bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of patients with low back pain: a survey of French chiropractors
Authors: Debarle Michel , Aigron Rémi , Depernet Laure , Guillemard Amandine , Véron Thomas , Leboeuf-Yde Charlotte
Published: March 2014

Background

Little is known about the level of consensus within the French chiropractic profession regarding management of clinical issues. A previous Swedish study showed that chiropractors agreed relatively well on the management strategy for nine low back pain scenarios. We wished to investigate whether those findings could be reproduced among French chiropractors.

Objectives

1. To assess the level of consensus among French chiropractors regarding management strategies for nine different scenarios of low back pain. 2. To assess whether the management choices of the French chiropractors appeared reasonable for the low back pain scenarios. 3. To compare French management patterns with those described in the previous survey of Swedish chiropractors.

Method

A postal questionnaire was sent to a randomly selected sample of 167 French chiropractors in 2009. The questionnaire described a 40-year old man with low back pain, and presented nine hypothetical short-term outcome scenarios and six possible management strategies. For each of the nine scenarios, participants were asked to choose the management strategy that they would recommend. The percentages of respondents choosing the different management strategies were identified for each scenario. Appropriateness of the chosen management strategy was assessed using predetermined “best practice” for each scenario. Consensus was arbitrarily defined as “moderate” when 50- 69% of respondents agreed on the same management choice for a scenario, and “excellent” when 70% or more provided the same answer.

Results

Excellent consensus was achieved for only one scenario, and moderate consensus for two scenarios. For five of the nine scenarios, the most common answers were in agreement with the “best practice” management strategies. Consensus between the French and Swedish responses on the most appropriate management was seen in five of the nine scenarios and these were all in agreement with the expected answer.

Conclusion

There was reasonable consensus among the French chiropractors in their choice of treatment strategy for low back pain and choices were generally in line with “best practice”. The differences in response between the French and Swedish chiropractors suggest that cultural and/or educational differences influence the conceptual framework within which chiropractors practice.
Sex- and season-dependent differences in telomere length and telomerase activity in the leaves of ash and willow
Authors: Mu Ying , Ren Lan-fang , Xun Zhi-li , Zhang Dan-dan , Song Han , Lu Hai , Li Feng-lan , Liu Di
Published: March 2014

Telomeres and telomerase have important biological functions and can protect chromosome ends. In this study, sex- and season-dependent changes in telomere length and telomerase activity in ash and willow were analyzed. A statistical analysis showed that the telomere lengths of male and female trees differed significantly (P < 0.05). In ash, the telomere lengths of female trees were shorter than those of male trees. In willow, the telomere lengths of female trees were longer than those of male trees. During the annual developmental cycle, the telomere lengths of male and female ash and willow increased from April to May (P < 0.05), remained stable from May to August (P > 0.05), and decreased significantly in September and October (P < 0.05). Additionally, telomerase activities could be detected in both male and female ash and willow trees from April to October. Our results show that the telomere lengths changed according to season and sex in ash and willow. Telomere length did not have a direct positive correlation with telomerase activity.
Patients with community acquired pneumonia admitted to European intensive care units: an epidemiological survey of the GenOSept cohort
Authors: Walden Andrew P , Clarke Geraldine M , McKechnie Stuart , Hutton Paula , Gordon Anthony C , Rello Jordi , Chiche Jean-Daniel , Stueber Frank , Garrard Christopher S , Hinds Charles J
Published: April 2014

Introduction

Community acquired pneumonia (CAP) is the most common infectious reason for admission to the Intensive Care Unit (ICU). The GenOSept study was designed to determine genetic influences on sepsis outcome. Phenotypic data was recorded using a robust clinical database allowing a contemporary analysis of the clinical characteristics, microbiology, outcomes and independent risk factors in patients with severe CAP admitted to ICUs across Europe.

Methods

Kaplan-Meier analysis was used to determine mortality rates. A Cox Proportional Hazards (PH) model was used to identify variables independently associated with 28-day and six-month mortality.

Results

Data from 1166 patients admitted to 102 centres across 17 countries was extracted. Median age was 64 years, 62% were male. Mortality rate at 28 days was 17%, rising to 27% at six months. Streptococcus pneumoniae was the commonest organism isolated (28% of cases) with no organism identified in 36%. Independent risk factors associated with an increased risk of death at six months included APACHE II score (hazard ratio, HR, 1.03; confidence interval, CI, 1.01-1.05), bilateral pulmonary infiltrates (HR1.44; CI 1.11-1.87) and ventilator support (HR 3.04; CI 1.64-5.62). Haematocrit, pH and urine volume on day one were all associated with a worse outcome.

Conclusions

The mortality rate in patients with severe CAP admitted to European ICUs was 27% at six months. Streptococcus pneumoniae was the commonest organism isolated. In many cases the infecting organism was not identified. Ventilator support, the presence of diffuse pulmonary infiltrates, lower haematocrit, urine volume and pH on admission were independent predictors of a worse outcome.
Violence risk assessment as a medical intervention: ethical tensions
Authors: Roychowdhury Ashimesh , Adshead Gwen
Published: April 2014

Risk assessment differs from other medical interventions in that the welfare of the patient is not the immediate object of the intervention. However, improving the risk assessment process may reduce the chance of risk assessment itself being unjust. We explore the ethical arguments in relation to risk assessment as a medical intervention, drawing analogies, where applicable, with ethical arguments raised by general medical investigations. The article concludes by supporting the structured professional judgement approach as a method of risk assessment that is most consistent with the respect for principles of medical ethics. Recommendations are made for the future direction of risk assessment indicated by ethical theory.
Walk for Me
Authors: Moore Madison
Published: March 2014

In this article, Madison Moore discusses the work of choreographer Trajal Harrell, which critically crosses the downtown pedestrianism of postmodern dance with the high-fashion spectacle of uptown Harlem drag balls. By considering the social contexts of these apparently disparate scenes, Moore highlights the stylistic affinities and cultural clashes between postmodern dance and voguing in Harrell’s sweeping cycle of dance pieces titled Twenty Looks or Paris Is Burning at the Judson Church.
Interaction among Saccharomyces cerevisiae pheromone receptors during endocytosis
Authors: Chang Chien-I , Schandel Kimberly A. , Jenness Duane D.
Published: March 2014

This study investigates endocytosis of Saccharomyces cerevisiae α-factor receptor and the role that receptor oligomerization plays in this process. α-factor receptor contains signal sequences in the cytoplasmic C-terminal domain that are essential for ligand-mediated endocytosis. In an endocytosis complementation assay, we found that oligomeric complexes of the receptor undergo ligand-mediated endocytosis when the α-factor binding site and the endocytosis signal sequences are located in different receptors. Both in vitro and in vivo assays suggested that ligand-induced conformational changes in one Ste2 subunit do not affect neighboring subunits. Therefore, recognition of the endocytosis signal sequence and recognition of the ligand-induced conformational change are likely to be two independent events.
A new mouse model of Canavan leukodystrophy displays hearing impairment due to central nervous system dysmyelination
Authors: Carpinelli Marina R , Voss Anne K , Manning Michael G , Perera Ashwyn A , Cooray Anne A , Kile Benjamin T , Burt Rachel A
Published: March 2014

Canavan disease is a leukodystrophy caused by mutations in the ASPA gene. This gene encodes the enzyme that converts N-acetylaspartate into acetate and aspartic acid. In Canavan disease spongiform encephalopathy of the brain causes progressive mental retardation, motor deficit and death. We have isolated a mouse with a novel ethylnitrosourea-induced mutation in Aspa. This mutant, named deaf14, carries a c.516T>A mutation that is predicted to cause a p.Y172X protein truncation. No full-length ASPA protein is produced in deaf14 brain and there is extensive spongy degeneration. Interestingly, we found that deaf14 mice have an attenuated startle in response to loud noise. The first auditory brainstem response peak has normal latency and amplitude but peaks II, III, IV and V have increased latency and decreased amplitude in deaf14 mice. Our work reveals a hitherto unappreciated pathology in a mouse model of Canavan disease, implying that auditory brainstem response testing could be used in diagnosis and to monitor the progression of this disease.
Basal body proteins regulate Notch signaling via endosomal trafficking
Authors: Leitch Carmen C. , Lodh Sukanya , Prieto-Echagüe Victoria , Badano Jose L. , Zaghloul Norann A.
Published: March 2014

Proteins associated with primary cilia and basal bodies mediate numerous signaling pathways, but little is known about their role in Notch signaling. Here we report that loss of Bardet-Biedl syndrome proteins, BBS1 or BBS4, produced increased Notch-directed transcription in a zebrafish reporter line and in human cell lines. Pathway overactivation was accompanied by reduced localization of Notch receptor at both the plasma membrane and the cilium. In Drosophila mutants, overactivation of Notch can result from receptor accumulation in endosomes and recent studies implicate ciliary proteins in endosomal trafficking, suggesting a possible mechanism by which overactivation occurs in BBS mutants. Consistent with this, we observed genetic interaction of BBS1/4 with the ESCRT gene TSG101 and accumulation of receptor in late endosomes, reduced endosomal recycling and reduced receptor degradation in lysosomes. We observed similar defects with disruption of BBS3. Loss of another basal body protein, ALMS1, also enhanced Notch activation and accumulation of receptor in late endosomes, but did not disrupt recycling. These findings suggest a role for these proteins in regulation of Notch via endosomal trafficking of the receptor.
GEF-H1 functions in apical constriction and cell intercalations and is essential for vertebrate neural tube closure
Authors: Itoh Keiji , Ossipova Olga , Sokol Sergei Y.
Published: March 2014

Rho family GTPases regulate many morphogenetic processes during vertebrate development including neural tube closure. Here we report a function for GEF-H1/Lfc/ArhGEF2, a RhoA-specific guanine nucleotide exchange factor, in neurulation in Xenopus embryos. Morpholino-mediated depletion of GEF-H1 resulted in severe neural tube defects, which were rescued by GEF-H1 RNA. Lineage tracing of GEF-H1 morphants at different developmental stages revealed abnormal cell intercalation and apical constriction, suggesting that GEF-H1 regulates these cell behaviors. Molecular marker analysis documented defects in Myosin II light chain (MLC) phosphorylation, Rab11 and F-actin accumulation in GEF-H1-depleted cells. In gain-of-function studies, overexpressed GEF-H1 triggered Rho-associated kinase-dependent ectopic apical constriction, marked by apical accumulation of phospho-MLC, γ-tubulin and F-actin in superficial ectoderm, and stimulated apical protrusive activity of deep ectoderm cells. Together, our observations demonstrate novel functions of GEF-H1 in morphogenetic movements leading to neural tube closure.
Synthesis of Novel Nontoxic Yellow Pigments: Sr2Ce1−xTbxO4
Authors: Raj Athira K V , Rao P Prabhakar , Sameera S , James Vineetha , Divya S
Published: March 2014

Novel yellow inorganic pigments Sr2Ce1−xTbxO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by the conventional solid-state route. The structure and morphology of the developed pigments were characterized using powder X-ray diffractometer (XRD) and scanning electron microscope (SEM), respectively. A UV–vis–NIR spectrophotometer was employed to investigate the optical properties, and the color characteristics were evaluated by CIE 1976 L*a*b* color scales. The Tb substitution extends the absorption edge to longer wavelengths by introducing an additional electronic level between the valence and conduction bands. Consequently, the prepared pigments exhibit various yellow colors by fine tuning of the band gap from 3.03 (white) to 2.52 eV (reddish-greenish yellow). Doping of Tb into Sr2CeO4 enhances the NIR reflectance at 1100 nm from 87% to 91%. The coloring performance of the synthesized pigments was investigated in the polymer matrix for plastic coloring applications. The exhibition of high NIR reflectance with comparable color properties of these pigments makes them potential candidates as cool colorants to reduce the heat build-up.
Alteration of DNAzyme Activity by Silver Ion
Authors: Urata Shoma , Miyahata Takaaki , Matsuura Hirotaka , Kitamura Yusuke , Ihara Toshihiro
Published: March 2014

The thermal stability of the parallel motif triple helix DNA containing CG.CH+ base triplets is improved by silver ions. The N3 protons of cytosines on the third strand are replaced by the ions to form CG.CAg+, which are stable regardless of the pH values. The activity of the DNAzyme that binds its substrate DNA through triple helix formation was examined in the presence of silver ions. The DNAzyme activity was retained even at neutral pH with the assistance of silver ions.
Distortions in the International Migrant Labor Market: Evidence from Filipino Migration and Wage Responses to Destination Country Economic Shocks
Authors: McKenzie David , Theoharides Caroline , Yang Dean
Published: April 2014

We use an original panel dataset of migrant departures from the Philippines to identify the responsiveness of migrant numbers and wages to GDP shocks in destination countries. We find a large, significant response of migrant numbers to GDP shocks at destination, but no significant wage response. This is consistent with binding minimum wages for migrant labor. This result implies that labor market imperfections that make international migration attractive also make migrant flows more sensitive to global business cycles. Difference-in-differences analysis of a minimum wage change for maids confirms that minimum wages bind and demand is price sensitive without these distortions. (JEL F22, J31, J38, J61, O15)
In vitro characterization of 6S RNA release-defective mutants uncovers features of pRNA-dependent release from RNA polymerase in E. coli
Authors: Oviedo Ovando Mariana , Shephard Lindsay , Unrau Peter J.
Published: March 2014

6S RNA is a noncoding RNA that inhibits bacterial transcription by sequestering RNA polymerase holoenzyme (Eσ70) in low-nutrient conditions. This transcriptional block can be relieved by the synthesis of a short product RNA (pRNA) using the 6S RNA as a template. Here, we selected a range of 6S RNA release-defective mutants from a high diversity in vitro pool. Studying the release-defective variant R9-33 uncovered complex interactions between three regions of the 6S RNA. As expected, mutating the transcriptional start site (TSS) slowed and partially inhibited release. Surprisingly, additional mutations near the TSS were found that rescued this effect. Likewise, three mutations in the top strand of the large open bubble (LOB) could considerably slow release but were rescued by the addition of upstream mutations found between a highly conserved “-35” motif and the LOB. Combining the three top strand LOB mutations with mutations near the TSS, however, was particularly effective at preventing release, and this effect could be further enhanced by inclusion of the upstream mutations. Overexpressing R9-33 and a series of milder release-defective mutants in Escherichia coli resulted in a delayed entry into exponential phase together with a decrease in cell survival that correlated well with the severity of the in vitro phenotypes. The complex crosstalk observed between distinct regions of the 6S RNA supports a scrunching type model of 6S RNA release, where at least three regions of the 6S RNA must interact with Eσ70 in a cooperative manner so as to ensure effective pRNA-dependent release.
The use of infliximab in X-linked agammaglobulinaemia associated enteropathy
Authors: Davey PT , Tan CJ , Gardiner K
Published: March 2014

Granulomatous small bowel enteropathy is an unusual presentation associated with X-linked agammaglobulinaemia. We present a rare case of this condition that was further complicated by an enterocutaneous fistula and report our experience managing this condition successfully with infliximab, which has not been documented in the literature previously.
Sporadic bilateral synchronous multicentric papillary renal cell carcinoma masquerading as bilateral multifocal pyelonephritis
Authors: Karthikeyan VS , Dorairajan LN , Kumar S , Vijayakumar AR , Ramesh A , Ganesh Rajesh N , Halanaik D , Gupta A
Published: March 2014

Pyelonephritis is defined as an inflammation of the kidney and renal pelvis. The diagnosis is usually clinical. Acute multifocal bacterial nephritis is a rare form of pyelonephritis that is more severe and sepsis is more common. We report a patient who presented with fever and right-sided abdominal pain associated with right flank tenderness, suggesting right acute pyelonephritis. Bilateral multifocal pyelonephritis was diagnosed on ultrasonography, radionuclide renal scintigraphy and computed tomography. However, owing to non-resolution of symptoms, a biopsy was performed, which showed bilateral papillary renal cell carcinoma (PRCC). PRCC is known to exhibit multicentricity. To our knowledge, a case of bilateral multicentric PRCC masquerading as bilateral multifocal pyelonephritis has not been reported in the English literature. This case highlights the need to be vigilant while treating patients with focal lesions of the kidney as an inflammatory condition lest a malignancy should be missed.
The influence of FDG PET-CT on the detection of extrahepatic disease in patients being considered for resection of colorectal liver metastasis
Authors: Lake ES , Wadhwani S , Subar D , Kauser A , Harris C , Chang D , Lapsia S
Published: March 2014

Introduction

The aim of this study was to evaluate the influence of flurodeoxyglucose positron emission tomography computed tomography (FDG PET-CT), as an adjunct to conventional CT staging, in the detection of extrahepatic disease in patients with potentially resectable colorectal liver metastasis.

Methods

Overall, 133 consecutive patients with colorectal liver metastases staged with CT and PET-CT referred to the East Lancashire regional hepatobiliary multidisciplinary team over a two-year period were included in this study. Abnormal findings on PET-CT were correlated with follow-up imaging and/or histology. All imaging was reviewed by specialist hepatobiliary radiologists for the presence/absence of extrahepatic disease. The influence of the PET-CT findings was categorised for each patient in relation to operability and other significant findings.

Results

PET-CT had a major impact on staging of extra hepatic disease in 20% of patients, in comparison with the initial CT. Six per cent of patients were upstaged from operable CT findings to inoperable findings on PET-CT because of the discovery of inoperable occult extrahepatic disease. Five per cent had operable local regional nodal disease detected on PET-CT. A further 3% had premalignant colorectal lesions detected on PET-CT. Six per cent of patients were downstaged from indeterminate or suspected inoperable CT findings to operable findings on PET-CT.

Conclusions

The use of PET-CT in this setting may prevent futile operations, guide the resection of local regional nodal disease and downstage a number of patients thought to have extrahepatic disease on conventional imaging. This study has shown similar results to other recent studies and supports the use of PET-CT as a necessary staging modality in patients with potentially resectable colorectal liver metastases.
Troubling the family: coming out as lesbian and gay
Authors: Nordqvist Petra , Smart Carol
Published: March 2014

Legal and social attitudes towards gay men and lesbians have altered considerably in latter years and yet recent research suggests that ‘coming out’ as lesbian and gay may remain a troubled business, especially in one’s own family. Exploring this theme, we situate gay and lesbian identities in wider family networks and explore how gay men and women negotiate family relationships at particular and significant moments in their lives, such as weddings and childbirth. In doing so, we draw together three qualitative datasets: the Mass Observation Project and two interview studies exploring same-sex commitment ceremonies and lesbian motherhood, all conducted in Britain in the 2000s. We investigate how hostility in families may shape the ‘coming out’ process and also how a culture of silence plays an important role in maintaining family relationships. We suggest that to understand what it means to ‘come out’, we need to examine the meaning of non-heterosexuality in the context of kin relationality and situate gay and lesbian lives in webs of intergenerational relationships.
Social Approach and Emotion Recognition in Fragile X Syndrome
Authors: Williams Tracey A. , Porter Melanie A. , Langdon Robyn
Published: March 2014

Evidence is emerging that individuals with Fragile X syndrome (FXS) display emotion recognition deficits, which may contribute to their significant social difficulties. The current study investigated the emotion recognition abilities, and social approachability judgments, of FXS individuals when processing emotional stimuli. Relative to chronological age- (CA-) and mental age- (MA-) matched controls, the FXS group performed significantly more poorly on the emotion recognition tasks, and displayed a bias towards detecting negative emotions. Moreover, after controlling for emotion recognition deficits, the FXS group displayed significantly reduced ratings of social approachability. These findings suggest that a social anxiety pattern, rather than poor socioemotional processing, may best explain the social avoidance observed in FXS.
Child Behavior Problems and Parental Well-Being in Families of Children With Autism: The Mediating Role of Mindfulness and Acceptance
Authors: Jones Leah , Hastings Richard Patrick , Totsika Vasiliki , Keane Lisa , Rhule Neisha
Published: March 2014

Few research studies have explored how the level of a child's behavior problems leads to psychological distress in parents of children with autism. The authors explored whether psychological acceptance and mindfulness mediated this relationship between child behavior and parental distress. Seventy-one mothers and 39 fathers of children with autism participated, by reporting on their own positive and negative psychological well-being and their child's behavior problems. Psychological acceptance was found to act as a mediator variable for maternal anxiety, depression, and stress, and for paternal depression. General mindfulness and mindful parenting had significant mediation effects for maternal anxiety, depression, and stress. These results contribute to evidence that mindfulness and acceptance may be important parental psychological processes, with implications for parent support.
The Use of Mouse Models of Breast Cancer and Quantitative Image Analysis to Evaluate Hormone Receptor Antigenicity after Microwave-assisted Formalin Fixation
Authors: Engelberg Jesse A. , Giberson Richard T. , Young Lawrence J.T. , Hubbard Neil E. , Cardiff Robert D.
Published: March 2014

Microwave methods of fixation can dramatically shorten fixation times while preserving tissue structure; however, it remains unclear if adequate tissue antigenicity is preserved. To assess and validate antigenicity, robust quantitative methods and animal disease models are needed. We used two mouse mammary models of human breast cancer to evaluate microwave-assisted and standard 24-hr formalin fixation. The mouse models expressed four antigens prognostic for breast cancer outcome: estrogen receptor, progesterone receptor, Ki67, and human epidermal growth factor receptor 2. Using pathologist evaluation and novel methods of quantitative image analysis, we measured and compared the quality of antigen preservation, percentage of positive cells, and line plots of cell intensity. Visual evaluations by pathologists established that the amounts and patterns of staining were similar in tissues fixed by the different methods. The results of the quantitative image analysis provided a fine-grained evaluation, demonstrating that tissue antigenicity is preserved in tissues fixed using microwave methods. Evaluation of the results demonstrated that a 1-hr, 150-W fixation is better than a 45-min, 150-W fixation followed by a 15-min, 650-W fixation. The results demonstrated that microwave-assisted formalin fixation can standardize fixation times to 1 hr and produce immunohistochemistry that is in every way commensurate with longer conventional fixation methods.
On Formal Cause
Authors: McLuhan Eric
Published: March 2014

Aristotle identified four causes of natural phenomena: formal, efficient, material, and final. The efficient cause is the maker and the making process. The material cause is the matter involved (solder, bricks . . .). The final cause is the result or object itself. Formal cause, however, remains enigmatic. Long thought to be “plans” or “blueprints,” it is found to be situational or environmental cause and to operate in many fields, particularly the arts, and the study of media and their ecologies.
A Man for All Media: Orson Welles as Media Ecologist/Medium Theorist
Authors: Heyer Paul
Published: March 2014

This article contends that Orson Welles’ (1915–1985) success in a variety of media results in part from his astute understanding of the audio and visual potential of these media. Parallels are drawn between his intuitive grasp of media as an artistic practitioner and the academic tradition of media ecology and medium theory. Welles’ “media sense” is seen as complemented by his skill at adaptation—the ability to alter source material in ways that innovatively utilize the full sensory possibilities of theater, radio, and cinema. Examples discussed include theatrical productions, such as Marlowe’s Faustus, the Les Misérables radio broadcast, his first feature film, Citizen Kane, and his last completed film, F For Fake.
The “Domestic Goddess”: Postfeminist Representation in the Televisual Kitchen: A Media Ecological Analysis of Nigella Bites
Authors: Greene Carlnita P.
Published: March 2014

Sparking controversy among British and American audiences, Nigella Bites is certainly not your typical cooking show. However, by viewing the show from a media ecological standpoint, we see that it is an example of how television as an “information system” can change our views about gender roles. The show’s appeal is categorically one with a postfeminist perspective that is an assertive form of femininity merged with a feminist consciousness. Therefore, it calls into question the extent to which we perform gender roles and provides a more complex outlook of women’s roles than some of the one-dimensional televisual representations of the past.
Emergent Surgical Pulmonary Embolectomy in a Pregnant Woman: Case Report and Literature Review
Authors: Saeed Giovanni , Möller Michael , Neuzner Jörg , Gradaus Rainer , Stein Werner , Langebrake Uwe , Dimpfl Thomas , Matin Meradjoddin , Peivandi Ali
Published: April 2014

Acute pulmonary embolism is a leading cause of death during pregnancy and delivery in the United States. We describe the case of a 25-year-old woman who presented in car-diogenic shock in week 38 of her first pregnancy. After the emergent cesarean delivery of a healthy male neonate, the mother underwent immediate surgical pulmonary embolec-tomy. We confirmed the diagnosis of pulmonary embolism intraoperatively by means of transesophageal echocardiography and removed large clots from the patient's pulmonary arteries. Mother and child were doing well, 27 months later. In addition to presenting our patient's case, we discuss the other relevant reports and the options for treating massive pulmonary embolism during pregnancy.
Endovascular Repair as a Bridge to Surgical Repair of an Aortobronchial Fistula Complicating Chronic Residual Aortic Dissection
Authors: Matos Jesus M. , de la Cruz Kim I. , Ouzounian Maral , Preventza Ourania , LeMaire Scott A. , Coselli Joseph S.
Published: April 2014

Endovascular and open surgical repair have been used in patients with descending thoracic aortic dissection; however, the appropriate treatment is debated. We describe the case of a 60-year-old woman who had a symptomatic, chronic, residual, descending thoracic aortic dissection that was complicated by an aortobronchial fistula. She underwent emergent thoracic endovascular stent-grafting but remained symptomatic. Computed tomographic angiograms showed a contained rupture into the lower lobe of the left lung. The patient underwent definitive surgery to remove the stents, reconstruct the aorta, and resect the nonviable lung tissue. The remainder of her postoperative course was uneventful, and she was discharged from the hospital 13 days after the 2nd operation. Results of genetic testing confirmed an earlier presumptive diagnosis of Marfan syndrome.

In an emergency, the best initial option for patients with a complicated descending thoracic aortic dissection might be thoracic endovascular aortic repair, which could serve as a bridge to definitive open repair.
Life-Saving Systemic Thrombolysis in a Patient with Massive Pulmonary Embolism and a Recent Hemorrhagic Cerebrovascular Accident
Authors: Bottinor Wendy , Turlington Jeremy , Raza Syed , Roberts Charlotte S. , Malhotra Rajiv , Jovin Ion S. , Abbate Antonio
Published: April 2014

Massive pulmonary embolism is associated with mortality rates exceeding 50%. Current practice guidelines include the immediate administration of thrombolytic therapy in the absence of contraindications. However, thrombolysis for pulmonary embolism is said to be absolutely contraindicated in the presence of recent hemorrhagic stroke and other conditions. The current contraindications to thrombolytic therapy have been extrapolated from data on acute coronary syndrome and are not specific for venous thromboembolic disease. Some investigators have proposed that the current contraindications be viewed as relative, rather than absolute, in cases of high-risk pulmonary embolism.

We present the case of a 60-year-old woman in whom massive pulmonary embolism led to cardiac arrest with pulseless electrical activity. Eight weeks earlier, she had sustained a hemorrhagic cerebrovascular accident—a classic absolute contraindication to thrombolytic therapy. Despite this practice guideline, we administered tissue plasminogen activator systemically in order to save the patient's life. This therapy did not evoke intracranial bleeding, and the patient was eventually discharged from the hospital. Until guidelines specific to venous thromboembolic disease are developed, we think that the current contraindications to thrombolysis should be considered on an individual basis in patients who are at high risk of death from massive pulmonary embolism.
Percutaneous Retrograde Transfemoral Closure of Mitral Paravalvular Leak in 3 Patients without Construction of an Arteriovenous Wire Loop
Authors: Kilic Teoman , Sahin Tayfun , Ural Ertan
Published: April 2014

Percutaneous closure of paravalvular leaks has emerged as an alternative to repeated surgeries. Different percutaneous techniques and various devices have been used, off-label, for paravalvular leak closure. For mitral leaks, antegrade transseptal, retrograde transfemoral, and retrograde transapical techniques have been developed. In the antegrade transseptal approach, an arteriovenous guidewire loop is often created to advance the delivery sheath. In retrograde transfemoral closure, the wire in the left atrium is usually snared after transseptal puncture, to pull it from the femoral vein. The delivery sheath and closure device will subsequently be deployed from the left atrium. Each of these procedures takes time, is costly, and increases the risk of complications.

We present the cases of 3 patients in whom we closed mitral paravalvular leaks by means of a retrograde transfemoral approach, with use of an Amplatzer™ Duct Occluder II device and without the construction of an arteriovenous wire loop. We think that this approach can be very useful in a specific group of patients—reducing costs, fluoroscopy times, and complications related to transseptal puncture and construction of an arteriovenous wire loop. In our institution, this reported technique is routinely used for mitral paravalvular leak closure.
Takotsubo Cardiomyopathy as a Sequela of Elective Direct-Current Cardioversion for Atrial Fibrillation
Authors: Siegfried Jonathan S. , Bhusri Satjit , Guttenplan Nils , Coplan Neil L.
Published: April 2014

In takotsubo cardiomyopathy, the clinical appearance is that of an acute myocardial infarction in the absence of obstructive coronary artery disease, with apical ballooning of the left ventricle. The condition is usually precipitated by a stressful physical or psychological experience. The mechanism is unknown but is thought to be related to catecholamine excess. We present the case of a 67-year-old woman who experienced cardiogenic shock caused by takotsubo cardiomyopathy, immediately after undergoing elective direct-current cardio-version for atrial fibrillation. After a course complicated by left ventricular failure, cardiogenic shock, and ventricular tachycardia, she made a complete clinical and echocardiographic recovery. In addition to this case, we discuss the possible direct effect of cardioversion in takotsubo cardiomyopathy.
Acute Coronary Thrombosis and Multiple Coronary Aneurysms in a 22-Year-Old Man with the Human Immunodeficiency Virus
Authors: Ayers Jennifer , Mandell Ryan , Sanghvi Kintur , Aboujaoude Rania , Hsi David H.
Published: April 2014

The human immunodeficiency virus (HIV) can cause diverse cardiovascular complications. In HIV patients on antiretroviral therapy, the prevalence of myocardial infarction has steadily increased over the years. Young patients who are naïve to antiretroviral therapy and who experience coronary events are not well represented in the medical literature. We describe the case of a 22-year-old man, infected with HIV for 4 years and never treated with antiretroviral therapy, who emergently presented with a non-ST-segment-elevation myocardial infarction. Coronary angiograms revealed thrombosis and multiple coronary artery aneurysms; however, no areas of atherosclerotic stenosis were apparent. He was successfully treated with coronary stenting, antiplatelet therapy, and anticoagulation. Nine months after the initial presentation, he exhibited excellent exercise capacity, and no ischemia was evident. We discuss the various therapeutic approaches in this case.
Staged Balloon Aortic Valvuloplasty before Standard Aortic Valve Replacement in Selected Patients with Severe Aortic Valve Stenosis
Authors: Altarabsheh Salah Eldien , Greason Kevin L. , Schaff Hartzell V. , Suri Rakesh M. , Li Zhuo , Mathew Verghese , Joyce Lyle D. , Park Soon J. , Dearani Joseph A.
Published: April 2014

This study evaluated preoperative balloon aortic valvuloplasty (BAV) as a technique to decrease aortic valve replacement (AVR) risk in patients who have severe symptomatic aortic valve stenosis with substantial comorbidity.

We report the outcomes of 18 high-risk patients who received BAV within 180 days before AVR from November 1993 through December 2011. Their median age was 78 years (range, 51–93 yr), and there were 11 men (61%). The pre-BAV median calculated Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) was 18.3% (range, 9.4%–50.7%). Preoperative left ventricular ejection fraction measured a median of 0.23 (range, 0.05–0.68), and the median aortic valve area index was 0.4 cm2/m2 (range, 0.2–0.7 cm2/m2). The median interval from BAV to AVR was 28 days (range, 1–155 d). There were no strokes or deaths after BAV; however, 4 patients (22%) required mechanical circulatory support, 3 (17%) required femoral artery operation, and 1 (6%) developed severe aortic valve regurgitation. After BAV, the median STS PROM fell to 9.1% (range, 2.6%–25.7%) (compared with pre-BAV, P <0.001). Echocardiography before AVR showed that the median left ventricular ejection fraction had improved to 0.35 (range, 0.15–0.66), and the aortic valve area index to 0.5 cm2/m2 (range, 0.3–0.7 cm2/m2) (compared with pre-BAV, both P <0.05). All patients received AVR. Operative death occurred in 2 patients (11%), and combined operative death and morbidity in 7 patients (39%).

Staged BAV substantially reduces the operative risk associated with AVR in selected patients.
Cardiac Magnetic Resonance Imaging for the Investigation of Cardiovascular Disorders. Part 2: Emerging Applications
Authors: Goenka Ajit H. , Wang Hui , Flamm Scott D.
Published: April 2014

Cardiac magnetic resonance imaging has emerged as a robust noninvasive technique for the investigation of cardiovascular disorders. The coming-of-age of cardiac magnetic resonance—and especially its widening span of applications—has generated both excitement and uncertainty in regard to its potential clinical use and its role vis-à-vis conventional imaging techniques. The purpose of this evidence-based review is to discuss some of these issues by highlighting the current (Part 1, previously published) and emerging (Part 2) applications of cardiac magnetic resonance. Familiarity with the versatile uses of cardiac magnetic resonance will facilitate its wider clinical acceptance for improving the management of patients with cardiovascular disorders.
Evaluation of Fifty-Two Cavitation Erosion Tunnel Tests
Authors: Meged Y.
Published: March 2014

In the framework of the International Cavitation Erosion Test (ICET), 52 cavitation erosion tests were performed in cavitation tunnels. These tests were performed by six labs in eight test groups, on five metallic reference materials. The subjects studied are: cavitation erosion trail, test specimen, calculation of mean depth of erosion (MDE), values, cavitation erosion–time curves, measuring accuracy, variation of test results, and material classification. In all these categories, deficiencies were detected such as: lack of data on eroded areas, water flow velocity at the specimen’s surface, and an evaluation misconception based on the assumption that the eroded area is equal to the specimen area. These deficiencies cast heavy doubt on the reliability of the test results. Only eighteen tests were found relevant for obtaining quantitative data. Recommendations are made to overcome some of the detected deficiencies and to improve both reliability and applicability of future cavitation erosion tunnel test results.
Local Strains That Lead to the Thermo-mechanical Fatigue of Thick-walled Pressure Vessels
Authors: Okrajni Jerzy , Twardawa Mariusz
Published: March 2014

This paper discusses the issue of the modeling of strains and stresses resulting from the heating and cooling processes of components in power plants. The main purpose of this work was to determine the mechanical behavior of power plant components operating under mechanical and thermal loading. The finite element method has been used to evaluate the temperature and stress changes in components as a function of time. The temperature fields in the components of power plants are dependent, apart from other relevant parameters, on variable heat-transfer conditions between these components and the fluid medium (which may change its state) flowing inside them. For this reason an evaluation of the temperature field and the consequent stress fields requires the consideration of heat-transfer coefficients as time-dependent variables, which in turn calls for suitable techniques for the determination of appropriate values for these coefficients. Methodology that combines computer modeling of the temperature fields with temperature measurements performed at selected points of the pipelines may be used in this case. It is readily apparent from the stress-versus-time graphs that under unsteady operating conditions the components analyzed in this study, especially in the case of boiler restarts, may operate with transient thermal stresses that sometimes reach values higher than a yield point. Consequently, a thermo-mechanical fatigue process takes place in the materials of the components in question. Local stress-strain diagrams for the selected points of the plant components describe this kind of fatigue. These diagrams characterize the intensity of the process and are necessary when the fatigue life is predicted. Such diagrams are part of thermo-mechanical fatigue life prediction methods. The problem of their description is important in the development of a new design methodology for highly reliable pressure vessels.
The Design of a Laboratory Test Machine to Simulate Thermal Fatigue in Hot-Working Tool Steels
Authors: Torres-Garza A. , Quiñones-Salinas M. A. , Barragan-Serna I. A. , Mercado-Solis R. D.
Published: March 2014

A laboratory-scale thermal fatigue simulator has been designed, constructed, and commissioned by the authors for studying thermal fatigue of hot-working tool steels by means of rapid alternated heating and cooling. The basic design features, construction characteristics, and test capabilities of the thermal fatigue simulator are presented in this paper. Thermal fatigue simulations were run on hardened and tempered AISI H13 hot-working tool steel specimens in time-control with heating and cooling times of 15 and 10 s, respectively, and a total number of 500 and 2000 thermal fatigue cycles. The experimental results have demonstrated that the simulator is capable of producing thermal fatigue cracks with the same characteristics of those seen in real industrial hot-working tools. Based on their size and the extent of propagation, a clear distinction between primary, secondary, and craze cracks could be established at the failed surfaces. Additionally, a thermo-mechanical finite element model of the first 10 thermal fatigue cycles was developed to compute the transient temperatures, stresses, and strains distributions within the test specimen during thermal cycling. Based on the model results, the low cycle fatigue life was estimated using the Coffin–Manson equation, which relates the number of cycles to crack initiation to the plastic strain range per cycle. The experimentally obtained fatigue lives were appreciably shorter than the calculated ones, arguably due to surface roughness and oxidation effects.
Aspirin Allergy Desensitization in Cerebrovascular Disease
Authors: Zuckerman Scott L , Seder David B , Tsujiura Crystiana , Cushing Deborah , Gallup Holly , Mocco J , Hanel Richard A , Ecker Robert D
Published: March 2014

Aspirin (ASA) is the mainstay of treatment in cerebrovascular and systemic vascular disease. ASA hypersensitivity can pose a challenge to achieving optimum medical management prior to and after neurointerventional treatment. Desensitization to ASA is well described in the allergy and cardiovascular literature, but there are no similar discussions specific to neurointervention. The purpose of our study was to describe our experience with ASA hypersensitivity management and review the relevant literature.

Two cases of patients with symptomatic cerebrovascular disease requiring neurointervention who were successfully desensitized to their ASA hypersensitivity prior to treatment are described. The subsequent literature is reviewed. Several ASA desensitization protocols exist and have been proven to successfully treat ASA hypersensitivity and allow for ASA therapy to be safely initiated. We describe several previously published protocols.

ASA desensitization is a safe and simple way to manage ASA hypersensitivity. We provide comprehensive management guidelines for the neurointerventionalist engaging in ASA desensitization.
Sole Stenting with Large Cell Stents for Very Small Ruptured Intracranial Aneurysms
Authors: Kim Young-Joon , Ko Jung HO
Published: March 2014

A flow-diverting stent such as the Pipeline embolization device (PED, ev3 Endovascular, Plymouth, MN, USA) and Silk flow-diverting stent (Balt Extrusion, Montmorency, France) offers an acceptable alternative for the treatment of difficult aneurysms according to their morphologies, including giant, wide-necked, fusiform, and blister types. However, complications arising from the use of these stents have frequently been reported including several cases of branch artery occlusion and delayed occlusion of the stented parent vessel shortly after antiplatelet medications were discontinued, highlighting the potential need for long-term antiplatelet therapy, and disastrous bleeding complications in unruptured aneurysm. In addition, these microcell stents are difficult to use in distal aneurysms located over the ICA bifurcation and basilar tip because of the stiffness of the device, and perforating vessel occlusion is more likely to occur due to the characteristics of the stent. Before the era of flow-diverting microcell stents, large cell intracranial stents like the Neuroform stent (Boston Scientific/Target Therapeutic, Fremont, CA, USA) and Enterprise stent (Cordis Neurovascular, Miami, FL, USA) without coiling were used to provide flow-diverting effects for complex intracranial aneurysms. Sole stenting has been used even in cases of ruptured aneurysm, with patients on different antiplatelet medications. However, no single endovascular institute has embraced sole stenting using large cell intracranial stents as a systemized treatment for ruptured intracranial aneurysms. Here we designed this study to evaluate the possibility of safely treating very small aneurysms using one or two stents without coiling during the period of subarachnoid hemorrhage (SAH). This retrospective study was conducted with eight patients who had rupture of very small intracranial aneurysms (less than 3 mm in size). All were treated using the Neuroform and the Enterprise stents; there was single stenting in five, in-stent telescopic stenting in two, and Y-configured stenting in one. The angiographic results with clinical outcomes were collected and analyzed. Complete aneurysm obliteration was observed in three cases, and size reduction or stable angiographic findings was found in five cases on the last follow-up angiography. No growing aneurysm or rebleeding was found on any follow-up angiography. Thromboembolic complications were found in one patient. It is difficult to make conclusions on the long-term efficacy of this technique with such a small number of cases, however sole stenting with a large cell intracranial stent for the treatment of very small aneurysms may be used safely as an alternative treatment even during an episode of SAH.