bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar wind charge exchange during geomagnetic storms
Authors: Robertson I.P. , Cravens T.E. , Sibeck D.G. , Collier M.R. , Kuntz K.D.
Published: April 2012

On 2001 March 31 a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMC) employed a global magnetohydrodynamic (MHD) model to simulate the solar wind‐magnetosphere interaction during the peak of this geomagnetic storm. Robertson et al. then modeled the expected soft X‐ray emission due to solar wind charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on 2000 July 14 (Bastille Day). We again modeled X‐ray emission due to solar wind charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X‐ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AXIOM: Advanced X‐ray imaging of the magnetosheath
Authors: Sembay S. , Branduardi‐Raymont G. , Eastwood J.P. , Sibeck D.G. , Abbey A. , Brown P. , Carter J.A. , Carr C.M. , Forsyth C. , Kataria D. , Kemble S. , Milan S. , Owen C.J. , Read A.M. , Peacocke L. , Arridge C.S. , Coates A.J. , Collier M.R. , Cowley S.W.H. , Fazakerley A.N. , Fraser G. , Jones G.H. , Lallement R. , Lester M. , Porter F.S. , Yeoman T.
Published: April 2012

AXIOM (Advanced X‐ray Imaging Of the Magnetosphere) is a concept mission which aims to explain how the Earth's magnetosphere responds to the changing impact of the solar wind using a unique method never attempted before; performing wide‐field soft X‐ray imaging and spectroscopy of the magnetosheath, magnetopause and bow shock at high spatial and temporal resolution. Global imaging of these regions is possible because of the solar wind charge exchange (SWCX) process which produces elevated soft X‐ray emission from the interaction of high charge‐state solar wind ions with primarily neutral hydrogen in the Earth's exosphere and near‐interplanetary space (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tracing low‐energy cosmic‐rays by charge exchange X‐ray emission
Authors: Tatischeff V.
Published: April 2012

Hadronic cosmic rays of energies below about 100 MeV nucleon–1 are thought to be an important component of the Galactic ecosystem. However, since these particles cannot be detected near Earth due to the solar modulation effect, their composition and flux in the interstellar medium are very uncertain. Atomic interactions of low‐energy cosmic rays with interstellar gas can produce a characteristic nonthermal X‐ray emission comprising very broad lines from de‐excitations in fast ions following charge exchange. We suggest that broad lines at ∼0.57 and ∼0.65 keV could be detected from a dark molecular cloud in the local interstellar medium. These lines would be produced by fast oxygen ions of kinetic energies around 1 MeV nucleon–1 (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐rays from charge transfer in astrophysics: Overview
Authors: Raymond J.C.
Published: April 2012

X‐rays produced by charge transfer provide a major fraction of the soft X‐ray background. If they contribute significantly to emission from other astrophysical sources, then model fits that ignore them will yield wrong answers, and an important diagnostic opportunity will be missed. Several recent papers suggest charge transfer contributions to observed X‐ray spectra. This informal overview discusses analysis that might confirm the charge transfer interpretation and carry it toward the status of a useful diagnostic (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge‐exchange X‐ray emission at hot/cool gas interfaces
Authors: Lallement R.
Published: April 2012

Charge‐transfer (CT) X‐ray emission may occur at interfaces between a partially neutral gas and gas possessing high ions, provided there is a relative motion between those two phases. The CTX surface brightness from distant objects must be taken into account if it is not far below other “classical” emission sources, especially the thermal emission from the hot phase. I discuss those conditions and potential spectroscopic or photometric diagnostics. I also mention potential indirect effects of the CT reactions by means of pickup ion production, acceleration and subsequent modification of interface and plasma properties (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge transfer reactions at interfaces between neutral gas and plasma: Dynamical effects and X‐ray emission
Authors: Provornikova E. , Izmodenov V.V. , Lallement R.
Published: April 2012

Charge‐transfer is the main process linking neutrals and charged particles in the interaction regions of neutral (or partly ionized) gas with a plasma. In this paper we illustrate the importance of charge‐transfer with respect to the dynamics and the structure of neutral gas‐plasma interfaces. We consider the following phenomena: (1) the heliospheric interface ‐ region where the solar wind plasma interacts with the partly‐ionized local interstellar medium (LISM) and (2) neutral interstellar clouds embedded in a hot, tenuous plasma such as the million degree gas that fills the so‐called “Local Bubble”. In (1), we discuss several effects in the outer heliosphere caused by charge exchange of interstellar neutral atoms and plasma protons. In (2) we describe the role of charge exchange in the formation of a transition region between the cloud and the surrounding plasma based on a two‐component model of the cloud‐plasma interaction. In the model the cloud consists of relatively cold and dense atomic hydrogen gas, surrounded by hot, low density, fully ionized plasma. We discuss the structure of the cloud‐plasma interface and the effect of charge exchange on the lifetime of interstellar clouds. Charge transfer between neutral atoms and minor ions in the plasma produces X‐ray emission. Assuming standard abundances of minor ions in the hot gas surrounding the cold interstellar cloud, we estimate the X‐ray emissivity consecutive to the charge transfer reactions. Our model shows that the charge‐transfer X‐ray emission from the neutral cloud‐plasma interface may be comparable to the diffuse thermal X‐ray emission from the million degree gas cavity itself (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gastrointestinal Dysfunction in Autism: Parental Report, Clinical Evaluation, and Associated Factors
Authors: Gorrindo Phillip , Williams Kent C. , Lee Evon B. , Walker Lynn S. , McGrew Susan G. , Levitt Pat
Published: April 2012

The objectives of this study were to characterize gastrointestinal dysfunction (GID) in autism spectrum disorder (ASD), to examine parental reports of GID relative to evaluations by pediatric gastroenterologists, and to explore factors associated with GID in ASD. One hundred twenty‐one children were recruited into three groups: co‐occurring ASD and GID, ASD without GID, and GID without ASD. A pediatric gastroenterologist evaluated both GID groups. Parents in all three groups completed questionnaires about their child's behavior and GI symptoms, and a dietary journal. Functional constipation was the most common type of GID in children with ASD (85.0%). Parental report of any GID was highly concordant with a clinical diagnosis of any GID (92.1%). Presence of GID in children with ASD was not associated with distinct dietary habits or medication status. Odds of constipation were associated with younger age, increased social impairment, and lack of expressive language (adjusted odds ratio in nonverbal children: 11.98, 95% confidence interval 2.54–56.57). This study validates parental concerns for GID in children with ASD, as parents were sensitive to the existence, although not necessarily the nature, of GID. The strong association between constipation and language impairment highlights the need for vigilance by health‐care providers to detect and treat GID in children with ASD. Medications and diet, commonly thought to contribute to GID in ASD, were not associated with GID status. These findings are consistent with a hypothesis that GID in ASD represents pleiotropic expression of genetic risk factors.
Chondroitin sulfate and dynamic loading alter chondrogenesis of human MSCs in PEG hydrogels
Authors: Steinmetz Neven J. , Bryant Stephanie J.
Published: April 2012

While biochemical and biomechanical cues are known to play important roles in directing stem cell differentiation, there remains little known regarding how these inextricably linked biological cues impact the differentiation fate of human marrow stromal cells (hMSCs). This study investigates the chondrogenic differentiation potential of hMSCs when encapsulated in a three dimensional (3D) hydrogel and exposed to a biochemical cue, chondroitin sulfate (ChS), a biomechanical cue, dynamic loading, and their combination. hMSCs were encapsulated in bioinert poly(ethylene glycol) (PEG) hydrogels only, PEG hydrogels modified with covalently incorporated methacrylated ChS and cultured under free swelling conditions or subjected to delayed intermittent dynamic loading for 2 weeks. The 3D hydrogel environment led to the expression of chondrogenic genes (SOX9) and proteins (aggrecan and collagen II), but also upregulated hypertrophic genes (RUNX2 and Col X mRNA) and proteins (collagen X), while the application of loading generally led to a downregulation in chondrogenic proteins (collagen II). The presence of ChS led to elevated levels of aggrecan, but also collagen I, protein expression and when combined with dynamic loading downregulated, but did not suppress, hypertrophic genes (Col X and RUNX2) and collagen I protein expression. Taken together, this study demonstrates that while the 3D environment induces early terminal differentiation during chondrogenesis of hMSCs, the incorporation of ChS into PEG hydrogels may slow the terminal differentiation process down the hypertrophic lineage particularly when dynamic loading is applied. Biotechnol. Bioeng. 2012; 109: 2671–2682. © 2012 Wiley Periodicals, Inc.
Predictive models for transient protein expression in tobacco (Nicotiana tabacum L.) can optimize process time, yield, and downstream costs
Authors: Buyel J.F. , Fischer R.
Published: April 2012

The transient expression of recombinant biopharmaceutical proteins in plants can suffer inter‐batch variation, which is considered a major drawback under the strict regulatory demands imposed by current good manufacturing practice (cGMP). However, we have achieved transient expression of the monoclonal antibody 2G12 and the fluorescent marker protein DsRed in tobacco leaves with ∼15% intra‐batch coefficients of variation, which is within the range reported for transgenic plants. We developed models for the transient expression of both proteins that predicted quantitative expression levels based on five parameters: The OD600nm of Agrobacterium tumefaciens (from 0.13 to 2.00), post‐inoculation incubation temperature (15–30°C), plant age (harvest at 40 or 47 days after seeding), leaf age, and position within the leaf. The expression models were combined with a model of plant biomass distribution and extraction, generating a yield model for each target protein that could predict the amount of protein in specific leaf parts, individual leaves, groups of leaves, and whole plants. When the yield model was combined with a cost function for the production process, we were able to perform calculations to optimize process time, yield, or downstream costs. We illustrate this procedure by transferring the cost function from a production process using transgenic plants to a hypothetical process for the transient expression of 2G12. Our models allow the economic evaluation of new plant‐based production processes and provide greater insight into the parameters that affect transient protein expression in plants. Biotechnol. Bioeng. 2012; 109: 2575–2588. © 2012 Wiley Periodicals, Inc.
Improvement of surfactin production in Bacillus subtilis using synthetic wastewater by overexpression of specific extracellular signaling peptides, comX and phrC
Authors: Jung Ju , Yu Kyung Ok , Ramzi Ahmad Bazli , Choe Se Hoon , Kim Seung Wook , Han Sung Ok
Published: April 2012

Surfactin is a biological surfactant with numerous potential applications. In this study, Bacillus subtilis was engineered to improve surfactin production by the activation of two competence‐stimulating pheromones, ComX and competence and sporulation factor (CSF) to stimulate the transcription of srfA operon. Both signaling factors, encoded by comX and phrC, were successfully overexpressed and subsequently increased surfactin production. Surfactin produced by engineered strains showed functional groups similar to the commercially available surfactin analyzed via Fourier transform infrared spectroscopy (FTIR). Surfactin production in the B. subtilis (pHT43‐comXphrC) strain was 6.4‐fold greater than in the wild strain, with approximately 135.1 mg/L surfactin produced after 48 h cultivation. To reduce the production costs of surfactin, synthetic wastewater was used, from which the B. subtilis (pHT43‐comXphrC) strain produced approximately 140.2 mg/L surfactin. The results obtained demonstrated the production of surfactin from synthetic wastewater, which is beneficial in lowering the overall production costs. Biotechnol. Bioeng. 2012;109: 2349–2356. © 2012 Wiley Periodicals, Inc.
Photosynthetic efficiency of Chlamydomonas reinhardtii in attenuated, flashing light
Authors: Vejrazka Carsten , Janssen Marcel , Streefland Mathieu , Wijffels René H.
Published: April 2012

As a result of mixing and light attenuation, algae in a photobioreactor (PBR) alternate between light and dark zones and, therefore, experience variations in photon flux density (PFD). These variations in PFD are called light/dark (L/D) cycles. The objective of this study was to determine how these L/D cycles affect biomass yield on light energy in microalgae cultivation. For our work, we used controlled, short light path, laboratory, turbidostat‐operated PBRs equipped with a LED light source for square‐wave L/D cycles with frequencies from 1 to 100 Hz. Biomass density was adjusted that the PFD leaving the PBR was equal to the compensation point of photosynthesis. Algae were acclimated to a sub‐saturating incident PFD of 220 µmol m−2 s−1 for continuous light. Using a duty cycle of 0.5, we observed that L/D cycles of 1 and 10 Hz resulted on average in a 10% lower biomass yield, but L/D cycles of 100 Hz resulted on average in a 35% higher biomass yield than the yield obtained in continuous light. Our results show that interaction of L/D cycle frequency, culture density and incident PFD play a role in overall PBR productivity. Hence, appropriate L/D cycle setting by mixing strategy appears as a possible way to reduce the effect that dark zone exposure impinges on biomass yield in microalgae cultivation. The results may find application in optimization of outdoor PBR design to maximize biomass yields. Biotechnol. Bioeng. 2012; 109: 2567–2574. © 2012 Wiley Periodicals, Inc.
Rapid micropatterning of cell lines and human pluripotent stem cells on elastomeric membranes
Authors: Paik Isha , Scurr David J. , Morris Bryan , Hall Graham , Denning Chris , Alexander Morgan R. , Shakesheff Kevin M. , Dixon James E.
Published: April 2012

Tissue function during development and in regenerative medicine completely relies on correct cell organization and patterning at micro and macro scales. We describe a rapid method for patterning mammalian cells including human embryonic stem cells (HESCs) and induced pluripotent stem cells (iPSCs) on elastomeric membranes such that micron‐scale control of cell position can be achieved over centimeter‐length scales. Our method employs surface engineering of hydrophobic polydimethylsiloxane (PDMS) membranes by plasma polymerization of allylamine. Deposition of plasma polymerized allylamine (ppAAm) using our methods may be spatially restricted using a micro‐stencil leaving faithful hydrophilic ppAAm patterns. We employed airbrushing to create aerosols which deposit extracellular matrix (ECM) proteins (such as fibronectin and Matrigel™) onto the same patterned ppAAm rich regions. Cell patterns were created with a variety of well characterized cell lines (e.g., NIH‐3T3, C2C12, HL1, BJ6, HESC line HUES7, and HiPSC line IPS2). Individual and multiple cell line patterning were also achieved. Patterning remains faithful for several days and cells are viable and proliferate. To demonstrate the utility of our technique we have patterned cells in a variety of configurations. The ability to rapidly pattern cells at high resolution over macro scales should aid future tissue engineering efforts for regenerative medicine applications and in creating in vitro stem cell niches. Biotechnol. Bioeng. 2012; 109: 2630–2641. © 2012 Wiley Periodicals, Inc.
Hepatic venous pressure gradient in the assessment of portal hypertension before liver resection in patients with cirrhosis
Authors: Boleslawski E , Petrovai G , Truant S , Dharancy S , Duhamel A , Salleron J , Deltenre P , Lebuffe G , Mathurin P , Pruvot F R
Published: April 2012

Background

Preoperative measurement of hepatic venous pressure gradient (HVPG) is not performed routinely before hepatectomy in patients with cirrhosis, although it has been suggested to be useful. This study investigated whether preoperative HVPG values and indirect criteria of portal hypertension (PHT) predict the postoperative course in these patients.

Methods

Between January 2007 and December 2009, consecutive patients with resectable hepatocellular carcinoma (HCC) in a cirrhotic liver were included in this prospective study. PHT was assessed by transjugular HVPG measurement and by classical indirect criteria (oesophageal varices, splenomegaly and thrombocytopenia). The main endpoints were postoperative liver dysfunction and 90-day mortality.

Results

Forty patients were enrolled. A raised HVPG was associated with postoperative liver dysfunction (median 11 and 7 mmHg in those with and without dysfunction respectively; P = 0·017) and 90-day mortality (12 and 8 mmHg in those who died and survivors respectively; P = 0·026). Oesophageal varices, splenomegaly and thrombocytopenia were not associated with any of the endpoints. In multivariable analysis, body mass index, remnant liver volume ratio and preoperative HVPG were the only independent predictors of postoperative liver dysfunction.

Conclusion

An increased HVPG was associated with postoperative liver dysfunction and mortality after liver resection in patients with HCC and liver cirrhosis, whereas indirect criteria of PHT were not. This study suggests that preoperative HVPG measurement should be measured routinely in these patients.
Selective separation of biobutanol from acetone–butanol–ethanol fermentation broth by means of sorption methodology based on a novel macroporous resin
Authors: Lin Xiaoqing , Wu Jinglan , Jin Xiaohong , Fan Jiansheng , Li Renjie , Wen Qingshi , Qian Wenbin , Liu Dong , Chen Xiaochun , Chen Yong , Xie Jingjing , Bai Jianxin , Ying Hanjie
Published: April 2012

The traditional distillation method for recovery of butanol from fermentation broth is an energy‐intensive process. Separation of butanol based on adsorption methodology has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. However, the application of the commercial adsorbents in the integrated acetone–butanol–ethanol (ABE) fermentation process is restricted due to the low recovery (less than 85%) and the weak capability of enrichment in the eluent (3–4 times). In this study, we investigated the sorption properties of butanol onto three kinds of adsorbents with different polarities developed in our laboratory, that is, XD‐41, H‐511, and KA‐I resin. The sorption behaviors of single component and ABE ternary mixtures presented in the fermentation broths on KA‐I resin were investigated. KA‐I resin had higher affinity for butanol than for acetone, ethanol, glucose, acetic acid, and butyric acid. Multicomponent ABE sorption on KA‐I resin was modeled using a single site extended Langmuir isotherm model. In a desorption study, all the adsorbed components were desorbed in one bed volume of methanol, and the recovery of butanol from KA‐I resin was 99.7%. The concentration of butanol in the eluent was increased by a factor of 6.13. In addition, KA‐I resin was successfully regenerated by two bed volumes of water. Because of its quick sorption, high sorption capacity, low cost, and ease of desorption and regeneration, KA‐I resin exhibits good potential for compatibility with future ABE fermentation coupled with in situ recovery product removal techniques. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 962–972, 2012
Diminished left ventricular function is associated with poor mid‐term outcomes in neonates after balloon aortic valvuloplasty
Authors: Petit Christopher J. , Ing Frank F. , Mattamal Raphael , Pignatelli Ricardo H. , Mullins Charles E. , Justino Henri
Published: April 2012

Objectives

We studied outcomes of neonatal aortic valvuloplasty to determine the risk factors for poor outcomes.

Background

Balloon aortic valvuloplasty (BAV) is the primary therapy for neonates with severe aortic stenosis (AS). Limited data are available on the mid‐term and long‐term outcomes in this population, and reported risk factors for poor outcomes vary among studies.

Methods

We reviewed all cases of BAV in neonates in our institution between 1998 and 2009. We reviewed patient characteristics, preintervention echocardiographic, and procedural details. We tracked repeat BAV, aortic valve replacement (AVR), and death/transplant. Kaplan–Meier and Cox regression analyses were performed. Changes in dimensions of left heart structures post‐BAV were also studied.

Results

Forty‐eight neonates were included—of these, 30 (62%) had critical AS. There was one procedural death. The remaining 47 neonates were followed for 4.8 ± 4.4 years. Repeat BAV was performed in 19 (40%) neonates; AVR was performed in 9 (19%), and death/transplant occurred in 4 (8%) neonates. Multivariate analysis revealed that lower LV shortening fraction pre‐BAV, higher pre‐BAV and final valve gradient, and need for inotropes were associated with poor long‐term outcomes. LV diastolic and systolic dimensions normalized over time, and left heart structures improved in size early and late after BAV.

Conclusions

Neonatal BAV is associated with low mortality. Lower LV shortening fraction pre‐BAV is associated with risk of future interventions, while repeat valvuloplasty is safe and effective for recurrent AS. There is significant improvement in dimensions of the LV and aortic valve annulus following BAV. © 2012 Wiley Periodicals, Inc.
Over‐the‐wire‐technique device implantation
Authors: Butera Gianfranco , Castaldi Biagio , MacDonald Simon T.
Published: April 2012

Introduction

Transcatheter closure of cardiac defects is a mainstay of treatment in congenital and structural heart disease. Occasionally, the devices used are useful in nonstandard or difficult positions but device embolization and malposition can be complicating factors necessitating percutaneous retrieval or emergency surgery. We describe a new “over‐the‐wire” technique that allows guided safe deployment and easy retrievability if required.

Methods

We describe 5 cases in which Amplatzer devices were delivered over a wire in challenging anatomy in high‐risk patients. These cases included baffle leak in complex congenital heart disease, paravalvular leak, a large patent ductus arteriosus, and complex ventricular septal defects. In each case, the device was punctured close to the release mechanism and a guidewire fed through it, the device and guidewire then being loaded into the appropriate delivery system. The procedure is described in each case, illustrating the use of the technique.

Conclusion

We describe a novel over‐the‐wire technique that is useful in deployment of Amplatzer devices in difficult and challenging anatomy, allowing careful controlled delivery and easy retrieval. This will help minimize procedural patient risk in complex cases. © 2012 Wiley Periodicals, Inc.
Novel use of the Mguard™ mesh‐covered stent to treat coronary arterial perforations
Authors: Romaguera Rafael , Gomez‐Hospital Joan Antoni , Cequier Angel
Published: April 2012

Covered stents seem to be an effective tool to seal severe perforations that have persisted despite prolonged balloon inflation. However, the high profile and low flexibility of previous covered stents compromise the deliverability of these devices, particularly in emergency situations. The Mguard™ stent (InspireMD, Tel Aviv, Israel) is a novel mesh‐covered stent that has been designed to prevent distal embolization in thrombotic lesions. We herein report two cases that describe a new potential use of the Mguard stent for sealing perforations in coronary circulation. © 2012 Wiley Periodicals, Inc.
Embolic protection device utilization during stenting of native coronary artery lesions with large lipid core plaques as detected by near‐infrared spectroscopy
Authors: Brilakis Emmanouil S. , Abdel‐Karim Abdul‐Rahman R. , Papayannis Aristotelis C. , Michael Tesfaldet T. , Rangan Bavana V. , Johnson Jason L. , Banerjee Subhash
Published: April 2012

Background

Stenting of large lipid core plaques (LCPs), as assessed by near‐infrared spectroscopy (NIRS), has been associated with periprocedural myocardial infarction (MI), possibly due to distal embolization.

Methods

An embolic protection device (EPD) was inserted before stenting in nine native coronary arteries with large LCP, as assessed by NIRS. Embolized material was assessed by histopathology.

Results

Mean age was 64 ± 7 years and all patients were men. The target lesion was located in the right (67%) or left anterior descending (33%) coronary artery. A filter was utilized in eight patients (89%) and proximal embolic protection in one (11%). In one patient two filters were required because the originally placed filter became obstructed with debris after initial stent placement. The mean percent angiographic stenosis prestenting and poststenting was 87% ± 9% and 2% ± 4%, respectively and final TIMI 3 flow was achieved in all patients. Embolized material was retrieved in eight of nine patients (89%) and consisted mainly of platelet and fibrin thrombi. The mean target segment lipid core burden index decreased from 395 ± 114 before stenting to 152 ± 106 after stenting (P < 0.001) and the lesion angular extent decreased from 312° ± 70° to 240° ± 90° (P = 0.07). Postprocedural MI occurred in two of nine patients (22%), in one of whom two filters were required.

Conclusion

Use of EPDs frequently resulted in embolized material retrieval after stenting of native coronary artery lesions with large LCPs. These findings support further study of EPDs as a means to prevent poststenting MI. © 2012 Wiley Periodicals, Inc.
Severe hemolysis associated with use of the impella LP 2.5 mechanical assist device
Authors: Sibbald Matthew , Džavík Vladimír
Published: April 2012

The Impella LP 2.5 is a percutaneously implantable axial flow device designed to offer circulatory support for patients in cardiogenic shock during percutaneous coronary interventions (PCI). While most axial flow devices are associated with hemolysis, clinically relevant hemolysis with this device has not been reported. We report a case of a 66‐year‐old woman with hemodynamic collapse during an elective PCI who was successfully resuscitated with an Impella device. She developed marked biochemical evidence of intravascular hemolysis. This necessitated device removal which resulted in prompt resolution of the hemolysis. We advise routine measurement of biochemical markers of hemolysis and serial hemoglobin values during Impella device support to allow timely detection and treatment of this important complication. © 2012 Wiley Periodicals, Inc.
Percutaneous isolated pharmaco‐mechanical thrombolysis‐thrombectomy system for the management of acute arterial limb ischemia: 30‐day results from a single‐center experience
Authors: Gupta Raghav , Hennebry Thomas A.
Published: April 2012

Objective

To study the efficacy of isolated pharmaco‐mechanical thrombolysis‐thrombectomy (IPMT) by Trellis™ device (Covidien, Mansfield, MA) in managing acute limb ischemic (ALI).

Background

ALI is both life and limb threatening disease with a reported 9–15% mortality and 15–25% limb loss in the first month after presentation. Pitfalls of current endovascular techniques include major bleeding, distal embolism, and prolonged thrombolytic infusion. IPMT isolates the thrombus between two balloons and utilizes wire oscillation to increase the thombus‐lytic exposure surface area followed by aspiration. It decreases systemic lytic exposure, procedure time, and distal embolism.

Methods

Technical aspects, success, and bleeding complications in 24 consecutive patients with ALI treated with IPMT between October 2009 and September 2010 were analyzed. In‐hospital and 30‐day mortality, amputation rates and treatment success rates were determined.

Results

24 patients constituted 32 arteries; 18 (56.25%) were suprainguinal including 3 grafts (9.4%) and 14 (43.75%) were infrainguinal native arteries. Substantial or complete response was seen in >90% vessels with 87.5% patients revealing TIMI three flow while none demonstrated TIMI 2 or 3 pretreatment. Only three patients required adjunctive post‐IPMT thrombolysis. In‐hospital and 30‐day all cause mortality was 4.16%. One patient died in‐hospital and no patient underwent amputation.

Conclusion

Besides being the largest series of ALI patients treated with IPMT, this is the first and largest series including 14 native infrainguinal arteries. These results suggest IPMT to be a promising and safer therapeutic option in ALI, likely due to its site‐specific nature and limited thrombolysis exposure time. © 2012 Wiley Periodicals, Inc.
An alternative angiographic view to unmask the hidden patent ductus arteriosus during device closure
Authors: Garg Naveen , Moorthy Nagaraja
Published: April 2012

Transcatheter closure of patent ductus arteriosus (PDA) with various devices has been evaluated worldwide and in selected cases can be performed successfully, thus avoiding the morbidity associated with surgical closure. Traditionally, left lateral projection is adopted for angiographic visualization of the PDA. However, rarely due to anatomical variations of the ductus, it may be difficult to properly visualize and deploy device in above‐said traditional view. In such cases, right anterior oblique projection may be used for proper visualization. © 2012 Wiley Periodicals, Inc.
Choice of stent and outcomes after treatment of drug‐eluting stent restenosis in highly complex lesions
Authors: Freixa Xavier , Almasood Ali S. , Khan Sohail Q. , Mackie Karen , Osten Mark , Ing Douglas , Overgaard Christopher B. , Horlick Eric M. , Seidelin Peter H. , Džavík Vladimír
Published: April 2012

Objectives

Our aim was to compare the outcomes of a same versus different drug‐eluting stent (DES) implantation strategy for the treatment of DES instent restenosis (ISR).

Background

The absence of clear data renders the treatment of DES ISR one of the most challenging situations in interventional cardiology.

Methods

We identified all cases of DES ISR treated with a second DES between January 2004 and January 2009. The lesions were divided into those treated with the same DES as the initial one that restenosed and those treated with a different DES. The main end‐point was repeat target lesion revascularization (TLR).

Results

We included 116 patients with a total of 132 lesions. The patient population was highly complex: 55.5% with diabetes, 56% with type‐C lesions, 15.9% with lesions previously stented with BMS and 18.2% with fluoroscopic evidence of stent fracture. A same and different stent strategy was conducted in 41 lesions (31%) and 91 lesions (69%), respectively. Overall TLR was 31.1% and occurred in 46.3% of patients treated with the same stent and 24.4% of those with a different stent (P = 0.012). Multivariable analysis found same stent strategy (OR 2.84, 95%CI 1.23–6.57;P = 0.014) and occurrence of stent fracture (OR 4.03, 95%CI 1.33–12.01;P = 0.012) to be the only independent predictors of TLR after a median follow‐up of 20.4 [12.1–30.2] months.

Conclusions

In highly complex lesions, DES implantation for DES ISR is linked to a high need of future revascularization. An association between implanting a DES type other than the original and lower rate of TLR is suggested. © 2012 Wiley Periodicals, Inc.
Imaging a spiral dissection of the superficial femoral artery in high resolution with optical coherence tomography—Seeing is believing
Authors: Stefano Gregory T. , Mehanna Emile , Parikh Sahil A.
Published: April 2012

Optical coherence tomography (OCT) offers an alternative to intravascular ultrasound (IVUS) for endovascular imaging. Clinical and research applications for OCT have emerged in percutaneous coronary intervention (PCI), however, OCT has not found similar utility in peripheral arterial interventions. Early generation time‐domain OCT systems required arterial occlusion to create the blood free environment needed for image acquisition and could not reliably scan vessel diameters encountered in the peripheral circulation. However, the frequency‐domain OCT (FD‐OCT) system currently FDA approved for use in the United States does not require arterial occlusion to generate images and permits a greater scan diameter allowing for exploratory use in peripheral arteries. To our knowledge, this is the first report using non‐occlusive OCT imaging to serve as an adjunct to endovascular intervention for femoropopliteal disease. We illustrate the feasibility of acquiring high resolution images of a spiral dissection of the superficial femoral artery following balloon angioplasty that was not adequately visualized by angiography. © 2012 Wiley Periodicals, Inc.
Percutaneous therapeutic approaches to closure of cardiac pseudoaneurysms
Authors: Kumar Prasanna Venkatesh , Alli Oluseun , Bjarnason Haruldur , Hagler Donald J. , Sundt Thoralf M. , Rihal Charanjit S.
Published: April 2012

Cardiac and aortic pseudoaneurysms are rare complications following myocardial infarction or cardiac surgery. They are characterized by a contained cardiac or aortic rupture within surrounding tissue and have a high mortality rate if left untreated. Percutaneous treatment of cardiac pseudoaneurysms might be a feasible treatment option in patients who are at high risk of reoperative surgery. There is limited literature on the outcomes and the approaches to percutaneous treatment of these pseudoaneurysms. We review nine cases of cardiac and aortic pseudoaneurysms and percutaneous techniques for closure. Pseudoaneurysms were categorized anatomically as left ventricular posterior (posterobasal or posterolateral), left ventricular outflow tract, left ventricular apical, and ascending aortic pseudoaneurysms. Two patients with posterior pseudoaneurysms (one posterobasal treated with an Amplatzer Septal Occluder device, and one wide‐mouthed posterolateral pseudoaneurysm which was not closed, are described. We further describe two left ventricular outflow tract pseudoaneurysms treated successfully with percutaneous coil embolization, one left ventricular apical pseudoaneurysm treated with coils, and three ascending aortic pseudoaneurysms treated with a septal occluder device or vascular plug. We review the technical approaches, device selection strategies, outcomes, and complications with these percutaneous treatment options. The size of the pseudoaneurysm dimensions of its neck and relative anatomy, particularly to the coronaries and valves, are critical issues to be addressed before percutaneous treatment of these pseudoaneurysms. © 2012 Wiley Periodicals, Inc.
Percutaneous retrograde left ventricular assist support for interventions in patients with aortic stenosis and left ventricular dysfunction
Authors: Martinez Claudia A. , Singh Vikas , Londoño Juan C. , Cohen Mauricio G. , Alfonso Carlos E. , O'Neill William W. , Heldman Alan W.
Published: April 2012

Objectives

To evaluate feasibility and technical outcomes in patients with aortic stenosis (AS) who have undergone high‐risk procedures with continuous flow left ventricular (LV) assist, with the Impella 2.5 system (Abiomed, Danvers, MA).

Background

In preparation for transcatheter aortic valve implantation, an increasing number of high‐risk patients with severe AS and left ventricular dysfunction are currently considered for percutaneous coronary interventions (PCI) and balloon aortic valvuloplasty (BAV). Hemodynamic support may be required in some patients.

Methods

We reviewed procedural and clinical findings and 30‐day outcomes in patients with symptomatic AS who underwent high‐risk percutaneous procedures supported by the Impella 2.5 system. All patients carried a high‐risk of operative mortality. Impella was used during PCI, BAV, and for hemodynamic support during emergencies.

Results

Over a 14‐month period, 21 patients with AS underwent insertion of Impella prior to high‐risk PCI (n = 3), BAV with subsequent PCI (n = 8), BAV alone (n = 7), or during cardiac arrest immediately following BAV (n = 3). The mean Society of Thoracic Surgeons (STS) predicted mortality risk was 14% (range 7.3–24.7%). Impella was inserted successfully in all patients attempted. Retrograde advancement of two catheters across the aortic valve (for concomitant BAV in 15 patients) was technically feasible. Retrograde continuous flow LV assist produced a reduction in LV end‐diastolic pressure and an increase in arterial pressure. Periprocedural complications occurred in 19% (n = 4) patients, with no periprocedural deaths. Mortality at 30 days was 14.2%.

Conclusion

Our data suggests that continuous flow LV assist with Impella 2.5 can be used in high‐risk patients with severe AS who require periprocedural hemodynamic support. © 2012 Wiley Periodicals, Inc.
Contemporary use of adjunctive thrombectomy during primary percutaneous coronary intervention for ST‐elevation myocardial infarction in the united states
Authors: Owan Theophilus E. , Roe Matthew T. , Messenger John C. , Dai David , Michaels Andrew D.
Published: April 2012

Objectives

We sought to examine the contemporary use of thrombectomy during primary percutaneous coronary intervention (PCI) in the United States.

Background

Adjunctive thrombectomy during primary PCI for patients with ST‐segment elevation myocardial infarction (STEMI) has demonstrated mixed results. While earlier studies showed either unfavorable or neutral effects with rheolytic thrombectomy, recent clinical trials have shown benefits with manual or rheolytic thrombectomy when compared to PCI alone.

Methods

We analyzed data from 122,449 patients undergoing primary PCI for STEMI from 1,181 centers reported to the CathPCI Registry® between July 2009 and December 2010. We used logistic regression analysis to examine factors associated with the use of manual and rheolytic thrombectomy.

Results

Thrombectomy was performed in 23,195 patients (18.9%): 22,404 (18.3%) had manual thrombectomy and 791 (0.6%) had rheolytic thrombectomy. The use of manual thrombectomy increased over time (P < 0.05). The use of rheolytic thrombectomy did not change. There was significant variation in the use of thrombectomy across hospitals. The strongest predictors of manual versus no thrombectomy included TIMI 0/1 flow (odds ratio 1.69), younger age (OR 0.90 per 10 year increase), saphenous vein graft (OR 2.22), glycoprotein IIb/IIIa inhibitor (OR 1.34), single‐vessel disease (OR 1.13), and year of admission (OR 1.20 per year; all P < 0.001). The strongest predictor of manual versus rheolytic thrombectomy was year of admission (OR 1.23, P < 0.001).

Conclusions

Our data show that thrombectomy is performed infrequently in the US during primary PCI for STEMI. There is significant variation in the use of thrombectomy across US hospitals. © 2012 Wiley Periodicals, Inc.
Antegrade percutaneous valve implantation for mitral ring dysfunction, a challenging case
Authors: Petronio Anna , Giannini Cristina , De Carlo Marco , Guarracino Fabio
Published: April 2012

The operative risk for reoperation of degenerated bioprosthetic valves or failing mitral‐valve annuloplasty is higher compared with the risks for first isolated native valve repair or replacement (Astor et al., Eur Heart J 2008;29:2382–2387). In the presence of comorbidities, these risks increase exponentially. The recent introduction of transcatheter valve implantation opened new perspectives for the treatment of patients at very high surgical risk. We report a percutaneous mitral valve (MV) implantation using a transatrial approach within a MV ring using the Edwars Sapien XT valve. © 2012 Wiley Periodicals, Inc.
Chronic renal artery dissection with aneurysm formation treated by stent implantation with coil embolization with detailed intravascular ultrasound evaluation
Authors: Muroya Takahiro , Koga Seiji , Maemura Koji
Published: April 2012

Treatment options for chronic renal artery dissection, which is a rare cause of renal artery stenosis and renovascular hypertension, such as medical management, percutaneous intervention, and open surgical repair remain controversial. We describe a 55‐year‐old man with a chronic dissecting aneurysm of a renal artery complicated with renovascular hypertension that was initially diagnosed by computed tomography angiography, evaluated by intravascular ultrasound, and treated by stent implantation with coil embolization.© 2012 Wiley Periodicals, Inc.
Revascularization of unprotected left main coronary artery disease: Strategy selection and systematic risk assessment
Authors: Palmerini Tullio , Alessi Laura , Dangas George
Published: April 2012

Refinement of interventional techniques, adjunctive pharmacological therapy, and the introduction of drug eluting stents have fostered new interest for the percutaneous treatment of unprotected left main coronary artery (ULMCA) stenosis. Several observational registries, some randomized controlled trials and several meta‐analyses have consistently shown no difference in mortality and myocardial infarction between percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery in patients with ULMCA stenosis, but a higher rate of target vessel revascularization in patients treated with PCI. As a consequence, PCI of ULMCA stenosis has been upgraded to class IIa or IIb indication in the current European or American College of Cardiology/American Heart Association practice guidelines. Although these results are promising, they do not still represent enough evidence for extending PCI of ULMCA stenosis to current clinical practice. The EXCEL trial will address the value of PCI in relation to CABG for the treatment of ULMCA stenosis in more than 2000 patients. A major breakthrough of the SYNTAX trial has been the demonstration of an interaction between the coronary complexity and the revascularization strategy, suggesting that optimal risk stratification is a key element when deciding the best strategy of revascularization in this high‐risk group of patients. Multidisciplinary team approach remains essential to provide a balanced information to the patient and to offer the beast treatment option. © 2012 Wiley Periodicals, Inc.
Product Regions of Multi Component Rectification
Authors: Vogelpohl Alfons
Published: April 2012

Die Kenntnis der erreichbaren Produktbereiche bei der Rektifikation von Vielstoffgemischen ist von großer Bedeutung bei der Auslegung von Rektifikationskolonnen. Auf der Grundlage der reversiblen Rektifikation wird eine allgemeingültige Methode zur Bestimmung der möglichen Produktbereiche und des minimalen Rücklaufverhältnisses angegeben, die sowohl für azeotrope Gemische als auch Gemische mit beliebig vielen Komponenten gültig ist.
Metastatic basal cell carcinoma in the era of hedgehog signaling pathway inhibitors
Authors: Weiss Glen J. , Korn Ronald L.
Published: April 2012

BACKGROUND:

Inhibition of the hedgehog signaling pathway (HHSP) for the treatment of locally advanced basal cell carcinoma (BCC) and metastatic BCC (mBCC) has produced promising results. Typically, mBCC is not taken into consideration during the workup of a patient with multifocal metastatic disease who has a history of BCC. The objective of the current review, in which the authors evaluated the time from the first BCC diagnosis to metastasis, location of disease, and radiographic features, was to contribute to the general knowledge and awareness among providers, patients, and support groups about mBCC and to provide an outlook for the future of treatments for mBCC. A literature review on mBCC and a review of records from patients with mBCC who presented to Virginia G. Piper Cancer Center Clinical Trials (an oncology clinical trials center) were conducted. The clinical and radiographic findings of 22 patients with mBCC who were evaluated at that center from the initiation of smoothened (SMO) antagonist trials were analyzed along with a review of BCC epidemiology and pathogenesis, the HHSP, and current and future treatments for this rare presentation of the most common malignancy. The results indicated that, in the last 5 years, there has been a plethora of new agents targeting SMO, a key component of the HHSP that, for the majority of patients with mBCC, may be a good match for targeting tumor genetic vulnerability. Like with other targeted therapy for uncommon malignancies, such as chronic myelogenous leukemia and gastrointestinal stromal tumors, the authors anticipate that there will be clinical development of next‐generation HHSP inhibitors to combat mBCCs that are nonresponsive to or progress on current SMO antagonists. Cancer 2012. © 2012 American Cancer Society.
Clinical significance of gastritis cystica profunda and its association with Epstein‐Barr virus in gastric cancer
Authors: Choi Min‐Gew , Jeong Ji Yun , Kim Kyoung‐Mee , Bae Jae Moon , Noh Jae Hyung , Sohn Tae Sung , Kim Sung
Published: April 2012

BACKGROUND:

Gastritis cystica profunda (GCP) is a relatively rare disorder characterized by hyperplastic and cystic down growth of gastric glands into the submucosa. In the current study, the authors attempted to clarify the clinical and pathologic features of GCP in patients with gastric cancer.

METHODS:

The records of 10,728 patients with gastric cancer who underwent gastric cancer surgery were reviewed. The clinicopathologic features of patients who had GCP (n = 161) were compared with the features of patients without GCP (n = 10,567). In situ hybridization to determine Epstein‐Barr virus (EBV) positivity was performed in cancer tissues from patients with (n = 119) and without (n = 503) GCP.

RESULTS:

GCP was associated significantly with older age, male gender, proximal tumor location, differentiated histology and Lauren intestinal type compared with non‐GCP. GCP also was present more frequently in remnant and multiple gastric cancers. Patients who had GCP presented with earlier tumor stages in terms of depth of invasion and lymph node metastasis, and they had less lymphatic and perineural invasion than patients without GCP; however, the presence of GCP was not an independent prognostic factor. The EBV‐positive rate was significantly higher in the GCP group (31.1%) than in the non‐GCP group (5.8%).

CONCLUSIONS:

Patients with gastric cancer who had GCP had clinicopathologic features that differed from the features observed in patients without GCP. GCP was associated significantly with EBV‐positive gastric cancers, and its possible role as a premalignant lesion needs to be clarified. Cancer 2012. © 2012 American Cancer Society.