n=19 of 21). A larger study with longer follow up is required to consolidate this evidence.

Inorganic phosphate deprivation causes tRNA nuclear accumulation via retrograde transport in Saccharomyces cerevisiae.

PubMed

Hurto, Rebecca L; Tong, Amy Hin Yan; Boone, Charles; Hopper, Anita K

2007-06-01

Nuclear export of tRNA is an essential eukaryotic function, yet the one known yeast tRNA nuclear exporter, Los1, is nonessential. Moreover recent studies have shown that tRNAs can move retrograde from the cytosol to the nucleus by an undefined process. Therefore, additional gene products involved in tRNA nucleus-cytosol dynamics have yet to be identified. Synthetic genetic array (SGA) analysis was employed to identify proteins involved in Los1-independent tRNA transport and in regulating tRNA nucleus-cytosol distribution. These studies uncovered synthetic interactions between los1Delta and pho88Delta involved in inorganic phopsphate uptake. Further analysis revealed that inorganic phosphate deprivation causes transient, temperature-dependent nuclear accumulation of mature cytoplasmic tRNA within nuclei via a Mtr10- and retrograde-dependent pathway, providing a novel connection between tRNA subcellular dynamics and phosphate availability.

Inorganic Phosphate Deprivation Causes tRNA Nuclear Accumulation via Retrograde Transport in Saccharomyces cerevisiae

PubMed Central

Hurto, Rebecca L.; Tong, Amy Hin Yan; Boone, Charles; Hopper, Anita K.

2007-01-01

Nuclear export of tRNA is an essential eukaryotic function, yet the one known yeast tRNA nuclear exporter, Los1, is nonessential. Moreover recent studies have shown that tRNAs can move retrograde from the cytosol to the nucleus by an undefined process. Therefore, additional gene products involved in tRNA nucleus–cytosol dynamics have yet to be identified. Synthetic genetic array (SGA) analysis was employed to identify proteins involved in Los1-independent tRNA transport and in regulating tRNA nucleus–cytosol distribution. These studies uncovered synthetic interactions between los1Δ and pho88Δ involved in inorganic phopshate uptake. Further analysis revealed that inorganic phosphate deprivation causes transient, temperature-dependent nuclear accumulation of mature cytoplasmic tRNA within nuclei via a Mtr10- and retrograde-dependent pathway, providing a novel connection between tRNA subcellular dynamics and phosphate availability. PMID:17409072

Functional retrograde amnesia: a multiple case study.

PubMed

Fujiwara, Esther; Brand, Matthias; Kracht, Lutz; Kessler, Josef; Diebel, Andrea; Netz, Johannes; Markowitsch, Hans J

2008-01-01

Functional retrograde amnesia (RA) is a rare pathology and has been rarely studied in detail across different patients. We extensively examined five functional RA patients and compared their neuropsychological profile including anterograde and retrograde memory performance, executive functions, emotional processing, and formally assessed psychiatric symptoms. Across patients, neuropsychological deficits beyond RA were most consistently seen in executive functions and attention suggesting that these dysfunctions contribute to the remote memory deficit. In a majority of the patients, problems in social cognition and emotional behaviour were reflected in Theory of Mind deficits and accompanying psychiatric symptoms. Aberrances in a measure of social desirability were detected, pointing to repressive tendencies in three out of the five patients. Future studies of functional RA patients may investigate more specifically which frontal-lobe associated (dys-) functions contribute to the memory retrieval deficit. Moreover, studying more closely the interaction between social cognition, repressive personality style and memory inhibition in this disease seems worthwhile pursuing.

Retrograde spins of near-Earth asteroids from the Yarkovsky effect.

PubMed

La Spina, A; Paolicchi, P; Kryszczyńska, A; Pravec, P

2004-03-25

Dynamical resonances in the asteroid belt are the gateway for the production of near-Earth asteroids (NEAs). To generate the observed number of NEAs, however, requires the injection of many asteroids into those resonant regions. Collisional processes have long been claimed as a possible source, but difficulties with that idea have led to the suggestion that orbital drift arising from the Yarkovsky effect dominates the injection process. (The Yarkovsky effect is a force arising from differential heating-the 'afternoon' side of an asteroid is warmer than the 'morning' side.) The two models predict different rotational properties of NEAs: the usual collisional theories are consistent with a nearly isotropic distribution of rotation vectors, whereas the 'Yarkovsky model' predicts an excess of retrograde rotations. Here we report that the spin vectors of NEAs show a strong and statistically significant excess of retrograde rotations, quantitatively consistent with the theoretical expectations of the Yarkovsky model.

Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events.

PubMed

Murayama, Kou; Kitagami, Shinji

2014-02-01

Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Participants saw neutral pictures, followed by a reward or control cue in an unrelated context. Our results (and a direct replication study) demonstrated that the reward cue predicted a retrograde enhancement of memory for the preceding neutral pictures. This retrograde effect was observed only after a delay, not immediately upon testing. An additional experiment showed that emotional arousal or unconscious resource mobilization cannot explain the retrograde enhancement effect. These results provide support for the notion that the dopaminergic memory consolidation effect can result from extrinsic reward.

Long-distance endosome trafficking drives fungal effector production during plant infection

PubMed Central

Bielska, Ewa; Higuchi, Yujiro; Schuster, Martin; Steinberg, Natascha; Kilaru, Sreedhar; Talbot, Nicholas J.; Steinberg, Gero

2014-01-01

To cause plant disease, pathogenic fungi can secrete effector proteins into plant cells to suppress plant immunity and facilitate fungal infection. Most fungal pathogens infect plants using very long strand-like cells, called hyphae, that secrete effectors from their tips into host tissue. How fungi undergo long-distance cell signalling to regulate effector production during infection is not known. Here we show that long-distance retrograde motility of early endosomes (EEs) is necessary to trigger transcription of effector-encoding genes during plant infection by the pathogenic fungus Ustilago maydis. We demonstrate that motor-dependent retrograde EE motility is necessary for regulation of effector production and secretion during host cell invasion. We further show that retrograde signalling involves the mitogen-activated kinase Crk1 that travels on EEs and participates in control of effector production. Fungal pathogens therefore undergo long-range signalling to orchestrate host invasion. PMID:25283249

Retrograde endopyelotomy: a comparison between laser and Acucise balloon cutting catheter.

PubMed

el-Nahas, Ahmed R

2007-03-01

Endopyelotomy and laparoscopic pyeloplasty are the preferred modalities for treatment of ureteropelvic junction obstruction because of their minimally invasive nature. There are continuous efforts for improving endopyelotomy techniques and outcome. Retrograde access represents the natural evolution of endopyelotomy. The Acucise cutting balloon catheter (Applied Medical Resources Corp., Laguna Hills, CA) and ureteroscopic endopyelotomy using holmium laser are the most widely accepted techniques. The Acucise catheter was developed to simplify retrograde endopyelotomy and made it possible for all urologists, regardless of their endourologic skills. The Acucise catheter depends on incision and dilatation of the ureteropelvic junction under fluoroscopic guidance, whereas ureteroscopy allows visual control of the site, depth, and extent of the incision; the holmium laser is a perfect method for a clean precise incision. Review of the English literature showed that the Acucise technique was more widely performed, though laser had better (but not statistically significant) safety and efficacy profiles.

Learning the Languages of the Chloroplast: Retrograde Signaling and Beyond.

PubMed

Chan, Kai Xun; Phua, Su Yin; Crisp, Peter; McQuinn, Ryan; Pogson, Barry J

2016-04-29

The chloroplast can act as an environmental sensor, communicating with the cell during biogenesis and operation to change the expression of thousands of proteins. This process, termed retrograde signaling, regulates expression in response to developmental cues and stresses that affect photosynthesis and yield. Recent advances have identified many signals and pathways-including carotenoid derivatives, isoprenes, phosphoadenosines, tetrapyrroles, and heme, together with reactive oxygen species and proteins-that build a communication network to regulate gene expression, RNA turnover, and splicing. However, retrograde signaling pathways have been viewed largely as a means of bilateral communication between organelles and nuclei, ignoring their potential to interact with hormone signaling and the cell as a whole to regulate plant form and function. Here, we discuss new findings on the processes by which organelle communication is initiated, transmitted, and perceived, not only to regulate chloroplastic processes but also to intersect with cellular signaling and alter physiological responses.

Retrograde Accretion Discs in High-Mass Be/X-Ray Binaries

NASA Technical Reports Server (NTRS)

Christodoulou, D. M.; Laycock, S. G. T.; Kazanas, D.

2017-01-01

We have compiled a comprehensive library of all X-ray observations of Magellanic pulsars carried out by XMM-Newton, Chandra and RXTE in the period 1997-2014. In this work, we use the data from 53 high-mass Be/X-ray binaries in the Small Magellanic Cloud to demonstrate that the distribution of spin-period derivatives versus spin periods of spinning-down pulsars is not at all different from that of the accreting spinning-up pulsars. The inescapable conclusion is that the up and down samples were drawn from the same continuous parent population; therefore, Be/X-ray pulsars that are spinning down over periods spanning 18 yr are, in fact, accreting from retrograde discs. The presence of prograde and retrograde discs in roughly equal numbers supports a new evolutionary scenario for Be/X-ray pulsars in their spin period-period derivative diagram.

Long-distance endosome trafficking drives fungal effector production during plant infection.

PubMed

Bielska, Ewa; Higuchi, Yujiro; Schuster, Martin; Steinberg, Natascha; Kilaru, Sreedhar; Talbot, Nicholas J; Steinberg, Gero

2014-10-06

To cause plant disease, pathogenic fungi can secrete effector proteins into plant cells to suppress plant immunity and facilitate fungal infection. Most fungal pathogens infect plants using very long strand-like cells, called hyphae, that secrete effectors from their tips into host tissue. How fungi undergo long-distance cell signalling to regulate effector production during infection is not known. Here we show that long-distance retrograde motility of early endosomes (EEs) is necessary to trigger transcription of effector-encoding genes during plant infection by the pathogenic fungus Ustilago maydis. We demonstrate that motor-dependent retrograde EE motility is necessary for regulation of effector production and secretion during host cell invasion. We further show that retrograde signalling involves the mitogen-activated kinase Crk1 that travels on EEs and participates in control of effector production. Fungal pathogens therefore undergo long-range signalling to orchestrate host invasion.

Comet nongravitational forces and meteoritic impacts

NASA Technical Reports Server (NTRS)

Matese, John J.; Whitman, Patrick G.; Whitmire, Daniel P.

1992-01-01

We have considered those comets whose original orbits have been determined to be hyperbolic when only planetary perturbations are accounted for. It is found that formally unbound incident trajectories correlate most confidently with orbits that have small perihelion distances and move in a retrograde sense relative to planetary motion. Arguments are presented that these results are not due to measurement error or to selection effects. We conclude that the phenomenon is attributable to enhanced volatility leading to abnormally large nongravitational forces. Since the effect is absent in the prograde small-perihelia population, increased insolation is not the sole explanation. It is suggested that the significance of the retrograde correlation is connected with a larger energy of relative motion between retrograde comets and a population of prograde ecliptic meteoroids which impact the comet mantle exposing the underlying volatiles. The subsequent enhanced outgassing is the cause of the larger nongravitational forces.

Psychogenic amnesia: syndromes, outcome, and patterns of retrograde amnesia.

PubMed

Harrison, Neil A; Johnston, Kate; Corno, Federica; Casey, Sarah J; Friedner, Kimberley; Humphreys, Kate; Jaldow, Eli J; Pitkanen, Mervi; Kopelman, Michael D

2017-09-01

There are very few case series of patients with acute psychogenic memory loss (also known as dissociative/functional amnesia), and still fewer studies of outcome, or comparisons with neurological memory-disordered patients. Consequently, the literature on psychogenic amnesia is somewhat fragmented and offers little prognostic value for individual patients. In the present study, we reviewed the case records and neuropsychological findings in 53 psychogenic amnesia cases (ratio of 3:1, males:females), in comparison with 21 consecutively recruited neurological memory-disordered patients and 14 healthy control subjects. In particular, we examined the pattern of retrograde amnesia on an assessment of autobiographical memory (the Autobiographical Memory Interview). We found that our patients with psychogenic memory loss fell into four distinct groups, which we categorized as: (i) fugue state; (ii) fugue-to-focal retrograde amnesia; (iii) psychogenic focal retrograde amnesia following a minor neurological episode; and (iv) patients with gaps in their memories. While neurological cases were characterized by relevant neurological symptoms, a history of a past head injury was actually more common in our psychogenic cases (P = 0.012), perhaps reflecting a 'learning episode' predisposing to later psychological amnesia. As anticipated, loss of the sense of personal identity was confined to the psychogenic group. However, clinical depression, family/relationship problems, financial/employment problems, and failure to recognize the family were also statistically more common in that group. The pattern of autobiographical memory loss differed between the psychogenic groups: fugue cases showed a severe and uniform loss of memories for both facts and events across all time periods, whereas the two focal retrograde amnesia groups showed a 'reversed' temporal gradient with relative sparing of recent memories. After 3-6 months, the fugue patients had improved to normal scores for facts and near-normal scores for events. By contrast, the two focal retrograde amnesia groups showed less improvement and continued to show a reversed temporal gradient. In conclusion, the outcome in psychogenic amnesia, particularly those characterized by fugue, is better than generally supposed. Findings are interpreted in terms of Markowitsch's and Kopelman's models of psychogenic amnesia, and with respect to Anderson's neuroimaging findings in memory inhibition. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[BILIARY HYPERTENSION IN CHRONIC PANCREATITIS AND PECULIARITIES OF ITS DIAGNOSIS].

PubMed

Kopchak, V M; Pylypchuk, V I; Khomyak, I V; Pererva, L O; Shevkolenko, G G; Davydenko, N G

2016-02-01

Possibilities of various diagnostic methods for biliary hypertension detection in chronic pancreatitis were analyzed. Biliary hypertension was revealed in 163 (31%) patients, suffering chronic pancreatitis. The laboratory investigations data, ultrasonographic investigation, computer tomography, endoscopic retrograde cholangiopancreatography, magnet-resonance cholangiopancreatography, intraoperative measurement of the biliary ducts width, intraoperative measurement of biliary pressure were applied for diagnosis. Endoscopic retrograde cholangiopancreatography, magnet-resonance cholangiopancreatography and intraoperative measurement of biliary pressure are considered the most sensitive methods for chronic pancreatitis diagnosis.

Pseudotyped Lentiviral Vectors for Retrograde Gene Delivery into Target Brain Regions

PubMed Central

Kobayashi, Kenta; Inoue, Ken-ichi; Tanabe, Soshi; Kato, Shigeki; Takada, Masahiko; Kobayashi, Kazuto

2017-01-01

Gene transfer through retrograde axonal transport of viral vectors offers a substantial advantage for analyzing roles of specific neuronal pathways or cell types forming complex neural networks. This genetic approach may also be useful in gene therapy trials by enabling delivery of transgenes into a target brain region distant from the injection site of the vectors. Pseudotyping of a lentiviral vector based on human immunodeficiency virus type 1 (HIV-1) with various fusion envelope glycoproteins composed of different combinations of rabies virus glycoprotein (RV-G) and vesicular stomatitis virus glycoprotein (VSV-G) enhances the efficiency of retrograde gene transfer in both rodent and nonhuman primate brains. The most recently developed lentiviral vector is a pseudotype with fusion glycoprotein type E (FuG-E), which demonstrates highly efficient retrograde gene transfer in the brain. The FuG-E–pseudotyped vector permits powerful experimental strategies for more precisely investigating the mechanisms underlying various brain functions. It also contributes to the development of new gene therapy approaches for neurodegenerative disorders, such as Parkinson’s disease, by delivering genes required for survival and protection into specific neuronal populations. In this review article, we report the properties of the FuG-E–pseudotyped vector, and we describe the application of the vector to neural circuit analysis and the potential use of the FuG-E vector in gene therapy for Parkinson’s disease. PMID:28824385

Neurovascular Structures at Risk With Curved Retrograde TTC Fusion Nails.

PubMed

de Cesar Netto, Cesar; Johannesmeyer, David; Cone, Brent; Araoye, Ibukunoluwa; Hudson, Parke William; Sahranavard, Bahman; Johnson, Michael; Shah, Ashish

2017-10-01

The purpose of this study was to assess the risk of iatrogenic injury to plantar neurovascular structures of the foot during insertion of a curved retrograde tibiotalocalcaneal (TTC) fusion nail. Ten below-knee thawed fresh-frozen cadaveric specimens underwent curved retrograde nailing of the ankle. The shortest distance between the nail and the main plantar neurovascular branches and injured structures were recorded during dissection. We also evaluated the relative position of these structures along 2 lines (AB, connecting the calcaneus to the first metatarsal, and BC, connecting the first and fifth metatarsal). The lateral plantar artery was found to be in direct contact with the nail 70% of the time, with a macroscopic laceration 30% of the time. The Baxter nerve was injured 20% of the time, as was the lateral plantar nerve. The medial plantar artery and nerve were never injured. The most proximal structure to cross line AB was the Baxter nerve followed by the lateral plantar artery, the nail, the lateral plantar nerve, and the medial plantar nerve. Our cadaveric anatomic study found that the most common structures at risk for iatrogenic injury by lateral curved retrograde TTC fusion nails were the lateral plantar artery and nerve, and the Baxter nerve. Determination of a true neurovascular safe zone is challenging and therefore warrants careful operative dissection to minimize neurovascular injuries.

Mozart, Mozart Rhythm and Retrograde Mozart Effects: Evidences from Behaviours and Neurobiology Bases

PubMed Central

Xing, Yingshou; Xia, Yang; Kendrick, Keith; Liu, Xiuxiu; Wang, Maosen; Wu, Dan; Yang, Hua; Jing, Wei; Guo, Daqing; Yao, Dezhong

2016-01-01

The phenomenal finding that listening to Mozart K.448 enhances performance on spatial tasks has motivated a continuous surge in promoting music education over the past two decades. But there have been inconsistent reports in previous studies of the Mozart effect. Here conducted was a systematic study, with Mozart and retrograde Mozart music, Mozart music rhythm and pitch, behaviours and neurobiology tests, rats and humans subjects. We show that while the Mozart K.448 has positive cognitive effects, the retrograde version has a negative effect on rats’ performance in the Morris water maze test and on human subjects’ performance in the paper folding and cutting test and the pencil-and-paper maze test. Such findings are further confirmed by subsequent immunohistochemical analyses in rats on the neurogenesis and protein levels of BDNF and its receptor, TrkB. Furthermore, when the rhythm and pitch of the normal and retrograde Mozart music are manipulated independently, the learning performance of the rats in the Morris water maze test indicated that rhythm is a crucial element in producing the behavioural effects. These findings suggest that the nature of Mozart effect is the Mozart rhythm effect, and indicate that different music may have quite different to opposite effects. Further study on rhythm effect may provide clues to understand the common basis over animals from rats to humans. PMID:26795072

Numerical Simulations of Naturally Tilted, Retrogradely Precessing, Nodal Superhumping Accretion Disks

NASA Astrophysics Data System (ADS)

Montgomery, M. M.

2012-02-01

Accretion disks around black hole, neutron star, and white dwarf systems are thought to sometimes tilt, retrogradely precess, and produce hump-shaped modulations in light curves that have a period shorter than the orbital period. Although artificially rotating numerically simulated accretion disks out of the orbital plane and around the line of nodes generate these short-period superhumps and retrograde precession of the disk, no numerical code to date has been shown to produce a disk tilt naturally. In this work, we report the first naturally tilted disk in non-magnetic cataclysmic variables using three-dimensional smoothed particle hydrodynamics. Our simulations show that after many hundreds of orbital periods, the disk has tilted on its own and this disk tilt is without the aid of radiation sources or magnetic fields. As the system orbits, the accretion stream strikes the bright spot (which is on the rim of the tilted disk) and flows over and under the disk on different flow paths. These different flow paths suggest the lift force as a source to disk tilt. Our results confirm the disk shape, disk structure, and negative superhump period and support the source to disk tilt, source to retrograde precession, and location associated with X-ray and He II emission from the disk as suggested in previous works. Our results identify the fundamental negative superhump frequency as the indicator of disk tilt around the line of nodes.

Rabies Virus Envelope Glycoprotein Targets Lentiviral Vectors to the Axonal Retrograde Pathway in Motor Neurons*

PubMed Central

Hislop, James N.; Islam, Tarin A.; Eleftheriadou, Ioanna; Carpentier, David C. J.; Trabalza, Antonio; Parkinson, Michael; Schiavo, Giampietro; Mazarakis, Nicholas D.

2014-01-01

Rabies pseudotyped lentiviral vectors have great potential in gene therapy, not least because of their ability to transduce neurons following their distal axonal application. However, very little is known about the molecular processes that underlie their retrograde transport and cell transduction. Using multiple labeling techniques and confocal microscopy, we demonstrated that pseudotyping with rabies virus envelope glycoprotein (RV-G) enabled the axonal retrograde transport of two distinct subtypes of lentiviral vector in motor neuron cultures. Analysis of this process revealed that these vectors trafficked through Rab5-positive endosomes and accumulated within a non-acidic Rab7 compartment. RV-G pseudotyped vectors were co-transported with both the tetanus neurotoxin-binding fragment and the membrane proteins thought to mediate rabies virus endocytosis (neural cell adhesion molecule, nicotinic acetylcholine receptor, and p75 neurotrophin receptor), thus demonstrating that pseudotyping with RV-G targets lentiviral vectors for transport along the same pathway exploited by several toxins and viruses. Using motor neurons cultured in compartmentalized chambers, we demonstrated that axonal retrograde transport of these vectors was rapid and efficient; however, it was not able to transduce the targeted neurons efficiently, suggesting that impairment in processes occurring after arrival of the viral vector in the soma is responsible for the low transduction efficiency seen in vivo, which suggests a novel area for improvement of gene therapy vectors. PMID:24753246

Anterograde and retrograde tracing with high molecular weight biotinylated dextran amine through thalamocortical and corticothalamic pathways.

PubMed

Zhang, Wenjie; Xu, Dongsheng; Cui, Jingjing; Jing, Xianghong; Xu, Nenggui; Liu, Jianhua; Bai, Wanzhu

2017-02-01

Biotinylated dextran amine (BDA) has been used for neural pathway tracing in the central nervous system for many decades, in which high molecular weight BDA appeared to be transported predominantly in the anterograde direction and less in the retrograde direction. In the current study, we reexamined the properties of neural labeling with high molecular weight BDA through a reciprocal neural pathway between thalamus and somatosensory cortex. After injection of BDA into the ventral posteromedial nucleus of thalamus (VPM) in the rat, the BDA labeling was sequentially examined on somatosensory cortex at 3, 5, 7, 10, and 14 survival days. Both of anterogradely labeled axonal terminals and retrogradely labeled neuronal cell bodies were observed simultaneously on the somatosensory cortex. With the increasing of survival times after injection, morphological changes occurred on the labeled axonal arbors and neuronal dendrites, in which the high quality of BDA labeling appeared on the tenth survival day. These results indicate that high molecular weight BDA is not only a sensitive anterograde tracer but also an excellent retrograde marker to be used for tracing through thalamocortical and corticothalamic pathways. And the detailed structure of neural labeling with BDA similar to Golgi-like resolution can be obtained at optimal survival times of animals after the injection of high molecular weight BDA. © 2016 Wiley Periodicals, Inc.

Utility of the Anterior Oblique-Viewing Endoscope and the Double-Balloon Enteroscope for Endoscopic Retrograde Cholangiopancreatography in Patients with Billroth II Gastrectomy

PubMed Central

Sen-yo, Manabu; Kaino, Seiji; Suenaga, Shigeyuki; Uekitani, Toshiyuki; Yoshida, Kanako; Harano, Megumi; Sakaida, Isao

2012-01-01

Background/Purpose. The difficulties of endoscopic retrograde cholangiopancreatography in patients with Billroth II gastrectomy have been reported. We evaluated the usefulness of an anterior oblique-viewing endoscope and a double-balloon enteroscope for endoscopic retrograde cholangiopancreatography in such patients. Methods. From January 2003 to December 2011, 65 patients with Billroth II gastrectomy were enrolled in this study. An anterior oblique-viewing endoscope was used for all patients. From February 2007, a double-balloon enteroscope was used for the failed cases. The success rate of procedures was compared with those in 20 patients with Billroth II gastrectomy using forward-viewing endoscope or side-viewing endoscope from March 1996 to July 2002 as historical controls. Results. In all patients in whom the papilla was reached (60/65), selective cannulation was achieved. The success rate of selective cannulation and accomplishment of planned procedures in the anterior oblique-viewing endoscope group were both significantly higher than that in the control group (100% versus 70.1%, 100 versus 58.8%, resp.). A double-balloon enteroscope was used in 2 patients, and the papilla could be reached and the planned procedures completed. Conclusions. An anterior oblique-viewing endoscope and double-balloon enteroscope appear to be useful in performing endoscopic retrograde cholangiopancreatography in patients with Billroth II gastrectomy. PMID:23056039

Retrograde and Wallerian Axonal Degeneration Occur Synchronously after Retinal Ganglion Cell Axotomy

PubMed Central

Kanamori, Akiyasu; Catrinescu, Maria-Magdalena; Belisle, Jonathan M.; Costantino, Santiago; Levin, Leonard A.

2013-01-01

Axonal injury and degeneration are pivotal pathological events in diseases of the nervous system. In the past decade, it has been recognized that the process of axonal degeneration is distinct from somal degeneration and that axoprotective strategies may be distinct from those that protect the soma. Preserving the cell body via neuroprotection cannot improve function if the axon is damaged, because the soma is still disconnected from its target. Therefore, understanding the mechanisms of axonal degeneration is critical for developing new therapeutic interventions for axonal disease treatment. We combined in vivo imaging with a multilaser confocal scanning laser ophthalmoscope and in vivo axotomy with a diode-pumped solid-state laser to assess the time course of Wallerian and retrograde degeneration of unmyelinated retinal ganglion cell axons in living rats for 4 weeks after intraretinal axotomy. Laser injury resulted in reproducible axon loss both distal and proximal to the site of injury. Longitudinal polarization-sensitive imaging of axons demonstrated that Wallerian and retrograde degeneration occurred synchronously. Neurofilament immunostaining of retinal whole-mounts confirmed axonal loss and demonstrated sparing of adjacent axons to the axotomy site. In vivo fluorescent imaging of axonal transport and photobleaching of labeled axons demonstrated that the laser axotomy model did not affect adjacent axon function. These results are consistent with a shared mechanism for Wallerian and retrograde degeneration. PMID:22642911

Retrograde nailing for distal third femoral shaft fractures: a prospective study.

PubMed

Acharya, K N; Rao, M R

2006-12-01

To evaluate the postoperative knee function and results of unreamed retrograde nailing for distal third femoral shaft fractures. Between January 2002 and 2003 inclusive, a consecutive series of 27 patients (with 28 fractures) who underwent retrograde nailing were prospectively evaluated. Outcome measures were union time, initiation of weight bearing, deformity and shortening, functional length of the nail, knee function assessed using a modified Knee Society Knee Score. Correlations between union time and other variables were also studied. In these patients 26 (93%) of the 28 fractures achieved union, of which 5 underwent dynamisation; the mean union time for the other 21 fractures was 4.4 months. Angular malalignment was present in 4 patients and shortening in 4 others. There was negligible correlation between union time and variables of nail-canal diameter mismatch, functional length of nail, fracture geometry, or initiation of partial weight bearing ambulation. Knee flexion of more than 100 degrees was achieved in 26 patients. 19 patients had anterior knee pain and 10 had instability. By the end of one year, excellent or good scores for pain and function were recorded in 77% and 73% respectively, of the 26 patients. In view of such favourable union rates but significant deterioration in overall knee joint function, at best retrograde nailing is a reliable alternative in the management of selected complicated fractures of the distal femoral shaft.

Thylakoid redox signals are integrated into organellar-gene-expression-dependent retrograde signaling in the prors1-1 mutant

PubMed Central

Tadini, Luca; Romani, Isidora; Pribil, Mathias; Jahns, Peter; Leister, Dario; Pesaresi, Paolo

2012-01-01

Perturbations in organellar gene expression (OGE) and the thylakoid redox state (TRS) activate retrograde signaling pathways that adaptively modify nuclear gene expression (NGE), according to developmental and metabolic needs. The prors1-1 mutation in Arabidopsis down-regulates the expression of the nuclear gene Prolyl-tRNA Synthetase1 (PRORS1) which acts in both plastids and mitochondria, thereby impairing protein synthesis in both organelles and triggering OGE-dependent retrograde signaling. Because the mutation also affects thylakoid electron transport, TRS-dependent signals may likewise have an impact on the changes in NGE observed in this genotype. In this study, we have investigated whether signals related to TRS are actually integrated into the OGE-dependent retrograde signaling pathway. To this end, the chaos mutation (for chlorophyll a/b binding protein harvesting-organelle specific), which shows a partial loss of PSII antennae proteins and thus a reduction in PSII light absorption capability, was introduced into the prors1-1 mutant background. The resulting double mutant displayed a prors1-1-like reduction in plastid translation rate and a chaos-like decrease in PSII antenna size, whereas the hyper-reduction of the thylakoid electron transport chain, caused by the prors1-1 mutation, was alleviated, as determined by monitoring chlorophyll (Chl) fluorescence and thylakoid phosphorylation. Interestingly, a substantial fraction of the nucleus-encoded photosynthesis genes down-regulated in the prors1-1 mutant are expressed at nearly wild-type rates in prors1-1 chaos leaves, and this recovery is reflected in the steady-state levels of their protein products in the chloroplast. We therefore conclude that signals related to photosynthetic electron transport and TRS, and indirectly to carbohydrate metabolism and energy balance, are indeed fed into the OGE-dependent retrograde pathway to modulate NGE and adjust the abundance of chloroplast proteins. PMID:23293642

Synaptic plasticity in the medial vestibular nuclei: role of glutamate receptors and retrograde messengers in rat brainstem slices.

PubMed

Grassi, S; Pettorossi, V E

2001-08-01

The analysis of cellular-molecular events mediating synaptic plasticity within vestibular nuclei is an attempt to explain the mechanisms underlying vestibular plasticity phenomena. The present review is meant to illustrate the main results, obtained in vitro, on the mechanisms underlying long-term changes in synaptic strength within the medial vestibular nuclei. The synaptic plasticity phenomena taking place at the level of vestibular nuclei could be useful for adapting and consolidating the efficacy of vestibular neuron responsiveness to environmental requirements, as during visuo-vestibular recalibration and vestibular compensation. Following a general introduction on the most salient features of vestibular compensation and visuo-vestibular adaptation, which are two plastic events involving neuronal circuitry within the medial vestibular nuclei, the second and third sections describe the results from rat brainstem slice studies, demonstrating the possibility to induce long-term potentiation and depression in the medial vestibular nuclei, following high frequency stimulation of the primary vestibular afferents. In particular the mechanisms sustaining the induction and expression of vestibular long-term potentiation and depression, such as the role of various glutamate receptors and retrograde messengers have been described. The relevant role of the interaction between the platelet-activating factor, acting as a retrograde messenger, and the presynaptic metabotropic glutamate receptors, in determining the full expression of vestibular long-term potentiation is also underlined. In addition, the mechanisms involved in vestibular long-term potentiation have been compared with those leading to long-term potentiation in the hippocampus to emphasize the most significant differences emerging from vestibular studies. The fourth part, describes recent results demonstrating the essential role of nitric oxide, another retrograde messenger, in the induction of vestibular potentiation. Finally the fifth part suggests the possible functional significance of different action times of the two retrograde messengers and metabotropic glutamate receptors, which are involved in mediating the presynaptic mechanism sustaining vestibular long-term potentiation.

Percutaneous Retrograde Recanalization of the Celiac Artery by Way of the Superior Mesenteric Artery for Chronic Mesenteric Ischemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joseph, George, E-mail: joseph59@gmail.com; Chacko, Sujith Thomas

2013-02-15

A 52-year-old man presented with recurrent postprandial abdominal pain, sitophobia, and progressive weight loss. Chronic mesenteric ischemia (CMI) due to subtotal occlusion of the superior mesenteric artery (SMA) and flush occlusion of the celiac artery (CA) was diagnosed. Retrograde recanalization of the CA by way of a collateral channel from the SMA was performed using contemporary recanalization equipment. The CA and SMA were then stented, resulting in sustained resolution of CMI-related symptoms.

Bleeding Duodenal Varices Successfully Treated with Balloon-Occluded Retrograde Transvenous Obliteration (B-RTO) Assisted by CT During Arterial Portography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsurusaki, Masakatsu, E-mail: he3m-trsk@asahi-net.or.jp; Sugimoto, Koji; Matsumoto, Shinichi

2006-12-15

A 60-year-old woman with massive hemorrhage from duodenal varices was transferred to our hospital for the purpose of transcatheter intervention. Although digital subtraction arterial portography could not depict the entire pathway of collateral circulation, the efferent route of the duodenal varices was clearly demonstrated on subsequent CT during arterial portography. Balloon-occluded retrograde transvenous obliteration (B-RTO) of the varices was performed via the efferent vein and achieved complete thrombosis of the varices.

Neurocognitive and Biomarker Evaluation of Combination mTBI from Blast Overpressure and Traumatic Stress

DTIC Science & Technology

2013-09-01

such as anterograde amnesia (Ahlers, et al., 2012). Additionally, we used three BOP exposures (1/day). This regimen has been used previously and...second interpretation of this result is that the BOP produced a retrograde amnesia . In this regard, it is notable that the BOP exposures took place...produce a retrograde amnesia for events already presumed to be consolidated into long term memory (e.g., Chen, et al., 2009). It is also notable that BOP

Improved brachial artery shear patterns and increased flow-mediated dilation after low-volume high-intensity interval training in type 2 diabetes.

PubMed

Ghardashi Afousi, Alireza; Izadi, Mohammad Reza; Rakhshan, Kamran; Mafi, Farnoosh; Biglari, Soheil; Gandomkar Bagheri, Habibalah

2018-06-22

What is the central question of this study? Endothelial function is impaired because of increased oscillatory and retrograde shear in patients with type 2 diabetes. It is unclear whether low-volume high-intensity interval training and continuous moderate intensity exercise can modulate oscillatory and retrograde shear, blood flow and flow-mediated arterial dilation in these patients. What is the main finding and its importance? We found that low-volume high-intensity interval training, by increasing anterograde shear and decreasing retrograde shear and oscillatory index, can increase nitric oxide production and consequently result in increased flow-mediated dilation and outward arterial remodelling in patients with type 2 diabetes. Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction associated with impaired flow-mediated dilation (FMD) and increases retrograde and oscillatory shear. The present study investigated endothelium-dependent vasodilation and shear rate in patients with type 2 diabetes at baseline and follow-up after 12 weeks of low-volume high-intensity interval training (LV-HIIT) or continuous moderate intensity training (CMIT). Seventy five sedentary patients with type 2 diabetes and untreated pre- or stage I hypertension were randomly divided into LV-HIIT, CMIT and control groups. The LV-HIIT group intervention was 12 intervals of 1.5 min at 85%-90% HR max and 2 min at 55%-60% HR max . The CMIT group intervention was 42 min of exercise at 70% HR max for 3 sessions per week during 12 weeks. High-resolution Doppler ultrasound was used to measure FMD, arterial diameter, anterograde and retrograde blood flow and shear rate patterns. Brachial artery FMD increased significantly in the LV-HIIT group (3.83 ± 1.13 baseline, 7.39 ± 3.6% follow-up), whereas there were no significant increase in the CMIT group (3.45 ± 0.97 baseline, 4.81 ± 2.36% follow-up) compared to the control group (3.16 ± 0.78 baseline, 4.04 ± 1.28% follow-up) (P < 0.05). Retrograde shear in the LV-HIIT group decreased significantly (P < 0.05), and no significant decrease in retrograde shear was seen in the CMIT group. Anterograde shear after LV-HIIT increased significantly (P < 0.05) but was unchanged in the CMIT group. However, oscillatory shear index in both exercise groups decreased significantly (P = 0.029). Nitrite/nitrate (NOx) level increased in both exercise groups, but the increase was greater in the LV-HIIT group (P < 0.001). Our results indicate that by increasing NOx, HIIT decreases the oscillatory shear-induced improvement in FMD and outward artery remodelling in patients with T2D. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Acute Fasting Regulates Retrograde Synaptic Enhancement through a 4E-BP-Dependent Mechanism.

PubMed

Kauwe, Grant; Tsurudome, Kazuya; Penney, Jay; Mori, Megumi; Gray, Lindsay; Calderon, Mario R; Elazouzzi, Fatima; Chicoine, Nicole; Sonenberg, Nahum; Haghighi, A Pejmun

2016-12-21

While beneficial effects of fasting on organismal function and health are well appreciated, we know little about the molecular details of how fasting influences synaptic function and plasticity. Our genetic and electrophysiological experiments demonstrate that acute fasting blocks retrograde synaptic enhancement that is normally triggered as a result of reduction in postsynaptic receptor function at the Drosophila larval neuromuscular junction (NMJ). This negative regulation critically depends on transcriptional enhancement of eukaryotic initiation factor 4E binding protein (4E-BP) under the control of the transcription factor Forkhead box O (Foxo). Furthermore, our findings indicate that postsynaptic 4E-BP exerts a constitutive negative input, which is counteracted by a positive regulatory input from the Target of Rapamycin (TOR). This combinatorial retrograde signaling plays a key role in regulating synaptic strength. Our results provide a mechanistic insight into how cellular stress and nutritional scarcity could acutely influence synaptic homeostasis and functional stability in neural circuits. Copyright © 2016 Elsevier Inc. All rights reserved.

Pre-electroconvulsive shock administration of calcium channel blockers reduces retrograde amnesia induced by ECS.

PubMed

Sushma, M; Sudha, S; Guido, S

2004-11-01

Effect of pre-electroconvulsive shock (ECS) administration of calcium channel blockers (CCBs) like verapamil, diltiazem, nifedipine, nimodipine, flunarizine and cinnarizine on retrograde amnesia induced by ECS was examined using passive avoidance paradigm in rats. The groups (Gr 1-7) of adult, male Wistar rats received true ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; ip) and other groups (Gr 8-14) received sham ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; i.p). The anti-amnestic activity of CCBs were evaluated using the passive avoidance paradigm in rats. Results showed that, the baseline latencies for all the groups did not differ significantly. Rats receiving true ECS produced significantly lower latencies. There was increase in the post ECS step through latencies of the rats administered CCBs before ECS. Therefore, pre-ECS administration of calcium channel blockers might reduce retrograde amnesia produced by ECS without altering seizure duration.

A Simple and Novel Method to Attain Retrograde Ureteral Access after Previous Cohen Cross-Trigonal Ureteral Reimplantation

PubMed Central

Adam, Ahmed

2017-01-01

Objective To describe a simple, novel method to achieve ureteric access in the Cohen crossed reimplanted ureter, which will allow retrograde working access via the conventional transurethral method. Materials and Methods Under cystoscopic vision, suprapubic needle puncture was performed. The needle was directed (bevel facing) towards the desired ureteric orifice (UO). A guidewire (with a floppy-tip) was then inserted into the suprapubic needle passing into the bladder, and then easily passed into the crossed-reimplanted UO. The distal end of the guidewire was then removed through the urethra with cystoscopic grasping forceps. The straightened ureter then easily facilitated ureteroscopy access, retrograde pyelogram studies, and JJ stent insertion in a conventional transurethral method. Results The UO and ureter were aligned in a more conventional orthotopic course, to allow for conventional transurethral working access. Conclusion A novel method to access the Cohen crossed reimplanted ureter was described. All previously published methods of accessing the crossed ureter were critically appraised. PMID:29463976

The impact of baking time and bread storage temperature on bread crumb properties.

PubMed

Bosmans, Geertrui M; Lagrain, Bert; Fierens, Ellen; Delcour, Jan A

2013-12-15

Two baking times (9 and 24 min) and storage temperatures (4 and 25 °C) were used to explore the impact of heat exposure during bread baking and subsequent storage on amylopectin retrogradation, water mobility, and bread crumb firming. Shorter baking resulted in less retrogradation, a less extended starch network and smaller changes in crumb firmness and elasticity. A lower storage temperature resulted in faster retrogradation, a more rigid starch network with more water inclusion and larger changes in crumb firmness and elasticity. Crumb to crust moisture migration was lower for breads baked shorter and stored at lower temperature, resulting in better plasticized biopolymer networks in crumb. Network stiffening, therefore, contributed less to crumb firmness. A negative relation was found between proton mobilities of water and biopolymers in the crumb gel network and crumb firmness. The slope of this linear function was indicative for the strength of the starch network. Copyright © 2013 Elsevier Ltd. All rights reserved.

Relative importance of moisture migration and amylopectin retrogradation for pound cake crumb firming.

PubMed

Luyts, A; Wilderjans, E; Van Haesendonck, I; Brijs, K; Courtin, C M; Delcour, J A

2013-12-15

Moisture migration largely impacts cake crumb firmness during storage at ambient temperature. To study the importance of phenomena other than crumb to crust moisture migration and to exclude moisture and temperature gradients during baking, crustless cakes were baked using an electrical resistance oven (ERO). Cake crumb firming was evaluated by texture analysis. First, ERO cakes with properties similar to those baked conventionally were produced. Cake batter moisture content (MC) was adjusted to ensure complete starch gelatinisation in the baking process. In cakes baked conventionally, most of the increase in crumb firmness during storage was caused by moisture migration. Proton nuclear magnetic resonance ((1)H NMR) showed that the population containing protons of crystalline starch grew during cake storage. These and differential scanning calorimetry (DSC) data pointed to only limited amylopectin retrogradation. The limited increase in amylopectin retrogradation during cake storage cannot solely account for the significant firming of ERO cakes and, hence, other phenomena are involved in cake firming. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microstructural characteristics and gastro-small intestinal digestion in vitro of potato starch: Effects of refrigerated storage and reheating in microwave.

PubMed

Colussi, Rosana; Singh, Jaspreet; Kaur, Lovedeep; Zavareze, Elessandra da Rosa; Dias, Alvaro Renato Guerra; Stewart, Robert B; Singh, Harjinder

2017-07-01

The objective of our study was to evaluate paste clarity, retrogradation (syneresis %), thermal characteristics and kinetics of glucose release during in vitro gastro-small intestinal digestion of freshly cooked and refrigerated potato starch. Freshly cooked starch pastes had a paste clarity of 71%, which decreased to 35.4% whereas syneresis (%) increased after 7days of refrigerated storage. The X-ray and thermal characteristics of native, retrograded and microwave reheated starch samples differed significantly from each other. For the freshly cooked starch pastes, ∼88% starch hydrolysis was observed at the end (150min) of digestion under simulated gastro-small intestinal conditions that decreased to ∼70% for the 7day stored pastes. The hydrolysis (%) of refrigerated pastes increased to 86% and 92% after one and two cycles of microwave reheating, respectively. These results contribute to the understanding of starch retrogradation in relation to starch digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of high hydrostatic pressure and retrogradation treatments on structural and physicochemical properties of waxy wheat starch.

PubMed

Hu, Xiao-Pei; Zhang, Bao; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

2017-10-01

In this study, the effects of high hydrostatic pressure and retrogradation (HHPR) treatments on in vitro digestibility, structural and physicochemical properties of waxy wheat starch were investigated. The waxy wheat starch slurries (10%, w/v) were treated with high hydrostatic pressures of 300, 400, 500, 600MPa at 20°C for 30min, respectively, and then retrograded at 4°C for 4d. The results indicated that the content of slowly digestible starch (SDS) in HHPR-treated starch samples increased with increasing pressure level, and it reached the maximum (31.12%) at 600MPa. HHPR treatment decreased the gelatinization temperatures, the gelatinization enthalpy, the relative crystallinity and the peak viscosity of the starch samples. Moreover, HHPR treatment destroyed the surface and interior structures of starch granules. These results suggest that the in vitro digestibility, physicochemical, and structural properties of waxy wheat starch are effectively modified by HHPR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heterotopic ossification of the elbow after closed reduction and retrograde intramedullary nailing for radial neck fracture treated by anconeus interposition.

PubMed

Sreenivas, T; Menon, Jagdish; Nataraj, A R

2013-12-01

Heterotopic ossification around the elbow can lead to considerable functional disability. We describe a case of a 42-year-old man who developed heterotopic ossification of his elbow after closed reduction of the elbow dislocation and radial neck fracture and retrograde intramedullary nailing for radial neck fracture. During the follow-up after initial surgery, movements of the elbow were gradually deteriorated and diagnosed as heterotopic ossification of the elbow. Implant removal, radial head excision along with heterotopic mass, and also interposition of the anconeus muscle resulted in improvement of his elbow mobility. At 18 months of follow-up, patient had elbow flexion arc of 15°-110°, 70° of supination, and 50° of pronation without recurrence of heterotopic ossification. The uniqueness of this case lies in the treatment of heterotopic ossification of the elbow to prevent its recurrence, which was developed after retrograde intramedullary nailing for radial neck fracture following closed reduction.

Arthroscopic retrograde osteochondral autologous transplantation to chondral lesion in femoral head.

PubMed

Cetinkaya, Sarper; Toker, Berkin; Taser, Omer

2014-06-01

This report describes the treatment of 2 cases of full-thickness cartilage defect of the femoral head. The authors performed osteochondral autologous transplantation with a different technique that has not been reported to date. One patient was 37 years old, and the other was 42 years old. Both presented with hip pain. In both patients, radiograph and magnetic resonance imaging scan showed a focal chondral defect on the weight-bearing area of the femoral head and acetabular impingement. A retrograde osteochondral autologous transplantation technique combined with hip arthroscopy and arthroscopic impingement treatment was performed. After a 2-month recovery period, the symptoms were resolved. In the first year of follow-up, Harris Hip scores improved significantly (case 1, 56.6 to 87.6; case 2, 58.6 to 90). The technique described yielded good short- and midterm clinical and radiologic outcomes. To the authors' knowledge, this report is the first to describe a retrograde osteochondral transplantation technique performed with hip arthroscopy in the femoral head. Copyright 2014, SLACK Incorporated.

Retrograde Signaling from Progranulin to Sort1 Counteracts Synapse Elimination in the Developing Cerebellum.

PubMed

Uesaka, Naofumi; Abe, Manabu; Konno, Kohtarou; Yamazaki, Maya; Sakoori, Kazuto; Watanabe, Takaki; Kao, Tzu-Huei; Mikuni, Takayasu; Watanabe, Masahiko; Sakimura, Kenji; Kano, Masanobu

2018-02-21

Elimination of redundant synapses formed early in development and strengthening of necessary connections are crucial for shaping functional neural circuits. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs) with similar strengths. A single CF is strengthened whereas the other CFs are eliminated in each PC during postnatal development. The underlying mechanisms, particularly for the strengthening of single CFs, are poorly understood. Here we report that progranulin, a multi-functional growth factor implicated in the pathogenesis of frontotemporal dementia, strengthens developing CF synaptic inputs and counteracts their elimination from postnatal day 11 to 16. Progranulin derived from PCs acts retrogradely onto its putative receptor Sort1 on CFs. This effect is independent of semaphorin 3A, another retrograde signaling molecule that counteracts CF synapse elimination. We propose that progranulin-Sort1 signaling strengthens and maintains developing CF inputs, and may contribute to selection of single "winner" CFs that survive synapse elimination. Copyright © 2018 Elsevier Inc. All rights reserved.

Actin Filament Elasticity and Retrograde Flow Shape the Force-Velocity Relation of Motile Cells

PubMed Central

Zimmermann, Juliane; Brunner, Claudia; Enculescu, Mihaela; Goegler, Michael; Ehrlicher, Allen; Käs, Josef; Falcke, Martin

2012-01-01

Cells migrate through a crowded environment during processes such as metastasis or wound healing, and must generate and withstand substantial forces. The cellular motility responses to environmental forces are represented by their force-velocity relation, which has been measured for fish keratocytes but remains unexplained. Even pN opposing forces slow down lamellipodium motion by three orders of magnitude. At larger opposing forces, the retrograde flow of the actin network accelerates until it compensates for polymerization, and cell motion stalls. Subsequently, the lamellipodium adapts to the stalled state. We present a mechanism quantitatively explaining the cell's force-velocity relation and its changes upon application of drugs that hinder actin polymerization or actomyosin-based contractility. Elastic properties of filaments, close to the lamellipodium leading edge, and retrograde flow shape the force-velocity relation. To our knowledge, our results shed new light on how these migratory responses are regulated, and on the mechanics and structure of the lamellipodium. PMID:22339865

Effect of bacosides, alcoholic extract of Bacopa monniera Linn. (brahmi), on experimental amnesia in mice.

PubMed

Kishore, Kamal; Singh, Manjeet

2005-07-01

To investigate the effect of bacosides (alcoholic extract of brahmi) on scopolamine (3 mg kg(-1), ip), sodium nitrite (75 mg kg(-1), ip) and BN52021 (15 mg kg(-1), ip) induced experimental amnesia in mice, using Morris water maze test, all the agents were administered 30 min before the acquisition trials on each day and repeated for 4 consecutive days, and on 5th day during the retrieval trials. Bacosides on anterograde administration (before training) in mice, significantly decreased the escape latency time (ELT) during the acquisition trials for 4 consecutive days and increased the time spent (TS) in target quadrant during the retrieval trials on 5th day, and on retrograde administration (after training) bacosides were found not to affect TS significantly. Bacosides also significantly decreased the ELT and increased the TS in mice treated anterogradely with scopolamine and sodium nitrite. Bacosides did not exhibit any significant effect on TS of mice treated retrogradely with sodium nitrite. On the other hand, bacosides significantly increased the TS of mice treated retrogradely with BN52021. On the basis of the present results it can be concluded that bacosides facilitate anterograde memory and attenuate anterograde experimental amnesia induced by scopolamine and sodium nitrite possibly by improving acetylcholine level and hypoxic conditions, respectively. Beside this bacosides also reversed BN52021 induced retrograde amnesia, probably due to increase in platelet activating factor (PAF) synthesis by enhancing cerebral glutamate level.

Mutism and amnesia following high-voltage electrical injury: psychogenic symptomatology triggered by organic dysfunction?

PubMed

Mishra, Nishant K; Russmann, Heike; Granziera, Cristina; Maeder, Philippe; Annoni, Jean-Marie

2011-01-01

Mutism and dense retrograde amnesia are found both in organic and dissociative contexts. Moreover, dissociative symptoms may be modulated by right prefrontal activity. A single case, M.R., developed left hemiparesis, mutism and retrograde amnesia after a high-voltage electric shock without evidence of lasting brain lesions. M.R. suddenly recovered from his mutism following a mild brain trauma 2 years later. M.R.'s neuropsychological pattern and anatomoclinical correlations were studied through (i) language and memory assessment to characterize his deficits, (ii) functional neuroimaging during a standard language paradigm, and (iii) assessment of frontal and left insular connectivity through diffusion tractography imaging and transcranial magnetic stimulation. A control evaluation was repeated after recovery. M.R. recovered from the left hemiparesis within 90 days of the accident, which indicated a transient right brain impairment. One year later, neurobehavioral, language and memory evaluations strongly suggested a dissociative component in the mutism and retrograde amnesia. Investigations (including MRI, fMRI, diffusion tensor imaging, EEG and r-TMS) were normal. Twenty-seven months after the electrical injury, M.R. had a very mild head injury which was followed by a rapid recovery of speech. However, the retrograde amnesia persisted. This case indicates an interaction of both organic and dissociative mechanisms in order to explain the patient's symptoms. The study also illustrates dissociation in the time course of the two different dissociative symptoms in the same patient. Copyright © 2011 S. Karger AG, Basel.

Enkephalin-containing neurons in the inferior mesenteric ganglion projecting to the distal colon of cat: evidence from combined retrograde tracing by fluorescent microspheres and immunohistochemistry.

PubMed

Bagnol, D; Jule, Y; Kirchner, G; Cupo, A; Roman, C

1993-02-01

Retrograde tracing with rhodamine fluorescent microspheres combined with fluorescein immunolabelling of methionine-enkephalin showed the presence of enkephalin-like material in neurons of the inferior mesenteric ganglion (sympathetic prevertebral ganglion) projecting to the distal colon in cat. Two weeks after injecting the microspheres into the wall of the distal colon, the inferior mesenteric ganglion was dissected out and incubated for 24 hours in a colchicine-containing culture medium in order to facilitate the detection of enkephalins in the soma of ganglion neurons. It was observed that retrogradely labelled ganglion cells contained enkephalin-like immunoreactive material. These ganglion cells corresponded to enkephalin-like postganglionic neurons, the terminals of which were located inside the wall of the distal colon. These enkephalin-like neurons were numerous and scattered throughout the ganglion. Sometimes enkephalin-like immunoreactive fibers, probably originating from spinal preganglionic neurons, ran close to immunoreactive and non-immunoreactive retrogradely labelled ganglion cells. This suggests that enkephalin-like immunoreactive fibers may make synaptic connections with enkephalin-like and non-enkephalin-like postganglionic neurons projecting to the distal colon. The present study establishes for the first time the existence of an enkephalin-like postganglionic pathway to the digestive tract originating from a sympathetic prevertebral ganglion. This finding indicates that the enkephalinergic innervation of the cat digestive tract may have at least two possible sources: (i) the sympathetic prevertebral ganglia; and (ii) the enteric nervous ganglia.

Selective binding, uptake, and retrograde transport of tetanus toxin by nerve terminals in the rat iris. An electron microscope study using colloidal gold as a tracer

PubMed Central

1978-01-01

A series of specific macromolecules (tetanus toxin, cholera toxin, nerve growth factor [NGF], and several lectins) have been shown to be transported retrogradely with high selectivity from terminals to cell bodies in various types of neurons. Under identical experimental conditions (low protein concentrations injected), most other macromolecules, e.g. horseradish peroxidase (HRP), albumin, ferritin, are not transported in detectable amounts. In the present EM study, we demonstrate selective binding of tetanus toxin to the surface membrane of nerve terminals, followed by uptake and subsequent retorgrade axonal transport. Tetanus toxin or albumin was adsorbed to colloidal gold particles (diam 200 A). The complex was shown to be stable and well suited as an EM tracer. 1-4 h after injection into the anterior eye chamber of adult rats, tetanus toxin-gold particles were found to be selectively associated with membranes of nerve terminals and preterminal axons. Inside terminals and axons, the tracer was localized mainly in smooth endoplasmic reticulum (SER)-like membrane compartments. In contrast, association of albumin-gold complexes with nervous structures was never observed, in spite of extensive uptake into fibroblasts. Electron microscope and biochemical experiments showed selective retrograde transport of tetanus toxin-gold complexes to the superior cervical ganglion. Specific binding to membrane components at nerve terminals and subsequent internalization and retrograde transport may represent an important pathway for macromolecules carrying information from target organs to the perikarya of their innervating neurons. PMID:659508

Retrograde Amnesia for Episodic and Semantic Memories in Amnestic Mild Cognitive Impairment.

PubMed

De Simone, Maria Stefania; Fadda, Lucia; Perri, Roberta; De Tollis, Massimo; Aloisi, Marta; Caltagirone, Carlo; Carlesimo, Giovanni Augusto

2017-01-01

Retrograde amnesia (RA), which includes loss of memory for past personal events (autobiographical RA) and for acquired knowledge (semantic RA), has been largely documented in patients with amnestic mild cognitive impairment (aMCI). However, previous studies have produced controversial results particularly concerning the temporal extent of memory impairment. Here we investigated whether, with the onset of hippocampal pathology, age of memory acquisition and retrieval frequency play different roles in modulating the progressive loss of semantic and episodic contents of retrograde memory respectively. For this purpose, aMCI patients and healthy controls were tested for the ability to recall semantic and autobiographical information related to famous public events as a function of both age of acquisition and retrieval frequency. In aMCI patients, we found that the impairment in recollecting past personal incidents was modulated by the combined action of memory age and retrieval frequency, because older and more frequently retrieved episodes are less susceptible to loss than more recent and less frequently retrieved ones. On the other side, we found that the loss of semantic information depended only on memory age, because the remoteness of the trace allows for better preservation of the memory. Our results provide evidence that the loss of the two components of retrograde memory is regulated by different mechanisms. This supports the view that diverse neural mechanisms are involved in episodic and semantic memory trace storage and retrieval, as postulated by the Multiple Trace Theory.

The dynamic time course of memory recovery in transient global amnesia.

PubMed

Guillery-Girard, B; Desgranges, B; Urban, C; Piolino, P; de la Sayette, V; Eustache, F

2004-11-01

To investigate the dynamic time course of transient global amnesia (TGA)--that is, the process of recovery and the interindividual variability--by testing four patients during the day of TGA itself (on three occasions) and at follow up (on two occasions). A specially designed protocol focusing on semantic (both conceptual and autobiographical knowledge) and episodic (both anterograde and retrograde components) memory. Every patient showed marked impairment of both anterograde and retrograde episodic memory during the acute phase, with a relative preservation of personal and conceptual semantic knowledge. During the following phase, the authors observed similarities and differences among the patients' patterns of recovery. In general, retrograde amnesia recovered before the anterograde amnesia and anterograde episodic memory was recovered gradually in every case. In contrast, shrinkage of retrograde amnesia was more heterogeneous. In two of the patients, this shrinkage followed a chronological gradient and the most remote events were recovered first. In the two other patients, it depended more on the strength of the trace, and there was no temporal gradient. For the latter, an executive deficit could account for difficulties in accessing both conceptual knowledge and autobiographical memories. This profile of recovery suggests a "neocortical to medial temporal" process in every case, and the possibility of an additional frontal dysfunction in some cases. Hence, the acute phase seems to be characterised by a common episodic impairment. This variability between subjects appears in the recovery phase with two different patterns of impairment.

Rabies virus envelope glycoprotein targets lentiviral vectors to the axonal retrograde pathway in motor neurons.

PubMed

Hislop, James N; Islam, Tarin A; Eleftheriadou, Ioanna; Carpentier, David C J; Trabalza, Antonio; Parkinson, Michael; Schiavo, Giampietro; Mazarakis, Nicholas D

2014-06-06

Rabies pseudotyped lentiviral vectors have great potential in gene therapy, not least because of their ability to transduce neurons following their distal axonal application. However, very little is known about the molecular processes that underlie their retrograde transport and cell transduction. Using multiple labeling techniques and confocal microscopy, we demonstrated that pseudotyping with rabies virus envelope glycoprotein (RV-G) enabled the axonal retrograde transport of two distinct subtypes of lentiviral vector in motor neuron cultures. Analysis of this process revealed that these vectors trafficked through Rab5-positive endosomes and accumulated within a non-acidic Rab7 compartment. RV-G pseudotyped vectors were co-transported with both the tetanus neurotoxin-binding fragment and the membrane proteins thought to mediate rabies virus endocytosis (neural cell adhesion molecule, nicotinic acetylcholine receptor, and p75 neurotrophin receptor), thus demonstrating that pseudotyping with RV-G targets lentiviral vectors for transport along the same pathway exploited by several toxins and viruses. Using motor neurons cultured in compartmentalized chambers, we demonstrated that axonal retrograde transport of these vectors was rapid and efficient; however, it was not able to transduce the targeted neurons efficiently, suggesting that impairment in processes occurring after arrival of the viral vector in the soma is responsible for the low transduction efficiency seen in vivo, which suggests a novel area for improvement of gene therapy vectors. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Asna1/TRC40 Controls β-Cell Function and Endoplasmic Reticulum Homeostasis by Ensuring Retrograde Transport.

PubMed

Norlin, Stefan; Parekh, Vishal S; Naredi, Peter; Edlund, Helena

2016-01-01

Type 2 diabetes (T2D) is characterized by insulin resistance and β-cell failure. Insulin resistance per se, however, does not provoke overt diabetes as long as compensatory β-cell function is maintained. The increased demand for insulin stresses the β-cell endoplasmic reticulum (ER) and secretory pathway, and ER stress is associated with β-cell failure in T2D. The tail recognition complex (TRC) pathway, including Asna1/TRC40, is implicated in the maintenance of endomembrane trafficking and ER homeostasis. To gain insight into the role of Asna1/TRC40 in maintaining endomembrane homeostasis and β-cell function, we inactivated Asna1 in β-cells of mice. We show that Asna1(β-/-) mice develop hypoinsulinemia, impaired insulin secretion, and glucose intolerance that rapidly progresses to overt diabetes. Loss of Asna1 function leads to perturbed plasma membrane-to-trans Golgi network and Golgi-to-ER retrograde transport as well as to ER stress in β-cells. Of note, pharmacological inhibition of retrograde transport in isolated islets and insulinoma cells mimicked the phenotype of Asna1(β-/-) β-cells and resulted in reduced insulin content and ER stress. These data support a model where Asna1 ensures retrograde transport and, hence, ER and insulin homeostasis in β-cells. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Isoflurane causes anterograde but not retrograde amnesia for pavlovian fear conditioning.

PubMed

Dutton, Robert C; Maurer, Anya J; Sonner, James M; Fanselow, Michael S; Laster, Michael J; Eger, Edmond I

2002-05-01

Production of retrograde amnesia by anesthetics would indicate that these drugs can disrupt mechanisms that stabilize memory. Such disruption would allow suppression of memory of previous untoward events. The authors examined whether isoflurane provides retrograde amnesia for classic (Pavlovian) fear conditioning. Rats were trained to fear tone by applying three (three-trial) or one (one-trial) tone-shock pairs while breathing various constant concentrations of isoflurane. Immediately after training, isoflurane administration was either discontinued, maintained unchanged, or rapidly increased to 1.0 minimum alveolar concentration for 1 h longer. Groups of rats were similarly trained to fear context while breathing isoflurane by applying shocks (without tones) in a distinctive environment. The next day, memory for the conditioned stimuli was determined by presenting the tone or context (without shock) and measuring the proportion of time each rat froze (appeared immobile). For each conditioning procedure, the effects of the three posttraining isoflurane treatments were compared. Rapid increases in posttraining isoflurane administration did not suppress conditioned fear for any of the training procedures. In contrast, isoflurane administration during conditioning dose-dependently suppressed conditioning (P < 0.05). Training to tone was more resistant to the effects of isoflurane than training to context (P < 0.05), and the three-trial learning procedure was more was more resistant than the one-trial procedure (P < 0.05). Isoflurane provided intense dose-dependent anterograde but not retrograde amnesia for classic fear conditioning. Isoflurane appears to disrupt memory processes that occur at or within a few minutes of the conditioning procedure.

A Case of Chronic Total Occlusion of the Left Anterior Descending Artery Successfully Treated with Side Branch Technique Using the Soutenir CV

PubMed Central

Niizeki, Takeshi; Ikeno, Eiichiro; Kubota, Isao

2017-01-01

Patient: Male, 54 Final Diagnosis: Old myocardial infarction Symptoms: Lower extremity swelling • respiratory distress Medication: — Clinical Procedure: Success Specialty: Cardiology Objective: Unusual setting of medical care Background: Success rates for treatment of chronic total occlusion (CTO) have dramatically improved in recent years with the development of new CTO guidewires and development of new techniques such as the retrograde approach. In the antegrade approach, a guidewire is occasionally passed through a side branch despite successful wire crossing of the CTO lesion. In order to pass a wire through the main artery, there are a few side branch techniques such as a reverse wire technique. Case Report: A 54-year-old man with symptoms of heart failure was admitted to our hospital. Coronary angiography showed CTO of the proximal left anterior descending artery. Percutaneous coronary intervention with an antegrade approach was started. We succeeded in passing the wire through a side branch but not the main artery. Unfortunately, a reverse wire technique failed in this case. Next, the wire passed through a side branch was exchanged with the Soutenir CV, and a retrograde approach was started. The wire crossing from retrograde was entwined around the Soutenir CV. After that, the retrograde wire was snared and guided to the antegrade guiding catheter, which resulted in successful wiring into the main artery easily. Conclusions: The side branch technique using the Soutenir CV may be an effective strategy in some cases. PMID:28082733

The central nucleus of the amygdala modulates gut-related neurons in the dorsal vagal complex in rats

PubMed Central

Zhang, Xueguo; Cui, Jinjuan; Tan, Zhenjun; Jiang, Chunhui; Fogel, Ronald

2003-01-01

Using retrograde tract-tracing and electrophysiological methods, we characterized the anatomical and functional relationship between the central nucleus of the amygdala and the dorsal vagal complex. Retrograde tract-tracing techniques revealed that the central nucleus of the amygdala projects to the dorsal vagal complex with a topographic distribution. Following injection of retrograde tracer into the vagal complex, retrogradely labelled neurons in the central nucleus of the amygdala were clustered in the central portion at the rostral level and in the medial part at the middle level of the nucleus. Few labelled neurons were seen at the caudal level. Electrical stimulation of the central nucleus of the amygdala altered the basal firing rates of 65 % of gut-related neurons in the nucleus of the solitary tract and in the dorsal motor nucleus of the vagus. Eighty-one percent of the neurons in the nucleus of the solitary tract and 47 % of the neurons in the dorsal motor nucleus were inhibited. Electrical stimulation of the central nucleus of the amygdala also modulated the response of neurons in the dorsal vagal complex to gastrointestinal stimuli. The predominant effect on the neurons of the nucleus of the solitary tract was inhibition. These results suggest that the central nucleus of the amygdala influences gut-related neurons in the dorsal vagal complex and provides a neuronal circuitry that explains the regulation of gastrointestinal activity by the amygdala. PMID:14555729

Retrograde transcatheter device closure of a complex paravalvular leak after bioprosthetic pulmonary valve replacement in a pediatric patient.

PubMed

Chikkabyrappa, Sathish; Mosca, Ralph S; McElhinney, Doff B

2016-06-01

We report a case of retrograde transcatheter device closure of a complex paravalvular leak (PVL) after bioprosthetic pulmonary valve replacement (PVR) in a 13-year-old patient with congenital pulmonary valve stenosis. There are prior reports of pulmonary PVL closure after PVR in adults (Seery and Slack, Congenit Heart Dis 2014;9:E19-F22), but indications for and technical considerations in PVL closure after bioprosthetic PVR, particularly in children, are not well defined. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Conservative Management of an Epicardial Collateral Perforation During Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention.

PubMed

Ngo, Christian; Christopoulos, George; Brilakis, Emmanouil S

2016-01-01

Coronary artery perforation is a highly feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and can lead to pericardial effusion, tamponade, and, rarely, emergent cardiac surgery. Perforation of epicardial collaterals during retrograde CTO-PCI may be particularly challenging to treat, as embolization from both sides of the perforation may be required to control the bleeding. However, conservative measures can occasionally be effective. We present a case of epicardial collateral vessel perforation that was managed conservatively with anticoagulation reversal.

The first retrograde Trojan asteroid

NASA Astrophysics Data System (ADS)

Wiegert, Paul; Connors, Martin; Veillet, Christian

2018-04-01

There are about six thousand asteroids which share Jupiter's orbit around the Sun. Called the 'Trojan asteroids', they co-exist easily with this giant planet because they travel in the same direction as it ('direct' or 'prograde' motion), and remain roughly 60 degrees ahead of or behind it in its orbit. Newly discovered asteroid 2015 BZ509 is on a retrograde orbit, but is nonetheless in a state dynamically analogous to that of the prograde Trojans. The discovery circumstances and the nature of the motion of this curious asteroid -the first of its kind- will be outlined.

Axonal transport: cargo-specific mechanisms of motility and regulation.

PubMed

Maday, Sandra; Twelvetrees, Alison E; Moughamian, Armen J; Holzbaur, Erika L F

2014-10-22

Axonal transport is essential for neuronal function, and many neurodevelopmental and neurodegenerative diseases result from mutations in the axonal transport machinery. Anterograde transport supplies distal axons with newly synthesized proteins and lipids, including synaptic components required to maintain presynaptic activity. Retrograde transport is required to maintain homeostasis by removing aging proteins and organelles from the distal axon for degradation and recycling of components. Retrograde axonal transport also plays a major role in neurotrophic and injury response signaling. This review provides an overview of axonal transport pathways and discusses their role in neuronal function.

Selective labeling of retinal ganglion cells with calcium indicators by retrograde loading in vitro

PubMed Central

Behrend, Matthew R.; Ahuja, Ashish K.; Humayun, Mark S.; Weiland, James D.; Chow, Robert H.

2012-01-01

Here we present a retrograde loading technique that makes it possible for the first time to rapidly load a calcium indicator in the majority of retinal ganglion cells (RGCs) in salamander retina, and then to observe physiological activity of these dye-loaded cells. Dextran-conjugated calcium indicator, dissolved in water, was applied to the optic nerve stump. Following dye loading, the isolated retina was mounted on a microelectrode array to demonstrate that electrical activity and calcium activity were preserved, as the retina responded to electrical stimuli. PMID:19428523

Flexible endoscopes: structure and function: the endoscopic retrograde cholangiopancreatography elevator system.

PubMed

Holland, Pat; Shoop, Nancy M

2002-01-01

Flexible endoscopes are complex medical instruments that are easily damaged. In order to maintain the flexible endoscope in optimum working condition, the user must have a thorough understanding of the structure and function of the instrument. This is the fourth in a series of articles presenting an in-depth look at the care and handling of the flexible endoscope. The first three articles discussed the air-water system, the suction channel system, and the mechanical system. This article will focus specifically on the endoscopic retrograde cholangiopancreatography elevator system.

A Class of Selenocentric Retrograde Orbits With Innovative Applications to Human Lunar Operations

NASA Technical Reports Server (NTRS)

Adamo, Daniel R.; Lester, Daniel F.; Thronson, Harley A.; Barbee, Brent

2014-01-01

Selenocentric distant retrograde orbits with radii from approx. 12,500 km to approx. 25,000 km are assessed for stability and for suitability as crewed command and control infrastructure locations in support of telerobotic lunar surface operations and interplanetary human transport. Such orbits enable consistent transits to and from Earth at virtually any time if they are coplanar with the Moon's geocentric orbit. They possess multiple attributes and applications distinct from NASA's proposed destination orbit for a redirected asteroid about 70,000 km from the Moon.

Iron mineralization and associated skarn development around southern contact of the Eğrigöz pluton (northern Menderes Massif-Turkey)

NASA Astrophysics Data System (ADS)

Uǧurcan, Okşan Gökçen; Oyman, Tolga

2016-11-01

The Eğrigöz pluton is located in the northern portion of the Menderes Massif, which is the largest known metamorphic core complex that is also characterized by large-scale extension. Kalkan and Karaağıl skarn deposits are located on the southern border of the Eğrigöz Pluton, whereas Katrandağ mineralization developed along the roof pendant. Skarnization in these three areas is associated with the peraluminous, I-type, calc-alkaline, high-K calc-alkaline Eğrigöz Pluton. Geochemical characteristics of the pluton indicate that it was generated in a continental arc setting. Kalkan, Karaağıl, and Katrandağ skarns are hosted in marble bands in two-mica gneiss of the Kalkan Formation, a locally dolomitic and clay-bearing limestone of the Arıkaya Formation and locally dolomitised limestone of the Balıkbaşı Formation, respectively. Skarn development occurred sequentially in two stages, prograde and retrograde. In Kalkan skarn, prograde stage is characterized by clinopyroxene (Di56-73 Hd26-43 Joh1-2), garnet (Adr45-69 Grs30-52 Alm0-1.4 Sps0.7-2.3), amphibole, and magnetite, whereas retrograde stage is dominated by epidote, amphibole, chlorite, quartz, and calcite. In Karaağıl, both calcic and magnesian skarn association occurred as a result of local variations in dolomite content in Arıkaya Formation. The prograde assemblage of magnesian skarn is composed chiefly of spinel, amphibole and olivine. These mineral assemblages were, partially or fully, altered to serpentine, talc, and chlorite during retrograde alteration. Mesh textures of the serpentine indicates that the serpentine was altered from olivine. Olivine was completely destroyed during retrograde alteration without relict grains remaining. Calcic skarn paragenesis include garnet (Grs36-80Adr20-62Alm0-2.2Sps0.2-2.6), clinopyroxene (Di81-92 Hd7-19 Jo0-1), and plagioclase, that belongs to the earlier stage, and amphibole of the retrograde stage. High grossular end member of the garnet probably reflects host rock composition. The Katrandağ area differs from Kalkan and Karaağıl deposits in terms of initial metal content and gossan alteration due to the supergene alteration of galena dominated mineralization. In the Katrandağ, skarn that associated with iron and lead mineralization, both contain clinopyroxene and garnet. In the Kalkan skarn, fluid inclusion assemblages of prograde skarn association yield homogenization temperatures from 379 °C to over 600 °C, whereas those of retrograde minerals vary between 235 °C and 412 °C. Salinity values of the inclusions which obtained from prograde and retrograde assemblages are 9.2-22.4 and 6.4-20.1 wt%NaCl eq., respectively. Homogenization temperatures and salinity values of inclusions in clinopyroxene of Karaağıl calcic skarn are 420 to over 600 °C and 21-30 wt%NaCl eq., respectively.

Antinociceptive effect of vinpocetine--a comprehensive survey.

PubMed

Csillik, Bertalan; Mihály, András; Knyihár-Csillik, Elizabeth

2010-05-30

Blockade of retrograde transport of nerve growth factor (NGF) in a peripheral sensory nerve is known to induce transganglionic degenerative atrophy (TDA) of central sensory terminals in the upper dorsal horn of the related, ipsilateral segments(s) of the spinal cord. The ensuing temporary blockade of transmission of nociceptive impulses has been utilized in the therapy of intractable pain, using transcutaneous iontophoresis of the microtubule inhibitors vincristin and vinblastin, drugs which inhibit retrograde transport of NGF. Since microtubule inhibition might inhibit (at least theoretically) mitotic processes in general, we sought to find a drug which inhibits retrograde transport of NGF without microtubule inhibition. Vinpocetine, a derivate of vincamine, which does not interfere with microtubular function, was found to inhibit retrograde axoplasmic transport of NGF in peripheral sensory nerves, similarly to vincristin and vinblastin. Blockade of NGF transport is followed by transganglionic degenerative atrophy in the segmentally related, ipsilateral superficial spinal dorsal horn, characterized by depletion of the marker enzymes of nociception, fluoride resistant acid phosphatase (FRAP) and thiamine monophosphatase (TMP) from the Rolando substance and by decrease of the pain-related neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) from lamina I-II-III. Based upon these findings, it has been suggested that vinpocetine may result in a locally restricted decrease of nociception. Herewith, the structural and behavioral effects of perineurally administered vinpocetine are discussed. Nociception, induced by intraplantar injection of formalin, was mitigated by perineural application of vinpocetine; also formalin-induced expression of c-fos in the ipsilateral, segmentally related superficial dorsal horn, was prevented by this treatment. Since vinpocetine is not a microtubule inhibitor, its mode of action is enigmatic. It is assumed that the effect of vinpocetine might be related to interaction with membrane-trafficking proteins, such as signalling endosomes and the endocytosis-mediating "pincher" protein, involved in retrograde axoplasmic transport of NGF, or to interaction with glial elements, recently reported to be involved in the modulation of pain in the spinal cord. Based on animal experiments it is assumed that the temporary, locally restricted decrease of nociception, induced by vinpocetine applied via transcutaneous iontophoresis, might open up new avenues in the clinical treatment of intractable pain.

Uncontrolled diabetes as a potential risk factor in tibiotalocalcaneal fusion using a retrograde intramedullary nail.

PubMed

Lee, Moses; Choi, Woo Jin; Han, Seung Hwan; Jang, Jinyoung; Lee, Jin Woo

2017-07-22

Tibiotalocalcaneal (TTC) fusion using a retrograde intramedullary (IM) nail is an effective salvage option for terminal-stage hindfoot problems. However, as many patients who receive TTC fusion bear unfavorable medical comorbidities, the risk of nonunion, infection and other complications increases. This study was performed to identify the factors influencing outcomes after TTC fusion using a retrograde IM nail. Between September 2008 and February 2012, 34 consecutive patients received TTC fusion using a retrograde IM nail for limb salvage. All patients had a minimum follow-up of two years. Throughout follow-up, standard ankle radiography was performed along with clinical outcome assessment using a visual analog scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society Ankle-Hind Foot Scale (AOFAS A/H scale) and the Foot and Ankle Outcome Score (FAOS). For the retrospective analysis, demographic factors, preoperative medical status, laboratory markers, and etiology were comprehensively reviewed using medical records. The success of the index operation was determined using clinical and radiological outcomes. Finally, the effect of each factor on failure after the operation was analyzed using univariate logistic regression. In a mean of seven months, 82% (28/34) achieved union, as evaluated by standard radiography. All clinical outcome parameters improved significantly after the operation, including VAS, AOFAS A/H scale, and FAOS (P<0.001). At the last follow-up, five cases of nonunion with less than AOFAS A/H scale of 80 and two cases of below knee amputation due to uncontrolled infection were determined to be failures. None of the factors (etiology, demographics, laboratory markers and medical status) significantly influenced failures. However, uncontrolled DM significantly increased the failure rate with an odds ratio of 10 (P=0.029). TTC fusion with a retrograde intramedullary nail is a successful treatment for complicated hindfoot problems such as traumatic osteoarthritis, Charcot arthropathy and failed TAA. However, it should be used judiciously in patients with uncontrolled DM, as the risk of failure increases. Retrospective cohort study. Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

The ins and outs of nuclear re-export of retrogradely transported tRNAs in Saccharomyces cerevisiae

PubMed Central

Pierce, Jacqueline B; Eswara, Manoja BK

2010-01-01

In Saccharomyces cerevisiae intron-containing pre-tRNAs are exported from the nucleus to the cytoplasm for removal of the introns, and the spliced tRNAs are returned to the nucleus for reasons that are not understood. The re-imported spliced tRNAs are then subjected to aminoacylation in the nucleolus to ensure that they are functional prior to re-export to the cytoplasm. Previous studies have shown that re-imported spliced tRNAs and mature tRNAs made entirely in the nucleus from intronless precursors are retained in the nucleus of S. cerevisiae in response to glucose, amino acid, nitrogen or inorganic phosphate deprivation. Contrary to these studies, we recently reported that starvation of S. cerevisiae of amino acids or nitrogen results in nuclear accumulation of re-imported spliced tRNAs, but not tRNAs made from intronless precursors. This finding suggests that separate pathways are used for nuclear export of retrogradely transported spliced tRNAs and tRNAs made from intronless pre-tRNAs. In addition, the data support the conclusion that the nuclear re-export pathway for retrogradely transported spliced tRNAs, but not the pathway responsible for nuclear export of tRNAs derived from intronless precursors is regulated during amino acid or nitrogen starvation. This regulation appears to occur at a step after the re-imported spliced tRNAs have undergone aminoacylation quality assurance and, in part, involves the TORC1 signalling pathway. Moreover, it was established that Utp9p is an intranuclear component that only facilitates nuclear re-export of retrogradely transported spliced tRNAs by the β-karyopherin Msn5p. Utp9p acts in concert with Utp8p, a key player in nuclear tRNA export in S. cerevisiae, to translocate aminoacylated re-imported spliced tRNAs from the nucleolus to Msn5p and assist with formation of the Msn5p-tRNA-Gsp1p-GTP export complex. This pathway, however, is not the only one responsible for nuclear re-export of retrogradely transported spliced tRNAs. PMID:21327067

Combining the Cutting and Mulliken methods for primary repair of the bilateral cleft lip nose.

PubMed

Morovic, Carmen Gloria; Cutting, Court

2005-11-01

Since 1990, primary bilateral cleft nasal reconstruction has been focused on placing the lower lateral cartilages into normal anatomical position. Of the four major techniques in this class, the Cutting (i.e., retrograde) method and the Mulliken method have been most successful. The retrograde method makes no external nasal incisions, but requires either preoperative or postoperative nasal molding to achieve maximum benefit. Mulliken's technique does not require molding, but leaves the footplates of the medial crura in the depression above the projecting premaxilla associated with the diminutive anterior nasal spine. Leaving the footplates in place also prevents adequate approximation of the alar bases. In this article, the two methods are combined to achieve the benefits of both. We report our experience with the retrograde nasal approach associated with marginal rim incisions (Mulliken method) in a series of 25 consecutive bilateral cleft lip cases simultaneous with lip repair. We performed a retrograde approach through membranous septum incisions elevating a prolabial-columellar flap. To facilitate alar cartilage manipulation we added bilateral marginal rim incisions. Nasal width, columella length and width, tip projection, and nasolabial angle were analyzed after a minimum of 2 years after surgery. These were compared with a normal, age-matched, control group. We also examined nostril symmetry and marginal nostril scars. Columellar length was not statistically significantly different from that of the control group (p = 0.122442). Nasal width, columellar width, tip projection, and nasolabial angle were all significantly greater in the cleft group than normal (p < 0.001). No hypertrophied scars were found associated with the marginal rim scar. Adding the Mulliken approach allows alar cartilage manipulation to be performed more easily than when using the retrograde approach alone. Tip projection and alar base narrowing are facilitated using the combined technique rather than the Mulliken approach alone. Prolabial flap manipulation is safe using this combined approach, even in cases with a severely projected premaxilla. We believe that the combined approach is safe and yields better long-term results than either technique alone.

Dynamical lifetimes of asteroids in retrograde orbits

NASA Astrophysics Data System (ADS)

Kankiewicz, Paweł; Włodarczyk, Ireneusz

2017-07-01

The population of known minor bodies in retrograde orbits (I > 90°) that are classified as asteroids is still growing. The aim of our study was to estimate the dynamical lifetimes of these bodies using the latest observational data, including astrometry and physical properties. We selected 25 asteroids with the best-determined orbital elements. We studied their dynamical evolution in the past and future for ±100 Myr (±1 Gyr for three particular cases). We first used orbit determination and cloning to produce swarms of test particles. These swarms were then input into long-term numerical integrations, and the orbital elements were averaged. Next, we collected the available thermal properties of our objects and we used them in an enhanced dynamical model with Yarkovsky forces. We also used a gravitational model for comparison. Finally, we estimated the median lifetimes of 25 asteroids. We found three objects whose retrograde orbits were stable with a dynamical lifetime τ ˜ 10-100 Myr. A large portion of the objects studied displayed smaller values of τ (τ ˜ 1 Myr). In addition, we studied the possible influence of the Yarkovsky effect on our results. We found that the Yarkovsky effect can have a significant influence on the lifetimes of asteroids in retrograde orbits. Because of the presence of this effect, it is possible that the median lifetimes of these objects are extended. Additionally, the changes in orbital elements, caused by Yarkovsky forces, appear to depend on the integration direction. To explain this more precisely, the same model based on new physical parameters, determined from future observations, will be required.

Development of prognostic model for predicting survival after retrograde placement of ureteral stent in advanced gastrointestinal cancer patients and its evaluation by decision curve analysis.

PubMed

Kawano, Shingo; Komai, Yoshinobu; Ishioka, Junichiro; Sakai, Yasuyuki; Fuse, Nozomu; Ito, Masaaki; Kihara, Kazunori; Saito, Norio

2016-10-01

The aim of this study was to determine risk factors for survival after retrograde placement of ureteral stents and develop a prognostic model for advanced gastrointestinal tract (GIT: esophagus, stomach, colon and rectum) cancer patients. We examined the clinical records of 122 patients who underwent retrograde placement of a ureteral stent against malignant extrinsic ureteral obstruction. A prediction model for survival after stenting was developed. We compared its clinical usefulness with our previous model based on the results from nephrostomy cases by decision curve analysis. Median follow-up period was 201 days (8-1490) and 97 deaths occurred. The 1-year survival rate in this cohort was 29%. Based on multivariate analysis, primary site of colon origin, absence of retroperitoneal lymph node metastasis and serum albumin >3g/dL were significantly associated with a prolonged survival time. To develop a prognostic model, we divided the patients into 3 risk groups of favorable: 0-1 factors (N.=53), intermediate: 2 risk factors (N.=54), and poor: 3 risk factors (N.=15). There were significant differences in the survival profiles of these 3 risk groups (P<0.0001). Decision curve analyses revealed that the current model has a superior net benefit than our previous model for most of the examined probabilities. We have developed a novel prognostic model for GIT cancer patients who were treated with retrograde placement of a ureteral stent. The current model should help urologists and medical oncologists to predict survival in cases of malignant extrinsic ureteral obstruction.

Endoscopic retrograde cholangiopancreatography-associated AmpC Escherichia coli outbreak.

PubMed

Wendorf, Kristen A; Kay, Meagan; Baliga, Christopher; Weissman, Scott J; Gluck, Michael; Verma, Punam; D'Angeli, Marisa; Swoveland, Jennifer; Kang, Mi-Gyeong; Eckmann, Kaye; Ross, Andrew S; Duchin, Jeffrey

2015-06-01

We identified an outbreak of AmpC-producing Escherichia coli infections resistant to third-generation cephalosporins and carbapenems (CR) among 7 patients who had undergone endoscopic retrograde cholangiopancreatography at hospital A during November 2012-August 2013. Gene sequencing revealed a shared novel mutation in a bla CMY gene and a distinctive fumC/ fimH typing profile. To determine the extent and epidemiologic characteristics of the outbreak, identify potential sources of transmission, design and implement infection control measures, and determine the association between the CR E. coli and AmpC E. coli circulating at hospital A. We reviewed laboratory, medical, and endoscopy reports, and endoscope reprocessing procedures. We obtained cultures from endoscopes after reprocessing as well as environmental samples and conducted pulsed-field gel electrophoresis and gene sequencing on phenotypic AmpC isolates from patients and endoscopes. Cases were those infected with phenotypic AmpC isolates (both carbapenem-susceptible and CR) and identical bla CMY-2, fumC, and fimH alleles or related pulsed-field gel electrophoresis patterns. Thirty-five of 49 AmpC E. coli tested met the case definition, including all CR isolates. All cases had complicated biliary disease and had undergone at least 1 endoscopic retrograde cholangiopancreatography at hospital A. Mortality at 30 days was 16% for all patients and 56% for CR patients. Two of 8 reprocessed endoscopic retrograde cholangiopancreatography scopes harbored AmpC that matched case isolates by pulsed-field gel electrophoresis. Environmental cultures were negative. No breaches in infection control were identified. Endoscopic reprocessing exceeded manufacturer's recommended cleaning guidelines. Recommended reprocessing guidelines are not sufficient.

Dync1h1 Mutation Causes Proprioceptive Sensory Neuron Loss and Impaired Retrograde Axonal Transport of Dorsal Root Ganglion Neurons.

PubMed

Zhao, Jing; Wang, Yi; Xu, Huan; Fu, Yuan; Qian, Ting; Bo, Deng; Lu, Yan-Xin; Xiong, Yi; Wan, Jun; Zhang, Xiang; Dong, Qiang; Chen, Xiang-Jun

2016-07-01

Sprawling (Swl) is a radiation-induced mutation which has been identified to have a nine base pair deletion in dynein heavy chain 1 (DYNC1H1: encoded by a single gene Dync1h1). This study is to investigate the phenotype and the underlying mechanism of the Dync1h1 mutant. To display the phenotype of Swl mutant mice, we examined the embryos of homozygous (Swl/Swl) and heterozygous (Swl/+) mice and their postnatal dorsal root ganglion (DRG) of surviving Swl/+ mice. The Swl/+ mice could survive for a normal life span, while Swl/Swl could only survive till embryonic (E) 8.5 days. Excessive apoptosis of Swl/+ DRG neurons was revealed during E11.5-E15.5 days, and the peak rate was at E13.5 days. In vitro study of mutated DRG neurons showed impaired retrograde transport of dynein-driven nerve growth factor (NGF). Mitochondria, another dynein-driven cargo, demonstrated much slower retrograde transport velocity in Swl/+ neurons than in wild-type (WT) neurons. Nevertheless, the Swl, Loa, and Cra mutations did not affect homodimerization of DYNC1H1. The Swl/Swl mutation of Dync1h1 gene led to embryonic mal-development and lethality, whereas the Swl/+ DRG neurons demonstrated deficient retrograde transport in dynein-driven cargos and excessive apoptosis during mid- to late-developmental stages. The underlying mechanism of the mutation may not be due to impaired homodimerization of DYNC1H1. © 2016 John Wiley & Sons Ltd.

N-Acetylcysteine Prevents Retrograde Motor Neuron Death after Neonatal Peripheral Nerve Injury.

PubMed

Catapano, Joseph; Zhang, Jennifer; Scholl, David; Chiang, Cameron; Gordon, Tessa; Borschel, Gregory H

2017-05-01

Neuronal death may be an overlooked and unaddressed component of disability following neonatal nerve injuries, such as obstetric brachial plexus injury. N-acetylcysteine and acetyl-L-carnitine improve survival of neurons after adult nerve injury, but it is unknown whether they improve survival after neonatal injury, when neurons are most susceptible to retrograde neuronal death. The authors' objective was to examine whether N-acetylcysteine or acetyl-L-carnitine treatment improves survival of neonatal motor or sensory neurons in a rat model of neonatal nerve injury. Rat pups received either a sciatic nerve crush or transection injury at postnatal day 3 and were then randomized to receive either intraperitoneal vehicle (5% dextrose), N-acetylcysteine (750 mg/kg), or acetyl-L-carnitine (300 mg/kg) once or twice daily. Four weeks after injury, surviving neurons were retrograde-labeled with 4% Fluoro-Gold. The lumbar spinal cord and L4/L5 dorsal root ganglia were then harvested and sectioned to count surviving motor and sensory neurons. Transection and crush injuries resulted in significant motor and sensory neuron loss, with transection injury resulting in significantly less neuron survival. High-dose N-acetylcysteine (750 mg/kg twice daily) significantly increased motor neuron survival after neonatal sciatic nerve crush and transection injury. Neither N-acetylcysteine nor acetyl-L-carnitine treatment improved sensory neuron survival. Proximal neonatal nerve injuries, such as obstetric brachial plexus injury, produce significant retrograde neuronal death after injury. High-dose N-acetylcysteine significantly increases motor neuron survival, which may improve functional outcomes after obstetrical brachial plexus injury.

Formation of Tidally Induced Bars in Galactic Flybys: Prograde versus Retrograde Encounters

NASA Astrophysics Data System (ADS)

Łokas, Ewa L.

2018-04-01

Bars in disk galaxies can be formed by interactions with other systems, including those of comparable mass. It has long been established that the effect of such interactions on galaxy morphology depends strongly on the orbital configuration, in particular the orientation of the intrinsic spin of the galactic disk with respect to its orbital angular momentum. Prograde encounters modify the morphology strongly, including the formation of tidally induced bars, while retrograde flybys should have little effect on morphology. Recent works on the subject reached conflicting conclusions, one using the impulse approximation and claiming no dependence on this angle in the properties of tidal bars. To resolve the controversy, we performed self-consistent N-body simulations of hyperbolic encounters between two identical Milky Way-like galaxies assuming different velocities and impact parameters, with one of the galaxies on a prograde and the other on a retrograde orbit. The galaxies were initially composed of an exponential stellar disk and an NFW dark halo, and they were stable against bar formation in isolation for 3 Gyr. We find that strong tidally induced bars form only in galaxies on prograde orbits. For smaller impact parameters and lower relative velocities, the bars are stronger and have lower pattern speeds. Stronger bars undergo extended periods of buckling instability that thicken their vertical structure. The encounters also lead to the formation of two-armed spirals with strength inversely proportional to the strength of the bars. We conclude that proper modeling of prograde and retrograde encounters cannot rely on the simplest impulse approximation.

[Application of bone flap pedicled on retrograde branch of radial artery for treatment of old scaphoid bone fractures of type AO-B].

PubMed

Sun, Qing-peng

2015-05-01

To investigate application of the bone flap pedicled on the retrograde branch of radial artery for treatment of old scaphoid bone fractures of type AO-B. From October 2007 to October 2011,41 patients with old scaphoid bone fractures of type AO-B were treated by transplantation of the bone flap pedicled on the retrograde branch of radial artery including 26 males and 15 females with an average of (27.3±4.5) years old ranging from 16 to 43 years old. The courses before operation ranged from 6 to 22 months with an average of 11 months. All fractures belonged to the type B of AO classification, that is old wrist fracture of scaphoid bone. All patients' wrist function (pain, function, motion, grip strength) were evaluated by Cooney's modifiedwrist scoring system before and 6 months after operation,and the conditions of bone healing were observed during the follow-up time. Among them, 36 patients were followed up from 4 to 15 months with an average of 8.3 months. The wounds were healed well without other complications as infection appearing. X-rays or CT confirmed that all fractures were healed completely. The Cooney wrist score was improved from preoperative 53.61±13.97 to postoperative 81.81±8.71 (P<0.01). The operation of transplantation of the bone flap pedicled on the retrograde branch of radial artery is an effective method to treat old scaphoid bone fractures,which is scientific and has curative effects, and valuable for clinical application.

Vertical canaliculotomy with retrograde expression of concretions for the treatment of canaliculitis.

PubMed

Perumal, Balaji; Meyer, Dale R

2015-01-01

To evaluate the efficacy and safety of the technique of vertical canaliculotomy with retrograde expression of concretions for the treatment of canaliculitis. This is a retrospective, interventional case series. Patients who underwent vertical canaliculotomy by 1 surgeon (D.R.M.) from August 2011 to December 2013 were identified. On initial diagnosis of canaliculitis, all patients were treated with a combination antibiotic/steroid eyedrop and an oral antibiotic. The procedure was performed 1 month later and consisted of a 2-mm vertical canaliculotomy with sharp-tipped scissors followed by retrograde expression of the canalicular contents by compressing the canaliculus medial to lateral with 2 cotton-tipped applicators. All concretion specimens were sent for pathologic examination. Pre- and postoperative subjective complaints and objective findings on examination, including eyelid thickening and probing/irrigation results, were recorded. Canalicular contents were readily expressed from all 8 patients who underwent the procedure. Pathologic analysis revealed Actinomyces species in 5 of 8 specimens and other Gram-negative and Gram-positive bacteria in the remaining specimens. All patients reported significant improvement in their symptoms and were patent to irrigation. Many reported surgical procedures for the treatment of canaliculitis involve the use of a curette, an instrument with sharp edges, that could potentially damage the lining of the canaliculus. Previous studies examining these procedures have reported canalicular stricture and dysfunction postoperatively. The current technique of vertical canaliculotomy with retrograde expression of canalicular contents described herein has been effective, limits iatrogenic trauma, and had a low incidence of postoperative complications in this series.

A role for cyclin-dependent kinase(s) in the modulation of fast anterograde axonal transport: effects defined by olomoucine and the APC tumor suppressor protein

NASA Technical Reports Server (NTRS)

Ratner, N.; Bloom, G. S.; Brady, S. T.

1998-01-01

Proteins that interact with both cytoskeletal and membrane components are candidates to modulate membrane trafficking. The tumor suppressor proteins neurofibromin (NF1) and adenomatous polyposis coli (APC) both bind to microtubules and interact with membrane-associated proteins. The effects of recombinant NF1 and APC fragments on vesicle motility were evaluated by measuring fast axonal transport along microtubules in axoplasm from squid giant axons. APC4 (amino acids 1034-2844) reduced only anterograde movements, whereas APC2 (aa 1034-2130) or APC3 (aa 2130-2844) reduced both anterograde and retrograde transport. NF1 had no effect on organelle movement in either direction. Because APC contains multiple cyclin-dependent kinase (CDK) consensus phosphorylation motifs, the kinase inhibitor olomoucine was examined. At concentrations in which olomoucine is specific for cyclin-dependent kinases (5 microM), it reduced only anterograde transport, whereas anterograde and retrograde movement were both affected at concentrations at which other kinases are inhibited as well (50 microM). Both anterograde and retrograde transport also were inhibited by histone H1 and KSPXK peptides, substrates for proline-directed kinases, including CDKs. Our data suggest that CDK-like axonal kinases modulate fast anterograde transport and that other axonal kinases may be involved in modulating retrograde transport. The specific effect of APC4 on anterograde transport suggests a model in which the binding of APC to microtubules may limit the activity of axonal CDK kinase or kinases in restricted domains, thereby affecting organelle transport.

[The randomized controlled trial of the treatment for clavicular fracture by rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation].

PubMed

Bi, Hong-zheng; Yang, Mao-qing; Tan, Yuan-chao; Fu, Song

2008-07-01

To study the curative effect and safety of rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation in treating clavicular fracture. All 201 cases of clavicular fractures were randomly divided into treatment group (101 cases) and control group (100 cases). The treatment group was treated by rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation. The control group was treated by open reduction and internal fixation with Kirschner pin. All cases were followed up for 4 to 21 months (mean 10.6 months). SPSS was used to analyze clinic healing time of fracture and shoulder-joint function in both two groups. After operation, 101 cases of treatment group achieved union of fracture and the clinical healing time was 28 to 49 days (mean 34.5+/-2.7 days). In control group,there were 4 cases with nonunion of fracture,the other 96 cases were union,the clinical healing time was 36 to 92 days (mean 55.3+/-4.8 days). The excellent and good rate of shoulder-joint function was 100% in treatment group and 83% in control group. By t-test and chi2-test, there was significant difference between the two groups in curative effect (P<0.05). Rotatory manual reduction with forceps holder and retrograde pinning transfixation can be used in various kinds of clavicular shaft fracture, with many virtues such as easy operation, reliable fixation, short union time of fracture, good functional recovery of shoulder-joint and no incision scar affecting appearance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gandini, Roberto; Pipitone, Vincenzo; Stefanini, Matteo

The purpose of this study was to describe the efficacy of planned combined subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) to obtain the precise recanalization of the patent portion of a distal runoff vessel in critical limb ischemia (CLI) patients presenting long occlusions involving the popliteal trifurcation. Four patients at risk of limb loss due to long occlusions involving the leg vessel tree and not suitable for a surgical bypass were treated by the subintimal antegrade and retrograde (posterior tibial or anterior tibial artery) approach. The patent portion of the runoff vessel was previously assessed by magnetic resonance angiography (MRA)more » and directly punctured under Doppler ultrasound (US) guidance. A subintimal channel rendezvous was performed to allow snaring of the guidewires. Subsequently, a balloon dilatation was performed without stent deployment. All patients were successfully recanalized and had complete healing of the limb lesions. At the 12-month follow-up all patients showed clinical improvement with no major complications related to the procedure. This combined antegrade and retrograde subintimal approach is currently an excellent endovascular option in patients with long occlusions extending onto the leg vessels trifurcation and at risk of limb loss.« less

Palatine tonsillar metastasis of a small pulmonary adenocarcinoma showing an invasive micropapillary carcinoma pattern and Pagetoid spread at the tonsil: a case suggesting retrograde lymphatic metastasis from bulky lymph node metastases of the neck.

PubMed

Tajima, Shogo; Koda, Kenji

2015-01-01

Metastasis rarely occurs in the palatine tonsils. Among primary pulmonary carcinoma subtypes, small cell carcinoma more frequently metastasizes to this site. Herein, we present an exceedingly rare case of a small pulmonary adenocarcinoma that metastasized to the cervical lymph nodes and the right palatine tonsil in a 62-year-old man. In spite of the small size of the primary site, such extensive metastasis may have occurred because of the invasive micropapillary carcinoma pattern seen in the metastatic sites. The manner of metastasis to the palatine tonsil was considered retrograde lymphatic metastasis originating from carcinoma cells in the cervical lymph nodes. Furthermore, Pagetoid spread was observed at the palatine tonsil. Although there have been only a few cases showing retrograde lymphatic metastasis and Pagetoid spread at the metastatic site, we should be careful when speculating about the primary site based on such metastatic sites, especially when dealing with a biopsy sample exhibiting Pagetoid spread.

Processing of hemojuvelin requires retrograde trafficking to the Golgi in HepG2 cells.

PubMed

Maxson, Julia E; Enns, Caroline A; Zhang, An-Sheng

2009-02-19

Hemojuvelin (HJV) was recently identified as a critical regulator of iron homeostasis. It is either associated with cell membranes through a glycosylphosphatidylinositol anchor or released as a soluble form. Membrane-anchored HJV acts as a coreceptor for bone morphogenetic proteins and activates the transcription of hepcidin, a hormone that regulates iron efflux from cells. Soluble HJV antagonizes bone morphogenetic protein signaling and suppresses hepcidin expression. In this study, we examined the trafficking and processing of HJV. Cellular HJV reached the plasma membrane without obtaining complex oligosaccharides, indicating that HJV avoided Golgi processing. Secreted HJV, in contrast, has complex oligosaccharides and can be derived from HJV with high-mannose oligosaccharides at the plasma membrane. Our results support a model in which retrograde trafficking of HJV before cleavage is the predominant processing pathway. Release of HJV requires it to bind to the transmembrane receptor neogenin. Neogenin does not, however, play a role in HJV trafficking to the cell surface, suggesting that it could be involved either in retrograde trafficking of HJV or in cleavage leading to HJV release.

Processing of hemojuvelin requires retrograde trafficking to the Golgi in HepG2 cells

PubMed Central

Maxson, Julia E.; Enns, Caroline A.

2009-01-01

Hemojuvelin (HJV) was recently identified as a critical regulator of iron homeostasis. It is either associated with cell membranes through a glycosylphosphatidylinositol anchor or released as a soluble form. Membrane-anchored HJV acts as a coreceptor for bone morphogenetic proteins and activates the transcription of hepcidin, a hormone that regulates iron efflux from cells. Soluble HJV antagonizes bone morphogenetic protein signaling and suppresses hepcidin expression. In this study, we examined the trafficking and processing of HJV. Cellular HJV reached the plasma membrane without obtaining complex oligosaccharides, indicating that HJV avoided Golgi processing. Secreted HJV, in contrast, has complex oligosaccharides and can be derived from HJV with high-mannose oligosaccharides at the plasma membrane. Our results support a model in which retrograde trafficking of HJV before cleavage is the predominant processing pathway. Release of HJV requires it to bind to the transmembrane receptor neogenin. Neogenin does not, however, play a role in HJV trafficking to the cell surface, suggesting that it could be involved either in retrograde trafficking of HJV or in cleavage leading to HJV release. PMID:19029439

Neutralizing Monoclonal Antibodies against Disparate Epitopes on Ricin Toxin’s Enzymatic Subunit Interfere with Intracellular Toxin Transport

PubMed Central

Yermakova, Anastasiya; Klokk, Tove Irene; O’Hara, Joanne M.; Cole, Richard; Sandvig, Kirsten; Mantis, Nicholas J.

2016-01-01

Ricin is a member of the A-B family of bacterial and plant toxins that exploit retrograde trafficking to the Golgi apparatus and endoplasmic reticulum (ER) as a means to deliver their cytotoxic enzymatic subunits into the cytoplasm of mammalian cells. In this study we demonstrate that R70 and SyH7, two well-characterized monoclonal antibodies (mAbs) directed against distinct epitopes on the surface of ricin’s enzymatic subunit (RTA), interfere with toxin transport from the plasma membrane to the trans Golgi network. Toxin-mAb complexes formed on the cell surface delayed ricin’s egress from EEA-1+ and Rab7+ vesicles and enhanced toxin accumulation in LAMP-1+ vesicles, suggesting the complexes were destined for degradation in lysosomes. Three other RTA-specific neutralizing mAbs against different epitopes were similar to R70 and SyH7 in terms of their effects on ricin retrograde transport. We conclude that interference with toxin retrograde transport may be a hallmark of toxin-neutralizing antibodies directed against disparate epitopes on RTA. PMID:26949061

Neutralizing Monoclonal Antibodies against Disparate Epitopes on Ricin Toxin's Enzymatic Subunit Interfere with Intracellular Toxin Transport.

PubMed

Yermakova, Anastasiya; Klokk, Tove Irene; O'Hara, Joanne M; Cole, Richard; Sandvig, Kirsten; Mantis, Nicholas J

2016-03-07

Ricin is a member of the A-B family of bacterial and plant toxins that exploit retrograde trafficking to the Golgi apparatus and endoplasmic reticulum (ER) as a means to deliver their cytotoxic enzymatic subunits into the cytoplasm of mammalian cells. In this study we demonstrate that R70 and SyH7, two well-characterized monoclonal antibodies (mAbs) directed against distinct epitopes on the surface of ricin's enzymatic subunit (RTA), interfere with toxin transport from the plasma membrane to the trans Golgi network. Toxin-mAb complexes formed on the cell surface delayed ricin's egress from EEA-1(+) and Rab7(+) vesicles and enhanced toxin accumulation in LAMP-1(+) vesicles, suggesting the complexes were destined for degradation in lysosomes. Three other RTA-specific neutralizing mAbs against different epitopes were similar to R70 and SyH7 in terms of their effects on ricin retrograde transport. We conclude that interference with toxin retrograde transport may be a hallmark of toxin-neutralizing antibodies directed against disparate epitopes on RTA.

Anterograde and retrograde amnesia in a person with bilateral fornix lesions following removal of a colloid cyst.

PubMed

Poreh, Amir; Winocur, Gordon; Moscovitch, Morris; Backon, Matti; Goshen, Elinor; Ram, Zvi; Feldman, Zeev

2006-01-01

AD, a 45-year-old man, presented with a severe and global anterograde amnesia following surgery for removal of a colloid cyst. Structural neuroimaging confirmed bilateral lesions to the fornix and a small lesion in the basal forebrain. Testing for remote episodic memory of autobiographical events, and for remote semantic memory of personal and public events, and of famous people, revealed that AD had a severe retrograde amnesia for autobiographical episodes that covered his entire lifetime, and a time-limited retrograde amnesia for semantic memory. Because the fornix and basal forebrain lesions disrupted major afferent and efferent pathways of the hippocampus, it was concluded that the integrity of the hippocampus and its projections are needed to retain and/or recover autobiographical memories no matter how old they are. By contrast, hippocampal contribution to semantic memory is time-limited. These findings were interpreted as consistent with Multiple Trace Theory, which holds that the hippocampal system is essential for recovering contextually rich memories no matter how old they are, but is not needed for recovering semantic memories.

Slit2 as a β-catenin/Ctnnb1-dependent retrograde signal for presynaptic differentiation

PubMed Central

Wu, Haitao; Barik, Arnab; Lu, Yisheng; Shen, Chengyong; Bowman, Andrew; Li, Lei; Sathyamurthy, Anupama; Lin, Thiri W; Xiong, Wen-Cheng; Mei, Lin

2015-01-01

Neuromuscular junction formation requires proper interaction between motoneurons and muscle cells. β-Catenin (Ctnnb1) in muscle is critical for motoneuron differentiation; however, little is known about the relevant retrograde signal. In this paper, we dissected which functions of muscle Ctnnb1 are critical by an in vivo transgenic approach. We show that Ctnnb1 mutant without the transactivation domain was unable to rescue presynaptic deficits of Ctnnb1 mutation, indicating the involvement of transcription regulation. On the other hand, the cell-adhesion function of Ctnnb1 is dispensable. We screened for proteins that may serve as a Ctnnb1-directed retrograde factor and identified Slit2. Transgenic expression of Slit2 specifically in the muscle was able to diminish presynaptic deficits by Ctnnb1 mutation in mice. Slit2 immobilized on beads was able to induce synaptophysin puncta in axons of spinal cord explants. Together, these observations suggest that Slit2 serves as a factor utilized by muscle Ctnnb1 to direct presynaptic differentiation. DOI: http://dx.doi.org/10.7554/eLife.07266.001 PMID:26159615

Vomiting and gastric electrical dysrhythmia in dogs.

PubMed

Ueno, T; Chen, J D Z

2004-04-01

The correlation between gastric myoelectrical activity (GMA) and gastrointestinal symptoms such as nausea and vomiting is poorly understood. The aim of this study was to assess the association of GMA with vomiting induced by retrograde gastric electrical stimulation or duodenal balloon distention. Ten dogs were involved in this study. Vomiting was induced by retrograde gastric electrical stimulation in 6 dogs and by duodenal balloon distention in 4 dogs. Computerized spectral analysis and visual analysis were applied to detect the GMA change during various periods before and after vomiting. Gastric dysrhythmia preceded vomiting but was of brief duration. The major pattern of dysrhythmia immediately before vomiting was tachyarrhythmia and gastric slow wave was completely uncoupled before vomiting. Gastric dysrhythmia and slow wave uncoupling were also noticed immediately after vomiting but the dogs recovered quickly. The major pattern of dysrhythmia after vomiting was arrhythmia. GMA was normal during the periods other than 5 min before and during vomiting and 5 min after vomiting. Gastric dysrhythmia seems to be the cause of vomiting induced by retrograde gastric electrical stimulation or duodenal balloon distention. It is brief and characterized with tachyarrhythmia and uncoupling.

Impaired retrograde transport of axonal autophagosomes contributes to autophagic stress in Alzheimer’s disease neurons

PubMed Central

Tammineni, Prasad; Ye, Xuan; Feng, Tuancheng; Aikal, Daniyal; Cai, Qian

2017-01-01

Neurons face unique challenges of transporting nascent autophagic vacuoles (AVs) from distal axons toward the soma, where mature lysosomes are mainly located. Autophagy defects have been linked to Alzheimer’s disease (AD). However, the mechanisms underlying altered autophagy remain unknown. Here, we demonstrate that defective retrograde transport contributes to autophagic stress in AD axons. Amphisomes predominantly accumulate at axonal terminals of mutant hAPP mice and AD patient brains. Amyloid-β (Aβ) oligomers associate with AVs in AD axons and interact with dynein motors. This interaction impairs dynein recruitment to amphisomes through competitive interruption of dynein-Snapin motor-adaptor coupling, thus immobilizing them in distal axons. Consistently, deletion of Snapin in mice causes AD-like axonal autophagic stress, whereas overexpressing Snapin in hAPP neurons reduces autophagic accumulation at presynaptic terminals by enhancing AV retrograde transport. Altogether, our study provides new mechanistic insight into AD-associated autophagic stress, thus establishing a foundation for ameliorating axonal pathology in AD. DOI: http://dx.doi.org/10.7554/eLife.21776.001 PMID:28085665

Control of synaptic function by endocannabinoid-mediated retrograde signaling.

PubMed

Kano, Masanobu

2014-01-01

Since the first reports in 2001, great advances have been made towards the understanding of endocannabinoid-mediated synaptic modulation. Electrophysiological studies have revealed that one of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), is produced from membrane lipids upon postsynaptic Ca(2+) elevation and/or activation of Gq/11-coupled receptors, and released from postsynaptic neurons. The released 2-AG then acts retrogradely onto presynaptic cannabinoid CB1 receptors and induces suppression of neurotransmitter release either transiently or persistently. These forms of 2-AG-mediated retrograde synaptic modulation are functional throughout the brain. The other major endocannabinoid, anandamide, mediates a certain form of endocannabinoid-mediated long-term depression (LTD). Anandamide also functions as an agonist for transient receptor potential vanilloid receptor type 1 (TRPV1) and mediates endocannabinoid-independent and TRPV1-dependent forms of LTD. It has also been demonstrated that the endocannabinoid system itself is plastic, which can be either up- or down-regulated by experimental or environmental conditions. In this review, I will make an overview of the mechanisms underlying endocannabinoid-mediated synaptic modulation.

Control of synaptic function by endocannabinoid-mediated retrograde signaling

PubMed Central

KANO, Masanobu

2014-01-01

Since the first reports in 2001, great advances have been made towards the understanding of endocannabinoid-mediated synaptic modulation. Electrophysiological studies have revealed that one of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), is produced from membrane lipids upon postsynaptic Ca2+ elevation and/or activation of Gq/11-coupled receptors, and released from postsynaptic neurons. The released 2-AG then acts retrogradely onto presynaptic cannabinoid CB1 receptors and induces suppression of neurotransmitter release either transiently or persistently. These forms of 2-AG-mediated retrograde synaptic modulation are functional throughout the brain. The other major endocannabinoid, anandamide, mediates a certain form of endocannabinoid-mediated long-term depression (LTD). Anandamide also functions as an agonist for transient receptor potential vanilloid receptor type 1 (TRPV1) and mediates endocannabinoid-independent and TRPV1-dependent forms of LTD. It has also been demonstrated that the endocannabinoid system itself is plastic, which can be either up- or down-regulated by experimental or environmental conditions. In this review, I will make an overview of the mechanisms underlying endocannabinoid-mediated synaptic modulation. PMID:25169670

Aβ1-42 triggers the generation of a retrograde signaling complex from sentinel mRNAs in axons.

PubMed

Walker, Chandler A; Randolph, Lisa K; Matute, Carlos; Alberdi, Elena; Baleriola, Jimena; Hengst, Ulrich

2018-05-14

Neurons frequently encounter neurodegenerative signals first in their periphery. For example, exposure of axons to oligomeric Aβ 1-42 is sufficient to induce changes in the neuronal cell body that ultimately lead to degeneration. Currently, it is unclear how the information about the neurodegenerative insult is transmitted to the soma. Here, we find that the translation of pre-localized but normally silenced sentinel mRNAs in axons is induced within minutes of Aβ 1-42 addition in a Ca 2+ -dependent manner. This immediate protein synthesis following Aβ 1-42 exposure generates a retrograde signaling complex including vimentin. Inhibition of the immediate protein synthesis, knock-down of axonal vimentin synthesis, or inhibition of dynein-dependent transport to the soma prevented the normal cell body response to Aβ 1-42 These results establish that CNS axons react to neurodegenerative insults via the local translation of sentinel mRNAs encoding components of a retrograde signaling complex that transmit the information about the event to the neuronal soma. © 2018 The Authors.

Retrograde nail for tibiotalocalcaneal arthrodesis as a limb salvage procedure for open distal tibia and talus fractures with severe bone loss.

PubMed

Ochman, Sabine; Evers, Julia; Raschke, Michael J; Vordemvenne, Thomas

2012-01-01

The treatment of complex fractures of the distal tibia, ankle, and talus with soft tissue damage, bone loss, and nonreconstructable joints for which the optimal timing for reduction and fixation has been missed is challenging. In such cases primary arthrodesis might be a treatment option. We report a series of multi-injured patients with severe soft tissue damage and bone loss, who were treated with a retrograde tibiotalocalcaneal arthrodesis nail as a minimally invasive treatment option for limb salvage. After a median follow-up of 5.4 years, all patients returned to their former profession. The ankle and bone fusion was complete, with moderate functional results and quality of life. Calcaneotibial arthrodesis using a retrograde nail is a good treatment option for nonreconstructable fractures of the ankle joint with severe bone loss and poor soft tissue quality in selected patients with multiple injuries, in particular, those involving both lower extremities, as a salvage procedure. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Genome-wide siRNA screen identifies the retromer as a cellular entry factor for human papillomavirus

PubMed Central

Lipovsky, Alex; Popa, Andreea; Pimienta, Genaro; Wyler, Michael; Bhan, Ashima; Kuruvilla, Leena; Guie, Marie-Aude; Poffenberger, Adrian C.; Nelson, Christian D. S.; Atwood, Walter J.; DiMaio, Daniel

2013-01-01

Despite major advances in our understanding of many aspects of human papillomavirus (HPV) biology, HPV entry is poorly understood. To identify cellular genes required for HPV entry, we conducted a genome-wide screen for siRNAs that inhibited infection of HeLa cells by HPV16 pseudovirus. Many retrograde transport factors were required for efficient infection, including multiple subunits of the retromer, which initiates retrograde transport from the endosome to the trans-Golgi network (TGN). The retromer has not been previously implicated in virus entry. Furthermore, HPV16 capsid proteins arrive in the TGN/Golgi in a retromer-dependent fashion during entry, and incoming HPV proteins form a stable complex with retromer subunits. We propose that HPV16 directly engages the retromer at the early or late endosome and traffics to the TGN/Golgi via the retrograde pathway during cell entry. These results provide important insights into HPV entry, identify numerous potential antiviral targets, and suggest that the role of the retromer in infection by other viruses should be assessed. PMID:23569269

A Case of Traumatic Retrograde Type A Aortic Dissection Accompanied by Multiorgan Injuries.

PubMed

Tsukioka, Katsuaki; Kono, Tetsuya; Takahashi, Kohei; Kehara, Hiromu; Urashita, Shuichi; Komatsu, Kazunori

2018-03-25

A 75-year-old woman was involved in a traffic accident and suffered retrograde type A aortic dissection, multiple rib fractures, and grade II hepatic injury accompanied by intraperitoneal bleeding. We performed total arch replacement using an open stent graft with cardiopulmonary bypass and circulatory arrest. This procedure requires anticoagulation and hypothermia, which are principally contraindicated in severe trauma patients. However, this situation was resolved by managing the patient non-operatively for 7 days, confirming the stabilization of other injured organs, and then performing the surgery. She required prolonged postoperative rehabilitation; however, she recovered steadily.

Hippocampal amnesia.

PubMed

Spiers, H J; Maguire, E A; Burgess, N

2001-01-01

This article reviews 147 cases of amnesia following damage including the hippocampus or fornix as reported in 179 publications. The aetiology, mnestic abilities and reference(s) are tabulated for each case. Consistent findings across cases include the association of bilateral hippocampal damage with a deficit in anterograde episodic memory combined with spared procedural and working memory. The limited nature of retrograde amnesia following lesions to the fornix is also noted. Less consistent and thus more controversial findings, include effects of lesion size or laterality, deficits in semantic memory or familiarity-based recognition and the extent of retrograde amnesia. The evidence concerning these issues is reviewed across cases.

Remembering and knowing the past: a case study of isolated retrograde amnesia.

PubMed

Dalla Barba, G; Mantovan, M C; Ferruzza, E; Denes, G

1997-03-01

We describe a patient, RM, who suddenly became amnesic for premorbid autobiographic events in the absence of any known precipitating event. Learning abilities as well as semantic knowledge were normal. Knowledge of famous facts and persons was good, although not perfect. Whether RM suffered from organic or psychogenic isolated retrograde amnesia (IRA) could not be established on the basis of available clinical and neuropsychological elements. Regardless of its aetiology, RM's case respects the boundaries between semantic and episodic memory and so gives further support to the distinction between these two memory systems.

Brain protection in aortic arch aneurysm: antegrade or retrograde?

PubMed

Harky, Amer; Fok, Matthew; Bashir, Mohamad; Estrera, Anthony L

2018-01-03

During open aortic arch repair, there is an interruption of cerebral perfusion and to prevent neurological sequelae, the hypothermic circulatory arrest has been established to provide sufficient brain protection coupled with adjuncts including retrograde and antegrade cerebral perfusion. To date, brain protection during open aortic arch repair is a contested topic as to which provides superior brain protection with little evidence existing to suggest supremacy of one modality over the other. This article reviews current literature reflecting on key and emerging studies in brain protection and their associated outcomes in patients undergoing open aortic arch surgery.

Retrograde ejaculation, painful ejaculation and hematospermia

PubMed Central

Parnham, Arie

2016-01-01

Although there has been an increased interest on premature ejaculation in the recent years, our understanding regarding the disorders of retrograde ejaculation, painful ejaculation and hematospermia remain limited. All three of these conditions require a keen clinical acumen and willingness to engage in thinking outside of the standard established treatment paradigm. The development of novel investigational techniques and treatments has led to progress in the management of these conditions symptoms; however, the literature almost uniformly is limited to small series and rare randomised trials. Further investigation and randomised controlled trials are needed for progress in these often challenging cases. PMID:27652230

Multicenter study of retrograde open mesenteric artery stenting through laparotomy for treatment of acute and chronic mesenteric ischemia.

PubMed

Oderich, Gustavo S; Macedo, Rodrigo; Stone, David H; Woo, Edward Y; Panneton, Jean M; Resch, Timothy; Dias, Nuno V; Sonesson, Björn; Schermerhorn, Marc L; Lee, Jason T; Kalra, Manju; DeMartino, Randall R; Sandri, Giuliano de A; Ramos Tenorio, Emanuel J

2018-03-13

Retrograde open mesenteric stenting (ROMS) through laparotomy was introduced as an alternative to surgical bypass in patients with acute mesenteric ischemia (AMI). The purpose of this study was to evaluate the indications and outcomes of ROMS for treatment of AMI and chronic mesenteric ischemia. We reviewed the clinical data and outcomes of all consecutive patients treated by ROMS in seven academic centers from 2001 to 2013. ROMS was performed through laparotomy with retrograde access into the target mesenteric artery and stent placement using a retrograde or antegrade approach. End points were early (<30 days) and late mortality, morbidity, patency rates, and freedom from symptom recurrence and reintervention. There were 54 patients, 13 male and 41 female, with a mean age of 72 ± 11 years. Indications for ROMS were AMI in 44 patients (81%) and subacute-on-chronic mesenteric ischemia with flush mesenteric occlusion in 10 patients (19%). A total of 56 target mesenteric vessels were stented, including 52 superior mesenteric arteries and 4 celiac axis lesions, with a mean treatment length of 42 ± 26 mm. Retrograde mesenteric access was used in all patients, but 16 patients also required a simultaneous antegrade brachial approach. The retrograde puncture was closed primarily in 34 patients and with patch angioplasty in 17 patients; 1 patient had manual compression. Bowel resection was needed in 29 patients (66%) with AMI because of perforation or gangrene. Technical success was achieved in all (98%) except one patient for whom ROMS failed, who was treated by bypass. Early mortality was 45% (20/44) for AMI and 10% (1/10) for subacute-on-chronic mesenteric ischemia (P = .04). Early morbidity was 73% for AMI and 50% for subacute-on-chronic mesenteric ischemia (P = .27). Patient survival for the entire cohort was 43% ± 9% at 2 years. Primary patency and secondary patency at 2 years were 76% ± 8% and 90% ± 8%, respectively. Freedom from symptom recurrence and freedom from reinterventions were 72% ± 8% and 74% ± 8% at the same interval. ROMS offers an alternative to bypass or percutaneous stenting in patients with AMI who require abdominal exploration and in those who have flush mesenteric occlusions and have failed to respond to or are considered unsuitable for stenting by a percutaneous approach. Despite high technical success, mortality remains elevated in patients with AMI. Patency rates and freedom from symptom recurrence and reinterventions are comparable to the results achieved with stenting using percutaneous technique. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Nephron segment-specific gene expression using AAV vectors.

PubMed

Asico, Laureano D; Cuevas, Santiago; Ma, Xiaobo; Jose, Pedro A; Armando, Ines; Konkalmatt, Prasad R

2018-02-26

AAV9 vector provides efficient gene transfer in all segments of the renal nephron, with minimum expression in non-renal cells, when administered retrogradely via the ureter. It is important to restrict the transgene expression to the desired cell type within the kidney, so that the physiological endpoints represent the function of the transgene expressed in that specific cell type within kidney. We hypothesized that segment-specific gene expression within the kidney can be accomplished using the highly efficient AAV9 vectors carrying the promoters of genes that are expressed exclusively in the desired segment of the nephron in combination with administration by retrograde infusion into the kidney via the ureter. We constructed AAV vectors carrying eGFP under the control of: kidney-specific cadherin (KSPC) gene promoter for expression in the entire nephron; Na + /glucose co-transporter (SGLT2) gene promoter for expression in the S1 and S2 segments of the proximal tubule; sodium, potassium, 2 chloride co-transporter (NKCC2) gene promoter for expression in the thick ascending limb of Henle's loop (TALH); E-cadherin (ECAD) gene promoter for expression in the collecting duct (CD); and cytomegalovirus (CMV) early promoter that provides expression in most of the mammalian cells, as control. We tested the specificity of the promoter constructs in vitro for cell type-specific expression in mouse kidney cells in primary culture, followed by retrograde infusion of the AAV vectors via the ureter in the mouse. Our data show that AAV9 vector, in combination with the segment-specific promoters administered by retrograde infusion via the ureter, provides renal nephron segment-specific gene expression. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Plug-Assisted Retrograde Transvenous Obliteration for the Treatment of Gastric Varices: The Role of Intra-Procedural Cone-Beam Computed Tomography

PubMed Central

Ko, Gi-Young; Kwon, Young Baek; Yoon, Hyun-Ki; Sung, Kyu-Bo

2018-01-01

Objective To investigate the technical and clinical outcomes of plug-assisted retrograde transvenous obliteration (PARTO) for the treatment of gastric varices (GV) and to evaluate the role of intra-procedural cone-beam computed tomography (CBCT) performed during PARTO to confirm its technical success. Materials and Methods From January 2016 to December 2016, 17 patients with GV who had undergone PARTO were retrospectively evaluated. When the proximal part of the afferent vein was identified on a fluoroscopy, non-contrast CBCT images were obtained. In patients with incomplete embolization of GV, an additional injection of gelatin sponges was performed. Follow-up data from contrast-enhanced CT and upper intestinal endoscopy, as well as clinical and laboratory data were collected. Results Plug-assisted retrograde transvenous obliteration procedures were technically successful in all 17 patients. Complete embolization of GV was detected on CBCT images in 15 patients; whereas, incomplete embolization was detected in two. Complete embolization of GV was then achieved after an additional injection of gelatin sponges in these two patients as demonstrated on the 2nd CBCT image. The mean follow-up period after PARTO was 193 days (range, 73–383 days). A follow-up CT obtained 2–4 months after PARTO demonstrated marked shrinkage or complete obliteration of GV and portosystemic shunts in all 17 patients. There were no cases of variceal bleeding during the follow-up. Conclusion Plug-assisted retrograde transvenous obliteration is technically and clinically effective for the treatment of GV. In addition, intra-procedural CBCT can be an adjunct tool to fluoroscopy, because it can provide an immediate and accurate evaluation of the technical success of PARTO. PMID:29520179

Outcome of retrograde ureteric stenting as a urinary drainage procedure in ureteric obstruction related to malignant lesions.

PubMed

Wijayarathna, S; Suvendran, S; Ishak, M; Weligamage, A; Epa, A; Munasinghe, S; Abeygunaskera, A M

2014-12-01

We investigated the outcome of endoscopic retrograde ureteric stenting (RUS) in patients with ureteric obstruction related to malignant lesions. Data were prospectively collected from patients with ureteric obstruction related to malignant lesions treated at a single urology unit from 1 January 2011 to 30 April 2014. All patients had radiologically significant hydronephrosis by ultrasonography and CT scanning. First choice of urinary drainage was placing a retrograde ureteric stent cystoscopically. Outcome of patients who had stenting were recorded after following them until death or removal of stents. Eighty two patients with ureteric obstruction related to malignant lesions had complete data. In 33 (25%) patients, retrograde ureteric stenting was possible. Fifteen of them had recurrent tumour in the pelvis at the time of stenting and 13 (87%) were dead within 3 months of stenting. Four of the five patients who did not have pelvic tumour recurrence were alive at the end of the study. All eight patients who underwent stenting before surgery as a prophylactic measure and three of the five patients who had retroperitoneal tumour mass and underwent RUS were alive. Stenting was not possible in 42 patients. Thirty eight of them had pelvic tumour recurrences and two were having retroperitoneal tumour masses. Only one did not have tumour in the pelvis.CT evidence of tumour recurrence in the pelvis (OR 12.7; 95% CI 1.3-117.6; p=0.026) and high serum creatinine (OR 4.3; 95% CI 1.6-11.7; p=0.004) were associated with failure to ureteric stenting. Chances of successful RUS were low in patients with ureteric obstruction in the presence of tumour recurrences or elevated serum creatinine. Even if ureteric stenting was successful, their life expectancy was short.

Torques on Low-mass Bodies in Retrograde Orbit in Gaseous Disks

NASA Astrophysics Data System (ADS)

Sánchez-Salcedo, F. J.; Chametla, Raúl O.; Santillán, A.

2018-06-01

We evaluate the torque acting on a gravitational perturber on a retrograde circular orbit in the midplane of a gaseous disk. We assume that the mass of this satellite is so low that it weakly disturbs the disk (type I migration). The perturber may represent the companion of a binary system with a small mass ratio. We compare the results of hydrodynamical simulations with analytic predictions. Our 2D simulations indicate that the torque acting on a perturber with softening radius R soft can be accounted for by a scattering approach if {R}soft}< 0.3H, where H is defined as the ratio between the sound speed and the angular velocity at the orbital radius of the perturber. For R soft > 0.3H, the torque may present large and persistent oscillations, but the resultant time-averaged torque decreases rapidly with increasing R soft/H, in agreement with previous analytical studies. We then focus on the torque acting on small-size perturbers embedded in full 3D disks and argue that the density waves propagating at distances ≲H from the perturber contribute significantly to the torque because they transport angular momentum. We find a good agreement between the torque found in 3D simulations and analytical estimates based on ballistic orbits. We compare the radial migration timescales of prograde versus retrograde perturbers. For a certain range of the perturber’s mass and aspect ratio of the disk, the radial migration timescale in the retrograde case may be appreciably shorter than in the prograde case. We also provide the smoothing length required in 2D simulations in order to account for 3D effects.

Coil-Assisted Retrograde Transvenous Obliteration (CARTO) for the Treatment of Portal Hypertensive Variceal Bleeding: Preliminary Results

PubMed Central

Lee, Edward W; Saab, Sammy; Gomes, Antoinette S; Busuttil, Ronald; McWilliams, Justin; Durazo, Francisco; Han, Steven-Huy; Goldstein, Leonard; Tafti, Bashir A; Moriarty, John; Loh, Christopher T; Kee, Stephen T

2014-01-01

OBJECTIVES: To describe the technical feasibility, safety, and clinical outcomes of coil-assisted retrograde transvenous obliteration (CARTO) in treating portal hypertensive non-esophageal variceal hemorrhage. METHODS: From October 2012 to December 2013, 20 patients who received CARTO for the treatment of portal hypertensive non-esophageal variceal bleeding were retrospectively evaluated. All 20 patients had at least 6-month follow-up. All patients had detachable coils placed to occlude the efferent shunt and retrograde gelfoam embolization to achieve complete thrombosis/obliteration of varices. Technical success, clinical success, rebleeding, and complications were evaluated at follow-up. RESULTS: A 100% technical success rate (defined as achieving complete occlusion of efferent shunt with complete thrombosis/obliteration of bleeding varices and/or stopping variceal bleeding) was demonstrated in all 20 patients. Clinical success rate (defined as no variceal rebleeding) was 100%. Follow-up computed tomography after CARTO demonstrated decrease in size with complete thrombosis and disappearance of the varices in all 20 patients. Thirteen out of the 20 had endoscopic confirmation of resolution of varices. Minor post-CARTO complications, including worsening of esophageal varices (not bleeding) and worsening of ascites/hydrothorax, were noted in 5 patients (25%). One patient passed away at 24 days after the CARTO due to systemic and portal venous thrombosis and multi-organ failure. Otherwise, no major complication was noted. No variceal rebleeding was noted in all 20 patients during mean follow-up of 384±154 days. CONCLUSIONS: CARTO appears to be a technically feasible and safe alternative to traditional balloon-occluded retrograde transvenous obliteration or transjugular intrahepatic portosystemic shunt, with excellent clinical outcomes in treating portal hypertensive non-esophageal variceal bleeding. PMID:25273155

Stability of planetary orbits in triple star systems

NASA Astrophysics Data System (ADS)

Busetti, Franco; Beust, Hervé; Harley, Charis

2018-06-01

Triple stellar systems comprising a central binary orbited by a third star at a larger distance are fairly common. However, there have been very few studies on the stability of planetary orbits in such systems. There has been almost no work on generalised systems, little on retrograde planetary orbits and none on retrograde stellar orbits, with nearly all being for coplanar orbits and for a limited number of orbital parameters. We provide a generalised numerical mapping of the regions of planetary stability in triples, using the symplectic N-body code HJS (Beust 2003) designed for the dynamics of multiple hierarchical systems. We investigate all these orbit types and extend the parameters used to all relevant orbital elements of the triple’s stars, also expanding these elements and mass ratios to wider ranges.This establishes the regions of secular stability and results in empirical models describing the stability bounds for planets in each type of triple configuration, as functions of the various system parameters. These results are compared to the corresponding results for binaries in the limit of a vanishing mass of the third star. A general feature is that retrograde planetary orbits appear more stable than prograde ones, and that stable regions also tend to be wider when the third star's motion is retrograde. Conversely, we point out the destabilizing role of Kozai-Lidov resonance in non-coplanar systems, which shrinks the stability regions as a result of large induced eccentricity variations. Nonetheless, large enough stability regions for planets do exist in triples, and this should motivate future observational campaigns.Refs : Beust, 2003, A&A 400, 1129 Busetti, Beust, Harley, 2018, to be submitted to A&A

Diagnosis of Acute Appendicitis by Endoscopic Retrograde Appendicitis Therapy (ERAT): Combination of Colonoscopy and Endoscopic Retrograde Appendicography.

PubMed

Li, Yingchao; Mi, Chen; Li, Weizhi; She, Junjun

2016-11-01

Acute appendicitis is the most common abdominal emergency, but the diagnosis of appendicitis remains a challenge. Endoscopic retrograde appendicitis therapy (ERAT) is a new and minimally invasive procedure for the diagnosis and treatment of acute appendicitis. To investigate the diagnostic value of ERAT for acute appendicitis by the combination of colonoscopy and endoscopic retrograde appendicography (ERA). Twenty-one patients with the diagnosis of suspected uncomplicated acute appendicitis who underwent ERAT between November 2014 and January 2015 were included in this study. The main outcomes, imaging findings of acute appendicitis including colonoscopic direct-vision imaging and fluoroscopic ERA imaging, were retrospectively reviewed. Secondary outcomes included mean operative time, mean hospital stay, rate of complication, rate of appendectomy during follow-up period, and other clinical data. The diagnosis of acute appendicitis was established in 20 patients by positive ERA (5 patients) or colonoscopy (1 patient) alone or both (14 patients). The main colonoscopic imaging findings included mucosal inflammation (15/20, 75 %), appendicoliths (14/20, 70 %), and maturation (5/20, 25 %). The key points of ERA for diagnosing acute appendicitis included radiographic changes of appendix (17/20, 85 %), intraluminal appendicoliths (14/20, 70 %), and perforation (1/20, 5 %). Mean operative time of ERAT was 49.7 min, and mean hospital stay was 3.3 days. No patient converted to emergency appendectomy. Perforation occurred in one patient after appendicoliths removal was not severe and did not require invasive procedures. During at least 1-year follow-up period, only one patient underwent laparoscopic appendectomy. ERAT is a valuable procedure of choice providing a precise yield of diagnostic information for patients with suspected acute appendicitis by combination of colonoscopy and ERA.

Textural and isotopic development of marble assemblages during the Barrovian-style M2 metamorphic event, Naxos, Greece

NASA Astrophysics Data System (ADS)

Baker, Judy; Matthews, Alan

1994-03-01

A detailed petrological analysis of the marble assemblages observed within the M2 metamorphic complex on Naxos is presented. Two distinct periods of mineral growth are documented; the first is associated with prograde M2 metamorphism and the second with retrograde M2 metamorphism occurring during ductile extensional thinning of the complex. The textural and miner-alogical characteristics and the carbon and oxygen isotope compositions of each generation are described, and the P-T-X CO 2 conditions at which these two mineral generations were stable, and the compositions of the fluids present during metamorphism are characterised. Whereas the low variance and stable isotope compositions of prograde siliceous dolomite assemblages are consistent with internally buffered fluid evolution, the retrograde mineral generation is shown to have grown as a result of the infiltration of a water-rich fluid phase that transported silica, Al2O3, Na2O and FeO into the host rocks. This observation, together with the stable isotope compositions of the retrograde calcite, and the fact that occurrences of veins of this type are limited to marbles in the highest grade areas ( T>600° C) of the metamorphic complex, suggests that the fluids responsible for vein formation were generated during the crystallisation of melts as the metamorphic complex cooled from peak temperatures. The existence of this second generation of minerals has significant implications for previous studies of heat transport by fluid flow on Naxos, because many of the unusually low δ18O compositions of pelites at high grades may be ascribable to the effects of interaction with retrograde M2 fluids, rather than with prograde fluids.

Union rate of tibiotalocalcaneal nails with internal or external bone stimulation.

PubMed

De Vries, J George; Berlet, Gregory C; Hyer, Christopher F

2012-11-01

The use of bone growth stimulation has been reported in the application of hindfoot and ankle arthrodesis. Most studies have been retrospective case series with few patients. The authors present a comparative analysis of patients undergoing tibiotalocalcaneal (TTC) arthrodesis via a retrograde intramedullary arthrodesis nail to evaluate the influence of internal versus external bone stimulation in this population. One hundred fifty-four patients were treated with retrograde intramedullary nailing. A comprehensive chart and radiographic review was performed from a database of patients who underwent TTC fusion with or without bone stimulation. Ninety-one patients with retrograde TTC nailing were treated with direct current internal bone stimulation at the time of the index procedure (internal group) and 63 were treated with combined magnetic field external bone stimulation (external group). The primary end point was fusion with potential variables evaluated for influence on fusion rates. Demographically the cohorts were similar groups in age and comorbidities. Surgical and outcome data were examined, and there were few statistically significant differences between the two groups. There was no statistically significant difference in rate of union (52.7% and 57.1%, p = .63) or rate of complications between the internal and external groups. Overall, the success rate for achieving a stable, functional limb for the groups was 81.3% (74/91 patients) and 82.5% (52/63 patients) in the internal and external groups, respectively (p = .62). The authors demonstrated there were no statistically significant differences between the union and complication rate when comparing these types of internal and external bone stimulation in this patient population. Consideration of these results may help guide physicians when considering bone stimulation as an adjunct to TTC fusions with a retrograde intramedullary nail.

Vascularized Pedicled Fibula Onlay Bone Graft Augmentation for Complicated Tibiotalocalcaneal Arthrodesis With Retrograde Intramedullary Nail Fixation: A Case Series.

PubMed

Roukis, Thomas S; Kang, Rachel B

2016-01-01

Tibiotalocalcaneal arthrodesis stabilized with retrograde intramedullary nail fixation is associated with a high incidence of complications. This is especially true when performed with a bulk structural allograft and poor soft tissue quality. In select high-risk limb salvage cases, we have augmented tibiotalocalcaneal arthrodesis procedures stabilized using retrograde intramedullary nail fixation with a vascularized pedicled fibular onlay bone graft. We present the data from 10 such procedures with a mean follow-up period of 10.9 ± 5.4 (range 6 to 20) months involving 10 patients (9 males and 1 female). The etiology was avascular osteonecrosis of the talus and/or distal tibia and a resultant large volume cavitary bone defect (8 ankles), severe equinocavovarus contracture (1 ankle), and failed total ankle replacement (1 ankle). A frozen femoral head bulk allograft was used twice, a whole frozen talus allograft once, and a freeze-dried calcaneal allograft once. The fibula was mobilized with intact musculoperiosteal perforating branches of the peroneal artery as a vascularized pedicle onlay bone graft fixated with a screw and washer construct. The mean fibular graft length was 10.2 ± 2.3 cm. The mean interval to radiographic fusion was 2.6 ± 0.6 months and to weightbearing was 3.1 ± 1.4 months. Two stable bulk allograft-host bone and fibular graft-host bone nonunions occurred after intramedullary nail hardware failure. Tibiotalocalcaneal arthrodesis augmented by vascularized pedicled fibular graft stabilized with retrograde compression intramedullary nail fixation offers a reliable option for complex salvage situations when few other options exist. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

The effect of recombinant bone morphogenetic protein-2 in revision tibiotalocalcaneal arthrodesis: utilization of the Retrograde Arthrodesis Intramedullary Nail database.

PubMed

DeVries, J George; Nguyen, Minh; Berlet, Gregory C; Hyer, Christopher F

2012-01-01

The use of bone morphogenetic protein-2 (BMP-2) has been recommended for high-risk fusions and nonunion. Patients undergoing revisional tibiotalocalcaneal (TTC) arthrodesis via a retrograde arthrodesis nail to evaluate the influence of BMP-2 on rate of fusion in this high-risk population are presented. A retrospective chart and radiographic review were performed on 23 patients with failed prior fusion attempts at the ankle treated with retrograde intramedullary nailing. Sixteen patients were treated without BMP-2 (None group) and 7 were treated with BMP-2 (BMP group). The primary and secondary end-points were successful fusion, and time to fusion, respectively, with a variety of variables evaluated for influence. Other than the use of BMP-2, there were no statistical differences in the patient population. Overall, 11 of 16 ankles (68.8%) in the None group and 5 of 7 ankles (71.4%) in the BMP group resulted in a stable, functional limb. Rate of complication was similar between the 2 groups (p > .05). Time to radiographic ankle union was 115.2 and 184.0 days in the None and BMP groups (p > .05). The effect of BMP-2 on revisional TTC fusions with retrograde nails is reported here. The overall result as a stable, functional limb was 69.6%, which suggests that revision surgery in this high-risk population is a reasonable consideration. Even though this study was unable to demonstrate statistically significant differences, biologic augmentation with BMP-2 did not increase the complication rate and showed a slightly enhanced salvage rate for revision TTC fusions with an intramedullary nail. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Thulium laser urethrotomy for urethral stricture: a preliminary report.

PubMed

Wang, Linhui; Wang, Zhixiang; Yang, Bo; Yang, Qing; Sun, Yinghao

2010-09-01

The outcome of thulium laser urethrotomy for patients with urethral stricture had not been reported. The purpose of this study was to evaluate outcome of endourethrotomy with the thulium laser as a minimally invasive treatment for urethral stricture. Twenty-one consecutive patients with urethral stricture were evaluated by retrograde uroflowmetry, International Prostate Symptom Score (IPSS), and quality of life preoperatively at a single academic center. All patients were treated with thulium laser urethrotomy. All patients were followed up for 12-24 months postoperatively by uroflowmetry and by retrograde with voiding cystourethrogram every 3 months. And all patients were followed up by mailed questionnaire, including IPSS and quality of life. Retrograde endoscopic thulium laser urethrotomy was performed in all 21 patients. Most patients (N = 16; 76.2%) did not need any reintervention. Five patients developed recurrent strictures, of them two patients were treated by another laser urethrotomy, one patient was treated by open urethroplasty with buccal mucosa and the other two patients' reintervention were treated by urethral dilation. No intraoperative complications were encountered, although in 9.5% (N = 2) of patients, a urinary tract infection was diagnosed postoperatively. No gross hematuria occurred. Including two patients treated with repeat laser urethrotomy, 17(81.0%) showed good flow of urine (Q(ave)>16.0 ml/second) and adequate caliber urethra in retrograde urethrogram (RGU) 12 months after operation. Three (14.3%) patients showed narrow stream of urine (Q(ave)<8.0 ml/second) and urethral dilation was done every month or 2 months. There was one patient whose Q(ave) was between 8.0 and 16.0 ml/second. And this patient was treated by neither urethral dilation nor another laser urethrotomy. The thulium laser urethrotomy was a safe and effective minimally invasive therapeutic modality for urethral stricture. 2010 Wiley-Liss, Inc.

Intrathecal Bupivacaine Monotherapy with a Retrograde Catheter for the Management of Complex Regional Pain Syndrome of the Lower Extremity.

PubMed

McRoberts, W Porter; Apostol, Catalina; Haleem, Abdul

2016-01-01

Complex regional pain syndrome (CRPS) presents a therapeutic challenge due to its many presentations and multifaceted pathophysiology. There is no approved treatment algorithm and clinical interventions are often applied empirically. In cases of CRPS where symptoms are localized to an extremity, a targeted treatment is indicated. We describe the use of intrathecal bupivacaine monotherapy, delivered through a retrograde catheter, in the treatment of CRPS affecting the lower extremity. The patient, a 57-year-old woman with a history of failed foot surgery, was seen in our office after 2 years of ineffective treatments with local blocks and neurolytic procedures. We advanced therapy to moderately invasive procedures with an emphasis on neuromodulation. A combined central and peripheral stimulation technique that initially provided 75% pain relief, failed to provide lasting analgesia. We proceeded with an intrathecal pump implant. Based on the results of dorsal root ganglion (DRG) mapping, L5-S1 was identified as the optimal target for therapy and a retrograde catheter was placed at this level. Various intrathecal medications were tested individually. An intrathecal morphine trial was ineffective (visual analog scale [VAS] 7), while intrathecal clonidine provided excellent pain relief (VAS 0) that was limited by severe side effects. Bupivacaine provided 100% analgesia with tolerable side effects (lower extremity weakness and minor bladder incontinence) and was selected for intrathecal infusion. After 14 months, bupivacaine treatment continued to control pain exacerbations. We conclude that CRPS patients benefit from early identification of the predominant underlying symptoms and a targeted treatment with moderately invasive techniques when less invasive techniques fail. Intrathecal bupivacaine, bupivacaine monotherapy, retrograde catheter, complex regional pain syndrome (CRPS), dual stimulation, dosal root ganglion (DRG) testing.

Predicting Retrograde Autobiographical Memory Changes Following Electroconvulsive Therapy: Relationships between Individual, Treatment, and Early Clinical Factors.

PubMed

Martin, Donel M; Gálvez, Verònica; Loo, Colleen K

2015-06-19

Loss of personal memories experienced prior to receiving electroconvulsive therapy is common and distressing and in some patients can persist for many months following treatment. Improved understanding of the relationships between individual patient factors, electroconvulsive therapy treatment factors, and clinical indicators measured early in the electroconvulsive therapy course may help clinicians minimize these side effects through better management of the electroconvulsive therapy treatment approach. In this study we examined the associations between the above factors for predicting retrograde autobiographical memory changes following electroconvulsive therapy. Seventy-four depressed participants with major depressive disorder were administered electroconvulsive therapy 3 times per week using either a right unilateral or bitemporal electrode placement and brief or ultrabrief pulse width. Verbal fluency and retrograde autobiographical memory (assessed using the Columbia Autobiographical Memory Interview - Short Form) were tested at baseline and after the last electroconvulsive therapy treatment. Time to reorientation was measured immediately following the third and sixth electroconvulsive therapy treatments. Results confirmed the utility of measuring time to reorientation early during the electroconvulsive therapy treatment course as a predictor of greater retrograde amnesia and the importance of assessing baseline cognitive status for identifying patients at greater risk for developing later side effects. With increased number of electroconvulsive therapy treatments, older age was associated with increased time to reorientation. Consistency of verbal fluency performance was moderately correlated with change in Columbia Autobiographical Memory Interview - Short Form scores following right unilateral electroconvulsive therapy. Electroconvulsive therapy treatment techniques associated with lesser cognitive side effects should be particularly considered for patients with lower baseline cognitive status or older age. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Predicting Retrograde Autobiographical Memory Changes Following Electroconvulsive Therapy: Relationships between Individual, Treatment, and Early Clinical Factors

PubMed Central

Gálvez, Verònica; Loo, Colleen K.

2015-01-01

Background: Loss of personal memories experienced prior to receiving electroconvulsive therapy is common and distressing and in some patients can persist for many months following treatment. Improved understanding of the relationships between individual patient factors, electroconvulsive therapy treatment factors, and clinical indicators measured early in the electroconvulsive therapy course may help clinicians minimize these side effects through better management of the electroconvulsive therapy treatment approach. In this study we examined the associations between the above factors for predicting retrograde autobiographical memory changes following electroconvulsive therapy. Methods: Seventy-four depressed participants with major depressive disorder were administered electroconvulsive therapy 3 times per week using either a right unilateral or bitemporal electrode placement and brief or ultrabrief pulse width. Verbal fluency and retrograde autobiographical memory (assessed using the Columbia Autobiographical Memory Interview – Short Form) were tested at baseline and after the last electroconvulsive therapy treatment. Time to reorientation was measured immediately following the third and sixth electroconvulsive therapy treatments. Results: Results confirmed the utility of measuring time to reorientation early during the electroconvulsive therapy treatment course as a predictor of greater retrograde amnesia and the importance of assessing baseline cognitive status for identifying patients at greater risk for developing later side effects. With increased number of electroconvulsive therapy treatments, older age was associated with increased time to reorientation. Consistency of verbal fluency performance was moderately correlated with change in Columbia Autobiographical Memory Interview – Short Form scores following right unilateral electroconvulsive therapy. Conclusions: Electroconvulsive therapy treatment techniques associated with lesser cognitive side effects should be particularly considered for patients with lower baseline cognitive status or older age. PMID:26091817

Low RNA translation activit limits the efficacy of hydrodynamic gene transfer to pig liver in vivo.

PubMed

Sendra, Luis; Carreño, Omar; Miguel, Antonio; Montalvá, Eva; Herrero, María José; Orbis, Francisco; Noguera, Inmaculada; Barettino, Domingo; López-Andújar, Rafael; Aliño, Salvador F

2014-01-01

Hydrodynamic gene delivery has proved an efficient strategy for nonviral gene therapy in the murine liver but it has been less efficient in pigs. The reason for such inefficiency remains unclear. The present study used a surgical strategy to seal the whole pig liver in vivo. A solution of enhanced green fluorescent protein (eGFP) DNA was injected under two different venous injection conditions (anterograde and retrograde), employing flow rates of 10 and 20 ml/s in each case, with the aim of identifying the best gene transfer conditions. The gene delivery and information decoding steps were evaluated by measuring the eGFP DNA, mRNA and protein copy number 24 h after transfection. In addition, gold nanoparticles (diameters of 4 and 15 nm) were retrogradely injected (10 ml/s) to observe, by electron microscopy, the ability of the particle to access the hepatocyte. The gene delivery level was higher with anterograde injection, whereas the efficacy of gene expression was better with retrograde injection, suggesting differences in the decoding processes. Thus, retrograde injection mediates gene transcription (mRNA copy/cell) equivalent to that of intermediate expression proteins but the mRNA translation was lower than that of rare proteins. Electron microscopy showed that nanoparticles within the hepatocyte were almost exclusively 4 nm in diameter. The results suggest that the low activity of mRNA translation limits the final efficacy of the gene transfer procedure. On the other hand, the gold nanoparticles study suggests that elongated DNA conformation could offer advantages in that the access of 15-nm particles is very limited. Copyright © 2014 John Wiley & Sons, Ltd.

Definition of a core module for the nuclear retrograde response to altered organellar gene expression identifies GLK overexpressors as gun mutants.

PubMed

Leister, Dario; Kleine, Tatjana

2016-07-01

Retrograde signaling can be triggered by changes in organellar gene expression (OGE) induced by inhibitors such as lincomycin (LIN) or mutations that perturb OGE. Thus, an insufficiency of the organelle-targeted prolyl-tRNA synthetase PRORS1 in Arabidopsis thaliana activates retrograde signaling and reduces the expression of nuclear genes for photosynthetic proteins. Recently, we showed that mTERF6, a member of the so-called mitochondrial transcription termination factor (mTERF) family, is involved in the formation of chloroplast (cp) isoleucine-tRNA. To obtain further insights into its functions, co-expression analysis of MTERF6, PRORS1 and two other genes for organellar aminoacyl-tRNA synthetases was conducted. The results suggest a prominent role of mTERF6 in aminoacylation activity, light signaling and seed storage. Analysis of changes in whole-genome transcriptomes in the mterf6-1 mutant showed that levels of nuclear transcripts for cp OGE proteins were particularly affected. Comparison of the mterf6-1 transcriptome with that of prors1-2 showed that reduced aminoacylation of proline (prors1-2) and isoleucine (mterf6-1) tRNAs alters retrograde signaling in similar ways. Database analyses indicate that comparable gene expression changes are provoked by treatment with LIN, norflurazon or high light. A core OGE response module was defined by identifying genes that were differentially expressed under at least four of six conditions relevant to OGE signaling. Based on this module, overexpressors of the Golden2-like transcription factors GLK1 and GLK2 were identified as genomes uncoupled mutants. © 2016 Scandinavian Plant Physiology Society.

Quantification of in vivo colonic motor patterns in healthy humans before and after a meal revealed by high-resolution fiber-optic manometry

PubMed Central

DINNING, P. G.; WIKLENDT, L.; MASLEN, L.; GIBBINS, I.; PATTON, V.; ARKWRIGHT, J. W.; LUBOWSKI, D. Z.; O'GRADY, G.; BAMPTON, P. A.; BROOKES, S. J.; COSTA, M.

2015-01-01

Background Until recently, investigations of the normal patterns of motility of the healthy human colon have been limited by the resolution of in vivo recording techniques. Methods We have used a new, high-resolution fiber-optic manometry system (72 sensors at 1-cm intervals) to record motor activity from colon in 10 healthy human subjects. Key Results In the fasted colon, on the basis of rate and extent of propagation, four types of propagating motor pattern could be identified: (i) cyclic motor patterns (at 2–6/min); (ii) short single motor patterns; (iii) long single motor patterns; and (iv) occasional retrograde, slow motor patterns. For the most part, the cyclic and short single motor patterns propagated in a retrograde direction. Following a 700 kCal meal, a fifth motor pattern appeared; high-amplitude propagating sequences (HAPS) and there was large increase in retrograde cyclic motor patterns (5.6±5.4/2 h vs 34.7±19.8/2 h; p < 0.001). The duration and amplitude of individual pressure events were significantly correlated. Discriminant and multivariate analysis of duration, gradient, and amplitude of the pressure events that made up propagating motor patterns distinguished clearly two types of pressure events: those belonging to HAPS and those belonging to all other propagating motor patterns. Conclusions & Inferences This work provides the first comprehensive description of colonic motor patterns recorded by high-resolution manometry and demonstrates an abundance of retrograde propagating motor patterns. The propagating motor patterns appear to be generated by two independent sources, potentially indicating their neurogenic or myogenic origin. PMID:25131177

Trafficking of cell surface beta-amyloid precursor protein: retrograde and transcytotic transport in cultured neurons

PubMed Central

1995-01-01

Amyloid beta-protein (A beta), the principal constituent of senile plaques seen in Alzheimer's disease (AD), is derived by proteolysis from the beta-amyloid precursor protein (beta PP). The mechanism of A beta production in neurons, which are hypothesized to be a rich source of A beta in brain, remains to be defined. In this study, we describe a detailed localization of cell surface beta PP and its subsequent trafficking in primary cultured neurons. Full-length cell surface beta PP was present primarily on perikarya and axons, the latter with a characteristic discontinuous pattern. At growth cones, cell surface beta PP was inconsistently detected. By visualizing the distribution of beta PP monoclonal antibodies added to intact cultures, beta PP was shown to be internalized from distal axons or terminals and retrogradely transported back to perikarya in organelles which colocalized with fluid-phase endocytic markers. Retrograde transport of beta PP was shown in both hippocampal and peripheral sympathetic neurons, the latter using a compartment culture system that isolated cell bodies from distal axons and terminals. In addition, we demonstrated that beta PP from distal axons was transcytotically transported to the surface of perikarya from distal axons in sympathetic neurons. Indirect evidence of this transcytotic pathway was obtained in hippocampal neurons using antisense oligonucleotide to the kinesin heavy chain to inhibit anterograde beta PP transport. Taken together, these results demonstrate novel aspects of beta PP trafficking in neurons, including retrograde axonal transport and transcytosis. Moreover, the axonal predominance of cell surface beta PP is unexpected in view of the recent report of polarized sorting of beta PP to the basolateral domain of MDCK cells. PMID:7721945

Robot-assisted laparoscopic radical prostatectomy with early retrograde release of the neurovascular bundle and endopelvic fascia sparing

PubMed Central

de Albuquerque, George Augusto Monteiro Lins; Guglielmetti, Giuliano Betoni; Cordeiro, Maurício Dener; Nahas, William Carlos; Coelho, Rafael Ferreira

2017-01-01

ABSTRACT Introduction Robotic-assisted radical prostatectomy (RAP) is the dominant minimally invasive surgical treatment for patients with localized prostate cancer. The introduction of robotic assistance has the potential to improve surgical outcomes and reduce the steep learning curve associated with conventional laparoscopic radical prostatectomy. The purpose of this video is to demonstrate the early retrograde release of the neurovascular bundle without open the endopelvic fascia during RAP. Materials and Methods A 51-year old male, presenting histological diagnosis of prostate adenocarcinoma, Gleason 6 (3+3), in 4 cores of 12, with an initial PSA=3.41ng/dl and the digital rectal examination demonstrating a prostate with hardened nodule in the right lobe of the prostate base (clinical stage T2a). Surgical treatment with the robot-assisted technique was offered as initial therapeutic option and the critical technical point was the early retrograde release of the neurovascular bundle with endopelvic fascia preservation, during radical prostatectomy. Results The operative time was of 89 minutes, blood loss was 100ml. No drain was left in the peritoneal cavity. The patient was discharged within 24 hours. There were no intraoperative or immediate postoperative complications. The pathological evaluation revealed prostate adenocarcinoma, Gleason 6, with free surgical margins and seminal vesicles free of neoplastic involvement (pathologic stage T2a). At 3-month-follow-up, the patient lies with undetectable PSA, continent and potent. Conclusion This is a feasible technique combining the benefits of retrograde release of the neurovascular bundle, the preservation of the pubo-prostatic collar and the preservation of the antero-lateral cavernous nerves. PMID:27802002

Terminal field specificity of forebrain efferent axons to the pontine parabrachial nucleus and medullary reticular formation

PubMed Central

Zhang, Chi; Kang, Yi; Lundy, Robert F.

2010-01-01

The pontine parabrachial nucleus (PBN) and medullary reticular formation (RF) are hindbrain regions that, respectively, process sensory input and coordinate motor output related to ingestive behavior. Neural processing in each hindbrain site is subject to modulation originating from several forebrain structures including the insular gustatory cortex (IC), bed nucleus of the stria terminalis (BNST), central nucleus of the amygdala (CeA), and lateral hypothalamus (LH). The present study combined electrophysiology and retrograde tracing techniques to determine the extent of overlap between neurons within the IC, BNST, CeA and LH that target both the PBN and RF. One fluorescent retrograde tracer, red (RFB) or green (GFB) latex microbeads, was injected into the gustatory PBN under electrophysiological guidance and a different retrograde tracer, GFB or fluorogold (FG), into the ipsilateral RF using the location of gustatory NST as a point of reference. Brain tissue containing each forebrain region was sectioned, scanned using a confocal microscope, and scored for the number of single and double labeled neurons. Neurons innervating the RF only, the PBN only, or both the medullary RF and PBN were observed, largely intermingled, in each forebrain region. The CeA contained the largest number of cells retrogradely labeled after tracer injection into either hindbrain region. For each forebrain area except the IC, the origin of descending input to the RF and PBN was almost entirely ipsilateral. Axons from a small percentage of hindbrain projecting forebrain neurons targeted both the PBN and RF. Target specific and non specific inputs from a variety of forebrain nuclei to the hindbrain likely reflect functional specialization in the control of ingestive behaviors. PMID:21040715

Outcomes of long retrograde intramedullary nailing for periprosthetic supracondylar femoral fractures following total knee arthroplasty.

PubMed

Lee, Sung-San; Lim, Seung-Jae; Moon, Young-Wan; Seo, Jai-Gon

2014-01-01

The treatment of periprosthetic supracondylar femoral fractures following total knee arthroplasty (TKA) is challenging because of osteopenia and the limited bone available for distal fixation. The purpose of this study was to report the outcomes of periprosthetic supracondylar femoral fractures treated with long retrograde intramedullary nailing. We conducted a retrospective review of 25 patients who were treated with a long retrograde intramedullary nail for periprosthetic supracondylar femoral fractures following TKA. Clinical evaluation included range of motion of knee, Knee Society Score (KSS), Western Ontario and McMaster Universities Arthritis (WOMAC) score, and radiologic evaluation including time to union, coronal and sagittal alignment of femoral component, lower limb alignment, and implant loosening. The mean duration of follow-up after the fracture repair was 39 months (range 12-47). All 25 fractures were united with a mean time of 12 weeks (range 8-20). At the last follow-up, the mean knee flexion was 111° (range 60°-130°), the mean KSS was 81.5 (range 50-100), and the mean WOMAC score was 30.2 (range 5-55). Four (16%) of the 25 patients developed malalignment according to Rorabeck and Taylor criteria, but all patients had a knee flexion of more than 90°. Coronal and sagittal alignments of femoral component and lower limb alignment did not differ significantly between before and after the fracture repair. Complications included the loosening or breakage of distal interlocking screws in three patients. No deep infection or prosthesis loosening was detected at the last follow-up. Surgical treatment of periprosthetic supracondylar femoral fractures following TKA with long retrograde intramedullary nailing resulted in high union rates and encouraging functional outcomes.

Combat Veterans with Comorbid PTSD and Mild TBI Exhibit a Greater Inhibitory Processing ERP from the Dorsal Anterior Cingulate Cortex

DTIC Science & Technology

2014-08-08

Blast-related n¼13 n¼14 1.00 Number of blasts 13.8720.1 6.277.3 0.20 LOC n¼7 n¼6 0.72 Retrograde amnesia n¼3 n¼2 0.65 PCS n¼10 n¼11 0.70 BDI-II, Beck...e.g. loss of consciousness or retrograde amnesia ) (Table 1). Behaviorally, groups did not differ on total number of errors during Stop Trials. One...B., Schmahl, C., Bremner, J.D., Spiegel, D., 2010. Emotion modulation in PTSD: clinical and neurobiological evidence for a dissociative subtype

Endovascular Treatment of Totally Occluded Superior Mesenteric Artery by Retrograde Crossing via the Villemin Arcade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferro, Carlo; Rossi, Umberto G., E-mail: urossi76@hotmail.com; Seitun, Sara

2013-06-15

Chronic mesenteric ischemia (CMI) is a rare disorder that is commonly caused by progressive atherosclerotic stenosis or occlusion of one or more mesenteric arteries. Endovascular treatment for symptomatic CMI represents a viable option, especially in high-operative risk patients. We report a case of acute symptomatic CMI with chronic totally occlusion of the superior mesenteric artery (SMA) associated with significant stenosis of celiac trunk (CT) and inferior mesenteric artery (IMA) that underwent endovascular treatment of all the three mesenteric arteries: stenting of CT and IMA stenosis, and recanalization of the SMA occlusion by retrograde crossing via the Villemin arcade.

A new mode of mitochondrial transport and polarized sorting regulated by Dynein, Milton and Miro.

PubMed

Melkov, Anna; Baskar, Raju; Alcalay, Yehonatan; Abdu, Uri

2016-11-15

Intrinsic cell microtubule (MT) polarity, together with molecular motors and adaptor proteins, determines mitochondrial polarized targeting and MT-dependent transport. In polarized cells, such as neurons, mitochondrial mobility and transport require the regulation of kinesin and dynein by two adaptor proteins, Milton and Miro. Recently, we found that dynein heavy chain 64C (Dhc64C) is the primary motor protein for both anterograde and retrograde transport of mitochondria in the Drosophila bristle. In this study, we show that a molecular lesion in the Dhc64C allele that reduced bristle mitochondrial velocity generated a variant that acts as a 'slow' dynein in an MT-gliding assay, indicating that dynein directly regulates mitochondrial transport. We also showed that in milton-RNAi flies, mitochondrial flux into the bristle shaft, but not velocity, was significantly reduced. Surprisingly, mitochondria retrograde flux, but not net velocity, was significantly decreased in miro-RNAi flies. We thus reveal a new mode of mitochondrial sorting in polarized cell growth, whereby bi-directional mitochondrial transport undertaken exclusively by dynein is regulated by Milton in the anterograde direction and by a Miro-dependent switch to the retrograde direction. © 2016. Published by The Company of Biologists Ltd.

The diagnosis and treatment of penile fracture: our 19-year experience.

PubMed

Gedik, Abdullah; Kayan, Devrim; Yamiş, Sait; Yılmaz, Yakup; Bircan, Kamuran

2011-01-01

The aim of this study was to retrospectively evaluate our approach to the diagnosis and treatment of penile fracture. We retrospectively evaluated the results of 107 patients with penile fracture treated in our clinic between January 1990 and January 2009. Patient age, etiology of each fracture, history, physical examination results, radiologic findings, type of treatment, and postoperative complications were recorded. In 5 cases cavernosography was performed and in 8 cases retrograde urethrography. The most common etiologies of penile fracture were coitus and manually bending the penis for detumescence. Diagnoses were made based on history and physical examination in 102 patients and cavernosography in 5 patients. In order to evaluate urethral injury in 8 cases, retrograde urethrography was performed. Rupture was repaired surgically in 101 patients, but 6 patients were treated conservatively. Among the 6 conservatively treated patients, 3 developed penile curvature 6 months post-treatment; no complications occurred in the surgically treated patients. Cavernosography should be performed only when history and physical examination are insufficient for diagnosis, and retrograde urethrography should be performed when urethral injury is suspected. In order to prevent the development of penile curvature and to ensure rapid recovery, early surgical repair is advised.

Impact of sodium chloride on wheat flour dough for yeast-leavened products. II. Baking quality parameters and their relationship.

PubMed

Beck, Margit; Jekle, Mario; Becker, Thomas

2012-01-30

The traditional use of sodium chloride (NaCl) fulfills various important rheological, technological and sensory properties in the manufacturing of yeast-leavened products. However, the use of NaCl in food production has been discussed controversially since a high intake of sodium seems to be associated with hypertension. This study investigates the baking quality parameters of wheat breads containing various levels of NaCl (0-40 g NaCl kg(-1) flour). Crumb firmness and rate of bread staling decreased with decreasing NaCl levels. A slight increase in loaf volume was observed based on the increased yeast leavening ability resulting from additional NaCl. Higher crumb retrogradation (measured by differential scanning calorimetry) was observed with low NaCl levels. The retrogradation effect is based on the theory that NaCl probably leads to Na(+) inclusion in starch molecules during storage and thus reduces retrogradation. Further, significant (P⩽0.05) linear relationships (r ≥ 0.829) between Rheofermentometer results, bread volume and crumb firmness were found, suggesting a predictability of bread quality by measurement of gas release. Copyright © 2011 Society of Chemical Industry.

Pulsatile extracorporeal circulation during on-pump cardiac surgery enhances aortic wall shear stress.

PubMed

Assmann, Alexander; Benim, Ali Cemal; Gül, Fethi; Lux, Philipp; Akhyari, Payam; Boeken, Udo; Joos, Franz; Feindt, Peter; Lichtenberg, Artur

2012-01-03

Controversy on superiority of pulsatile versus non-pulsatile extracorporeal circulation in cardiac surgery still continues. Stroke as one of the major adverse events during cardiopulmonary bypass is, in the majority of cases, caused by mobilization of aortic arteriosclerotic plaques that is inducible by pathologically elevated wall shear stress values. The present study employs computational fluid dynamics to evaluate the aortic blood flow and wall shear stress profiles under the influence of antegrade or retrograde perfusion with pulsatile versus non-pulsatile extracorporeal circulation. While, compared to physiological flow, a non-pulsatile perfusion resulted in generally decreased blood velocities and only moderately increased shear forces (48 Pa versus 20 Pa antegradely and 127 Pa versus 30 Pa retrogradely), a pulsatile perfusion extensively enhanced the occurrence of turbulences, maximum blood flow speed and maximum wall shear stress (1020 Pa versus 20 Pa antegradely and 1178 Pa versus 30 Pa retrogradely). Under these circumstances arteriosclerotic embolism has to be considered. Further simulations and experimental work are necessary to elucidate the impact of our findings on the scientific discourse of pulsatile versus non-pulsatile extracorporeal circulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of thyroid state on respiration of perfused rat and guinea pig hearts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Read, L.C.; Wallace, P.G.; Berry, M.N.

1987-09-01

The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na{sup 131}I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. Inmore » the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses.« less

AP2/EREBP transcription factors are part of gene regulatory networks and integrate metabolic, hormonal and environmental signals in stress acclimation and retrograde signalling.

PubMed

Dietz, Karl-Josef; Vogel, Marc Oliver; Viehhauser, Andrea

2010-09-01

To optimize acclimation responses to environmental growth conditions, plants integrate and weigh a diversity of input signals. Signal integration within the signalling networks occurs at different sites including the level of transcription factor activation. Accumulating evidence assigns a major and diversified role in environmental signal integration to the family of APETALA 2/ethylene response element binding protein (AP2/EREBP) transcription factors. Presently, the Plant Transcription Factor Database 3.0 assigns 147 gene loci to this family in Arabidopsis thaliana, 200 in Populus trichocarpa and 163 in Oryza sativa subsp. japonica as compared to 13 to 14 in unicellular algae ( http://plntfdb.bio.uni-potsdam.de/v3.0/ ). AP2/EREBP transcription factors have been implicated in hormone, sugar and redox signalling in context of abiotic stresses such as cold and drought. This review exemplarily addresses present-day knowledge of selected AP2/EREBP with focus on a function in stress signal integration and retrograde signalling and defines AP2/EREBP-linked gene networks from transcriptional profiling-based graphical Gaussian models. The latter approach suggests highly interlinked functions of AP2/EREBPs in retrograde and stress signalling.

Distal axotomy enhances retrograde presynaptic excitability onto injured pyramidal neurons via trans-synaptic signaling.

PubMed

Nagendran, Tharkika; Larsen, Rylan S; Bigler, Rebecca L; Frost, Shawn B; Philpot, Benjamin D; Nudo, Randolph J; Taylor, Anne Marion

2017-09-20

Injury of CNS nerve tracts remodels circuitry through dendritic spine loss and hyper-excitability, thus influencing recovery. Due to the complexity of the CNS, a mechanistic understanding of injury-induced synaptic remodeling remains unclear. Using microfluidic chambers to separate and injure distal axons, we show that axotomy causes retrograde dendritic spine loss at directly injured pyramidal neurons followed by retrograde presynaptic hyper-excitability. These remodeling events require activity at the site of injury, axon-to-soma signaling, and transcription. Similarly, directly injured corticospinal neurons in vivo also exhibit a specific increase in spiking following axon injury. Axotomy-induced hyper-excitability of cultured neurons coincides with elimination of inhibitory inputs onto injured neurons, including those formed onto dendritic spines. Netrin-1 downregulation occurs following axon injury and exogenous netrin-1 applied after injury normalizes spine density, presynaptic excitability, and inhibitory inputs at injured neurons. Our findings show that intrinsic signaling within damaged neurons regulates synaptic remodeling and involves netrin-1 signaling.Spinal cord injury can induce synaptic reorganization and remodeling in the brain. Here the authors study how severed distal axons signal back to the cell body to induce hyperexcitability, loss of inhibition and enhanced presynaptic release through netrin-1.

Dissociative amnesia.

PubMed

Staniloiu, Angelica; Markowitsch, Hans J

2014-08-01

Dissociative amnesia is one of the most enigmatic and controversial psychiatric disorders. In the past two decades, interest in the understanding of its pathophysiology has surged. In this report, we review new data about the epidemiology, neurobiology, and neuroimaging of dissociative amnesia and show how advances in memory research and neurobiology of dissociation inform proposed pathogenetic models of the disorder. Dissociative amnesia is characterised by functional impairment. Additionally, preliminary data suggest that affected people have an increased and possibly underestimated suicide risk. The prevalence of dissociative amnesia differs substantially across countries and populations. Symptoms and disease course also vary, indicating a possibly heterogeneous disorder. The accompanying clinical features differ across cultural groups. Most dissociative amnesias are retrograde, with memory impairments mainly involving the episodic-autobiographical memory domain. Anterograde dissociative amnesia occurring without significant retrograde memory impairments is rare. Functional neuroimaging studies of dissociative amnesia with prevailing retrograde memory impairments show changes in the network that subserves autobiographical memory. At present, no evidence-based treatments are available for dissociative amnesia and no broad framework exists for its rehabilitation. Further research is needed into its neurobiology, course, treatment options, and strategies to improve differential diagnoses. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibitors of retrograde trafficking active against ricin and Shiga toxins also protect cells from several viruses, Leishmania and Chlamydiales.

PubMed

Gupta, Neetu; Noël, Romain; Goudet, Amélie; Hinsinger, Karen; Michau, Aurélien; Pons, Valérie; Abdelkafi, Hajer; Secher, Thomas; Shima, Ayaka; Shtanko, Olena; Sakurai, Yasuteru; Cojean, Sandrine; Pomel, Sébastien; Liévin-Le Moal, Vanessa; Leignel, Véronique; Herweg, Jo-Ana; Fischer, Annette; Johannes, Ludger; Harrison, Kate; Beard, Philippa M; Clayette, Pascal; Le Grand, Roger; Rayner, Jonathan O; Rudel, Thomas; Vacus, Joël; Loiseau, Philippe M; Davey, Robert A; Oswald, Eric; Cintrat, Jean-Christophe; Barbier, Julien; Gillet, Daniel

2017-04-01

Medical countermeasures to treat biothreat agent infections require broad-spectrum therapeutics that do not induce agent resistance. A cell-based high-throughput screen (HTS) against ricin toxin combined with hit optimization allowed selection of a family of compounds that meet these requirements. The hit compound Retro-2 and its derivatives have been demonstrated to be safe in vivo in mice even at high doses. Moreover, Retro-2 is an inhibitor of retrograde transport that affects syntaxin-5-dependent toxins and pathogens. As a consequence, it has a broad-spectrum activity that has been demonstrated both in vitro and in vivo against ricin, Shiga toxin-producing O104:H4 entero-hemorrhagic E. coli and Leishmania sp. and in vitro against Ebola, Marburg and poxviruses and Chlamydiales. An effect is anticipated on other toxins or pathogens that use retrograde trafficking and syntaxin-5. Since Retro-2 targets cell components of the host and not directly the pathogen, no selection of resistant pathogens is expected. These lead compounds need now to be developed as drugs for human use. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Long-term memory following transient global amnesia: an investigation of episodic and semantic memory.

PubMed

Guillery-Girard, B; Quinette, P; Desgranges, B; Piolino, P; Viader, F; de la Sayette, V; Eustache, F

2006-11-01

Several studies noted persistence of memory impairment following an episode of transient global amnesia (TGA) with standard tests. To specify long-term memory impairments in a group of patients selected with stringent criteria. Both retrograde and anterograde memory were investigated in 32 patients 13-67 months after a TGA episode with original tasks encompassing retrograde semantic memory (academic, public and personal knowledge), retrograde episodic memory (autobiographical events) and anterograde episodic memory. Patients had preserved academic and public knowledge. Pathological scores were obtained in personal verbal fluency for the two most recent periods, and patients produced less autobiographical events than controls. However, when they were provided time to detail, memories were as episodic as in controls regardless of their remoteness. Anterograde episodic tasks revealed a mild but significant impairment of the capacity of re-living the condition of encoding, i.e. the moment at which words were presented. Patients who have suffered from an episode of TGA manifest deficits of memory focused on the retrieval of both recent semantic information and episodic memories and especially the capacity of re-living. These deficits may not result from a deterioration of memory per se but rather from difficulties in accessing memories.

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF

PubMed Central

Ravenna, F.; Feo, C.; Calia, N.; Avoscan, C.; Barbetta, C.; Cavallesco, G. N.

2012-01-01

We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula's bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain. PMID:23091498

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF.

PubMed

Ravenna, F; Feo, C; Calia, N; Avoscan, C; Barbetta, C; Cavallesco, G N

2012-01-01

We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula's bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain.

Is local anesthesia the optimum strategy in retrograde transcatheter aortic valve implantation? A systematic review and meta-analysis.

PubMed

O' Sullivan, Katie E; Bracken-Clarke, Darragh; Segurado, Ricardo; Barry, Mitchel; Sugrue, Declan; Flood, Georgina; Hurley, John

2014-09-01

Retrograde transcatheter aortic valve implantation (TAVI) can be performed under local anesthesia (LA) or general anesthesia (GA); however, a wide variation in practice exists. PubMed was searched between 2009 and 2013. Data were extracted from eligible studies. Random-effects meta-analysis was performed using DerSimonian Laird between-study variance. There was no statistically significant difference identified between groups based on age or EuroSCORE. There was no statistically significant difference seen in all-cause mortality, or complication rates between groups. Mean procedural duration was 36 minutes shorter in the LA group (p = 0.001). There was increased vasopressor use in the GA group (odds ratio 3.92; p = 0.017). Mean hospital stay was 3.41 days shorter in the LA group (p = 0.018). Results suggest that the use of LA for retrograde TAVI is feasible. There are several potential benefits associated, shorter procedural duration, and hospital stay with lower vasopressor requirements. Further studies and randomized trials are mandatory to confirm the presented findings and to identify those patients for whom LA would be appropriate. Georg Thieme Verlag KG Stuttgart · New York.

Structural optimization of a retrograde trafficking inhibitor that protects cells from infections by human polyoma- and papillomaviruses.

PubMed

Carney, Daniel W; Nelson, Christian D S; Ferris, Bennett D; Stevens, Julia P; Lipovsky, Alex; Kazakov, Teymur; DiMaio, Daniel; Atwood, Walter J; Sello, Jason K

2014-09-01

Human polyoma- and papillomaviruses are non-enveloped DNA viruses that cause severe pathologies and mortalities. Under circumstances of immunosuppression, JC polyomavirus causes a fatal demyelinating disease called progressive multifocal leukoencephalopathy (PML) and the BK polyomavirus is the etiological agent of polyomavirus-induced nephropathy and hemorrhagic cystitis. Human papillomavirus type 16, another non-enveloped DNA virus, is associated with the development of cancers in tissues like the uterine cervix and oropharynx. Currently, there are no approved drugs or vaccines to treat or prevent polyomavirus infections. We recently discovered that the small molecule Retro-2(cycl), an inhibitor of host retrograde trafficking, blocked infection by several human and monkey polyomaviruses. Here, we report diversity-oriented syntheses of Retro-2(cycl) and evaluation of the resulting analogs using an assay of human cell infections by JC polyomavirus. We defined structure-activity relationships and also discovered analogs with significantly improved potency as suppressors of human polyoma- and papillomavirus infection in vitro. Our findings represent an advance in the development of drug candidates that can broadly protect humans from non-enveloped DNA viruses and toxins that exploit retrograde trafficking as a means for cell entry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigating sub-spine actin dynamics in rat hippocampal neurons with super-resolution optical imaging.

PubMed

Tatavarty, Vedakumar; Kim, Eun-Ji; Rodionov, Vladimir; Yu, Ji

2009-11-09

Morphological changes in dendritic spines represent an important mechanism for synaptic plasticity which is postulated to underlie the vital cognitive phenomena of learning and memory. These morphological changes are driven by the dynamic actin cytoskeleton that is present in dendritic spines. The study of actin dynamics in these spines traditionally has been hindered by the small size of the spine. In this study, we utilize a photo-activation localization microscopy (PALM)-based single-molecule tracking technique to analyze F-actin movements with approximately 30-nm resolution in cultured hippocampal neurons. We were able to observe the kinematic (physical motion of actin filaments, i.e., retrograde flow) and kinetic (F-actin turn-over) dynamics of F-actin at the single-filament level in dendritic spines. We found that F-actin in dendritic spines exhibits highly heterogeneous kinematic dynamics at the individual filament level, with simultaneous actin flows in both retrograde and anterograde directions. At the ensemble level, movements of filaments integrate into a net retrograde flow of approximately 138 nm/min. These results suggest a weakly polarized F-actin network that consists of mostly short filaments in dendritic spines.

Prospective comparative study of two methods for fixation after distal femur corrective osteotomy for valgus deformity; retrograde intramedullary nailing versus less invasive stabilization system plating.

PubMed

Özcan, Çağrı; Sökücü, Sami; Beng, Kubilay; Çetinkaya, Engin; Demir, Bilal; Kabukçuoğlu, Yavuz Selim

2016-10-01

The aim of this study was to compare the radiological and functional results of two different methods of fixation for the correction of femoral valgus deformities. Patients who had undergone osteotomy and correction of a valgus deformity from 2007 to 2013 were prospectively followed. Thirty three patients (20 females, 13 males) with 39 lower limbs were included in the study. Seventeen lower limbs were treated with retrograde intramedullary nailing (IMN) and 22 with less invasive stabilization system plating. Standing orthoroentgenograms of the lower limbs were taken pre-operatively and at the final follow-up. mLDFA, aLDFA, mechanical axis deviation (MAD) were measured in this orthoroentgenograms. Knee osteoarthritis outcome score (KOOS) and knee range of motion were used pre-operatively and at the final follow-up as part of the evaluation of the clinical results. All patients duration of surgery, length of hospital stay were assessed. Operations were performed by two orthopedic surgeons. The choice of correction method for each patient was determined by the surgeon. Pre-operative and post-operative values were simultaneously measured by two additional orthopedic surgeons. The mean age of the patients was 26.2 years (18.0-51.0) in the plating group and 29.3 years (18.0-55.0) in the nailing group. Patients in the plating and nailing groups were followed up for 24.0 (12.0-60.0) and 27.8 (12.0-60.0) months. All patients were followed for a minimum of 12 months. No significant differences were observed between the groups in terms of age, sex, or duration of follow-up (p > 0.05) Comparison of the pre- and post-operative mLDFA, aLDFA, MAD, length of hospital stay, and duration of surgery between the plating group and nailing group, no significant difference was observed between the groups (p > 0.05). However, patients treated with retrograde IMN had significantly better post-operative results in terms of the KOOS and range of motion of the knee according to plating group (p < 0.05). Retrograde IMN does not provide a radiological advantage over the LISS plating technique for valgus deformity but retrograde IMN and correction offered better functional results in cases of femoral valgus deformity than did the LISS plating method.

Endoscopic balloon catheter dilatation via retrograde or static technique is safe and effective for cricopharyngeal dysfunction

PubMed Central

Chandrasekhara, Vinay; Koh, Joyce; Lattimer, Lakshmi; Dunbar, Kerry B; Ravich, William J; Clarke, John O

2017-01-01

AIM To evaluate the safety and efficacy of upper esophageal sphincter (UES) dilatation for cricopharyngeal (CP) dysfunction. To determine if: (1) indication for dilatation; or (2) technique of dilatation correlated with symptom improvement. METHODS All balloon dilatations performed at our institution from over a 3-year period were retrospectively analyzed for demographics, indication and dilatation site. All dilatations involving the UES underwent further review to determine efficacy, complications, and factors that predict success. Dilatation technique was separated into static (stationary balloon distention) and retrograde (brusque pull-back of a fully distended balloon across the UES). RESULTS Four hundred and eighty-eight dilatations were reviewed. Thirty-one patients were identified who underwent UES dilatation. Median age was 63 years (range 27-81) and 55% of patients were male. Indications included dysphagia (28 patients), globus sensation with evidence of UES dysfunction (2 patients) and obstruction to echocardiography probe with cricopharyngeal (CP) bar (1 patient). There was evidence of concurrent oropharyngeal dysfunction in 16 patients (52%) and a small Zenker’s diverticula (≤ 2 cm) in 7 patients (23%). Dilator size ranged from 15 mm to 20 mm. Of the 31 patients, 11 had dilatation of other esophageal segments concurrently with UES dilatation and 20 had UES dilatation alone. Follow-up was available for 24 patients for a median of 2.5 mo (interquartile range 1-10 mo), of whom 19 reported symptomatic improvement (79%). For patients undergoing UES dilatation alone, follow-up was available for 15 patients, 12 of whom reported improvement (80%). Nineteen patients underwent retrograde dilatation (84% response) while 5 patients had static dilatation (60% response); however, there was no significant difference in symptom improvement between the techniques (P = 0.5). Successful symptom resolution was also not significantly affected by dilator size, oropharyngeal dysfunction, Zenker’s diverticulum, age or gender (P > 0.05). The only complication noted was uvular edema and a shallow ulcer after static dilatation in one patient, which resolved spontaneously and did not require hospital admission. CONCLUSION UES dilatation with a through-the-scope balloon by either static or retrograde technique is safe and effective for the treatment of dysphagia due to CP dysfunction. To our knowledge, this is the first study evaluating retrograde balloon dilatation of the UES. PMID:28465785

[Tibio-talo-calcaneal arthrodesis with the retrograde intramedullary nail MEDIN].

PubMed

Popelka, S; Vavřík, P; Landor, I; Bek, J; Popelka ml, S; Hromádka, R

2013-01-01

When the talus and the talocalcaneal joint are both affected, their fusion is the method of treatment. Ankle arthrodesis is carried out using various osteosynthetic materials such as external fixators, screws and plates. One of the options is retrograde nailing. Tibio-talo-calcaneal arthrodesis is frequently indicated in patients with rheumatoid arthritis (RA) in whom both the talus and the subtalar joint are often affected. A retrograde nail for tibio-talo-calcaneal arthrodesis was developed at our department in cooperation with MEDIN Company. This is a titanium double-curved nail, with the distal part bent at 8 degrees ventrally and 10 degrees laterally. It is inserted from the transfibular approach. Sixty-two patients, 35 women and 27 men, were treated at our department from 2005. Since one patient had bilateral surgery, 63 ankles were included. The indications for arthrodesis involved rheumatoid arthritis in 42, post-traumatic arthritis in 10, failed ankle arthrodesis in two and failed total ankle arthroplasty in five ankles; tibial stress fractures close above the ankle in two RA patients, one patient with dermatomyositis and one with lupus erythematodes. The average age at the time of surgery was 64.2 years (range, 30 to 80). The average follow-up was 4.5 years (range, 1 to 9 years), Satisfaction with the treatment outcome and willingness to undergo surgery on the other side were reported by 82% of the patients. The AOFAS score improved from 35 to 74 points. Three (4.8%) patients complained of painful feet due to the fact that exact correction of the calcaneus was not achieved and the heel after arthrodesis remained in a slightly varus position. Of them, two had a failed total ankle arthroplasty. Post-operative complications included early infection managed by antibiotic treatment and early surgical revision with irrigation.in two (3.2%) RA patients, who were undergoing biological therapy. Late infection developed at 2 to 3 years after surgery in three (4.3%) patients (two had RA). The infection was managed by revision surgery with nail removal and irrigation. All patients healed well. Necrosis of the talus and development of a pseudoarthrosis were recorded in four (6.4%) patients, who subsequently underwent nail removal and repeat fusion using an external fixator. Retrograde nailing for tibio-talo-calcaneal arthrodesis is used by many authors. Its complication rate is comparable with the other methods of arthrodesis. The use of tibio-talo-calcaneal arthrodesis aims at a painless and stable joint. Arthrodesis of the talus and the subtalar joint using a retrograde nail is an effective surgical treatment of the joints affected. It is especially recommended for RA patients who have severe deviations. Retrograde nailing provides a stable osteosynthesis which does not require plaster cast immobilisation. The double-curved nail allows for its insertion in the solid part of the calcaneus and helps avoiding injury to the neurovascular bundle.

ERCP (Endoscopic Retrograde Cholangiopancreatography)

MedlinePlus

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Garnet zoning and metamorphism of the Barrovian type area, Scotland

NASA Astrophysics Data System (ADS)

Dempster, T. J.

1985-03-01

A microprobe investigation of the high grade metamorphic zones from the Barrovian type area in Angus, Scotland, shows the importance of local zones of retrograde cation exchange between garnet, staurolite and biotite. The interpretation of this zoning, established during a slow cooling history, is critical to any study of metamorphic reactions or conditions. The extent and intensity of these diffusion effects are dependent on a number of parameters including grainsize, fabric orientation, heating and cooling history, and the modal abundance of the phases. Increasing diffusion within garnets with metamorphic grade, and the subsequent retrograde effects are modelled using Temperature-Time-Transformation diagrams and provide information on the activation energy for Fe-Mg diffusion in garnet.

[Ejaculation inadequacy in sexual disorders].

PubMed

Schröder, K H; Krause, W

1982-01-01

Sixteen men with missing ejaculation were observed as outpatients in our department within the past years. Among these, four patients with retrograde ejaculation are included. Possible reasons for the missing ejaculation are operations in the genital region or the pelvis, and spinal cord injuries. Endocrine disorders, diabetes mellitus, drug dependence, and psychogenic alterations have to be discussed as etiologic factors. Secondary lack of ejaculation, which is acquired in later years of life, seems to have a poorer prognosis than the primary disease, which begins with puberty. This group of patients is well responsive to psychotherapy. Other therapeutic approaches are hormonal substitution, care of drug dependence, and treatment with sympathicomimetica in some cases of retrograde ejaculation.

Delusion of inanimate doubles: description of a case of focal retrograde amnesia.

PubMed

Abbate, Carlo; Trimarchi, Pietro Davide; Salvi, Gian Pietro; Quarenghi, Anna Maria; Vergani, Carlo; Luzzatti, Claudio

2012-01-01

This paper reports the case of a patient, M.P., who developed delusion of inanimate doubles, without Capgras syndrome, after traumatic brain injury. His delusional symptoms were studied longitudinally and the cognitive impairments associated with delusion were investigated. Data suggest that M.P. did 'perceive' the actual differences between doubles and originals rather than 'confabulate' them. The cognitive profile, characterized by retrograde episodic amnesia, but neither object processing impairment nor confabulations, supports this hypothesis. The study examines the nature of object misidentification based on Ellis' and Staton's account and proposes a new account based on concurrent unbiased retrieval of semantic memory traces and biased recollection of episodic memory traces.

Balloon-occluded Retrograde Transvenous Obliteration (BRTO): Technique and Intraprocedural Imaging

PubMed Central

Sabri, Saher S.; Saad, Wael E. A.

2011-01-01

Balloon-occluded retrograde transvenous obliteration (BRTO) is an endovascular technique used as a therapeutic adjunct or alternative to transjugular intrahepatic shunts (TIPS) in the management of gastric varices. Occlusion balloons are strategically placed to modulate flow within the gastrorenal or gastrocaval shunt to allow stagnation of the sclerosant material within the gastric varix. The approach and complexity of the procedure depends on the anatomic classification of inflow and outflow veins of the varix. Ethanolamine oleate has been described as the main sclerosant used in this procedure. Recently, foam sclerosants have gained popularity as alternative embolization agents, which provide the advantage of better variceal wall contact and potentially less dose of sclerosant. PMID:22942548

The use of intramedullary nails in tibiotalocalcaneal arthrodesis.

PubMed

Thomas, Ruth L; Sathe, Vinayak; Habib, Syed I

2012-01-01

Tibiotalocalcaneal arthrodesis is a salvage procedure undertaken for hindfoot problems that affect both the ankle and subtalar joints (eg, two-joint arthritis, severe acute trauma, osteonecrosis of the talus, severe malalignment deformities, significant hindfoot bone loss). Methods of achieving fusion include Steinmann pins, screws, plates, external fixators, and retrograde intramedullary nailing. Retrograde intramedullary nailing provides a load-sharing fixation device with superior biomechanical properties and is an excellent choice for use in tibiotalocalcaneal arthrodesis. This technique can be performed through relatively small incisions. In addition, recent design modifications include the availability of dynamization and the choice of curved or straight nails. Contraindications to the technique include the presence of infection, severe vascular disease, and severe malalignment of the tibia.

[Changes in proline-specific peptidase activity in experimental model of retrograde amnesia].

PubMed

Nazarova, G A; Zolotov, N N; Krupina, N A; Kraĭneva, V A; Garibova, T L; Voronina, T A

2007-01-01

Changes in proline-specific peptidase activity in the frontal cortex and hippocampus were studied using the experimental model of retrograde amnesia in rats. In one group, the amnesia was produced by a single injection of M-cholinergic antagonist scopolamine and the other group received the maximal electroconvulsive stimulation (MES). The amnesic effect was evaluated in passive avoidance test. In the amnesia models under consideration, the activity of prolylendopeptidase was significantly increased in both frontal cortex and hippocampus. The activity of dipeptidyl peptidase IV was significantly decreased in the cortex, whereas in the hippocampus it remained unchanged. Pyracetam inhibited prolylendopeptidase in the cortex and hippocampus, whereas dipeptidyl peptidase IV activity remained unchanged.

[Ascites and hematuria after falling in an alcoholic patient].

PubMed

Bürkner, A; Neuhaus, V; Schöb, O

2010-02-03

Isolated ruptures of the urinary bladder following minor traumas are a rare abdominal lesion. Diagnosis and treatment are a challenge to emergency physicians and surgeons. This case shows a 46-year-old patient admitted for a minor brain injury after falling during an episode of alcoholic intoxication. Ultrasound and CT scan of the abdomen showed intraabdominal fluid without a parenchymatous lesion. Also a hematuria was significant. The retrograde cystography showed intraabdominal contrast agent. The rupture of the urinary bladder was confirmed by laparoscopy and was intracorporal sutured in double layer technique. Without any postoperative complications the patient was discharged after 4 days. The retrograde cystography after 10 days showed no leckage and the urinary catheter could be removed.

Filling defects in the pancreatic duct on endoscopic retrograde pancreatography.

PubMed

Taylor, A J; Carmody, T J; Schmalz, M J; Wiedmeyer, D A; Stewart, E T

1992-12-01

Filling defects in the pancreatic duct are a frequent finding during endoscopic retrograde pancreatography (ERP) and have a variety of causes. Some filling defects may be artifactual or related to technical factors and, once their origin is recognized, can be disregarded. Others may be due to acute changes of pancreatitis and should prompt more careful injection of contrast material into the duct. Intraluminal masses may represent calculi or a neoplasm, either of which may require surgery or endoscopic intervention. The exact nature of these filling defects may not be apparent on radiographs, and other studies may be needed. This article reviews our approach to the evaluation of filling defects in the pancreatic duct.

[Current strategy in PCI for CTO].

PubMed

Asakura, Yasushi

2011-02-01

Recently, CTO PCI has come into wide use all over the world and it has been standardized. The 1st step is an antegrade approach using single wire. The 2nd strategy would be parallel wire technique. And the next would be a retrograde approach. In this method, retrograde wiring with Corsair is done at first. If it is successful, externalization is established using 300 cm wire, and this system is able to provide strong back-up support. If it fails, reverse CART technique is the next step. IVUS guided wiring is a last resort. The 2nd wire is manipulated with IVUS guidance. Now, initial success rate is more than 90% with these methods.

Periodontitis and periimplantitis: one and the same?

PubMed

Meffert, R M

1993-12-01

Research shows that the same anaerobic, gram-negative pathogens are present in the periodontal and implant pocket or crevice. The implants in a partially edentulous case are probably more at risk due to the bacteria being more pathogenic and a seeding mechanism from the tooth pocket to the implant crevice. In the face of a normal microbial flora, retrograde periimplantitis or radiographic bone loss without gingival changes may be due to trauma because of overloading, loading too soon, and/or loading in a lateral direction. Finally, the combination of an infective process (periimplantitis) and noninfective or traumatic process (retrograde periimplantitis) will result in rapid osseous destruction and, possibly, loss of the implant fixture(s).

Mechanical coupling of microtubule-dependent motor teams during peroxisome transport in Drosophila S2 cells.

PubMed

De Rossi, María Cecilia; Wetzler, Diana E; Benseñor, Lorena; De Rossi, María Emilia; Sued, Mariela; Rodríguez, Daniela; Gelfand, Vladimir; Bruno, Luciana; Levi, Valeria

2017-12-01

Intracellular transport requires molecular motors that step along cytoskeletal filaments actively dragging cargoes through the crowded cytoplasm. Here, we explore the interplay of the opposed polarity motors kinesin-1 and cytoplasmic dynein during peroxisome transport along microtubules in Drosophila S2 cells. We used single particle tracking with nanometer accuracy and millisecond time resolution to extract quantitative information on the bidirectional motion of organelles. The transport performance was studied in cells expressing a slow chimeric plus-end directed motor or the kinesin heavy chain. We also analyzed the influence of peroxisomes membrane fluidity in methyl-β-ciclodextrin treated cells. The experimental data was also confronted with numerical simulations of two well-established tug of war scenarios. The velocity distributions of retrograde and anterograde peroxisomes showed a multimodal pattern suggesting that multiple motor teams drive transport in either direction. The chimeric motors interfered with the performance of anterograde transport and also reduced the speed of the slowest retrograde team. In addition, increasing the fluidity of peroxisomes membrane decreased the speed of the slowest anterograde and retrograde teams. Our results support the existence of a crosstalk between opposed-polarity motor teams. Moreover, the slowest teams seem to mechanically communicate with each other through the membrane to trigger transport. Copyright © 2017 Elsevier B.V. All rights reserved.

Endoscope disinfection and its pitfalls--requirement for retrograde surveillance cultures.

PubMed

Buss, A J; Been, M H; Borgers, R P; Stokroos, I; Melchers, W J; Peters, F T; Limburg, A J; Degener, J E

2008-04-01

Several endoscopy-related outbreaks of infection have been reported in recent years. For early recognition of inadequate disinfection of endoscopes we designed a microbiological surveillance system to evaluate the efficacy of the cleaning and disinfection procedure, and to trace disinfection problems to individual endoscopes or washer-disinfectors. Our surveillance protocol included anterograde and retrograde sampling, a decision algorithm, genetic fingerprinting, and scanning electron microscopy. Over a period of 29 months we found an increasing number of patient-ready endoscopes testing positive for Candida species other than albicans, especially C. parapsilosis. These yeasts were also isolated from the washer-disinfectors. The number of positive tests for Candida species varied from 1 out of 21 to 14 out of 27 samples from nine frequently used endoscopes. The number of colony-forming units per milliliter ranged from 1 - 10 to 3000 for endoscopes and 0.002 to 0.06 for the washer disinfectors. DNA fingerprinting was not able to discriminate different strains within C. parapsilosis. Our protocol was able to detect a structural problem in the endoscope disinfection process. Retrograde sampling was crucial for this purpose, because it has much higher sensitivity than anterograde sampling. Endoscopes with damaged working channels are probably the source of the contamination problem with Candida species.

Memory consolidation from seconds to weeks: a three-stage neural network model with autonomous reinstatement dynamics

PubMed Central

Fiebig, Florian; Lansner, Anders

2014-01-01

Declarative long-term memories are not created in an instant. Gradual stabilization and temporally shifting dependence of acquired declarative memories in different brain regions—called systems consolidation—can be tracked in time by lesion experiments. The observation of temporally graded retrograde amnesia (RA) following hippocampal lesions points to a gradual transfer of memory from hippocampus to neocortical long-term memory. Spontaneous reactivations of hippocampal memories, as observed in place cell reactivations during slow-wave-sleep, are supposed to drive neocortical reinstatements and facilitate this process. We propose a functional neural network implementation of these ideas and furthermore suggest an extended three-state framework that includes the prefrontal cortex (PFC). It bridges the temporal chasm between working memory percepts on the scale of seconds and consolidated long-term memory on the scale of weeks or months. We show that our three-stage model can autonomously produce the necessary stochastic reactivation dynamics for successful episodic memory consolidation. The resulting learning system is shown to exhibit classical memory effects seen in experimental studies, such as retrograde and anterograde amnesia (AA) after simulated hippocampal lesioning; furthermore the model reproduces peculiar biological findings on memory modulation, such as retrograde facilitation of memory after suppressed acquisition of new long-term memories—similar to the effects of benzodiazepines on memory. PMID:25071536

Catheter ablation of junctional ectopic tachycardia in children, with preservation of atrioventricular conduction.

PubMed

Emmel, M; Sreeram, N; Brockmeier, K

2005-04-01

Idiopathic junctional ectopic tachycardia is a rare arrhythmia in children. Several studies have demonstrated that drug therapy is often ineffective and sometimes the only achieved effect is rate control. Early presentation and frequent recurrence are associated with adverse outcome. Three consecutive children, aged 9, 7 and 12 years respectively, underwent radiofrequency catheter ablation for junctional ectopic tachycardia, after having failed antiarrhythmic drug therapy. The entire His bundle was plotted out and marked, using the Localisa navigation system. The arrhythmia was readily and repeatedly inducible using intravenous isoprenaline infusion and the site of earliest retrograde conduction during tachycardia could be assessed. Ablations were performed in sinus rhythm, empirically targeting the site of earliest retrograde conduction during tachycardia. This approach was successful in abolishing tachyarrhythmia in the first two patients, in whom the successful ablation site was located superoparaseptally. In the third patient, junctional ectopic tachycardia was inducible, despite abolishing retrograde atrial activation, in a septal location on the tricuspid valve annulus. Further ablations in the superoparaseptal region, closer to the His bundle, were successful in rendering tachyarrhythmia noninducible. Over a median follow-up of 10 months, none of the patients has had recurrence of arrhythmia, despite discontinuing all antiarrhythmic medications. Radio frequency catheter ablation of junctional ectopic tachycardia is feasible with preservation of atrioventricular conduction.

Filopodial retraction force is generated by cortical actin dynamics and controlled by reversible tethering at the tip

PubMed Central

Bornschlögl, Thomas; Romero, Stéphane; Vestergaard, Christian L.; Joanny, Jean-François; Van Nhieu, Guy Tran; Bassereau, Patricia

2013-01-01

Filopodia are dynamic, finger-like plasma membrane protrusions that sense the mechanical and chemical surroundings of the cell. Here, we show in epithelial cells that the dynamics of filopodial extension and retraction are determined by the difference between the actin polymerization rate at the tip and the retrograde flow at the base of the filopodium. Adhesion of a bead to the filopodial tip locally reduces actin polymerization and leads to retraction via retrograde flow, reminiscent of a process used by pathogens to invade cells. Using optical tweezers, we show that filopodial retraction occurs at a constant speed against counteracting forces up to 50 pN. Our measurements point toward retrograde flow in the cortex together with frictional coupling between the filopodial and cortical actin networks as the main retraction-force generator for filopodia. The force exerted by filopodial retraction, however, is limited by the connection between filopodial actin filaments and the membrane at the tip. Upon mechanical rupture of the tip connection, filopodia exert a passive retraction force of 15 pN via their plasma membrane. Transient reconnection at the tip allows filopodia to continuously probe their surroundings in a load-and-fail manner within a well-defined force range. PMID:24198333

Relationships between structure, in vivo function and long-range axonal target of cortical pyramidal tract neurons.

PubMed

Rojas-Piloni, Gerardo; Guest, Jason M; Egger, Robert; Johnson, Andrew S; Sakmann, Bert; Oberlaender, Marcel

2017-10-11

Pyramidal tract neurons (PTs) represent the major output cell type of the neocortex. To investigate principles of how the results of cortical processing are broadcasted to different downstream targets thus requires experimental approaches, which provide access to the in vivo electrophysiology of PTs, whose subcortical target regions are identified. On the example of rat barrel cortex (vS1), we illustrate that retrograde tracer injections into multiple subcortical structures allow identifying the long-range axonal targets of individual in vivo recorded PTs. Here we report that soma depth and dendritic path lengths within each cortical layer of vS1, as well as spiking patterns during both periods of ongoing activity and during sensory stimulation, reflect the respective subcortical target regions of PTs. We show that these cellular properties result in a structure-function parameter space that allows predicting a PT's subcortical target region, without the need to inject multiple retrograde tracers.The major output cell type of the neocortex - pyramidal tract neurons (PTs) - send axonal projections to various subcortical areas. Here the authors combined in vivo recordings, retrograde tracings, and reconstructions of PTs in rat somatosensory cortex to show that PT structure and activity can predict specific subcortical targets.

Frequent sleep-related bitemporal focal seizures in transient epileptic amnesia syndrome: Evidence from ictal video-EEG.

PubMed

Burkholder, David B; Jones, Amy L; Jones, David T; Fabris, Rachel R; Britton, Jeffrey W; Lagerlund, Terrence D; So, Elson L; Cascino, Gregory D; Worrell, Gregory A; Shin, Cheolsu; St Louis, Erik K

2017-06-01

Two patients who shared similar presenting clinical features of anterograde and retrograde autobiographical amnesia typical of transient epileptic amnesia (TEA) underwent prolonged video electroencephalogram (VEEG) monitoring and were found to have sleep-activated epileptiform activity and frequent subclinical bitemporal seizures predominantly during sleep. Case 1 is a 59-year-old woman whose presenting complaint was memory impairment. Over 18 months, she had three distinct 8-h-long episodes of confusion and disorientation with persistent anterograde and retrograde autobiographical amnesia. VEEG recorded frequent interictal bitemporal sharp waves confined to sleep, and 14 subclinical seizures, also mostly during sleep. Case 2 is a 50-year-old woman with known focal epilepsy also presented with memory complaints. Over the course of 1 year, she had two discrete 2-h-long episodes of amnesia, with ongoing anterograde and retrograde autobiographical amnesia. VEEG recorded independent bitemporal sharp waves, and 14 subclinical seizures during sleep and drowsiness. Memory impairment improved in both patients with successful treatment of their seizures. Although the etiology of accelerated long-term forgetting (ALF) and remote memory impairment (RMI) in transient epileptic amnesia (TEA) is unknown, these cases suggest frequent sleep-related seizures may contribute, and they highlight the importance of video-EEG monitoring.

Functional brain imaging in 14 patients with dissociative amnesia reveals right inferolateral prefrontal hypometabolism.

PubMed

Brand, Matthias; Eggers, Carsten; Reinhold, Nadine; Fujiwara, Esther; Kessler, Josef; Heiss, Wolf-Dieter; Markowitsch, Hans J

2009-10-30

Dissociative amnesia is a condition usually characterized by severely impaired retrograde memory functioning in the absence of structural brain damage. Recent case studies nevertheless found functional brain changes in patients suffering from autobiographical-episodic memory loss in the cause of dissociative amnesia. Functional changes were demonstrated in both resting state and memory retrieval conditions. In addition, some but not all cases also showed other neuropsychological impairments beyond retrograde memory deficits. However, there is no group study available that examined potential functional brain abnormalities and accompanying neuropsychological deteriorations in larger samples of patients with dissociative retrograde amnesia. We report functional imaging and neuropsychological data acquired in 14 patients with dissociative amnesia following stressful or traumatic events. All patients suffered from autobiographical memory loss. In addition, approximately half of the patients had deficits in anterograde memory and executive functioning. Accompanying functional brain changes were measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Regional glucose utilization of the patients was compared with that of 19 healthy subjects, matched for age and gender. We found significantly decreased glucose utilization in the right inferolateral prefrontal cortex in the patients. Hypometabolism in this brain region, known to be involved in retrieval of autobiographical memories and self-referential processing, may be a functional brain correlate of dissociative amnesia.

A case of persistent retrograde amnesia following a dissociative fugue: neuropsychological and neurofunctional underpinnings of loss of autobiographical memory and self-awareness.

PubMed

Hennig-Fast, Kristina; Meister, Franziska; Frodl, Thomas; Beraldi, Anna; Padberg, Frank; Engel, Rolf R; Reiser, Maximilian; Möller, Hans-Jürgen; Meindl, Thomas

2008-10-01

Autobiographical memory relies on complex interactions between episodic memory contents, associated emotions and a sense of self-continuity over the course of one's life. This paper reports a study based upon the case of the patient NN who suffered from a complete loss of autobiographical memory and awareness of identity subsequent to a dissociative fugue. Neuropsychological, behavioral, and functional neuroimaging tests converged on the conclusion that NN suffered from a selective retrograde amnesia following an episode of dissociative fugue, during which he had lost explicit knowledge and vivid memory of his personal past. NN's loss of self-related memories was mirrored in neurobiological changes after the fugue whereas his semantic memory remained intact. Although NN still claimed to suffer from a stable loss of autobiographical, self-relevant memories 1 year after the fugue state, a proportionate improvement in underlying fronto-temporal neuronal networks was evident at this point in time. In spite of this improvement in neuronal activation, his anterograde visual memory had been decreased. It is posited that our data provide evidence for the important role of visual processing in autobiographical memory as well as for the efficiency of protective control mechanisms that constitute functional retrograde amnesia.

Retrograde episodic memory and emotion: a perspective from patients with dissociative amnesia.

PubMed

Reinhold, Nadine; Markowitsch, Hans J

2009-09-01

With his recent definition of episodic memory Tulving [Tulving, E. (2005). Episodic memory and autonoesis: Uniquely human? In H. Terrace & J. Metcalfe (Eds.), The missing link in cognition: Evolution of self-knowing consciousness (pp. 3-56). New York: Oxford University Press] claims that this memory system is uniquely human and thereby distinguishes human beings from other, even highly developed, mammals. First we will define the term episodic memory as it is currently used in neuropsychological research by specifying the three underlying concepts of subjective time, autonoëtic consciousness, and the self. By doing so, we will strongly focus on retrograde episodic memory and its relation to emotion and self-referential processing. We support this relation with a discussion of autobiographical memory functions in psychiatric disorders such as dissociative amnesia. To illustrate the connection of emotion and retrograde episodic memory we shortly present neuropsychological data of two cases of dissociative amnesia. Both cases serve to point to the protective mechanism of a block of self-endangering memories from the episodic memory system, often described as the mnestic block syndrome. On the basis of these cases and supportive results from further cases we will conclude by pointing out similarities and differences of patients with organic and dissociative (psychogenic) amnesia.

Antibody-Mediated Inhibition of Ricin Toxin Retrograde Transport

PubMed Central

Yermakova, Anastasiya; Klokk, Tove Irene; Cole, Richard; Sandvig, Kirsten; Mantis, Nicholas J.

2014-01-01

ABSTRACT Ricin is a member of the ubiquitous family of plant and bacterial AB toxins that gain entry into the cytosol of host cells through receptor-mediated endocytosis and retrograde traffic through the trans-Golgi network (TGN) and endoplasmic reticulum (ER). While a few ricin toxin-specific neutralizing monoclonal antibodies (MAbs) have been identified, the mechanisms by which these antibodies prevent toxin-induced cell death are largely unknown. Using immunofluorescence confocal microscopy and a TGN-specific sulfation assay, we demonstrate that 24B11, a MAb against ricin’s binding subunit (RTB), associates with ricin in solution or when prebound to cell surfaces and then markedly enhances toxin uptake into host cells. Following endocytosis, however, toxin-antibody complexes failed to reach the TGN; instead, they were shunted to Rab7-positive late endosomes and LAMP-1-positive lysosomes. Monovalent 24B11 Fab fragments also interfered with toxin retrograde transport, indicating that neither cross-linking of membrane glycoproteins/glycolipids nor the recently identified intracellular Fc receptor is required to derail ricin en route to the TGN. Identification of the mechanism(s) by which antibodies like 24B11 neutralize ricin will advance our fundamental understanding of protein trafficking in mammalian cells and may lead to the discovery of new classes of toxin inhibitors and therapeutics for biodefense and emerging infectious diseases. PMID:24713323

Retrograde amnesia in patients with hippocampal, medial temporal, temporal lobe, or frontal pathology.

PubMed

Bright, Peter; Buckman, Joseph; Fradera, Alex; Yoshimasu, Haruo; Colchester, Alan C F; Kopelman, Michael D

2006-01-01

There is considerable controversy concerning the theoretical basis of retrograde amnesia (R.A.). In the present paper, we compare medial temporal, medial plus lateral temporal, and frontal lesion patients on a new autobiographical memory task and measures of the more semantic aspects of memory (famous faces and news events). Only those patients with damage extending beyond the medial temporal cortex into the lateral temporal regions showed severe impairment on free recall remote memory tasks, and this held for both the autobiographical and the more semantic memory tests. However, on t-test analysis, the medial temporal group was impaired in retrieving recent autobiographical memories. Within the medial temporal group, those patients who had combined hippocampal and parahippocampal atrophy (H+) on quantified MRI performed somewhat worse on the semantic tasks than those with atrophy confined to the hippocampi (H-), but scores were very similar on autobiographical episodic recall. Correlational analyses with regional MRI volumes showed that lateral temporal volume was correlated significantly with performance on all three retrograde amnesia tests. The findings are discussed in terms of consolidation, reconsolidation, and multiple trace theory: We suggest that a widely distributed network of regions underlies the retrieval of past memories, and that the extent of lateral temporal damage appears to be critical to the emergence of a severe remote memory impairment.

A Case of Persistent Generalized Retrograde Autobiographical Amnesia Subsequent to the Great East Japan Earthquake in 2011.

PubMed

Odagaki, Yuji

2017-01-01

Functional retrograde autobiographical amnesia is often associated with physical and/or psychological trauma. On 11 March 2011, the largest earthquake on record in Japan took place, and subsequent huge tsunami devastated the Pacific coast of northern Japan. This case report describes a patient suffering from retrograde episodic-autobiographical amnesia for whole life, persisting for even more than five years after the disaster. A Japanese man, presumably in his 40s, got police protection in April 2016 but was unable to respond to question about his own name. He lost all information about his personal identity, and his memory was wholly lost until the disaster on 11 March 2011. He was able to recall his life after the disaster, and semantic memories and social abilities were largely preserved. A medical examination performed on 1 November 2016 verified that he was awake, alert, and oriented to time, place, and person (except for himself). General physical and neurological examinations revealed no pathological findings. He also experienced some symptoms associated with posttraumatic stress disorder (PTSD), such as intrusive thoughts, flashbacks, and nightmares. No abnormalities were detected by biochemical test and brain magnetic resonance imaging (MRI). Physicians and other professionals who take care of victims of disaster should be aware of dissociative spectrum disorders, such as psychogenic amnesia.

Multiple zonal jets and convective heat transport barriers in a quasi-geostrophic model of planetary cores

NASA Astrophysics Data System (ADS)

Guervilly, C.; Cardin, P.

2017-10-01

We study rapidly rotating Boussinesq convection driven by internal heating in a full sphere. We use a numerical model based on the quasi-geostrophic approximation for the velocity field, whereas the temperature field is 3-D. This approximation allows us to perform simulations for Ekman numbers down to 10-8, Prandtl numbers relevant for liquid metals (˜10-1) and Reynolds numbers up to 3 × 104. Persistent zonal flows composed of multiple jets form as a result of the mixing of potential vorticity. For the largest Rayleigh numbers computed, the zonal velocity is larger than the convective velocity despite the presence of boundary friction. The convective structures and the zonal jets widen when the thermal forcing increases. Prograde and retrograde zonal jets are dynamically different: in the prograde jets (which correspond to weak potential vorticity gradients) the convection transports heat efficiently and the mean temperature tends to be homogenized; by contrast, in the cores of the retrograde jets (which correspond to steep gradients of potential vorticity) the dynamics is dominated by the propagation of Rossby waves, resulting in the formation of steep mean temperature gradients and the dominance of conduction in the heat transfer process. Consequently, in quasi-geostrophic systems, the width of the retrograde zonal jets controls the efficiency of the heat transfer.

Nutritional State-Dependent Ghrelin Activation of Vasopressin Neurons via Retrograde Trans-Neuronal–Glial Stimulation of Excitatory GABA Circuits

PubMed Central

Haam, Juhee; Halmos, Katalin C.; Di, Shi

2014-01-01

Behavioral and physiological coupling between energy balance and fluid homeostasis is critical for survival. The orexigenic hormone ghrelin has been shown to stimulate the secretion of the osmoregulatory hormone vasopressin (VP), linking nutritional status to the control of blood osmolality, although the mechanism of this systemic crosstalk is unknown. Here, we show using electrophysiological recordings and calcium imaging in rat brain slices that ghrelin stimulates VP neurons in the hypothalamic paraventricular nucleus (PVN) in a nutritional state-dependent manner by activating an excitatory GABAergic synaptic input via a retrograde neuronal–glial circuit. In slices from fasted rats, ghrelin activation of a postsynaptic ghrelin receptor, the growth hormone secretagogue receptor type 1a (GHS-R1a), in VP neurons caused the dendritic release of VP, which stimulated astrocytes to release the gliotransmitter adenosine triphosphate (ATP). ATP activation of P2X receptors excited presynaptic GABA neurons to increase GABA release, which was excitatory to the VP neurons. This trans-neuronal–glial retrograde circuit activated by ghrelin provides an alternative means of stimulation of VP release and represents a novel mechanism of neuronal control by local neuronal–glial circuits. It also provides a potential cellular mechanism for the physiological integration of energy and fluid homeostasis. PMID:24790191

Combination of intracellular staining of retrogradely labeled neurons and anterograde fluorescent tracing: use of the confocal laser scanning microscope.

PubMed

Shi, C; Cassell, M D

1993-04-01

This report describes a combined retrograde tracing, intracellular injection and anterograde fluorescence labeling method using the application of confocal laser scanning microscopy. By simultaneously viewing the morphology of identified projection neurons and the distribution of anterogradely labeled fibers and terminals, this approach allows accurate characterization of the anatomical relationships between these two elements. To demonstrate this approach, the retrograde tracer Fast Blue was injected into the bed nucleus of stria terminalis (BNST) and the anterograde tracer tetramethylrhodamine-conjugated dextran was injected into the insular cortex in adult rats. After one week survival time, the brains were fixed and sectioned on a vibratome. Individual BNST projecting neurons identified in the amygdaloid complex on 120 microns thick sections were intracellularly injected with Lucifer Yellow under visual control and analyzed with confocal laser scanning microscopy. The results demonstrate that images from very thin optical sections can clearly show potential synaptic contacts between anterograde labeling and intracellularly labeled projecting neurons. Stacked images from optical sections show, in very great detail, the morphology of projection neurons in three-dimensions. Compared to other methodological combinations, the present method provides a more simple and efficient means to trace three successive components of a putative neuron chain.

Semaphorin 3A is a retrograde cell death signal in developing sympathetic neurons

PubMed Central

Wehner, Amanda B.; Abdesselem, Houari; Dickendesher, Travis L.; Imai, Fumiyasu; Yoshida, Yutaka; Giger, Roman J.; Pierchala, Brian A.

2016-01-01

ABSTRACT During development of the peripheral nervous system, excess neurons are generated, most of which will be lost by programmed cell death due to a limited supply of neurotrophic factors from their targets. Other environmental factors, such as ‘competition factors' produced by neurons themselves, and axon guidance molecules have also been implicated in developmental cell death. Semaphorin 3A (Sema3A), in addition to its function as a chemorepulsive guidance cue, can also induce death of sensory neurons in vitro. The extent to which Sema3A regulates developmental cell death in vivo, however, is debated. We show that in compartmentalized cultures of rat sympathetic neurons, a Sema3A-initiated apoptosis signal is retrogradely transported from axon terminals to cell bodies to induce cell death. Sema3A-mediated apoptosis utilizes the extrinsic pathway and requires both neuropilin 1 and plexin A3. Sema3A is not retrogradely transported in older, survival factor-independent sympathetic neurons, and is much less effective at inducing apoptosis in these neurons. Importantly, deletion of either neuropilin 1 or plexin A3 significantly reduces developmental cell death in the superior cervical ganglia. Taken together, a Sema3A-initiated apoptotic signaling complex regulates the apoptosis of sympathetic neurons during the period of naturally occurring cell death. PMID:27143756

Reality named endoscopic ultrasound biliary drainage

PubMed Central

Guedes, Hugo Gonçalo; Lopes, Roberto Iglesias; de Oliveira, Joel Fernandez; Artifon, Everson Luiz de Almeida

2015-01-01

Endoscopic ultrasound (EUS) is used for diagnosis and evaluation of many diseases of the gastrointestinal (GI) tract. In the past, it was used to guide a cholangiography, but nowadays it emerges as a powerful therapeutic tool in biliary drainage. The aims of this review are: outline the rationale for endoscopic ultrasound-guided biliary drainage (EGBD); detail the procedural technique; evaluate the clinical outcomes and limitations of the method; and provide recommendations for the practicing clinician. In cases of failed endoscopic retrograde cholangiopancreatography (ERCP), patients are usually referred for either percutaneous transhepatic biliary drainage (PTBD) or surgical bypass. Both these procedures have high rates of undesirable complications. EGBD is an attractive alternative to PTBD or surgery when ERCP fails. EGBD can be performed at two locations: transhepatic or extrahepatic, and the stent can be inserted in an antegrade or retrograde fashion. The drainage route can be transluminal, duodenal or transpapillary, which, again, can be antegrade or retrograde [rendezvous (EUS-RV)]. Complications of all techniques combined include pneumoperitoneum, bleeding, bile leak/peritonitis and cholangitis. We recommend EGBD when bile duct access is not possible because of failed cannulation, altered upper GI tract anatomy, gastric outlet obstruction, a distorted ampulla or a periampullary diverticulum, as a minimally invasive alternative to surgery or radiology. PMID:26504507

Differential TRPV1 and TRPV2 Channel Expression in Dental Pulp

PubMed Central

Gibbs, J.L.; Melnyk, J.L.; Basbaum, A.I.

2011-01-01

Hypersensitivity to thermal and mechanical stimuli can occur in painful pulpitis. To explore the neuro-anatomical basis of heat and mechanical sensitivity, we evaluated expression of TRPV1 (heat) and TRPV2 (heat/mechanical) channels in the cell bodies and terminal arborizations of neurons that innervate the dental pulp (DP) and periodontal tissues (PDL). We report that ~50% of trigeminal ganglion (TG) neurons retrogradely labeled from the DP express TRPV2, and this was significantly greater than the general expression of this channel in the TG (15%) and slightly more than what is expressed in the PDL by retrograde labeling (40%). The TRPV1 receptor, however, was less prevalent in neurons innervating the DP than their general expression in the TG (17% vs. 26%) and was more extensively expressed in neurons innervating the PDL (26%). Co-labeling studies showed that 70% of neurons that innervate the DP are myelinated. Approximately 1/3 of the retrogradely labeled neurons from the DP were calcitonin-gene-related-peptide-positive (peptide-expressing), but very few expressed the IB4 marker of non-peptidergic unmyelinated afferents. These findings suggest that the DP has a unique neurochemical innervation with regard to TRP receptor expression, which has significant implications for the mechanisms contributing to odontogenic pain and management strategies. PMID:21406609

Differential TRPV1 and TRPV2 channel expression in dental pulp.

PubMed

Gibbs, J L; Melnyk, J L; Basbaum, A I

2011-06-01

Hypersensitivity to thermal and mechanical stimuli can occur in painful pulpitis. To explore the neuro-anatomical basis of heat and mechanical sensitivity, we evaluated expression of TRPV1 (heat) and TRPV2 (heat/mechanical) channels in the cell bodies and terminal arborizations of neurons that innervate the dental pulp (DP) and periodontal tissues (PDL). We report that ~50% of trigeminal ganglion (TG) neurons retrogradely labeled from the DP express TRPV2, and this was significantly greater than the general expression of this channel in the TG (15%) and slightly more than what is expressed in the PDL by retrograde labeling (40%). The TRPV1 receptor, however, was less prevalent in neurons innervating the DP than their general expression in the TG (17% vs. 26%) and was more extensively expressed in neurons innervating the PDL (26%). Co-labeling studies showed that 70% of neurons that innervate the DP are myelinated. Approximately 1/3 of the retrogradely labeled neurons from the DP were calcitonin-gene-related-peptide-positive (peptide-expressing), but very few expressed the IB4 marker of non-peptidergic unmyelinated afferents. These findings suggest that the DP has a unique neurochemical innervation with regard to TRP receptor expression, which has significant implications for the mechanisms contributing to odontogenic pain and management strategies.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting.

PubMed

Ishii, Masashi; Hayashi, Morito; Yagi, Fumihiko; Sato, Kenichiro; Tomita, Goji; Iwabuchi, Satoshi

2016-01-01

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS ( P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow ( P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

[Intramedullary nailing combined with cannulated screw in treating femoral condyles fractures].

PubMed

Shen, Guo-Qing; Zhang, Hao; Long, Da-Fu; Li, Zheng-Wen; Tan, Ying-Dong

2017-07-25

To observe the clinical effects of retrograde intramedullary nailing and cannulated screws in the treatment of femoral condylar fracture. From June 2009 to June 2015, 13 patients with femoral condyles fracture were treated by retrograde intramedullary nailing and cannulated screws including 6 males and 7 females with an average age of 46.1 years old ranging from 16 to 76 years old. There were 10 cases of closed fractures, 3 cases of open fraetures. According to AO classification criteriam, 4 cases were type C1, 7 cases were type C2, 2 cases were type C3. Postoperative reduction of fracture and the knee joint function recovery were observed. All patients were followed up for 12 to 36 months with a mean of 24 months. X-ray examination showed that the union time of fracture was 18 to 24 weeks, 21 weeks on average. There were no cases of loosening, breakage of internal fixators and re-fracture. Hospital for Special Surgery(HSS) knee score was 90.07±4.99 at 1 year after the operation. The clinical efficacy for retrograde intramedullary nailing and cannulated screw for the treatment of femoral condyles fracture was excellent. It can improve the anatomical reattachment rate and reduce the complications and promote the knee functional recovery.

Pre-operative endoscopic ultrasonography can optimise the management of patients undergoing laparoscopic cholecystectomy with abnormal liver function tests as the sole risk factor for choledocholithiasis: a prospective study.

PubMed

Meroni, E; Bisagni, P; Bona, S; Fumagalli, U; Zago, M; Rosati, R; Malesci, A

2004-01-01

Pre-operative endosonography has been proposed as a cost-effective procedure in the management of patients who undergo laparoscopic cholecystectomy having an intermediate risk of common bile duct stones. We prospectively evaluated the impact of pre-operative endosonography on the management of patients facing laparoscopic cholecystectomy with abnormal liver function tests as the sole risk factor for choledocolithiasis. Among 587 consecutive patients scheduled for laparoscopic cholecystectomy, 47 (8%) patients having one or more abnormal liver function tests but a normal appearance of common bile duct at abdominal ultrasound, underwent pre-operative endosonography. In patients with endosonography-detected common bile duct stones, a pre-operative endoscopic retrograde cholangiography was performed, or an intra-operative endoscopic retrograde cholangiography was scheduled. In all endosonography-negative patients, an intra-operative trans-cystic cholangiography was performed. Endosonography detected common bile duct stones in nine patients (19%) but only in five of them stones were radiologically confirmed (PPV 0.55). Endosonography-detected stones were confirmed in four of four (100%) patients in whom cholangiography was performed within 1 week, but only in one of five (20%) patients in whom radiology was further delayed (P < 0.05). In three of four cases (75%), stones detected at endosonography but not confirmed at X-rays, were smaller than 2.0 mm. Among 38 patients with negative endosonography, common bile duct stones were found in two patients (NPV 0.95), whereas unplanned endoscopic stone extraction was needed only in one patient (NPV 0.97). Pre-operative endosonography can spare unnecessary pre-operative endoscopic retrograde cholangiography as well as inappropriate scheduling of intra-operative endoscopic retrograde cholangiography in patients undergoing laparoscopic cholecystectomy with abnormal liver function tests. To maximise the impact of endosonography on the management of these patients, the procedure should be performed immediately before laparoscopic cholecystectomy.

Staling of cereal bran enriched cakes and the effect of an endoxylanase enzyme on the physicochemical and sensorial characteristics.

PubMed

Lebesi, Dimitra M; Tzia, Constantina

2011-08-01

The staling of cakes enriched with untreated brans and endoxylanase-treated brans was evaluated by monitoring the changes in physicochemical, thermal, and sensorial properties of cakes during 7-d storage. Oat and rice bran were treated with different levels (0, 70, and 700 ppm) of an endoxylanase enzyme and added to cakes on 30% flour weight basis. Moisture losses, water activity, crumb firmness, starch retrogradation, and sensorial characteristics were used as staling indicators. Avrami-type equations were efficiently used for modeling the starch retrogradation kinetics, while linear models most adequately described crumb firming kinetics. Cake staling induced an increase in crumb firmness and enthalpy of amylopectin retrogradation, and a decrease in crumb moisture and sensory quality and acceptability scores of cakes. Oat bran-containing cakes better maintained their characteristics compared to the ones containing rice bran along the 7-d storage. Endoxylanase treatment of brans delayed the changes naturally induced during staling in crumb moisture content, amylopectin retrogradation enthalpy, and crumb firmness in the respective cakes. Deterioration of the sensorial characteristics was slower for the cakes containing endoxylanase-treated brans, as well. The level of endoxylanase treatment did not differentiate significantly (P < 0.05) any of the staling indicators. Overall, this study demonstrated that addition of endoxylanase-treated brans can result in cakes with improved nutritional characteristics and increased shelf life. The results of the study show the potential of using enzymes to modify underutilized food sources that can be properly incorporated in baked goods, improving their nutritional value, their quality characteristics, and providing longer shelf life. The developed procedure and results can be utilized by the bakery industry to make high fiber and low cost bakery products with improved sensorial characteristics that are appealing to the consumers. © 2011 Institute of Food Technologists®

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teyssandier, Jean; Naoz, Smadar; Lizarraga, Ian

Observations of exoplanets over the last two decades have revealed a new class of Jupiter-size planets with orbital periods of a few days, the so-called 'hot Jupiters'. Recent measurements using the Rossiter-McLaughlin effect have shown that many (∼50%) of these planets are misaligned; furthermore, some (∼15%) are even retrograde with respect to the stellar spin axis. Motivated by these observations, we explore the possibility of forming retrograde orbits in hierarchical triple configurations consisting of a star-planet inner pair with another giant planet, or brown dwarf, in a much wider orbit. Recently, it was shown that in such a system, themore » inner planet's orbit can flip back and forth from prograde to retrograde and can also reach extremely high eccentricities. Here we map a significant part of the parameter space of dynamical outcomes for these systems. We derive strong constraints on the orbital configurations for the outer perturber (the tertiary) that could lead to the formation of hot Jupiters with misaligned or retrograde orbits. We focus only on the secular evolution, neglecting other dynamical effects such as mean-motion resonances, as well as all dissipative forces. For example, with an inner Jupiter-like planet initially on a nearly circular orbit at 5 AU, we show that a misaligned hot Jupiter is likely to be formed in the presence of a more massive planetary companion (>2 M{sub J} ) within ∼140 AU of the inner system, with mutual inclination >50° and eccentricity above ∼0.25. This is in striking contrast to the test particle approximation, where an almost perpendicular configuration can still cause large-eccentricity excitations, but flips of an inner Jupiter-like planet are much less likely to occur. The constraints we derive can be used to guide future observations and, in particular, searches for more distant companions in systems containing a hot Jupiter.« less

Hybrid treatment of tandem, common carotid/innominate artery and ipsilateral carotid bifurcation stenoses by simultaneous, retrograde proximal stenting and eversion carotid endarterectomy: Preliminary results of a case series.

PubMed

Illuminati, Giulio; Pizzardi, Giulia; Pasqua, Rocco; Frezzotti, Francesca; Palumbo, Piergaspare; Macrina, Francesco; Calio', Francesco

2018-04-01

Tandem stenoses of the internal carotid artery (ICA) and proximal, ipsilateral common carotid artery (CCA) or innominate artery can be treated with a hybrid approach, combining conventional carotid endarterectomy (CEA) and retrograde stenting of the proximal stenosis, through surgical exposure of the carotid bifurcation. The purpose of this study was to evaluate the results of combining eversion CEA with retrograde CCA/innominate artery stenting. From January 2015 to July 2017, 7 patients, 6 men of a mean age of 72 years (range 59-83 years) underwent simultaneous, retrograde stenting of the proximal CCA/innominate artery and an eversion CEA of the ipsilateral ICA, through surgical exposure of the carotid bifurcation, for severe tandem stenoses. The proximal stenosis involved the left proximal CCA in 4 patients, the proximal innominate artery in 2 patients and the right CCA in one patient. The procedure was performed under general anesthesia in a conventional operating room equipped with a mobile C-arm. A covered, balloon expandable stent was deployed over the proximal stenosis via a 6-F sheath directly introduced into the proximal CCA through the obliquely transected carotid bulb. After removing the sheath, debris were flushed through the carotid bulb and eversion CEA completed the procedure. Study endpoints were: postoperative stroke/mortality rate, cardiac mortality and morbidity, peripheral nerve injury, cervical hematoma, overall late survival, freedom from ipsilateral stroke and patency of arterial reconstruction. No postoperative mortality or neurologic morbidity was observed in any patient. Cervical hematomas and peripheral nerve injuries were likewise absent. At a mean follow-up of 18 months, all the patients were alive, free from neurologic events of new onset and free from restenosis. Combined proximal stenting and eversion CEA for tandem lesions seems a valid treatment, with the advantages of eversion CEA over other techniques of carotid bifurcation revascularization. Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Changes in the HOAr isotope composition of clays during retrograde alteration

USGS Publications Warehouse

Wilson, M.R.; Kyser, T.K.; Mehnert, H.H.; Hoeve, J.

1987-01-01

K-Ar ages of illite alteration associated with Middle Proterozoic Athabasca unconformity-type U deposits in Saskatchewan range from 414 to 1493 Ma. The K-Ar ages correlate with water contents and ??D values such that illites with young K-Ar ages have ??D values as low as -169 and water contents as high as 7.7 wt.% whereas illites with older ages have ??D values near -70 and water contents near 4 wt.%. Water extracted at 400??C from illites with low ??D values and high water contents has low ??D and ??18O values similar to those of modern meteoric water suggesting that some of the illites associated with the original deposition of the ore underwent varying degrees of retrograde alteration. The alteration is initiated by hydration of sites in the interlayer region of the illite which results in the partial resetting of the K-Ar ages and introduction of excess structural water in the form of interlamellar water. The interlamellar water is enriched in 18O by about 7 per mil relative to the water that physically surrounded the clay particle. Further alteration decreases the ??D value and increases the ??18O value of the illite by isotopic exchange between the mineral and the interlamellar water. Although the chemical compositions and XRD patterns of the altered illites indicate that no detectable smectite component is present in the samples, the isotopic results suggest that the altered illites may be an early precursor in the formation of mixed-layer illite/smectite by retrograde alteration of pure illite. The wide variation of ??D values of chlorite and kaolinite from these U deposits is analogous to that of the illite suggesting that retrograde alteration of clays by meteoric water can be substantial. The general association of altered clays with areas containing the highest concentrations of U is probably related to localized permeability within the ore zone. ?? 1987.

Right ventral frontal hypometabolism and abnormal sense of self in a case of disproportionate retrograde amnesia.

PubMed

Piolino, Pascale; Hannequin, Didier; Desgranges, Beatrice; Girard, Carole; Beaunieux, Helene; Giffard, Benedicte; Lebreton, Karine; Eustache, Francis

2005-01-01

We report the case of a 42-year-old man (patient CL) who developed a particular profile of amnesia with two dates of onset. At the first onset, the patient suffered a mild/lmoderate injury that accounts for an initial anterograde and mild retrograde memory impairment. At the second onset, 8 months later, he suffered a sudden and persistent loss of personal identity and severe retrograde amnesia. We report an extensive neuropsychological investigation of his memory systems carried out 18 months after the second onset. Results indicated mild executive dysfunction (primary memory), intact procedural skills and perceptual representational system. In accordance with Kopelman's methodological recommendations, we have reliably compared post- and pre-onset semantic and episodic memory using strict matched procedures. We found that post-onset, though not pre-onset semantic (autobiographical and nonautobiographical) memory was entirely preserved. Post-onset episodic autobiographical memory was not intact, however, although it was clearly less affected compared with the total absence of the pre-onset memory. Moreover, a novel and high standard investigation of the subjective states of consciousness, which accompanied retrieval of autobiographical memories via the Remember/lKnow (R/lK) paradigm with a long time interval from the present, demonstrated a deterioration of R responses compared to matched controls. Interestingly, this result showed deficient autonoetic consciousness and suggested an underlying accelerated forgetting rate for post-onset autobiographical episodic memories. Last, a [18F] fluorodeoxyglucose resting PET study revealed a significant right-sided ventral frontal lobe hypometabolism in the absence of overt structural lesions. The involvement of this region is consistent with CL's autobiographical retrograde amnesia and his inability to re-experience information concerning the self across time. In our particular case, characterised by two dates of onset, the attribution of causality is thoroughly examined in terms of CL's organic and psychogenic aspects.

[Endovascular repair of primary retrograde Stanford type A aortic dissection].

PubMed

Wu, H W; Sun, L; Li, D M; Jing, H; Xu, B; Wang, C T; Zhang, L

2016-10-01

Objective: To summarize the short- and mid-term results on endovascular repair of primary retrograde Stanford type A aortic dissection with an entry tear in distal aortic arch or descending aorta. Methods: Between December 2009 and December 2014, 21 male patients of primary retrograde Stanford type A aortic dissection with a mean age of (52±9) years received endovascular repair in Department of Cardiothoracic Surgery, Jinling Hospital. Among the 21 cases, 17 patients were presented as ascending aortic intramural hematoma, 4 patients as active blood flow in false lumen and partial thrombosis, 8 patients as ulcer on descending aorta combined intramural hematoma in descending aorta, and 13 patients as typical dissection changes. All patients received endovascular stent-graft repair successfully, with 15 cases in acute phase and 6 cases in chronic phase. Results: Cone stent was implanted in 13 cases, while straight stent in 8 cases, including 1 case of left common carotid-left subclavian artery bypass surgery and 1 case of restrictive bare-metal stent implantation. No perioperative stroke, paraplegia, stent fracture or displacement, limbs or abdominal organ ischemia or other severe complications occured, except for tracheotomy in 2 patients. Active blood flow in ascending aorta or aortic arch disappeared, and intramural hematoma started being absorbed on CT angiography images before discharge. All patients were alive during follow-up (6 to 72 months), and intramural hematoma in ascending aorta and aortic arch was absorbed thoroughly. Type Ⅰ endoleak and ulcer expansion were found in 1 patient, and type Ⅳ endoleak in distal stent was found in another one patient. Secondary ascending aortic dissection was found in 1 case two years later, which was cured by hybrid procedure with cardiopulmonary bypass. Conclusion: Endovascular repair of primary retrograde Stanford type A aortic dissection was safe and effective, which correlated with favorable short- and mid-term results.

[Feasibility and safety evaluation of retrograde inserting of ureteric catheter via flexible cystoscope].

PubMed

Jin, Xiao-dong; Li, Zhong-yi; Luo, Xue-hong; Chen, Zhao-dian; Cai, Song-liang; Xie, Li-ping

2008-06-24

To introduce a method of retrograde ureteric catheter placement via flexible cystoscope , and to evaluate the feasibility and safety of this method. 112 patients, 62 males and 50 females undergoing retrograde ureteropyelography by 2 same physicians in cooperation were randomly divided into two equal groups with 31 males and 25 females each: one group via flexible cystoscope and the other group via rigid cystoscope. The catheterizing time, visual analogue scale (VAS) pain score, gross hematuria rate, and fever rate were compared between these 2 groups. Fifty-five patients underwent ureteric catheter placement successfully via flexible cystoscope (98%, 55/56), while 53 cases were technically successful by rigid cystoscope (95%, 53/56). The inserting time in women patients of the flexible cystoscopy group was (7.6 +/- 1.8) min, significantly shorter than that of the men [(8.0 +/- 1.8) min, P < 0.05]. The inserting time in women patients of the rigid cystoscopy group was (7.4 +/- 1.5) min, significantly shorter than that of the men [(8.2 +/- 1.2) min, P < 0.05]. However, there were not significant differences in the inserting times in both men and women between these 2 groups (both P > 0.05). The VAS pain scores in men and women of the flexible cystoscope group were 3. 5 and 2. 3 respectively, both significantly lower than those of the rigid cystoscopy group (7.2 and 3.3 respectively, both P < 0.05). The gross hematuria rate of the flexible cystoscope group was 8.6% (5/56), significantly lower than that of the rigid cystoscopy group (25.0%, 14/56, P < 0.05). Four patients had a fever after flexible cystoscopy while 6 cases did after rigid cystoscopy, however, without significant difference between these 2 groups (P > 0.05). Retrograde placement of ureteric catheter via flexible cystoscope is safe and reliable as rigid cystoscopy. Meanwhile, inserting ureteric catheter via flexible cystoscope causes the patients less pain and less chance of hematuria.

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

PubMed

Dai, Jian; Katoh, Osamu; Kyo, Eisho; Tsuji, Takafumi; Watanabe, Satoshi; Ohya, Hidefumi

2013-10-01

Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success. © 2013, Wiley Periodicals, Inc.

Rapidly transported organelles containing membrane and cytoskeletal components: their relation to axonal growth

PubMed Central

1987-01-01

We have examined the movements, composition, and cellular origin of phase-dense varicosities in cultures of chick sympathetic and sensory neurons. These organelles are variable in diameter (typically between 0.2 and 2 microns) and undergo saltatory movements both towards and away from the neuronal cell body. Their mean velocities vary inversely with the size of the organelle and are greater in the retrograde than the anterograde direction. Organelles stain with the lipophilic dye 1, 1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine and with antibodies to cytoskeletal components. In cultures double-stained with antibodies to alpha-tubulin and 70-kD neurofilament protein (NF-L), approximately 40% of the organelles stain for tubulin, 30% stain for NF- L, 10% stain for both tubulin and NF-L, and 40% show no staining with either antibody. The association of cytoskeletal proteins with the organelles shows that these proteins are able to move by a form of rapid axonal transport. Under most culture conditions the predominant direction of movement is towards the cell body, suggesting that the organelles are produced at or near the growth cone. Retrograde movements continue in culture medium lacking protein or high molecular mass components and increase under conditions in which the advance of the growth cone is arrested. There is a fourfold increase in the number of organelles moving retrogradely in neurites that encounter a substratum-associated barrier to elongation; retrograde movements increase similarly in cultures exposed to cytochalasin at levels known to block growth cone advance. No previously described organelle shows behavior coordinated with axonal growth in this way. We propose that the organelles contain membrane and cytoskeletal components that have been delivered to the growth cone, by slow or fast anterograde transport, in excess of the amounts required to synthesize more axon. In view of their rapid mobility and variable contents, we suggest that they be called "neuronal parcels." PMID:3693400

The dependence of neuronal encoding efficiency on Hebbian plasticity and homeostatic regulation of neurotransmitter release

PubMed Central

Faghihi, Faramarz; Moustafa, Ahmed A.

2015-01-01

Synapses act as information filters by different molecular mechanisms including retrograde messenger that affect neuronal spiking activity. One of the well-known effects of retrograde messenger in presynaptic neurons is a change of the probability of neurotransmitter release. Hebbian learning describe a strengthening of a synapse between a presynaptic input onto a postsynaptic neuron when both pre- and postsynaptic neurons are coactive. In this work, a theory of homeostatic regulation of neurotransmitter release by retrograde messenger and Hebbian plasticity in neuronal encoding is presented. Encoding efficiency was measured for different synaptic conditions. In order to gain high encoding efficiency, the spiking pattern of a neuron should be dependent on the intensity of the input and show low levels of noise. In this work, we represent spiking trains as zeros and ones (corresponding to non-spike or spike in a time bin, respectively) as words with length equal to three. Then the frequency of each word (here eight words) is measured using spiking trains. These frequencies are used to measure neuronal efficiency in different conditions and for different parameter values. Results show that neurons that have synapses acting as band-pass filters show the highest efficiency to encode their input when both Hebbian mechanism and homeostatic regulation of neurotransmitter release exist in synapses. Specifically, the integration of homeostatic regulation of feedback inhibition with Hebbian mechanism and homeostatic regulation of neurotransmitter release in the synapses leads to even higher efficiency when high stimulus intensity is presented to the neurons. However, neurons with synapses acting as high-pass filters show no remarkable increase in encoding efficiency for all simulated synaptic plasticity mechanisms. This study demonstrates the importance of cooperation of Hebbian mechanism with regulation of neurotransmitter release induced by rapid diffused retrograde messenger in neurons with synapses as low and band-pass filters to obtain high encoding efficiency in different environmental and physiological conditions. PMID:25972786

Effects of electroconvulsive seizures on depression-related behavior, memory and neurochemical changes in Wistar and Wistar-Kyoto rats.

PubMed

Kyeremanteng, C; MacKay, J C; James, J S; Kent, P; Cayer, C; Anisman, H; Merali, Z

2014-10-03

Investigations in healthy outbred rat strains have shown a potential role for brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis in the antidepressant and memory side effects of electroconvulsive therapy (ECT, or ECS in animals). The Wistar-Kyoto (WKY) rat strain is used as a genetic model of depression yet no studies to date have directly compared the impact of ECS on the WKY strain to its healthy outbred control (Wistar). The objective of this study is to examine behavioral (antidepressant and retrograde memory) and neurochemical (BDNF and HPA axis) changes immediately (1day) and at a longer delay (7days) after repeated ECS (5 daily administrations) in WKY and Wistar rats. Male Wistar and WKY rats received 5days of repeated ECS or sham treatment and were assessed 1 and 7days later for 1) depression-like behavior and mobility; 2) retrograde memory; and 3) brain BDNF protein, brain corticotropin-releasing factor (CRF) and plasma corticosterone levels. Both strains showed the expected antidepressant response and retrograde memory impairments at 1day following ECS, which were sustained at 7days. In addition, at 1day after ECS, Wistar and WKY rats showed similar elevations in brain BDNF and extra-hypothalamic CRF and no change in plasma corticosterone. At 7days after ECS, Wistar rats showed sustained elevations of brain BDNF and CRF, whereas WKY rats showed a normalization of brain BDNF, despite sustained elevations of brain CRF. The model of 5 daily ECS was effective at eliciting behavioral and neurochemical changes in both strains. A temporal association was observed between brain CRF levels, but not BDNF, and measures of antidepressant effectiveness of ECS and retrograde memory impairments suggesting that extra-hypothalamic CRF may be a potential important contributor to these behavioral effects after repeated ECS/ECT. Copyright © 2014 Elsevier Inc. All rights reserved.

Radiographic predictors of symptomatic screw removal after retrograde femoral nail insertion.

PubMed

Hamaker, Max; O'Hara, Nathan N; Eglseder, W Andrew; Sciadini, Marcus F; Nascone, Jason W; O'Toole, Robert V

2017-03-01

Removal of symptomatic implants is a common procedure performed by orthopaedic trauma surgeons. No guidance is available regarding which factors contribute to the likelihood of an implant becoming symptomatic. Our objective was to determine whether radiographic parameters associated with distal interlocks in retrograde femoral nails are associated with the rate of symptomatic screw removal. We conducted a retrospective review at a Level I trauma center. Study patients (n=442) had femoral fractures treated with retrograde intramedullary nails from 2007 to 2014 and at least 1year of follow-up. The main outcome measurement was symptomatic distal screw removal as predicted by radiographic parameters. Symptomatic screw removal occurred in 12% of the patients. Increased distance between the most distal screw and the articular surface of the femur significantly reduced likelihood of symptomatic screw removal. A cutoff of 40mm from the articular block was predictive of removal (≥40mm, 0% removal; <40mm, 18% removal, p<0.0001). In patients with distal screws placed within 40mm of the articular surface of the femur, a ratio of screw length to distance between medial and lateral femoral cortices that was ≥1 was a strong predictor of symptomatic screw removal (area under Receiver Operating Characteristic curve, 0.75; p<0.0001). More distal screws and screws that radiographically extend to or beyond the medial cortex are more likely to cause pain and require removal in femoral fractures treated with retrograde intramedullary nails. We identified a specific distance from the joint (<40mm) and a ratio of screw length to bone width (≥1) that significantly increased the likelihood of symptomatic screw removal. Clinicians can use these data to inform patients of the likely risk of implant removal and perhaps to better guide placement and length of screws when the clinical scenario allows some flexibility in location and length of screws. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Arabidopsis mitochondria-localized RRL protein mediates abscisic acid signal transduction through mitochondrial retrograde regulation involving ABI4.

PubMed

Yao, Xuan; Li, Juanjuan; Liu, Jianping; Liu, Kede

2015-10-01

The molecular mechanisms of abscisic acid (ABA) signalling have been studied for many years; however, how mitochondria-localized proteins play roles in ABA signalling remains unclear. Here an Arabidopsis mitochondria-localized protein RRL (RETARDED ROOT GROWTH-LIKE) was shown to function in ABA signalling. A previous study had revealed that the Arabidopsis mitochondria-localized protein RRG (RETARDED ROOT GROWTH) is required for cell division in the root meristem. RRL shares 54% and 57% identity at the nucleotide and amino acid sequences, respectively, with RRG; nevertheless, RRL shows a different function in Arabidopsis. In this study, disruption of RRL decreased ABA sensitivity whereas overexpression of RRL increased ABA sensitivity during seed germination and seedling growth. High expression levels of RRL were found in germinating seeds and developing seedlings, as revealed by β-glucuronidase (GUS) staining of ProRRL-GUS transgenic lines. The analyses of the structure and function of mitochondria in the knockout rrl mutant showed that the disruption of RRL causes extensively internally vacuolated mitochondria and reduced ABA-stimulated reactive oxygen species (ROS) production. Previous studies have revealed that the expression of alternative oxidase (AOX) in the alternative respiratory pathway is increased by mitochondrial retrograde regulation to regain ROS levels when the mitochondrial electron transport chain is impaired. The APETALA2 (AP2)-type transcription factor ABI4 is a regulator of ALTERNATIVE OXIDASE1a (AOX1a) in mitochondrial retrograde signalling. This study showed that ABA-induced AOX1a and ABI4 expression was inhibited in the rrl mutant, suggesting that RRL is probably involved in ABI4-mediated mitochondrial retrograde signalling. Furthermore, the results revealed that ABI4 is a downstream regulatory factor in RRL-mediated ABA signalling in seed germination and seedling growth. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Force Mapping during the Formation and Maturation of Cell Adhesion Sites with Multiple Optical Tweezers

PubMed Central

Schwingel, Melanie; Bastmeyer, Martin

2013-01-01

Focal contacts act as mechanosensors allowing cells to respond to their biomechanical environment. Force transmission through newly formed contact sites is a highly dynamic process requiring a stable link between the intracellular cytoskeleton and the extracellular environment. To simultaneously investigate cellular traction forces in several individual maturing adhesion sites within the same cell, we established a custom-built multiple trap optical tweezers setup. Beads functionalized with fibronectin or RGD-peptides were placed onto the apical surface of a cell and trapped with a maximum force of 160 pN. Cells form adhesion contacts around the beads as demonstrated by vinculin accumulation and start to apply traction forces after 30 seconds. Force transmission was found to strongly depend on bead size, surface density of integrin ligands and bead location on the cell surface. Highest traction forces were measured for beads positioned on the leading edge. For mouse embryonic fibroblasts, traction forces acting on single beads are in the range of 80 pN after 5 minutes. If two beads were positioned parallel to the leading edge and with a center-to-center distance less than 10 µm, traction forces acting on single beads were reduced by 40%. This indicates a spatial and temporal coordination of force development in closely related adhesion sites. We also used our setup to compare traction forces, retrograde transport velocities, and migration velocities between two cell lines (mouse melanoma and fibroblasts) and primary chick fibroblasts. We find that maximal force development differs considerably between the three cell types with the primary cells being the strongest. In addition, we observe a linear relation between force and retrograde transport velocity: a high retrograde transport velocity is associated with strong cellular traction forces. In contrast, migration velocity is inversely related to traction forces and retrograde transport velocity. PMID:23372781

Distant retrograde orbits for the Moon's exploration

NASA Astrophysics Data System (ADS)

Sidorenko, Vladislav

We discuss the properties of the distant retrograde orbits (which are called quasi-satellite orbits also) around Moon. For the first time the distant retrograde orbits were described by J.Jackson in studies on restricted three body problem at the beginning of 20th century [1]. In the synodic (rotating) reference frame distant retrograde orbit looks like an ellipse whose center is slowly drifting in the vicinity of minor primary body while in the inertial reference frame the third body is orbiting the major primary body. Although being away the Hill sphere the third body permanently stays close enough to the minor primary. Due to this reason the distant retrograde orbits are called “quasi-satellite” orbits (QS-orbits) too. Several asteroids in solar system are in a QS-orbit with respect to one of the planet. As an example we can mention the asteroid 2002VE68 which circumnavigates Venus [2]. Attention of specialists in space flight mechanics was attracted to QS-orbits after the publications of NASA technical reports devoted to periodic moon orbits [3,4]. Moving in QS-orbit the SC remains permanently (or at least for long enough time) in the vicinity of small celestial body even in the case when the Hill sphere lies beneath the surface of the body. The properties of the QS-orbit can be studied using the averaging of the motion equations [5,6,7]. From the theoretical point of view it is a specific case of 1:1 mean motion resonance. The integrals of the averaged equations become the parameters defining the secular evolution of the QS-orbit. If the trajectory is robust enough to small perturbations in the simplified problem (i.e., restricted three body problem) it may correspond to long-term stability of the real-world orbit. Our investigations demonstrate that under the proper choice of the initial conditions the QS-orbits don’t escape from Moon or don’t impact Moon for long enough time. These orbits can be recommended as a convenient technique for the large scale browsing of the Moon’s environment. [1] Jackson, J. (1913) MNRAS, 74, 62-82. [2] Mikkola, S., Brasser, R., Wiegert, P., Innanen, K. (2004) MNRAS, 351, L63-L65. [3] Broucke, R.A. (1968) NASA Technical Report 32-1168, JPL. [4] Broucke, R.A. (1969) NASA Technical Report 32-1360, JPL. [5] Kogan, A.I. (1989) Cosmic Research, 26, 705-710. [6] Namouni, F. (1999) Icarus, 6, 293-314. [7] Sidorenko, V.V., Neishtadt, A.I., Artemyev, A.V., Zelenyi, L.M. (2013) Doklady Physics, 58, 207-211.

Fluid-induced Blueschist Preservation on Syros, Cyclades, Southern Greece

NASA Astrophysics Data System (ADS)

Kleine, B. I.; Huet, B.; Skelton, A. D. L.

2012-04-01

Local examples of preservation of high-pressure, low-temperature (HP-LT) mineral assemblages within retrograde metamorphosed greenschist are recorded from the Cyclades, Greece. Several models have been proposed to explain the preservation of HP-LT rocks in these areas. On Sifnos, a capping effect of impermeable marble units below the preserved blueschists caused diversion of the upward, cross-layer infiltration of retrograde fluids [1]. On Tinos, blueschist preservation occurred due to retrograde fluid flow channelization along lithological contacts with high flux rates [2]. HP-LT minerals were preserved in regions adjacent to these contacts where fluid fluxes were smaller. We propose a different mechanism of blueschist preservation based on observations from a costal section near Fabrika on Syros. At this locality a high strain zone cuts through a retrograde greenschist. Along the fault a dark blue halo occurs within the greenschist. Whole rock analyses along a profile from the fault into the greenschist show that only the areas directly adjacent to the deformation zone show chemical evidence of metasomatism, whereas the areas further away are chemically similar to greenschist. Point counting of 1000 evenly spaced points in thin sections of the profile shows a clear blueschist to greenschist transition with a blueschist mineral assemblage (glaucophane+phengite+calcite) nearer to the metasomatic zone and a typical greenschist mineral assemblage (epidote+chlorite+albite) farther away. We propose the following model to explain preservation of HP-LT mineral assemblage in this locality. During retrograde metamorphism a water-rich fluid infiltrated the blueschist rock from below. This occurred close to the brittle-ductile transition. This fluid caused a reaction front to propagate into the overlying blueschist at which its mineral assemblage glaucophane+phengite+calcite was replaced by the greenschist mineral assemblage epidote+albite+chlorite. Upwards-flowing fluid passing through the reaction front is buffered to higher X(CO2) by the reaction glaucophane+phengite+calcite+H2O=albite+chlorite+epidote+quartz+CO2. This fluid travels faster along paths of structural weakness (e.g. shear zones, faults). If this fluid reaches colder regions more rapidly such that the fluid chemistry is unable to "keep up" with the position of the reaction equilibria as the temperature falls, X(CO2) will be effectively shifted back into the blueschist stability field and blueschist will be preserved, specifically within high flux regions, such as shear zones and faults. [1] Matthews & Schliestedt (1984), Contributions to Mineralogy and Petrology, 88, 150-163. [2] Breeding et al. (2003), Geochemistry Geophysics Geosystems, 4, 1-11.

Geochronology of multi-stage metamorphic events: Constraints on episodic zircon growth from the UHP eclogite in the South Altyn, NW China

NASA Astrophysics Data System (ADS)

Liu, Liang; Wang, Chao; Cao, Yu-Ting; Chen, Dan-Ling; Kang, Lei; Yang, Wen-Qiang; Zhu, Xiao-Hui

2012-04-01

Petrography, mineral chemistry and pressure-temperature (P-T) estimates were carried out for the eclogite from the South Altyn in NW China. The results suggest three stages of metamorphism: an ultra-high pressure (UHP) eclogite-facies metamorphism at 717-871 °C and ≥ 2.8 GPa, a high pressure (HP) granulite-facies metamorphism at 624-789 °C and 1.42-1.52 GPa, and an amphibolite-facies metamorphism at 597-728 °C and 0.99-1.17 GPa. Cathodoluminescence investigation revealed that zircons from the retrograde eclogite display a distinct core-rim structure. Cores are grey-white luminescent and contain mineral inclusions of Garnet + Omphacite + Rutile + Quartz, suggesting eclogite-facies metamorphic origin. The rims are dark grey luminescent and contain Garnet + Clinopyroxene + Pagioclase inclusions, forming at HP granulite-facies conditions. A few residual zircon grains with mottled internal structure also occur as the metamorphic cores. LA-ICPMS zircon U-Pb dating yielded three discrete age groups: (1) a Neoproterozoic protolith age of 752 ± 7 Ma for the residual grains, (2) an eclogite-facies metamorphic age of 500 ± 7 Ma for the metamorphic cores, and (3) a HP granulite-facies retrograde age of 455 ± 2 Ma for the rims. These ages indicate that the protolith of the Altyn eclogite probably formed in response to breakup of the Rodinia supercontinent during the Neoproterozoic; it was subjected to continental deep subduction and UHP metamorphism during early Paleozoic (~ 500 Ma) and subsequently underwent two stages of retrograde metamorphism during exhumation. The petrological and geochronological data suggest a clockwise P-T-t path for the UHP eclogite. According to pressures and ages for the peak UHP eclogite-facies and the retrograde HP granulite-facies metamorphism, an exhumation rate of 1.2 mm/yr was estimated for the eclogite, which is considerably slower than that of some UHP rocks from other UHP terranes (> 5 mm/yr). While the peak metamorphic age of 500 Ma is consistent with previous dates of 480-504 Ma, it is 40-60 Myr older than the HP/UHP metamorphic ages of 420-461 Ma for UHP eclogites in North Qaidam. The retrograde metamorphic age is 455 ± 2 Ma for the Altyn eclogite, which is 30-55 Myr older than ~ 400-425 Ma for the North Qaidam eclogites. These age differences suggest that the South Altyn and North Qaidam eclogites do not belong to the same HP/UHP metamorphic zone.

Regulation of Synaptic Amyloid-β Generation through BACE1 Retrograde Transport in a Mouse Model of Alzheimer's Disease

PubMed Central

Ye, Xuan; Chang, Qing; Jeong, Yu Young; Cai, Huaibin; Kusnecov, Alexander

2017-01-01

Amyloid-β (Aβ) peptides play a key role in synaptic damage and memory deficits in the early pathogenesis of Alzheimer's disease (AD). Abnormal accumulation of Aβ at nerve terminals leads to synaptic pathology and ultimately to neurodegeneration. β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is the major neuronal β-secretase for Aβ generation. However, the mechanisms regulating BACE1 distribution in axons and β cleavage of APP at synapses remain largely unknown. Here, we reveal that dynein–Snapin-mediated retrograde transport regulates BACE1 trafficking in axons and APP processing at presynaptic terminals. BACE1 is predominantly accumulated within late endosomes at the synapses of AD-related mutant human APP (hAPP) transgenic (Tg) mice and patient brains. Defective retrograde transport by genetic ablation of snapin in mice recapitulates late endocytic retention of BACE1 and increased APP processing at presynaptic sites. Conversely, overexpressing Snapin facilitates BACE1 trafficking and reduces synaptic BACE1 accumulation by enhancing the removal of BACE1 from distal AD axons and presynaptic terminals. Moreover, elevated Snapin expression via stereotactic hippocampal injections of adeno-associated virus particles in mutant hAPP Tg mouse brains decreases synaptic Aβ levels and ameliorates synapse loss, thus rescuing cognitive impairments associated with hAPP mice. Altogether, our study provides new mechanistic insights into the complex regulation of BACE1 trafficking and presynaptic localization through Snapin-mediated dynein-driven retrograde axonal transport, thereby suggesting a potential approach of modulating Aβ levels and attenuating synaptic deficits in AD. SIGNIFICANCE STATEMENT β-Site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) trafficking and synaptic localization significantly influence its β secretase activity and amyloid-β (Aβ) production. In AD brains, BACE1 is accumulated within dystrophic neurites, which is thought to augment Aβ-induced synaptotoxicity by Aβ overproduction. However, it remains largely unknown whether axonal transport regulates synaptic APP processing. Here, we demonstrate that Snapin-mediated retrograde transport plays a critical role in removing BACE1 from presynaptic terminals toward the soma, thus reducing synaptic Aβ production. Adeno-associated virus–mediated Snapin overexpression in the hippocampus of mutant hAPP mice significantly decreases synaptic Aβ levels, attenuates synapse loss, and thus rescues cognitive deficits. Our study uncovers a new pathway that controls synaptic APP processing by enhancing axonal BACE1 trafficking, thereby advancing our fundamental knowledge critical for ameliorating Aβ-linked synaptic pathology. PMID:28159908

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beilis, I. I.

A model was developed of vacuum arc cathode spot motion in a magnetic field that obliquely intercepts the cathode surface. The model takes into account a force under an electric field caused by retrograde spot motion across the normal component of the magnetic field, producing a drift velocity component in the direction of the acute angle between the magnetic field and the cathode surface. The relationship between velocity of the retrograde direction and drift velocity of the cathode spot motion to the acute angle was developed. The dependencies of the drift angle θ on the acute angle φ, magnetic fieldmore » strength B, and arc current I were calculated. It was found that the calculated θ increased with φ, B, and I in accordance with Robson's measurements.« less

Retrograde and Direct Powered Aero-Gravity-Assist Trajectories around Mars

NASA Astrophysics Data System (ADS)

Murcia, J. O.; Prado, A. F. B. A.; Gomes, V. M.

2018-04-01

A Gravity-Assist maneuver is used to reduce fuel consumption and/or trip times in interplanetary missions. It is based in a close approach of a spacecraft to a celestial body. Missions like Voyager and Ulysses used this concept. The present paper performs a study of a maneuver that combines three effects: the gravity of the planet, the application of an impulsive maneuver when the spacecraft is passing by the periapsis and the effects of the atmosphere of the planet. Direct and retrograde trajectories are considered, with particular attention to the differences due to the higher relative velocity between the spacecraft and the atmosphere, which increases the effects of the atmosphere. The planet Mars is used for the numerical examples.

Embolization with Tornado coils to control bleeding from an arterioureteral fistula.

PubMed

Jacobs, Bruce L; Maranchie, Jodi K

2007-12-01

Arterioureteral fistulae are rare, but potentially life-threatening causes of bleeding. We present a case of an 82 year-old woman with refractory, transfusion-dependent bleeding from an arterial fistula to her right ureteral stump, following right radical nephrectomy for advanced renal cell carcinoma. Cystoscopy with retrograde ureteral stump embolization using Tornado (Cook Medical, Bloomington, Indiana, USA) coils plus a slurry of thrombin-soaked Gelfoam (Pfizer Inc., New York, New York, USA) was performed, which led to prompt resolution of the patient's hematuria requiring no further hospitalizations or transfusions. Retrograde insertion of coils and injection of thrombin-soaked Gelfoam can be a minimally invasive, safe, and durable alternative for controlling hemorrhage from an arterioureteral fistula to a ureteral stump.

Retention of retinal axon collateral is responsible for induced ipsilateral retinotectal projections in adult goldfish.

PubMed

Sharma, S C; Tsai, C

1991-01-01

In normal goldfish, optic axons innervate only the contralateral optic tectum. When one eye was enucleated and the optic nerve of the other eye crushed, the regenerating optic axons innervated both optic tecta. We studied the presence of bilaterally projecting retinal ganglion cells by double retrograde cell labeling methods using Nuclear Yellow and True Blue dyes. About 10% of the retinal ganglion cells were double labeled and these cells were found throughout the retina. In addition, HRP application to the ipsilateral tectum revealed retrogradely-labeled retinal ganglion cells of all morphological types. These results suggest that induced ipsilateral projections are formed by regenerating axon collaterals and that all cell types are involved in the generation of normal mirror image typography.

[Pancreolauryl test, glucose tolerance test and endoscopic retrograde cholangiopancreatography in the diagnosis and monitoring of chronic pancreatitis].

PubMed

Wójcik, Z; Switka, S

1995-01-01

Fifteen patients with chronic pancreatitis were qualified for surgical treatment on the basis of the results of endoscopic retrograde cholangiopancreatography, pancreolauryl test and glucose tolerance test. Significant changes according to Cambridge scale correlated with exocrine-endocrine pancreatic failure. In patients with Wirsung duct of diameter above 6 mm Puestow operation was performed while in patients with narrow Wirsung duct resection procedures were carried out. Control examinations carried out one year after Puestow operation demonstrated in all 10 patients lack of improvement both in the exocrine and endocrine pancreatic function. In 70% of the patients after anastomotic operation and in 80% of the patients after resections, complete regression of preoperative pain was observed.

Retrograde Suction Decompression with an Inahara Carotid Shunt for Clipping a Large Distal Internal Carotid Artery Aneurysm.

PubMed

Park, Yong Sook; Nam, Taek Kyun

2017-03-01

We describe a technique to clip a large internal carotid artery (ICA) aneurysm via a retrograde suction decompression (RSD). A large aneurysm in the right distal ICA involving the bifurcation region measuring 1.2×1.1×0.7 cm with posterior projection was managed with assisted RSD technique. The anterior choroidal artery emerged from the side wall of the aneurysm. An Inahara shunt was inserted into the ICA with neck dissection, and RSD was applied after completely clipping the aneurysm. RSD with an Inahara carotid shunt is useful for complete visualization of the aneurysm, including its surrounding structures, and for proximal control of the parent vessels, subsequently achieving satisfactory clip placement.

In vivo degradation of alginate in the presence and in the absence of resistant starch.

PubMed

Jonathan, Melliana; Souza da Silva, Carol; Bosch, Guido; Schols, Henk; Gruppen, Harry

2015-04-01

This study evaluated the intestinal degradability of alginate during 74 days intake in pigs as models for humans. Diets contained pregelatinized starch, retrograded starch, alginate, or a mix of retrograded starch and alginate. Faeces were collected on day 1, 3, 7, 14, 39 and 74. Clear trends in intestinal alginate degradation were observed. Up to day 39, the total tract digestibility of alginate was limited (0.52 ± 0.10), and was lower with the inclusion of retrograded starch in the diet (0.34 ± 0.02). More than 90% of the faecal alginate was insoluble in water, which may explain the low digestibility of the alginate. The digestibility of mannuronic acid (M) was 2-3 times higher than that of guluronic acid (G). The changes of G:M ratio and the relative amounts of alginate oligosaccharides between day 39 and 74 indicated that the microbiota needed more than 39 days to adapt to alginate. This study demonstrated that in-depth analyses of dietary fibres are valuable in understanding the fate of the dietary fibres in the large intestine as it was shown that degradation of a dietary fibre depends not only on the properties of the fibre itself, but also on the other dietary fibres present in the diet and the adaptation time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Episodic future thinking and future-based decision-making in a case of retrograde amnesia.

PubMed

De Luca, Flavia; Benuzzi, Francesca; Bertossi, Elena; Braghittoni, Davide; di Pellegrino, Giuseppe; Ciaramelli, Elisa

2018-02-01

We investigated episodic future thinking (EFT) and future-based cognition and decision-making in patient SG, who developed a dense retrograde amnesia following hypoxia due to a cardiac arrest. Despite intact general cognitive and executive functioning, SG was unable to remember events from his entire lifetime. He had, however, relatively spared anterograde memory and general semantic knowledge. Voxel-based morphometry detected a reduction of gray matter in the thalamus, cerebellum and fusiform gyrus bilaterally, and, at a reduced threshold, in several regions of the autobiographical memory network, including the hippocampi. We show that SG is unable to imagine personal future events, but can imagine fictitious events not self-relevant and not located in subjective time. Despite severely impaired EFT, SG shows normal attitudes towards the future time, and normal delay discounting rates. These findings suggest that retrieval of autobiographical information from long-term memory is necessary for EFT. However, relatively spared anterograde memory and general semantic knowledge may be sufficient to allow construction of fictitious experiences. As well, EFT is not necessary to drive future-oriented cognition and choice. These findings highlight the relation between autobiographical memory and EFT, and the fractionation of human temporal consciousness. Moreover, they contribute to our understanding of retrograde amnesia as an impairment of memory as well as future thinking. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Korsakoff amnesia syndrome].

PubMed

Verstichel, P

2000-10-14

PATHOLOGY CORRELATIONS: The Korsakoff syndrome results from cerebral lesions due to thiamine depletion, usually of alcoholic etiology. Other nutritional, or genetic factors, could be implicated. Exceptionally, it results from thalamic disease or a tumor of the third ventricle floor. Anterograde and retrograde aspects of episodic memory are principally impaired, contrasting with the preservation of semantic and procedural memory. Opposition between explicit (impaired) and implicit (unimpaired) memory is one of the main cognitive features of this syndrome. Several cerebral structures, components of various memory systems, are simultaneously damaged. Critical lesion sites for anterograde amnesia involve the memillary bodies, the mamillotalamic tract and the anterior thalamus. Retrograde amnesia is dependent on function abnormalities of a circuit between the dorso-median thalamus and the prefrontal cortex. Impairment of retrieval and chronological disorganization of memories contribute to this extensive retrograde amnesia, probably because of frontal dysfunction. Confabulations and false recognitions are produced in the initial stage of the disease. They are, in the same way, interpreted as the consequence of frontal desafferentation due to dorso-median thalamus damage. The impact of diencephalic destruction on the frontal lobes is evidenced clinically by behavioral changes and dysexecutive syndrome. Neuroimaging studies of the brain show a decreased regional metabolic ration in the frontal areas. Korsakoff syndrome is a serious disorder, responsible for cognitive handicap. There is no curative treatment. Preventive measures, consisting in systematic prescription of thiamine in alcoholics, is the main effective measure.

Evidence for a SAL1-PAP chloroplast retrograde pathway that functions in drought and high light signaling in Arabidopsis.

PubMed

Estavillo, Gonzalo M; Crisp, Peter A; Pornsiriwong, Wannarat; Wirtz, Markus; Collinge, Derek; Carrie, Chris; Giraud, Estelle; Whelan, James; David, Pascale; Javot, Hélène; Brearley, Charles; Hell, Rüdiger; Marin, Elena; Pogson, Barry J

2011-11-01

Compartmentation of the eukaryotic cell requires a complex set of subcellular messages, including multiple retrograde signals from the chloroplast and mitochondria to the nucleus, to regulate gene expression. Here, we propose that one such signal is a phosphonucleotide (3'-phosphoadenosine 5'-phosphate [PAP]), which accumulates in Arabidopsis thaliana in response to drought and high light (HL) stress and that the enzyme SAL1 regulates its levels by dephosphorylating PAP to AMP. SAL1 accumulates in chloroplasts and mitochondria but not in the cytosol. sal1 mutants accumulate 20-fold more PAP without a marked change in inositol phosphate levels, demonstrating that PAP is a primary in vivo substrate. Significantly, transgenic targeting of SAL1 to either the nucleus or chloroplast of sal1 mutants lowers the total PAP levels and expression of the HL-inducible ASCORBATE PEROXIDASE2 gene. This indicates that PAP must be able to move between cellular compartments. The mode of action for PAP could be inhibition of 5' to 3' exoribonucleases (XRNs), as SAL1 and the nuclear XRNs modulate the expression of a similar subset of HL and drought-inducible genes, sal1 mutants accumulate XRN substrates, and PAP can inhibit yeast (Saccharomyces cerevisiae) XRNs. We propose a SAL1-PAP retrograde pathway that can alter nuclear gene expression during HL and drought stress.

Evidence for a SAL1-PAP Chloroplast Retrograde Pathway That Functions in Drought and High Light Signaling in Arabidopsis[C][W][OA

PubMed Central

Estavillo, Gonzalo M.; Crisp, Peter A.; Pornsiriwong, Wannarat; Wirtz, Markus; Collinge, Derek; Carrie, Chris; Giraud, Estelle; Whelan, James; David, Pascale; Javot, Hélène; Brearley, Charles; Hell, Rüdiger; Marin, Elena; Pogson, Barry J.

2011-01-01

Compartmentation of the eukaryotic cell requires a complex set of subcellular messages, including multiple retrograde signals from the chloroplast and mitochondria to the nucleus, to regulate gene expression. Here, we propose that one such signal is a phosphonucleotide (3′-phosphoadenosine 5′-phosphate [PAP]), which accumulates in Arabidopsis thaliana in response to drought and high light (HL) stress and that the enzyme SAL1 regulates its levels by dephosphorylating PAP to AMP. SAL1 accumulates in chloroplasts and mitochondria but not in the cytosol. sal1 mutants accumulate 20-fold more PAP without a marked change in inositol phosphate levels, demonstrating that PAP is a primary in vivo substrate. Significantly, transgenic targeting of SAL1 to either the nucleus or chloroplast of sal1 mutants lowers the total PAP levels and expression of the HL-inducible ASCORBATE PEROXIDASE2 gene. This indicates that PAP must be able to move between cellular compartments. The mode of action for PAP could be inhibition of 5′ to 3′ exoribonucleases (XRNs), as SAL1 and the nuclear XRNs modulate the expression of a similar subset of HL and drought-inducible genes, sal1 mutants accumulate XRN substrates, and PAP can inhibit yeast (Saccharomyces cerevisiae) XRNs. We propose a SAL1-PAP retrograde pathway that can alter nuclear gene expression during HL and drought stress. PMID:22128124

Discovery of New Retrograde Substructures: The Shards of ω Centauri?

NASA Astrophysics Data System (ADS)

Myeong, G. C.; Evans, N. W.; Belokurov, V.; Sanders, J. L.; Koposov, S. E.

2018-06-01

We use the SDSS-Gaia catalogue to search for substructure in the stellar halo. The sample comprises 62 133 halo stars with full phase space coordinates and extends out to heliocentric distances of ˜10 kpc. As actions are conserved under slow changes of the potential, they permit identification of groups of stars with a common accretion history. We devise a method to identify halo substructures based on their clustering in action space, using metallicity as a secondary check. This is validated against smooth models and numerical constructed stellar halos from the Aquarius simulations. We identify 21 substructures in the SDSS-Gaia catalogue, including 7 high significance, high energy and retrograde ones. We investigate whether the retrograde substructures may be material stripped off the atypical globular cluster ω Centauri. Using a simple model of the accretion of the progenitor of the ω Centauri, we tentatively argue for the possible association of up to 5 of our new substructures (labelled Rg1, Rg3, Rg4, Rg6 and Rg7) with this event. This sets a minimum mass of 5× 108M⊙ for the progenitor, so as to bring ω Centauri to its current location in action - energy space. Our proposal can be tested by high resolution spectroscopy of the candidates to look for the unusual abundance patterns possessed by ω Centauri stars.

Development of a tissue-specific ribosome profiling approach in Drosophila enables genome-wide evaluation of translational adaptations

PubMed Central

2017-01-01

Recent advances in next-generation sequencing approaches have revolutionized our understanding of transcriptional expression in diverse systems. However, measurements of transcription do not necessarily reflect gene translation, the process of ultimate importance in understanding cellular function. To circumvent this limitation, biochemical tagging of ribosome subunits to isolate ribosome-associated mRNA has been developed. However, this approach, called TRAP, lacks quantitative resolution compared to a superior technology, ribosome profiling. Here, we report the development of an optimized ribosome profiling approach in Drosophila. We first demonstrate successful ribosome profiling from a specific tissue, larval muscle, with enhanced resolution compared to conventional TRAP approaches. We next validate the ability of this technology to define genome-wide translational regulation. This technology is leveraged to test the relative contributions of transcriptional and translational mechanisms in the postsynaptic muscle that orchestrate the retrograde control of presynaptic function at the neuromuscular junction. Surprisingly, we find no evidence that significant changes in the transcription or translation of specific genes are necessary to enable retrograde homeostatic signaling, implying that post-translational mechanisms ultimately gate instructive retrograde communication. Finally, we show that a global increase in translation induces adaptive responses in both transcription and translation of protein chaperones and degradation factors to promote cellular proteostasis. Together, this development and validation of tissue-specific ribosome profiling enables sensitive and specific analysis of translation in Drosophila. PMID:29194454

A retrograde y-stenting of the trachea for treatment of mediastinal fistula in an unusual situation

PubMed Central

Hohenforst-Schmidt, Wolfgang; Zarogoulidis, Paul; Steinheimer, Michael; Schneider, Thomas; Benhassen, Naim; Rupprecht, Holger; Freitag, Lutz

2017-01-01

Introduction Stents have been used for quite some time for the treatment of benign and malignant airway stenosis. Silicon stents are preferred for benign situations, whereas metallic self-expanding stents are preferred for malignant comorbidities. Patient and methods In general, stents can be placed in different approach directions, although in pulmonary medicine it is logical to apply only antegrade techniques – until now. A 63-year-old patient, 168 cm height and 53 kg weight on referral, suffered chronical diseases. The patient was diagnosed with a papillary thyroid carcinoma in 1989, which was treated by resection and radiotherapy. In the following years, she developed a stenosis of the esophagus. The decision to try endobronchial stenting was made upon the plan to close that fistula with a pedicled omentum majus replacement through the diaphragmal opening of the esophagus. This surgical plastic needed an abutment and a secured continuous airway replacement above the tracheostoma level. A Freitag stent (FS), 11 cm in length (110–25–40) and an inner diameter of 13 mm, was placed successfully retrograde into the trachea and completely bridged the big fistula. Unfortunately the patient passed away due to pulmonary infections after several weeks. Discussion In this case report, a successful but unusual case of retrograde stent placement of a modified FS is presented. PMID:28579789

Treadmill Training Enhances Axon Regeneration In Injured Mouse Peripheral Nerves Without Increased Loss of Topographic Specificity

PubMed Central

English, Arthur W.; Cucoranu, Delia; Mulligan, Amanda; Sabatier, Manning

2009-01-01

We investigated the extent of misdirection of regenerating axons when that regeneration was enhanced using treadmill training. Retrograde fluorescent tracers were applied to the cut proximal stumps of the tibial and common fibular nerves two or four weeks after transection and surgical repair of the mouse sciatic nerve. The spatial locations of retrogradely labeled motoneurons were studied in untreated control mice and in mice receiving two weeks of treadmill training, either according to a continuous protocol (10 m/min, one hour/day, five day/week) or an interval protocol (20 m/min for two minutes, followed by a five minute rest, repeated 4 times, five days/week). More retrogradely labeled motoneurons were found in both treadmill trained groups. The magnitude of this increase was as great as or greater than that found after using other enhancement strategies. In both treadmill trained groups, the proportions of motoneurons labeled from tracer applied to the common fibular nerve that were found in spinal cord locations reserved for tibial motoneurons in intact mice was no greater than in untreated control mice and significantly less than found after electrical stimulation or chondroitinase treatment. Treadmill training in the first two weeks following peripheral nerve injury produces a marked enhancement of motor axon regeneration without increasing the propensity of those axons to choose pathways leading to functionally inappropriate targets. PMID:19731339

Functional Amnesia: Clinical Description and Neuropsychological Profile of 10 Cases

PubMed Central

Kritchevsky, Mark; Chang, Judy; Squire, Larry R.

2004-01-01

We carried out the first neuropsychological study of a series of patients with functional amnesia. We evaluated 10 patients, first with a neurological examination and then with three tests of anterograde amnesia and four tests of retrograde amnesia. Excluding one patient who later admitted to malingering, all patients had a significant premorbid psychiatric history and one or more possible precipitating factors for their amnesia. Eight of the 10 patients still had persistent retrograde amnesia at our last contact with them (median = 14 mo after the onset of amnesia). On tests of anterograde amnesia, the patients performed normally as a group, though some patients scored poorly on tests of verbal memory. On tests of retrograde amnesia, all patients had difficulty recollecting well-formed autobiographical memories of specific events from their past. In contrast, patients performed as well as controls at distinguishing the names of cities from fictitious city names. On remote memory tests for past public events and famous faces, different patients exhibited different but internally consistent patterns of impaired and spared performance. The variability in the clinical and neuropsychological findings among our patients may be understood by supposing that memory performance is poor in proportion to how directly a test appears to assess a patient's commonsense concept of memory. The presentation of patients with functional amnesia is as variable as humankind's concept of what memory is and how it works. PMID:15054137

Bilateral superiorly based full-thickness nasolabial island flaps for closure of residual anterior palatal fistulas in an unoperated elderly patient.

PubMed

Erçöçen, A R; Yilmaz, S; Saydam, M

2003-01-01

Unoperated bilateral complete cleft lip and palate in an adult or elderly patient is seen rarely, and the existence of unoperated clefts is a result of unfavorable economic and social circumstances. We report an unoperated 65-year-old patient with bilateral complete cleft lip and palate and present our preference for the surgical management. Repair of the bilateral complete cleft lip and palate was successfully carried out using straight-line closure for the bilateral cleft lip and two-flap pushback palatoplasty with superiorly based lateral port control pharyngeal flap for the wide cleft palate at the first stage, and large residual anterior palatal fistulas were closed using bilateral superiorly based (retrograde flow) full-thickness nasolabial island flaps at the second stage. To our knowledge based on a review of the literature, this is the first report of an elderly patient with bilateral complete cleft lip and palate and the first application of bilateral superiorly based (retrograde flow) full-thickness nasolabial island flaps for closure of large residual anterior palatal fistulas or alveolar clefts. The bilateral superiorly based (retrograde flow) full-thickness nasolabial island flap may be a good solution in large anterior palatal defects using unilaterally or bilaterally in a single stage with minimal donor site morbidity, in which there is not enough tissue for local repair or if previous attempts are unsuccessful.

Male Infertility

MedlinePlus

... ejaculation occurs when semen enters the bladder during orgasm instead of emerging out the tip of the penis. Various health conditions can cause retrograde ejaculation, including diabetes, spinal injuries, medications, and surgery of ...

Stent-Graft Treatment of Late Stenosis of the Left Common Carotid Artery Following Thoracic Graft Placement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medda, Massimo; Lioupis, Christos, E-mail: lioupisC@vodafone.net.gr; Mollichelli, Nadia

2008-03-15

We report the case of a patient with subtotal occlusion of the origin of the left common carotid artery (CCA) following thoracic graft placement. Retrograde endovascular placement of a stent-graft by minimal cervical access was undertaken to repair the occlusive lesion of the left CCA and prevent future complications of endoluminal thoracic reconstruction. The retrograde endovascular repair of CCA lesions, as other authors have already suggested, may be the treatment of choice in 'high-surgical-risk' patients. In these cases where the ostium of supra-aortic trunks is compromised following thoracic aorta stent-graft migration, endoluminal placement of a stent-graft in the CCA canmore » guarantee both maintenance of carotid flow and thoracic stent-graft fixation.« less

A Retrograde Transvenous Embolization Technique with Balloon-Assisted Arterial Aspiration for a Peripheral Arteriovenous Malformation with a Venous Pouch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhara, Asako, E-mail: kuhara-asako@med.kurume-u.ac.jp; Tanaka, Norimitsu; Koganemaru, Masamichi

Management of arteriovenous malformations (AVMs) is challenging, and there is no consensus regarding either the ideal approach or the treatment timing. Percutaneous embolization is the most frequent approach currently used and is considered the first-line technique for AVMs. There is an ongoing discussion about the best technical approach to embolize AVMs. AVMs associated with a dominant outflow vein (DOV) are rare. Embolization of both the DOV and the nidus is considered more effective. Herein, we report a novel technique of transvenous embolization of a DOV under negative pressure from an arterial balloon catheter in a case of a peripheral AVM.more » This technique allows the embolization of the DOV and the nidus retrogradely.« less

Combined Retrograde-Antegrade Arterial Recanalization Through Collateral Vessels: Redefinition of the Technique for Below-the-Knee Arteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graziani, L., E-mail: langrazi@tin.it; Morelli, L. G.

2011-02-15

The effectiveness of below-the-knee PTA to obtain successful revascularization in patients with critical limb ischemia (CLI) has been well established, and many centers have adopted endovascular intervention as the first-line treatment in patients with chronic lower-extremity disease. The well-known complex and multilevel arterial disease in patients with CLI have lead to interventionists to continuously implement different technologies and techniques. The aim of the present study was to standardize and redefine a technique characterized for combined retrograde-antegrade recanalization of a native leg artery through a collateral arterial branch by using a single access. This concept has been well described in coronarymore » arteries and recently in pelvic and tibial arteries.« less

A Quick Test on Rotation Period Clustering for the Small Members of the Koronis Family

NASA Astrophysics Data System (ADS)

Chang, Chan-Kao; Lin, Hsing-Wen; Ip, Wing-Huen

2016-01-01

Rotation period clustering in prograde/retrograde rotators might be the preliminary indication of the Slivan state in the Koronis family as a result of the Yarkovsky-O’Keefe-Radzievskii-Paddack effect. We follow the general scenario of dispersion in the semimajor axis of the asteroid family members to separate prograde and retrograde rotators in the Koronis family. From the available rotation periods obtained from PTF/iPTF, we were unable to find the rotation period clustering of objects with H ≳ 12 mag in the Koronis family. This could be the result of the intermittent collisional process of small asteroids (D ≲ 20 km) which leads to astray Yarkovsky drifting. Measurement of the pole orientations of our sample will verify our preliminary result and validate our method.

Multicenter Off-Label Use of Nit-Occlud Coil in Retrograde Closure of Small Patent Ductus Arteriosus.

PubMed

Zanjani, Keyhan Sayadpour; Sobhy, Rodina; El-Kaffas, Rania; El-Sisi, Amal

2017-04-01

We studied the safety and efficacy of closing patent ductus arteriosus by Nit-Occlud coils via retrograde approach. This is a retrospective study of 46 attempts to close ducts by this method in two hospitals in Egypt and Iran. Ductus arteriosus was crossed by left or right Judkins or endhole catheters. The coil was delivered via the same catheter or the provided endhole catheter after exchange. The procedure was successful in 42 out of 46 attempts. Fluoroscopy and procedural times were significantly shorter when the catheter was not exchanged. This method is effective and safe for the closure of small ducts. Crossing the duct and delivering the coil by a left Judkins catheter is the easiest and fastest way to perform this method.

Unexpected embolization of Teflon pledget in the left main stem during: a Bentall operation.

PubMed

Rubino, Antonino S; Serraino, Giuseppe F; Marsico, Roberto; Renzulli, Attilio

2011-01-01

We report the case of an 83-year-old man in whom acute left ventricular failure with ventricular arrhythmic storm developed during a Bentall operation. During re-exploration of the annular and coronary ostial anastomoses, no abnormality was seen, and none of the common sequelae of aortic root replacement was evident. The application of retrograde cardioplegia yielded a Teflon pledget that had migrated into the distal part of the left main stem. The pledget was removed, the anastomoses were reestablished, and the patient recovered uneventfully. This case suggests that left ostial anastomosis re-exploration should be carefully considered when no other cause of coronary insufficiency is obvious, and that retrograde cardioplegia may be useful to detect embolization in the left coronary system.

Unexpected Embolization of Teflon Pledget in the Left Main Stem during a Bentall Operation

PubMed Central

Rubino, Antonino S.; Serraino, Giuseppe F.; Marsico, Roberto; Renzulli, Attilio

2011-01-01

We report the case of an 83-year-old man in whom acute left ventricular failure with ventricular arrhythmic storm developed during a Bentall operation. During re-exploration of the annular and coronary ostial anastomoses, no abnormality was seen, and none of the common sequelae of aortic root replacement was evident. The application of retrograde cardioplegia yielded a Teflon pledget that had migrated into the distal part of the left main stem. The pledget was removed, the anastomoses were reestablished, and the patient recovered uneventfully. This case suggests that left ostial anastomosis re-exploration should be carefully considered when no other cause of coronary insufficiency is obvious, and that retrograde cardioplegia may be useful to detect embolization in the left coronary system. PMID:22163143

Mitochondrial morphology transitions and functions: implications for retrograde signaling?

PubMed Central

Picard, Martin; Shirihai, Orian S.; Gentil, Benoit J.

2013-01-01

In response to cellular and environmental stresses, mitochondria undergo morphology transitions regulated by dynamic processes of membrane fusion and fission. These events of mitochondrial dynamics are central regulators of cellular activity, but the mechanisms linking mitochondrial shape to cell function remain unclear. One possibility evaluated in this review is that mitochondrial morphological transitions (from elongated to fragmented, and vice-versa) directly modify canonical aspects of the organelle's function, including susceptibility to mitochondrial permeability transition, respiratory properties of the electron transport chain, and reactive oxygen species production. Because outputs derived from mitochondrial metabolism are linked to defined cellular signaling pathways, fusion/fission morphology transitions could regulate mitochondrial function and retrograde signaling. This is hypothesized to provide a dynamic interface between the cell, its genome, and the fluctuating metabolic environment. PMID:23364527

Retrograde exchange of heavily encrusted ureteric stents via the ileal conduit: a technical report.

PubMed

Tapping, Charles Ross; Boardman, Phil

2014-02-01

We describe two cases of retrograde ureteric stent exchange of heavily encrusted ureteric stents (JJ) via tortuous ileal conduits. The blocked ureteric stents were snared from inside the conduit so they could be accessed and a wire inserted. The lumens of the stents were unblocked with a wire but the stents could not be withdrawn due to heavy encrustation of the ureteric stent in the renal pelvis. A stiff wire was inserted to provide support and a 9 French peel away sheath was used to remove the encrustations allowing the stents to be withdrawn and exchanged. This is a safe and successful technique allowing ureteric stents to be removed when heavily encrusted. © 2013 The Royal Australian and New Zealand College of Radiologists.

Modification of atrioventricular nodal electrophysiology by selective radiofrequency delivery on the anterior or posterior approaches.

PubMed

Chorro, F J; Sanchis, J; Such, L; Artal, L; Llavador, J J; Llavador, E; Monmeneu, J V; López-Merino, V

1997-05-01

An analysis was made in 14 isolated and perfused rabbit hearts of the electrophysiological effects of selective radiofrequency (RF) delivery in the anterior (group I, n = 7) or posterior zone (group II, n = 7) of the Koch triangle, with the aim of modifying atrioventricular nodal (AVN) conduction without suppressing 1:1 transmission. After opening the right atrium, RF was delivered (0.5 W) with a 1-mm diameter unipolar electrode positioned in the selected zone until a prolongation of no less than 15% was obtained in the Wenckebach cycle length (WCL). Before and after (30 min) RF, anterograde and retrograde AVN refractoriness and conduction were evaluated, stimulating from the crista terminalis (CT), the interatrial septum (IAS), and from the RV epicardium. After RF, the following percentage increments were observed in group I: AH(CT) = 36% +/- 9%, AH(IAS) = 38% +/- 11%, WCL(CT) = 28% +/- 8%, WCL(IAS) = 22% +/- 6%, functional refractory period (FRP) of the AVN(CT) = 13% +/- 11%, FRP-AVN(IAS) = 13% +/- 8%, retrograde WCL = 20% +/- 19%, and retrograde FRPVA = 13% +/- 16%. The increments observed in group II and the significances of the differences with respect to group I were: AH(CT) = 11% +/- 14% (P < 0.01), AH(IAS) = 19% +/- 32% (NS), WCL(CT) = 42% +/- 14% (P < 0.05), WCL(IAS) = 42% +/- 16% (P < 0.01), FRP-AVN(CT) = 28% +/- 28% (NS), FRP-AVN(LAS) = 21% +/- 19% (NS), retrograde WCL = 35% +/- 24% (NS), and retrograde FRP = 16% +/- 13% (NS). In both groups, the AH interval variations were not correlated with those of the rest of the parameters analyzed. Truncated nodal function curves suggestive of a dual AV nodal pathway were obtained in three experiments, though in only one of them was this observed under basal conditions. In the other two experiments, with dual AV nodal physiology only after RF (one from each group), AV nodal reentrant tachycardias were triggered with atrial extrastimulus at coupling intervals equal to or shorter than at those that cause a sudden lengthening of the AH interval, RF delivered in the anterior and posterior zones of the Koch triangle produced effects of different magnitude on the AH interval and Wenckebach cycle length. In the anterior zone the AH interval was prolonged to a greater extent, while in the posterior zone the effects were greater on the Wenckebach cycle length. No correlation existed between the variations in AH interval and Wenckebach cycle length, regardless of where RF was delivered. The evaluation of anterograde AV nodal refractoriness was similar when stimulating from the crista terminalis or from the interatrial septum. By delivering RF, it was possible to induce dual AV nodal physiology and reentrant tachycardias.

Origin of retrograde fluid in ultrahigh-pressure metamorphic rocks: Constraints from mineral hydrogen isotope and water content changes in eclogite gneiss transitions in the Sulu orogen

NASA Astrophysics Data System (ADS)

Chen, Ren-Xu; Zheng, Yong-Fei; Gong, Bing; Zhao, Zi-Fu; Gao, Tian-Shan; Chen, Bin; Wu, Yuan-Bao

2007-05-01

By taking advantage of having depth profiles between contrasting lithologies from core samples of the Chinese Continental Scientific Drilling (CCSD) project, a combined study was carried out to examine changes in mineral H isotope, total water and hydroxyl contents in garnet and omphacite across the contacts between ultrahigh-pressure (UHP) eclogite and gneiss in the Sulu orogen, east-central China. The samples of interest were from two continuous core segments from the CCSD main hole at depths of 734.21-737.16 and 929.67-932.86 m, respectively. The results show δD values of -116‰ to - 64‰ for garnet and -104‰ to -82‰ for omphacite, consistent with incorporation of meteoric water into protoliths of UHP metamorphic rocks by high-T alteration. Both equilibrium and disequilibrium H isotope fractionations were observed between garnet and omphacite, suggesting fluid-assisted H isotope exchange at local scales during amphibolite-facies retrogression. While bulk water analysis gave total H 2O concentrations of 522-1584 ppm for garnet and 1170-20745 ppm for omphacite, structural hydroxyl analysis yielded H 2O contents of 80-413 ppm for garnet and 228-412 ppm for omphacite. It appears that significant amounts of molecular H 2O are present in the minerals, pointing to enhanced capacity of water storage in the UHP eclogite minerals. Hydrogen isotope variations in the transition between eclogite and gneiss show correlations with variations in their water contents. Petrographically, the degree of retrograde metamorphism generally increases with decreasing distance from the eclogite-gneiss boundary. Thus, retrograde metamorphism results in mineral reactions and H isotope variation. Because hydroxyl solubility in nominally anhydrous minerals decreases with dropping pressure, significant amounts of water are expected to be released from the minerals during decompression exhumation. Decompression exsolution of structural hydroxyl from 1 m 3 volume of eclogite composed of only garnet and omphacite results in release of a quantitative estimate of 3.07-3.44 kg water that can form 140-156 kg amphibole during exhumation. Therefore, it is concluded that fluid for retrogression of the eclogites away from the eclogite-gneiss boundary was derived from the decompression exsolution of structural hydroxyl and molecular H 2O in nominally anhydrous minerals. For the eclogites adjacent to gneiss, in contrast, the retrograde metamorphism was principally caused by aqueous fluid from the gneiss which is relatively rich in water. Consequently, both the origin and availability of metamorphic fluid during exhumation of deeply subducted continental crust are deciphered by this combined study focusing on the transitions and the retrograde processes between the felsic and mafic UHP rocks.

The Retrograde Motion of Mars.

ERIC Educational Resources Information Center

Erlichson, Herman

1999-01-01

Describes a laboratory activity in a liberal-arts physics course entitled "Galileo to Newton and Beyond" in which students examine the orbits of Earth and Mars from heliocentric and geocentric viewpoints. (WRM)

Retrograde cystography

MedlinePlus

... of computed tomography, magnetic resonance imaging, and plain film. In: Wein AJ, Kavoussi LR, Partin AW, Peters ... Guidelines Viewers & Players MedlinePlus Connect for EHRs For Developers U.S. National Library of Medicine 8600 Rockville Pike, ...

Retrograde ejaculation

MedlinePlus

... ejaculation. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology . 11th ed. Philadelphia, ... infertility. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology . 11th ed. Philadelphia, ...

Documenting a modern day transgressive surface in a carbonate ramp setting

NASA Astrophysics Data System (ADS)

Lokier, Stephen; Paul, Andreas

2017-04-01

The low-angle carbonate ramp geometry of the Abu Dhabi coastline provides an ideal site for studying the effects of marine transgression in a setting analogous to Mesozoic epeiric seas. Supratidal sabkha evaporite precipitation passes offshore, through a broad and complex carbonate-evaporite intertidal environment, into a subtidal carbonate depositional setting. The coast of the mainland is locally isolated from open-marine conditions by a number of peninsulas and islands associated with the east-west trending Great Pearl Bank. This study combined 12 years of fieldwork observations with historical satellite imagery in order to establish multiple lines of evidence for active retrogradation over a 15 km length of coastline in the Abu Dhabi sabkha. Surveyed transects of the sabkha yield an average slope angle of 0.02°. Employing a current estimate of global sea level rise of 3.3 mm/yr, we calculate an expected present-day marine transgression of 7.9 m/yr. The landward and seaward boundaries of the microbial mat facies belt are strongly controlled by the location of the intertidal zone. The seaward limit of the Recent microbial mat belt in the Abu Dhabi Sabkha is currently being buried beneath retrograding lower-intertidal sediments whilst the landward side is simultaneously backstepping over previously-supratidal gypsum-dominated facies. The landward migration of spits and beach ridges was monitored at several locations with rates of retrogradation of up to 28 m per year being recorded locally. The study also identified numerous erosive features that are consistent with an increase in energy regimes. There has been a significant increase in denudation of the microbial mat, causing underlying sediment to be increasingly susceptible to erosion. In the lowermost intertidal zone, erosion of the hardground and other facies is observed. Clasts from the hardground are transported landward onto the surface of the sabkha where they are incorporated within other facies. This study provides definitive evidence that the current sedimentary regime of the Abu Dhabi coastline has entered a retrogradational phase associated with marine transgression. From a sequence stratigraphic perspective, the current system would be identified as a flooding (transgressive) surface.

Behavioral and functional neuroanatomical correlates of anterograde autobiographical memory in isolated retrograde amnesic patient M.L.

PubMed

Levine, Brian; Svoboda, Eva; Turner, Gary R; Mandic, Marina; Mackey, Allison

2009-09-01

Patient M.L. [Levine, B., Black, S. E., Cabeza, R., Sinden, M., Mcintosh, A. R., Toth, J. P., et al. (1998). Episodic memory and the self in a case of isolated retrograde amnesia. Brain, 121, 1951-1973], lost memory for events occurring before his severe traumatic brain injury, yet his anterograde (post-injury) learning and memory appeared intact, a syndrome known as isolated or focal retrograde amnesia. Studies with M.L. demonstrated a dissociation between episodic and semantic memory. His retrograde amnesia was specific to episodic autobiographical memory. Convergent behavioral and functional imaging data suggested that his anterograde memory, while appearing normal, was accomplished with reduced autonoetic awareness (awareness of the self as a continuous entity across time that is a crucial element of episodic memory). While previous research on M.L. focused on anterograde memory of laboratory stimuli, in this study, M.L.'s autobiographical memory for post-injury events or anterograde autobiographical memory was examined using prospective collection of autobiographical events via audio diary with detailed behavioral and functional neuroanatomical analysis. Consistent with his reports of subjective disconnection from post-injury autobiographical events, M.L. assigned fewer "remember" ratings to his autobiographical events than comparison subjects. His generation of event-specific details using the Autobiographical Interview [Levine, B., Svoboda, E., Hay, J., Winocur, G., & Moscovitch, M. (2002). Aging and autobiographical memory: dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689] was low, but not significantly so, suggesting that it is possible to generate episodic-like details even when re-experiencing of those details is compromised. While listening to the autobiographical audio diary segments, M.L. showed reduced activation relative to comparison subjects in midline frontal and posterior nodes previously identified as part of the autobiographical memory network. Reductions were also evident in M.L. in association with personal semantic stimuli (e.g., recordings describing personal habits and routines). These data suggest an association between M.L.'s impoverished recollection of autobiographical material and reduced activation in midline sectors of the autobiographical memory network that support the autonoetic, first-person element of episodic memory.

The patient position for PNL: does it matter?

PubMed

Cracco, Cecilia Maria; Scoffone, Cesare Marco; Poggio, Massimiliano; Scarpa, Roberto Mario

2010-03-01

Currently, PNL is the treatment of choice for large and/or otherwise complex urolithiasis. PNL was initially performed with the patient in a supine-oblique position, but later on the prone position became the conventional one for habit and handiness. The prone position provides a larger area for percutaneous renal access, a wider space for instrument manipulation, and a claimed lower risk of splanchnic injury. Nonetheless, it implies important anaesthesiological risks, including circulatory, haemodynamic, and ventilatory difficulties; need of several nurses to be present for intraoperative changes of the decubitus in case of simultaneous retrograde instrumentation of the ureter, implying evident risks related to pressure points; an increased radiological hazard to the urologist's hands; patient discomfort. To overcome these drawbacks, various safe and effective changes in patient positioning for PNL have been proposed over the years, including the reverse lithotomy position, the prone split-leg position, the lateral decubitus, the supine position, and the Galdakao-modified supine Valdivia (GMSV) position. Among these, the GMSV position is safe and effective, and seems profitable and ergonomic. It allows optimal cardiopulmonary control during general anaesthesia; an easy puncture of the kidney; a reduced risk of colonic injury; simultaneous antero-retrograde approach to the renal cavities (PNL and retrograde ureteroscopy = ECIRS, Endoscopic Combined IntraRenal Surgery), with no need of intraoperative repositioning of the anaesthetized patient, less need for nurses in the operating room, less occupational risk due to shifting of heavy loads, less risk of pressure injuries related to inaccurate repositioning, and reduced duration of the procedure; facilitated spontaneous evacuation of stone fragments; a comfortable sitting position and a restrained X-ray exposure of the hands for the urologist. But, first of all, GMSV position fully supports a new comprehensive attitude of the urologist towards a variety of upper urinary tract pathologies, facing them with a rich armamentarium of rigid and flexible endoscopes and a versatile antero-retrograde approach. Prone position may still be useful in case of important vertebral malformations, specifically hindering the supine position, or for simultaneous bilateral PNL, without having to move the patient intraoperatively, so is still present in the complementary techniques of a skilled endourologist.

Implementation of Ultramini Percutaneous Nephrolithotomy for Treatment of 2-3 cm Kidney Stones: A Preliminary Report.

PubMed

Shah, Arvind K; Xu, Kewei; Liu, Hao; Huang, Hai; Lin, Tianxin; Bi, Liangkuan; Jinli, Han; Fan, Xinxiang; Shrestha, Rujan; Huang, Jian

2015-11-01

Miniatured percutaneous nephrolithotomy (PCNL) techniques such as micro-PCNL (microperc) and ultramini-PCNL (UMP) are usually indicated for renal stones <2 cm. We present our preliminary report of treating patients with 2 to 3 cm renal stones using UMP in a semisupine combined lithotomy position associated with a retrograde ureteral access sheath (UAS). From April 2013 to January 2014, we implemented 13F UMP for 22 patients with renal stones that were 2 to 3 cm with the patient positioned in a 45-degree semisupine combined lithotomy position. A retrograde 9.5/11.5F UAS was placed for maintaining low intrarenal pressure and debris drainage. Flexible ureteroscopy was used for stones inaccessible through the primary percutaneous tract in two patients. A 200-μ holmium laser was used for stone disintegration. Intrapelvic pressure was measured using an open end 5F ureteral catheter inserted through the UAS. All 22 cases were completed successfully. The mean preoperative stone size was 26.6 ± 4.7 mm (range 21-32 mm), mean operative time was 85.7 ± 18.0 minutes (range 47-112 min), and mean hemoglobin drop was 1.2 ± 0.3 g/dL (range 0.5-2.2 g/dL). Intrapelvic pressure during the surgical procedure ranged 5 to 10 cm H2O. The mean hospital stay was 3.1 ± 1.8 days (range 2-5 d). Complete stone clearance was 18/22 (81.8%) with solo UMP and 20/22 (90.9%) when associated with retrograde intrarenal surgery (RIRS). No major intra- or postoperative complications occurred. Implementation of UMP for the treatment of patients with renal stones 2-3 cm is feasible and safe. The procedure is less invasive and has a faster recovery period. Intraoperative retrograde UAS decreases intrarenal pressure, facilitates removal of stone fragments, and also allows simultaneous RIRS for stones in an inaccessible calix.

Healing process following application of set or fresh mineral trioxide aggregate as a root-end filling material.

PubMed

Habibi, Mehdi; Ghoddusi, Jamileh; Habibi, Ataollah; Mohtasham, Nooshin

2011-01-01

An unsuccessful attempt to reach the apical area or to place the retrograde material is a major difficulty in periradicular surgery. The aim of this study was to compare the histological evaluation of the healing process following an orthograde versus a retrograde application of mineral trioxide aggregate (MTA) as a root-end filling material during apical surgery on cats' teeth in order to find out whether orthograde placement of MTA before surgery can be used instead of retrograde placement during surgery. In this experimental study, 24 canine teeth in 12 mature and healthy cats were filled with either MTA or gutta-percha in an orthograde manner. Two weeks later, the teeth with MTA were surgically exposed and resected to the set-MTA within the canals. The teeth previously filled by gutta-percha were also surgically exposed, and retrograde cavities were prepared at the root ends and filled with fresh-MTA. After 8 weeks, the animals were euthanized by vital perfusion. Six-micron histological slices were prepared from samples, stained by Hematoxylin & Eosin, and histologically studied by means of a light microscope. The collected data was analyzed by the Chi-square and the T-test. One of the samples in the fresh-MTA group was omitted during processing because of inappropriate sectioning. In the set-MTA group, 5 out of 12 showed chronic abscess, while in the fresh-MTA group, 2 out of 11 were discovered to have chronic abscess; however, no significant difference was observed (P>.05). Hard tissue healing (cementum, bone, cementum + bone formation) in the set-MTA and fresh-MTA groups were 7 out of 12 and 9 out of 11, respectively. While healing seemed more likely to occur in the fresh-MTA group, the difference was statistically insignificant (P>.05). The magnitude of bone, cementum, or bone and cementum formation showed slight differences between the two groups; however, the figures failed to show any marked differences (P>.05). Orthograde placement of MTA could be used as an obturation material before surgery. In this way, after root-end resection, there would be no need for root-end preparation and filling procedures.

50 Myr. in a serpentinite subduction channel: Insights into slow eclogite exhumation

NASA Astrophysics Data System (ADS)

Flores, K. E.; Bonnet, G.; Cai, Y.; Martin, C.; Hemming, S. R.; Brueckner, H. K.; Harlow, G. E.

2017-12-01

Modern petrochronology shows that the exhumation of metamorphosed oceanic rocks in subduction zones is commonly a brief process (<10-20 Ma) characterized by rates of 2-5 km/Ma. This rapid exhumation is essential to avoid complete retrogression of high grade assemblages during ascension. However, our multi-approach P-T-t results on retrograde eclogites from the Northern Motagua Mélange (NMM) in Guatemala challenges those previous findings because they record remarkably slower exhumation rates ( 1 km/Ma). The retrograde eclogites occur as cm to tens of m sized blocks within a serpentinite matrix mélange that also contains blocks of subgreenschist to amphibolite and blueschist facies metabasites, jadeitites, omphacitites, albitites, mica-rocks, metatrondhjemites, and minor low grade metasediments. The studied samples range from almost unaltered eclogites to retrograde blueschist and ep-amphibolite facies metabasites containing eclogite relicts. The successive assemblages define classical clockwise P-T paths: comprised of (a) prograde blueschist/eclogite facies metamorphism within garnet cores, (b) eclogite facies peak recrystallization at 2.1 GPa and 500°C, (c) post-peak blueschist facies recrystallization, (d) amphibolite facies overprinting, and (e) late stage greenschist facies retrogression. This complex polymetamorphic history defines an exhumation path with a metamorphic peak at 136-125 Ma (Sm-Nd mineral isochrons) at 70 km depth, an ascent to the middle section of a subduction channel ( 40 km) at 99-92 Ma (Ar-Ar in Ph), and exhumation to 25-20 km at 80-75 Ma (Ar-Ar in Mhb). Synchronous jadeitite and mica-rocks yielded crystallization and exhumation ages of 95 Ma (U-Pb in Zrn) and 77-53 Ma (Ar-Ar in Ph), respectively. In contrast, an associated eclogite-bearing sheet of continental crust shows a younger eclogite metamorphic peak of 77-75 Ma at 80 km depth, but similar exhumation ages of 76-66 Ma and near surface regional exposure at 30 Ma (AFT). These new data argues for significantly low exhumation rate of 1 km/Ma, which satisfactorily explains the highly retrograde nature of most eclogites and the well documented rock-fluids interactions inside a serpentinite subduction channel. However, it contradicts most current buoyancy- low viscosity driven exhumation models.

[Tibiocalcaneal arthrodesis using retrograde insertion of a compression nail].

PubMed

Bölderl, A; Dallapozza, C; Wille, M

2011-12-01

OPERATION GOAL: Arthrodesis of the upper and lower ankle joint because of problematic bone positioning or failed arthrodesis. Osteosynthesis procedure using a retrograde compression nail. To achieve stable, fully weight-bearing osteosynthesis for early, pain-free mobilization. Rearthrodesis because of failure of the conventional arthrodesis technique and development of osteoarthritis of the lower ankle joint. Painful osteoarthritis of the upper ankle joint because of inadequate perfusion or a major bone defect because of sclerosis or necrosis. Primary arthrodesis because of facture of the lower leg (pilon tibial) with joint involvement and preexisting osteoarthritis. Acute osteitis/osteomyelitis, sclerosis in the marrow of the distal tibia, malalignment of the distal tibial shaft and local soft tissue inflammation. Preparation of the articular surface of the upper and lower ankle for arthrodesis using a transfibular approach. If necessary, correction of bone defects with iliac crest spongiosa. Stabile osteosynthesis by retrograde insertion of a compression nail. A split lower leg cast on the 2nd postoperative day, mobilization of the patient with underarm crutches with floor contact for 2 weeks, then with application of a lower leg walking cast for 8 weeks with partial weight-bearing for 4 weeks and full weight-bearing for the last 4 weeks of cast fixation. X-ray controls immediately postoperatively, then after 6 and 12 weeks. From 2006 to 2008, 12 patients (7 men, 5 women; mean age 59 years) with various indications were treated with retrograde insertion of a compression nail. All patients were routinely controlled radiologically and clinically after 2, 4, 8 and 12 weeks. Follow-up was carried out at 6, 12 and 24 months. All arthrodeses showed osseous consolidation 16 weeks postoperatively. Ten patients were able to use full weight-bearing without pain after 12 weeks. Two patients reported experiencing pain after walking for 2 h. In total three complications occurred: one hindfoot healed with varus malalignment; one patient fell, fracturing the lower leg above the nail; one distal locking screw loosened.

Gαq/11-mediated intracellular calcium responses to retrograde flow in endothelial cells.

PubMed

Melchior, Benoît; Frangos, John A

2012-08-15

Disturbed flow patterns, including reversal in flow direction, are key factors in the development of dysfunctional endothelial cells (ECs) and atherosclerotic lesions. An almost immediate response of ECs to fluid shear stress is the increase in cytosolic calcium concentration ([Ca(2+)](i)). Whether the source of [Ca(2+)](i) is extracellular, released from Ca(2+) intracellular stores, or both is still undefined, though it is likely dependent on the nature of forces involved. We have previously shown that a change in flow direction (retrograde flow) on a flow-adapted endothelial monolayer induces the remodeling of the cell-cell junction along with a dramatic [Ca(2+)](i) burst compared with cells exposed to unidirectional or orthograde flow. The heterotrimeric G protein-α q and 11 subunit (Gα(q/11)) is a likely candidate in effecting shear-induced increases in [Ca(2+)](i) since its expression is enriched at the junction and has been previously shown to be activated within seconds after onset of flow. In flow-adapted human ECs, we have investigated to what extent the Gα(q/11) pathway mediates calcium dynamics after reversal in flow direction. We observed that the elapsed time to peak [Ca(2+)](i) response to a 10 dyn/cm(2) retrograde shear stress was increased by 11 s in cells silenced with small interfering RNA directed against Gα(q/11). A similar lag in [Ca(2+)](i) transient was observed after cells were treated with the phospholipase C (PLC)-βγ inhibitor, U-73122, or the phosphatidylinositol-specific PLC inhibitor, edelfosine, compared with controls. Lower levels of inositol 1,4,5-trisphosphate accumulation seconds after the onset of flow correlated with the increased lag in [Ca(2+)](i) responses observed with the different treatments. In addition, inhibition of the inositol 1,4,5-trisphosphate receptor entirely abrogated flow-induced [Ca(2+)](i). Taken together, our results identify the Gα(q/11)-PLC pathway as the initial trigger for retrograde flow-induced endoplasmic reticulum calcium store release, thereby offering a novel approach to regulating EC dysfunctions in regions subjected to the reversal of blood flow.

Geology, mineralization, and fluid inclusion characteristics of the Kashkasu W-Mo-Cu skarn deposit associated with a high-potassic to shoshonitic igneous suite in Kyrgyzstan, Tien Shan: Toward a diversity of W mineralization in Central Asia

NASA Astrophysics Data System (ADS)

Soloviev, Serguei G.; Kryazhev, Sergey G.

2018-03-01

The Kashkasu deposit is part of the subduction-related Late Paleozoic (Late Carboniferous) metallogenic belt of Tien Shan. It is associated with a multiphase monzodiorite-monzonite-granodiorite-granite pluton of the magnetite-series high-K calc-alkaline to shoshonitic igneous suite. The deposit contains zones of W-Mo-Cu oxidized prograde and retrograde skarns, with abundant andraditic garnet, magnetite, locally scapolite and K-feldspar, as well as scheelite, chalcopyrite, and molybdenite. Skarns are overprinted by quartz-carbonate-sericite (phyllic alteration) zones with scheelite and sulfides. Prograde calcic skarn and initial retrograde skarns were formed from a high temperature (650 °C to 450-550 °C), high pressure (2000 bars to 600-900 bars) magmatic-hydrothermal low- to high-salinity aqueous chloride fluid. The gradual fluid evolution was interrupted by the intrusion of granodiorite and likely associated release of low-salinity (∼7-8 wt% NaCl equiv.) fluid. Ascent of this fluid to shallower levels and/or its cooling to 400-500 °C has resulted in phase separation into low-salinity (2.1-3.1 wt% NaCl equiv.) vapor and coexisting brine (35-40 wt% NaCl equiv.). The boiling was coincident with most intense scheelite deposition in retrograde skarn. Later retrograde skarn assemblages were formed from a gaseous, low- to moderate-salinity (3.4-8.1 wt% NaCl equiv.) fluid and then from high salinity (37-42 wt% NaCl equiv.) aqueous chloride fluids, the latter being enriched in Ca (17-20 wt% CaCl2) that could also affect scheelite deposition. Another cycle of fluid exsolution from crystallizing magma corresponded to quartz-carbonate-sericite-scheelite-sulfide (phyllic) alteration stage, with the early low-salinity (5.3-8.4 wt% NaCl-equiv.) fluid followed by later high-salinity (33.5-38.2 wt% NaCl-equiv.) fluid. The sulfur isotope data (δ34S = +5.1 to +9.0) suggest significant sulfur sourcing from sedimentary rocks enriched in seawater sulfate, possibly evaporites.

Targeted retrograde transfection of adenovirus vector carrying brain-derived neurotrophic factor gene prevents loss of mouse (twy/twy) anterior horn neurons in vivo sustaining mechanical compression.

PubMed

Xu, Kan; Uchida, Kenzo; Nakajima, Hideaki; Kobayashi, Shigeru; Baba, Hisatoshi

2006-08-01

Immunohistochemical analysis after adenovirus (AdV)-mediated BDNF gene transfer in and around the area of mechanical compression in the cervical spinal cord of the hyperostotic mouse (twy/twy). To investigate the neuroprotective effect of targeted AdV-BDNF gene transfection in the twy mouse with spontaneous chronic compression of the spinal cord motoneurons. Several studies reported the neuroprotective effects of neurotrophins on injured spinal cord. However, no report has described the effect of targeted retrograde neurotrophic gene delivery on motoneuron survival in chronic compression lesions of the cervical spinal cord resembling lesions of myelopathy. LacZ marker gene using adenoviral vector (AdV-LacZ) was used to evaluate retrograde delivery from the sternomastoid muscle in adult twy mice (16-week-old) and (control). Four weeks after the AdV-LacZ or AdV-BDNF injection, the compressed cervical spinal cord was removed en bloc for immunohistologic investigation of b-galactosidase activity and immunoreactivity and immunoblot analyses of BDNF. The number of anterior horn neurons was counted using Nissl, ChAT and AChE staining. Spinal accessory motoneurons between C1 and C3 segments were successfully transfected by AdV-LacZ in both twy and ICR mice after targeted intramuscular injection. Immunoreactivity to BDNF was significantly stronger in AdV-BDNF-gene transfected twy mice than in AdV-LacZ-gene transfected mice. At the cord level showing the maximum compression in AdV-BDNF-transfected twy mice, the number of anterior horn neurons was sinificantly higher in the topographic neuronal cell counting of Nissl-, ChAT-, and AChE-stained samples than in AdV-LacZ-injected twy mice. Targeted AdV-BDNF-gene delivery significantly increased Nissl-stained anterior horn neurons and enhanced cholinergic enzyme activities in the twy. Our results suggest that targeted retrograde AdV-BDNF-gene in vivo delivery may enhance neuronal survival even under chronic mechanical compression.

Bile duct obstruction

MedlinePlus

... Tumors that have spread to the biliary system Liver and bile duct worms (flukes) The risk factors include: History of ... Increased bilirubin level Increased alkaline phosphatase level Increased liver enzymes The ... CT scan Endoscopic retrograde cholangiopancreatography ( ...

Genetics Home Reference: CLN3 disease

MedlinePlus

... role in regulating anterograde and retrograde post-Golgi trafficking. Clin Lipidol. 2012 Feb;7(1):79-91. ... D, Hermey G. Revisiting the neuronal localization and trafficking of CLN3 in juvenile neuronal ceroid lipofuscinosis. J ...

Transurethral resection of the prostate - discharge

MedlinePlus

... men report a lower amount of semen during orgasm after having TURP. Urinary Catheters You may feel ... More Enlarged prostate Prostate resection - minimally invasive Retrograde ejaculation Simple prostatectomy Transurethral resection of the prostate Urinary ...

Nitroprusside and ECS-induced retrograde amnesia.

PubMed

Sudha, S; Andrade, C; Anand, A; Guido, S; Venkataraman, B V

2001-03-01

Previous research found that the administration of verapamil and felodipine immediately before electroconvulsive shocks (ECS) attenuated ECS-induced retrograde amnesia. This study examined whether sodium nitroprusside, an antihypertensive drug that does not affect calcium channels, has a similar action. Adult male Sprague-Dawley rats received nitroprusside (0.5 mg/kg ip) or saline 3 minutes before each of three once-daily true or sham ECS. Retention of pre-ECS learning was studied 1 day after ECS using a passive avoidance task. Nitroprusside was associated with increased seizure duration in ECS-treated rats, and with enhanced recall in both true and sham ECS groups. The latter finding suggests that nitroprusside nonspecifically improves cognitive functions, and does not support the hypothesis that ECS-induced cognitive impairment is a result of blood-brain barrier breach. Nitric oxide mechanisms may underlie the benefits purveyed by nitroprusside.

Trophic factors in neurologic disease.

PubMed

Stewart, S S; Appel, S H

1988-01-01

Recent studies suggest that diffusible factors released by neural targets enhance the survival, growth, and differentiation of neurons both peripherally and in the central nervous system. Evidence for such trophic factors exists for many of the neural systems involved in the degenerative neurologic diseases Alzheimer's disease, parkinsonism, and amyotrophic lateral sclerosis. It is our hypothesis that for each of these disorders there is both a primary insult and a secondary effect. The primary insult may have multiple etiologies, but the secondary effect is the result of retrograde degeneration. Such retrograde degeneration occurs because of an impairment of trophic factor function or an inadequacy of trophic effects to keep pace with the primary destructive process. Accordingly, it may be possible to exploit such trophic mechanisms to define further the pathobiology of neural degeneration and to develop specific treatments for currently incurable illnesses.

Emotion strengthens high priority memory traces but weakens low priority memory traces

PubMed Central

Sakaki, Michiko; Fryer, Kellie; Mather, Mara

2014-01-01

When encountering emotional events, memory for those events is typically enhanced. But it has been unclear how emotionally arousing events influence memory for preceding information. Does emotional arousal induce retrograde amnesia or retrograde enhancement? The current study revealed that this depends on the top-down goal relevance of the preceding information. Across three studies, we found that emotional arousal induced by one image facilitated memory for the preceding neutral item when people prioritized that neutral item. In contrast, an emotional image impaired memory for the preceding neutral item when people did not prioritize that neutral item. Emotional arousal elicited by negative and positive pictures both showed this pattern of enhancing or impairing memory for the preceding stimulus depending on its priority. These results indicate that emotional arousal amplifies the effects of top-down priority in memory formation. PMID:24311478

Balloon-Occluded Retrograde Transvenous Obliteration of a Gastric Vascular Malformation: An Innovative Approach to Treatment of a Rare Condition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansing, Catherine E., E-mail: catherine.e.hansing.mil@mail.mil; Marquardt, Joseph P.; Sutton, Daniel M.

Arteriovenous malformations (AVMs) are a high-flow form of a vascular malformation, which can be found anywhere in the body. While historically treated surgically, a multidisciplinary approach utilizing multiple specialties and treatment modalities is now commonly employed. In order to effectively treat an AVM, the nidus must be targeted and eradicated, which can be done via multiple approaches. We present the case of a 43-year-old male with a gastric wall AVM, which was initially incompletely treated using a percutaneous transarterial approach. The gastric AVM was noted to have dominant drainage through a gastrorenal shunt; therefore, Balloon-occluded Retrograde Transvenous Obliteration (BRTO) wasmore » utilized to eradicate the AVM nidus. This case illustrates the utility of Interventional Radiology, specifically BRTO, as another treatment option for challenging AVMs.« less

Vestibular efferent neurons project to the flocculus

NASA Technical Reports Server (NTRS)

Shinder, M. E.; Purcell, I. M.; Kaufman, G. D.; Perachio, A. A.

2001-01-01

A bilateral projection from the vestibular efferent neurons, located dorsal to the genu of the facial nerve, to the cerebellar flocculus and ventral paraflocculus was demonstrated. Efferent neurons were double-labeled by the unilateral injections of separate retrograde tracers into the labyrinth and into the floccular and ventral parafloccular lobules. Efferent neurons were found with double retrograde tracer labeling both ipsilateral and contralateral to the sites of injection. No double labeling was found when using a fluorescent tracer with non-fluorescent tracers such as horseradish peroxidase (HRP) or biotinylated dextran amine (BDA), but large percentages of efferent neurons were found to be double labeled when using two fluorescent substances including: fluorogold, microruby dextran amine, or rhodamine labeled latex beads. These data suggest a potential role for vestibular efferent neurons in modulating the dynamics of the vestibulo-ocular reflex (VOR) during normal and adaptive conditions.

Fatal air embolism during endoscopic retrograde cholangiopancreatography (ERCP): An 'impossible' diagnosis for the forensic pathologist.

PubMed

Marchesi, Matteo; Battistini, Alessio; Pellegrinelli, Moira; Gentile, Guendalina; Zoja, Riccardo

2016-01-01

Fatal air embolism related to endoscopic retrograde cholangiopancreatography is a very rare phenomenon. The authors describe the case of a 51-year-old female patient who developed this mortal complication; a computed tomography (CT) examination was performed in articulo mortis by the physicians. Autopsy was unreliable because of bizarre post-mortem changes (reabsorption of intra-cardiac gas vs. conservation of intra-cranial gas) and a lack of strong diagnostic value of histological findings. The right diagnosis was possible thanks only to the CT examination that permitted the assumption of this possible cause of death before the autopsy and to prepare the necessary procedures to recognise and probe air embolism. This case exemplifies how early post-mortem imaging can be crucial to avoid a wrong diagnosis. © The Author(s) 2015.

Retrograde intubation: an alternative way for the management of difficult airway.

PubMed

Lama, P; Shrestha, B R

2008-01-01

Inserting a retrograde wire into the pharynx through a cricothyroid puncture can facilitate tracheal intubation in difficult situations where either a flexible fiber-optic bronchoscope or an expert user of such a device is not available. Even in cases when fibropric can not be negotiated for the purpose, this method has been claimed to be useful to manage the airway. Some mouth opening is essential for the oral or nasal retrieval of the wire from the pharynx. Here, a case of post mandibular reconstructed wound infection required surgical debridement and plate removal from reconstructed lower mandible under general anesthesia. We retrieved the guide wire passed through a cricothyroid puncture and subsequently accomplished wire-guided oro-tracheal intubation. In the absence of a flexible fiber-optic bronchoscope, this technique is a very useful aid to intubate patients with limited mouth opening.

Look away: arterial and venous intravascular embolisation following shotgun injury.

PubMed

Vedelago, John; Dick, Elizabeth; Thomas, Robert; Jones, Brynmor; Kirmi, Olga; Becker, Jennifer; Alavi, Afshin; Gedroyc, Wladyslaw

2014-01-01

We describe two cases of intravascular embolization of shotgun pellets found distant to the entry site of penetrating firearm injury. The cases demonstrate antegrade embolization of a shotgun pellet from neck to right middle cerebral artery, and antegrade followed by retrograde venous embolization through the left lower limb to pelvis. Radiologists and Trauma Physicians should be aware that post shotgun injury, the likelihood of an embolised shot pellet is increased compared to other types of firearm missile injury, and should therefore search away from the site of injury to find such missiles. Shotgun pellets may travel in an antegrade or a retrograde intravascular direction - both were seen in these cases - and may not be clinically obvious. This underscores the importance of a meticuluous search through all images, including CT scout images, for evidence of their presence.

Anatomic structures at risk: curved hindfoot arthrodesis nail--a cadaveric approach.

PubMed

Knight, Timothy; Rosenfeld, Peter; Jones, Ioan Tudur; Clark, Callum; Savva, Nick

2014-01-01

Retrograde intramedullary nailing of the hindfoot and ankle is an established procedure for salvage of severe foot and ankle deformity, arthritis, tumor, and instability. In the present study, retrograde hindfoot (tibiotalocalcaneal) arthrodesis nailing was performed using a standardized technique on 7 cadaver specimens by trained senior surgeons. The specimens were then dissected to determine the distance of the subcalcaneal structures at risk from the insertion point of the nail. The findings showed that the distance of the lateral neurovascular bundle from the edge of the nail was 6.5 (range 3.5 to 8, 95% confidence interval 5.9 to 7.1) mm. No neurovascular bundle was compromised, and all were within a previously described "safe window." Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Retrograde intrarenal surgery for renal stones - Part 2

PubMed Central

Kılıç, Özcan; Akand, Murat; Van Cleynenbreugel, Ben

2017-01-01

Retrograde intrarenal surgery (RIRS) has become an effective and safe treatment modality in the management of urinary system stone disease. Recent developments and innovations in the flexible ureterorenoscope and auxiliary equipment have made this procedure easier and more effective with increased success rates. RIRS can be used as a primary treatment in patients with renal stones smaller than 2 cm, prior unsuccessful shock wave lithotripsy, infundibular stenosis, renoureteral malformation, skeletal-muscular deformity, bleeding diathesis and obese patients. In the second part of this detailed review for RIRS, effect of stone composition on success rate, preoperative assessment of stone-free rate, the cost of this modality, education for RIRS, fluoroscopy use, the current role of RIRS in the treatment of various urolithiasis types and special conditions, and combined treatment methods are discussed with up-to-date literature. PMID:28861294

Geometric calculus-based postulates for the derivation and extension of the Maxwell equations

NASA Astrophysics Data System (ADS)

McClellan, Gene E.

2012-09-01

Clifford analysis, particularly application of the geometric algebra of three-dimensional physical space and its associated geometric calculus, enables a compact formulation of Maxwell's electromagnetic (EM) equations from a set of physically relevant and mathematically pleasing postulates. This formulation results in a natural extension of the Maxwell equations yielding wave solutions in addition to the usual EM waves. These additional solutions do not contradict experiment and have three properties in common with the apparent properties of dark energy. These three properties are that the wave solutions 1) propagate at the speed of light, 2) do not interact with ordinary electric charges or currents, and 3) possess retrograde momentum. By retrograde momentum, we mean that the momentum carried by such a wave is directed oppositely to the direction of energy transport. A "gas" of such waves generates negative pressure.

Actin retrograde flow controls natural killer cell response by regulating the conformation state of SHP-1.

PubMed

Matalon, Omri; Ben-Shmuel, Aviad; Kivelevitz, Jessica; Sabag, Batel; Fried, Sophia; Joseph, Noah; Noy, Elad; Biber, Guy; Barda-Saad, Mira

2018-03-01

Natural killer (NK) cells are a powerful weapon against viral infections and tumor growth. Although the actin-myosin (actomyosin) cytoskeleton is crucial for a variety of cellular processes, the role of mechanotransduction, the conversion of actomyosin mechanical forces into signaling cascades, was never explored in NK cells. Here, we demonstrate that actomyosin retrograde flow (ARF) controls the immune response of primary human NK cells through a novel interaction between β-actin and the SH2-domain-containing protein tyrosine phosphatase-1 (SHP-1), converting its conformation state, and thereby regulating NK cell cytotoxicity. Our results identify ARF as a master regulator of the NK cell immune response. Since actin dynamics occur in multiple cellular processes, this mechanism might also regulate the activity of SHP-1 in additional cellular systems. © 2018 The Authors.

Low-Thrust Transfers from Distant Retrograde Orbits to L2 Halo Orbits in the Earth-Moon System

NASA Technical Reports Server (NTRS)

Parrish, Nathan L.; Parker, Jeffrey S.; Hughes, Steven P.; Heiligers, Jeannette

2016-01-01

This paper presents a study of transfers between distant retrograde orbits (DROs) and L2 halo orbits in the Earth-Moon system that could be flown by a spacecraft with solar electric propulsion (SEP). Two collocation-based optimal control methods are used to optimize these highly-nonlinear transfers: Legendre pseudospectral and Hermite-Simpson. Transfers between DROs and halo orbits using low-thrust propulsion have not been studied previously. This paper offers a study of several families of trajectories, parameterized by the number of orbital revolutions in a synodic frame. Even with a poor initial guess, a method is described to reliably generate families of solutions. The circular restricted 3-body problem (CRTBP) is used throughout the paper so that the results are autonomous and simpler to understand.