bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of the micro-injection moulding process: effect of the thermo-rheological status on the morphology
Authors: Nguyen-Chung T , Löser C , Jüttner G , Pham T , Obadal M , Gehde M
Published: October 2011

The software package Moldflow Plastics Insights was used to simulate the filling of a micro-cavity by considering precise material data and accurate boundary conditions. Experiments were carried out on an accurately controlled micro-injection moulding machine (formicaPlast) for providing important parameters to verify the simulation results and improve the accuracy of the simulation. Based on the relationship between the cavity pressure and the mould-filling ratio, the heat transfer coefficients can be appropriately determined for different process conditions. Finally, the transient thermo-rheological results were analysed with regard to their influence on the morphology of semi-crystalline (PP) micro-injection moulded parts, which not only give rise to the mechanisms of the morphological formation but also verify the quality of the simulation results.
Modeling of Hysteresis and Backlash for a Smart Fin with a Piezoelectric Actuator
Authors: Trabia M.B. , Yim W. , Saadeh M.
Published: October 2011

This work presents a dynamic model of a smart fin that is activated by a piezoelectric bimorph actuator, which is made by bonding two MFCs. The actuator is completely enclosed within the fin. Earlier research has indicated that the use of a linear model for the fin dynamics does not fully describe the fin. This work presents a more realistic approach to this problem by incorporating additional components into the model. Therefore, a proportional damping matrix is introduced. It is also observed that experimental results exhibit hysteresis and backlash. A Bouc-Wen hysteresis model, combined with four backlash operators, is proposed. These backlash operators are used to model the observed saturation and the non-symmetry of the response. HFSGA is used to identify the optimal set of parameters for the damping matrix constants, the Bouc-Wen model, and the backlash operators. One input case is considered for training the genetic algorithm. The results show that proposed model can predict the hysteresis of the smart fin-actuator system under various operational conditions.
Creating Public Science With the From Earth to the Universe Project
Authors: Arcand Kimberly K. , Watzke Megan
Published: October 2011

The authors propose formalizing an entity for the sciences and science communication that is akin to public art in the humanities: public science. Public science might be able to play a role in enhancing and supporting society’s relationship with science by embedding science content into everyday experiences. The authors examine one project and its potential impact in public science. From Earth to the Universe has placed astronomy images in “nontraditional” science communication venues such as parks and airports. From Earth to the Universe could serve as a model for a type of public science, an attempt to make science accessible to nonexperts in public spaces.
Numerical evaluation of the transient response due to non-smooth rolling contact using an arbitrary Lagrangian–Eulerian formulation
Authors: Draganis A , Larsson F , Ekberg A
Published: October 2011

A theoretical and numerical framework to evaluate rolling contact using an arbitrary Lagrangian–Eulerian (ALE) formulation is established. A finite element formulation is implemented featuring cylinder–plate contact, automated mesh refinement, non-reflecting boundary conditions, and the ability to incorporate surface roughness through user-defined gap functions. Presented examples include rolling contact on a corrugated surface and negotiation of a surface discontinuity. Sensitivity and validation analyses are presented and show the model to be robust and the trends in parametric responses to be reasonable as compared to results in literature. Owing to the ALE formulation, the model can be kept very compact and the computational demands very modest.
Δ12-prostaglandin J3, an omega-3 fatty acid–derived metabolite, selectively ablates leukemia stem cells in mice
Authors: Hegde Shailaja , Kaushal Naveen , Ravindra Kodihalli C. , Chiaro Christopher , Hafer Kelsey T. , Gandhi Ujjawal H. , Thompson Jerry T. , van den Heuvel John P. , Kennett Mary J. , Hankey Pamela , Paulson Robert F. , Prabhu K. Sandeep
Published: October 2011

Targeting cancer stem cells is of paramount importance in successfully preventing cancer relapse. Recently, in silico screening of public gene-expression datasets identified cyclooxygenase-derived cyclopentenone prostaglandins (CyPGs) as likely agents to target malignant stem cells. We show here that Δ12-PGJ3, a novel and naturally produced CyPG from the dietary fish-oil ω-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA; 20:5) alleviates the development of leukemia in 2 well-studied murine models of leukemia. IP administration of Δ12-PGJ3 to mice infected with Friend erythroleukemia virus or those expressing the chronic myelogenous leukemia oncoprotein BCR-ABL in the hematopoietic stem cell pool completely restored normal hematologic parameters, splenic histology, and enhanced survival. More importantly, Δ12-PGJ3 selectively targeted leukemia stem cells (LSCs) for apoptosis in the spleen and BM. This treatment completely eradicated LSCs in vivo, as demonstrated by the inability of donor cells from treated mice to cause leukemia in secondary transplantations. Given the potency of ω-3 polyunsaturated fatty acid–derived CyPGs and the well-known refractoriness of LSCs to currently used clinical agents, Δ12-PGJ3 may represent a new chemotherapeutic for leukemia that targets LSCs.
Presence of FLT3-ITD and high BAALC expression are independent prognostic markers in childhood acute myeloid leukemia
Authors: Staffas Anna , Kanduri Meena , Hovland Randi , Rosenquist Richard , Ommen Hans Beier , Abrahamsson Jonas , Forestier Erik , Jahnukainen Kirsi , Jónsson Ólafur G. , Zeller Bernward , Palle Josefine , Lönnerholm Gudmar , Hasle Henrik , Palmqvist Lars , Ehrencrona Hans ,   on behalf of the Nordic Society of Pediatric Hematology and Oncology (NOPHO)
Published: October 2011

Mutation status of FLT3, NPM1, CEBPA, and WT1 genes and gene expression levels of ERG, MN1, BAALC, FLT3, and WT1 have been identified as possible prognostic markers in acute myeloid leukemia (AML). We have performed a thorough prognostic evaluation of these genetic markers in patients with pediatric AML enrolled in the Nordic Society of Pediatric Hematology and Oncology (NOPHO) 1993 or NOPHO 2004 protocols. Mutation status and expression levels were analyzed in 185 and 149 patients, respectively. Presence of FLT3-internal tandem duplication (ITD) was associated with significantly inferior event-free survival (EFS), whereas presence of an NPM1 mutation in the absence of FLT3-ITD correlated with significantly improved EFS. Furthermore, high levels of ERG and BAALC transcripts were associated with inferior EFS. No significant correlation with survival was seen for mutations in CEBPA and WT1 or with gene expression levels of MN1, FLT3, and WT1. In multivariate analysis, the presence of FLT3-ITD and high BAALC expression were identified as independent prognostic markers of inferior EFS. We conclude that analysis of the mutational status of FLT3 and NPM1 at diagnosis is important for prognostic stratification of patients with pediatric AML and that determination of the BAALC gene expression level can add valuable information.
Quantitative trait mapping reveals a regulatory axis involving peroxisome proliferator-activated receptors, PRDM16, transforming growth factor-β2 and FLT3 in hematopoiesis
Authors: Avagyan Serine , Aguilo Francesca , Kamezaki Kenjiro , Snoeck Hans-Willem
Published: October 2011

Hematopoiesis is the process whereby BM HSCs renew to maintain their number or to differentiate into committed progenitors to generate all blood cells. One approach to gain mechanistic insight into this complex process is the investigation of quantitative genetic variation in hematopoietic function among inbred mouse strains. We previously showed that TGF-β2 is a genetically determined positive regulator of hematopoiesis. In the presence of unknown nonprotein serum factors TGF-β2, but not TGF-β1 or -β3, enhances progenitor proliferation in vitro, an effect that is subject to mouse strain-dependent variation mapping to a locus on chr.4, Tb2r1. TGF-β2–deficient mice show hematopoietic defects, demonstrating the physiologic role of this cytokine. Here, we show that TGF-β2 specifically and predominantly cell autonomously enhances signaling by FLT3 in vitro and in vivo. A coding polymorphism in Prdm16 (PR-domain-containing 16) underlies Tb2r1 and differentially regulates transcriptional activity of peroxisome proliferator-activated receptor-γ (PPARγ), identifying lipid PPAR ligands as the serum factors required for regulation of FLT3 signaling by TGF-β2. We furthermore show that PPARγ agonists play a FLT3-dependent role in stress responses of progenitor cells. These observations identify a novel regulatory axis that includes PPARs, Prdm16, and TGF-β2 in hematopoiesis.
Prospective Molecular Marker Analyses of EGFR and KRAS From a Randomized, Placebo-Controlled Study of Erlotinib Maintenance Therapy in Advanced Non–Small-Cell Lung Cancer
Authors: Brugger Wolfram , Triller Nadja , Blasinska-Morawiec Maria , Curescu Stefan , Sakalauskas Raimundas , Manikhas Georgy Moiseevich , Mazieres Julien , Whittom Renaud , Ward Carol , Mayne Karen , Trunzer Kerstin , Cappuzzo Federico
Published: October 2011

Purpose

The phase III, randomized, placebo-controlled Sequential Tarceva in Unresectable NSCLC (SATURN; BO18192) study found that erlotinib maintenance therapy extended progression-free survival (PFS) and overall survival in patients with advanced non–small-cell lung cancer (NSCLC) who had nonprogressive disease following first-line platinum-doublet chemotherapy. This study included prospective analysis of the prognostic and predictive value of several biomarkers.

Patients and Methods

Mandatory diagnostic tumor specimens were collected before initiating first-line chemotherapy and were tested for epidermal growth factor receptor (EGFR) protein expression by using immunohistochemistry (IHC), EGFR gene copy number by using fluorescent in situ hybridization (FISH), and EGFR and KRAS mutations by using DNA sequencing. An EGFR CA simple sequence repeat in intron 1 (CA-SSR1) polymorphism was evaluated in blood.

Results

All 889 randomly assigned patients provided tumor samples. EGFR IHC, EGFR FISH, KRAS mutation, and EGFR CA-SSR1 repeat length status were not predictive for erlotinib efficacy. A profound predictive effect on PFS of erlotinib relative to placebo was observed in the EGFR mutation–positive subgroup (hazard ratio [HR], 0.10; P < .001). Significant PFS benefits were also observed with erlotinib in the wild-type EGFR subgroup (HR, 0.78; P = .0185). KRAS mutation status was a significant negative prognostic factor for PFS.

Conclusion

This large prospective biomarker study found that patients with activating EGFR mutations derive the greatest PFS benefit from erlotinib maintenance therapy. No other biomarkers were predictive for outcomes with erlotinib, although the study was not powered for clinical outcomes in biomarker subgroups. EGFR IHC–positive KRAS mutations were prognostic for reduced PFS. The study demonstrated the feasibility of prospective tissue collection for biomarker analyses in NSCLC.
Second Cancer Risk After Chemotherapy for Hodgkin's Lymphoma: A Collaborative British Cohort Study
Authors: Swerdlow Anthony J. , Higgins Craig D. , Smith Paul , Cunningham David , Hancock Barry W. , Horwich Alan , Hoskin Peter J. , Lister T. Andrew , Radford John A. , Rohatiner Ama Z.S. , Linch David C.
Published: October 2011

Purpose

We investigated the long-term risk of second primary malignancy after chemotherapy for Hodgkin's lymphoma (HL) in a much larger cohort than any yet published, to our knowledge.

Patients and Methods

We followed 5,798 patients with HL treated with chemotherapy in Britain from 1963 to 2001—of whom 3,432 also received radiotherapy—to assess second primary malignancy risks compared with general population-based expectations.

Results

Second malignancies occurred in 459 cohort members. Relative risk (RR) of second cancer was raised after chemotherapy alone (RR, 2.0; 95% CI, 1.7 to 2.4) but was much lower than after combined modalities (RR, 3.9; 95% CI, 3.5 to 4.4). After chemotherapy alone, there were significantly raised risks of lung cancer, non-HL, and leukemia, each contributing approximately equal absolute excess risk. After combined modalities, there were raised risks of these and several other cancers. Second cancer risk peaked 5 to 9 years after chemotherapy alone, but it remained raised for 25 years and longer after combined modalities. Risk was raised after each common chemotherapy regimen except, based on limited numbers and follow-up, adriamycin, bleomycin, vinblastine, and dacarbazine. The age and time-course relations of lung cancer differed between chemotherapy alone and combined modalities.

Conclusion

Although chemotherapy alone leads to raised risk of second malignancy, this risk is lower and affects fewer anatomic sites than that after combined modalities, and it is slight if at all after 15 years follow-up. The mechanism of lung cancer etiology may differ between chemotherapy and radiotherapy.
Cisplatin, Irinotecan, and Bevacizumab for Untreated Extensive-Stage Small-Cell Lung Cancer: CALGB 30306, a Phase II Study
Authors: Ready Neal E. , Dudek Arkadiusz Z. , Pang Herbert H. , Hodgson Lydia D. , Graziano Stephen L. , Green Mark R. , Vokes Everett E.
Published: October 2011

Purpose

The efficacy of cisplatin, irinotecan, and bevacizumab was evaluated in patients with extensive-stage small-cell lung cancer (ES-SCLC).

Patients and Methods

Patients with ES-SCLC received cisplatin 30 mg/m2 and irinotecan 65 mg/m2 on days 1 and 8 plus bevacizumab 15 mg/kg on day 1 every 21 days for six cycles on this phase II study. The primary end point was to differentiate between 50% and 65% 12-month survival rates.

Results

Seventy-two patients were enrolled between March 2005 and April 2006; four patients canceled, and four were ineligible. Grade 3 or 4 toxicities included neutropenia (25%), all electrolyte (23%), diarrhea (16%), thrombocytopenia (10%), fatigue (10%), nausea (10%), hypertension (9%), anemia (9%), infection (7%), vascular access thrombosis (2%), stroke (2%), and bowel perforation (1%). Three deaths (5%) occurred on therapy as a result of pneumonitis (n = 1), stroke (n =1), and heart failure (n = 1). Complete response, partial response, and stable disease occurred in three (5%), 45 (70%), and 11 patients (17%), respectively. Progressive disease occurred in one patient (2%). Overall response rate was 75%. Median progression-free survival (PFS) was 7.0 months (95% CI, 6.4 to 8.4 months). Median overall survival (OS) was 11.6 months (95% CI, 10.5 to 15.1 months). Hypertension ≥ grade 1 was associated with improved OS after adjusting for performance status (PS) and age (hazard ratio [HR], 0.55; 95% CI, 0.31 to 0.97; P = .04). Lower vascular endothelial growth factor levels correlated with worse PFS after adjusting for age and PS (HR, 0.90; 95% CI, 0.83 to 0.99; P = .03).

Conclusion

PFS and OS times were higher compared with US trials in ES-SCLC with the same chemotherapy. However, the primary end point of the trial was not met. Hypertension was associated with improved survival after adjusting for age and PS.
Prediction of Early Death After Induction Therapy for Newly Diagnosed Acute Myeloid Leukemia With Pretreatment Risk Scores: A Novel Paradigm for Treatment Assignment
Authors: Walter Roland B. , Othus Megan , Borthakur Gautam , Ravandi Farhad , Cortes Jorge E. , Pierce Sherry A. , Appelbaum Frederick R. , Kantarjian Hagop A. , Estey Elihu H.
Published: October 2011

Purpose

Outcome in acute myeloid leukemia (AML) worsens with age, at least in part because of higher treatment-related mortality (TRM) in older patients. Eligibility for intensive AML treatment protocols is therefore typically based on age as the implied principal predictor of TRM, although other health- and disease-related factors modulate this age effect.

Patients and Methods

We empirically defined TRM using estimated weekly hazard rates in 3,365 adults of all ages administered intensive chemotherapy for newly diagnosed AML. We used the area under the receiver operator characteristic curve (AUC) to quantify the relative effects of age and other covariates on TRM in a subset of 2,238 patients. In this approach, an AUC of 1.0 denotes perfect prediction, whereas an AUC of 0.5 is analogous to a coin flip.

Results

Regardless of age, risk of death declined once 4 weeks had elapsed from treatment start, suggesting that patients who die during this time comprise a qualitatively distinct group. Performance status (PS) and age were the most important individual predictors of TRM (AUCs of 0.75 and 0.65, respectively). However, multicomponent models were significantly more accurate in predicting TRM (AUC of 0.83) than PS or age alone. Elimination of age from such multicomponent models only minimally affected their predictive accuracy (AUC of 0.82).

Conclusion

These data suggest that age is primarily a surrogate for other covariates, which themselves add significantly to predictive accuracy, thus challenging the wisdom of using age as primary or sole basis for assignment of intensive, curative intent treatment in AML.
Randomized Placebo-Controlled Phase II Trial of Perifosine Plus Capecitabine As Second- or Third-Line Therapy in Patients With Metastatic Colorectal Cancer
Authors: Bendell Johanna C. , Nemunaitis John , Vukelja Sasha J. , Hagenstad Christopher , Campos Luis T. , Hermann Robert C. , Sportelli Peter , Gardner Lesa , Richards Donald A.
Published: October 2011

Purpose

In a multicenter, double-blind phase II trial, we compared the efficacy and safety of perifosine plus capecitabine (P-CAP) with placebo plus capecitabine (CAP) in patients with metastatic colorectal cancer (mCRC) who had progressed after as many as two prior therapies.

Patients and Methods

Patients (n = 38) not previously treated with capecitabine received P-CAP (perifosine 50 mg orally once daily, days 1 to 21 and CAP 825 mg/m2 orally twice daily, days 1 to 14) or CAP (825 mg/m2 orally twice daily, days 1 to 14) in 21-day cycles until disease progression. The primary end point was time to progression (TTP). Secondary end points included overall survival (OS), overall response rate (ORR), safety, and tolerability.

Results

Twenty patients were randomly assigned to P-CAP and 18 to CAP. Median TTP (27.5 v 10.1 weeks; P < .001) and median OS (17.7 v 7.6 months; P = .0052) were improved in patients receiving P-CAP versus CAP. ORR was 20% v 7% in the P-CAP and CAP groups, respectively, and one patient in the P-CAP group had a complete response. A subset analysis of fluorouracil-refractory patients showed a median TTP of 17.6 v 9.0 weeks (P < .001) and median OS of 15.1 v 6.5 months (P = .0061). Toxicities, including diarrhea, nausea, fatigue, and hand-foot syndrome, were manageable.

Conclusion

P-CAP showed promising clinical activity compared with CAP in previously treated patients with mCRC. A phase III trial is underway comparing P-CAP with CAP in patients with refractory mCRC.
Mortality by Stage for Right- Versus Left-Sided Colon Cancer: Analysis of Surveillance, Epidemiology, and End Results–Medicare Data
Authors: Weiss Jennifer M. , Pfau Patrick R. , O'Connor Erin S. , King Jonathan , LoConte Noelle , Kennedy Gregory , Smith Maureen A.
Published: October 2011

Purpose

Recent studies have reported increased mortality for right-sided colon cancers but had limited adjustment for patient characteristics and conflicting results by stage. We examined the relationship between colon cancer location (right- v left-side) and 5-year mortality by stage.

Patients and Methods

We identified Medicare beneficiaries from 1992 to 2005 with American Joint Commission on Cancer stages I to III primary adenocarcinoma of the colon who underwent surgery for curative intent through Surveillance, Epidemiology, and End Results (SEER) –Medicare data. Adjusted hazard ratios (HRs) and 95% CIs for predictors of all-cause 5-year mortality were obtained by using Cox proportional hazards regression.

Results

Of 53,801 patients, 67% had right-sided colon cancer. Patients with right-sided cancer were more likely to be older, to be women, to be diagnosed with a more advanced stage, and to have more poorly differentiated tumors. Adjusted Cox regression showed no significant difference in mortality between right- and left-sided cancers for all stages combined (HR, 1.01; 95% CI, 0.98 to 1.04; P = .598) or for stage I cancers (HR, 0.95; 95% CI, 0.88 to 1.03; P = .211). Stage II right-sided cancers had lower mortality than left-sided cancers (HR, 0.92; 95% CI, 0.87 to 0.97; P = .001), and stage III right-sided cancers had higher mortality (HR, 1.12; 95% CI, 1.06 to 1.18; P < .001).

Conclusion

When analysis was adjusted for multiple patient, disease, comorbidity, and treatment variables, no overall difference in 5-year mortality was seen between right- and left-sided colon cancers. However, within stage II disease, right-sided cancers had lower mortality; within stage III, right-sided cancers had higher mortality.
Human Papillomavirus and Rising Oropharyngeal Cancer Incidence in the United States
Authors: Chaturvedi Anil K. , Engels Eric A. , Pfeiffer Ruth M. , Hernandez Brenda Y. , Xiao Weihong , Kim Esther , Jiang Bo , Goodman Marc T. , Sibug-Saber Maria , Cozen Wendy , Liu Lihua , Lynch Charles F. , Wentzensen Nicolas , Jordan Richard C. , Altekruse Sean , Anderson William F. , Rosenberg Philip S. , Gillison Maura L.
Published: October 2011

Purpose

Recent increases in incidence and survival of oropharyngeal cancers in the United States have been attributed to human papillomavirus (HPV) infection, but empirical evidence is lacking.

Patients and Methods

HPV status was determined for all 271 oropharyngeal cancers (1984-2004) collected by the three population-based cancer registries in the Surveillance, Epidemiology, and End Results (SEER) Residual Tissue Repositories Program by using polymerase chain reaction and genotyping (Inno-LiPA), HPV16 viral load, and HPV16 mRNA expression. Trends in HPV prevalence across four calendar periods were estimated by using logistic regression. Observed HPV prevalence was reweighted to all oropharyngeal cancers within the cancer registries to account for nonrandom selection and to calculate incidence trends. Survival of HPV-positive and HPV-negative patients was compared by using Kaplan-Meier and multivariable Cox regression analyses.

Results

HPV prevalence in oropharyngeal cancers significantly increased over calendar time regardless of HPV detection assay (P trend < .05). For example, HPV prevalence by Inno-LiPA increased from 16.3% during 1984 to 1989 to 71.7% during 2000 to 2004. Median survival was significantly longer for HPV-positive than for HPV-negative patients (131 v 20 months; log-rank P < .001; adjusted hazard ratio, 0.31; 95% CI, 0.21 to 0.46). Survival significantly increased across calendar periods for HPV-positive (P = .003) but not for HPV-negative patients (P = .18). Population-level incidence of HPV-positive oropharyngeal cancers increased by 225% (95% CI, 208% to 242%) from 1988 to 2004 (from 0.8 per 100,000 to 2.6 per 100,000), and incidence for HPV-negative cancers declined by 50% (95% CI, 47% to 53%; from 2.0 per 100,000 to 1.0 per 100,000). If recent incidence trends continue, the annual number of HPV-positive oropharyngeal cancers is expected to surpass the annual number of cervical cancers by the year 2020.

Conclusion

Increases in the population-level incidence and survival of oropharyngeal cancers in the United States since 1984 are caused by HPV infection.
Evaluation of Epidural Analgesic Paste Components in Lumbar Decompressive Surgery
Authors: Diaz Roberto Jose , Myles S. Terry , Hurlbert R. John
Published: October 2011

BACKGROUND:

Adjuncts for pain management in lumbar decompressive surgery are needed to reduce narcotic consumption and promote early mobility.

OBJECTIVE:

To evaluate the efficacy and active components of a previously described epidural analgesic paste in controlling postoperative pain and facilitating early discharge from hospital after lumbar decompressive surgery.

METHODS:

A randomized double-blind controlled trial was conducted. Two-hundred and one patients were randomized to 1 of 4 analgesic epidural pastes at the time of lumbar spinal surgery: combination paste (morphine + methylprednisolone), steroid paste (methylprednisolone alone), morphine paste (morphine alone), or placebo. The primary outcome measures used were analgesic consumption and the McGill Pain Questionnaire (MPQ). Secondary outcome measures were: modified American Spinal Cord Injury Association (ASIA) score, Short Form 36 General Health Survey (SF-36), Aberdeen Pain Index (ABPI), time to ambulation and time to discharge from hospital.

RESULTS:

Administration of combination and steroid paste, but not morphine paste, resulted in a statistically significant reduction in mean pain rating index (PRI) and present pain intensity (PPI) components of the MPQ in the first 3 days after surgery. Likewise, postoperative in-patient narcotic analgesic consumption was reduced in the combination paste and steroid paste group, but not in the morphine paste group. No difference in time to ambulation or discharge, SF-36 scores, ABPI scores, or neurologic recovery was observed.

CONCLUSION:

An analgesic paste containing methylprednisolone acetate is effective at reducing postoperative pain after lumbar decompressive surgery. Mixing effective doses of morphine sulfate in the paste abrogates the expected analgesic effects of epidural morphine.
Merci Retrievers as Access Adjuncts for Reperfusion Catheters
Authors: Hui Ferdinand K. , Hussain Muhammad S. , Spiotta Alejandro , Bhalla Tarun , Toth Gabor , Moskowitz Shaye I. , Elgabaly Mohamed , Sivapatham Thinesh , Rasmussen Peter A.
Published: October 2011

BACKGROUND:

Expeditious, stable access in acute ischemic stroke is foundational for mechanical revascularization. Proximal vascular tortuosity and unfavorable anatomy may impede the access necessary for revascularization, particularly when large-caliber catheters are used. We describe an approach using the Merci retriever to gain stable catheter access for aspiration.

OBJECTIVE:

To assess the technical feasibility of using the Merci retriever system as an access adjunct in acute ischemic stroke and tortuous ophthalmic segment anatomy.

METHODS:

The acute ischemic stroke database was queried, and 3 patients presenting with acute ischemic stroke and tortuous proximal anatomy who were treated with mechanical thrombectomy and the Merci retriever as an access adjunct were identified. Patient charts and procedure reports were reviewed.

RESULTS:

In each of the patients, the ophthalmic segment of the internal carotid artery proved difficult to navigate. An appropriately sized Merci retriever was deployed in the M1 segment. Gentle tension on the retriever was applied, altering the angle at which the aspiration catheter navigated the ophthalmic segment, affording rapid access past the ophthalmic artery origin and into the target vessel. The 18 L microcatheter and retriever were withdrawn, followed by aspiration and clot maceration with the Penumbra aspiration system.

CONCLUSION:

Tortuous proximal anatomy may impede access to an occluded vessel. Use of tension on a deployed Merci retriever straightens the course of the wire, changing the angle that the aspiration catheter makes with the vessel. In the setting of unfavorable anatomy, this technique may be used to advance an aspiration catheter to the target lesion.
Implications of Spinopelvic Alignment for the Spine Surgeon
Authors: Mehta Vivek A. , Amin Anubhav , Omeis Ibrahim , Gokaslan Ziya L. , Gottfried Oren N.
Published: October 2011

The relation of the pelvis to the spine has previously been overlooked as a contributor to sagittal balance. However, it is now recognized that spinopelvic alignment is important to maintain an energy-efficient posture in normal and disease states. The pelvis is characterized by an important anatomic landmark, the pelvic incidence (PI). The PI does not change after adolescence, and it directly influences pelvic alignment, including the parameters of pelvic tilt (PT) and sacral slope (SS) (PI = PT 1 SS), overall sagittal spinal balance, and lumbar lordosis. In the setting of an elevated PI, the spineadapts with increased lumbar lordosis. To prevent or limit sagittal imbalance, the spine may also compensate with increased PT or pelvic retroversion to attempt to maintain anupright posture. Abnormal spinopelvic parameters contribute to multiple spinal conditions including isthmic spondylolysis, degenerative spondylolisthesis, deformity, and impact outcome after spinal fusion. Sagittal balance, pelvic incidence, and all spinopelvic parameters are easily and reliably measured on standing, full-spine (lateral) radiographs, and it is essential to accurately assess and measure these sagittal values to understand their potential role in the disease process, and to promote spinopelvic balance at surgery. In this article, we provide a comprehensive review of the literature regarding the implications of abnormal spinopelvic parameters and discuss surgical strategies for correction of sagittal balance. Additionally, the authors rate and critique the quality of the literature cited in a systematic review approach to give the reader an estimate of the veracity of the conclusions reached from these reports.
Comparison of the Diagnostic Utility of Electromyography, Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging in Idiopathic Carpal Tunnel Syndrome Determined by Clinical Findings
Authors: Deniz Fatih Ersay , Öksüz Erol , Sarikaya Bas‚ar , Kurt Semiha , Erkorkmaz Ünal , Ulusoy Hasan , Arslan Șule
Published: October 2011

Background:

Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome. It is sometimes difficult to diagnose, and a late diagnosis may result in permanent nerve damage. Electromyography (EMG), ultrasonography (US), magnetic resonance imaging (MRI), and computed tomography (CT) may be performed for the diagnosis. The diagnostic accuracy of these tests is well documented, but most of these studies accept EMG as the gold standard.

Objective:

To evaluate the diagnostic accuracy of EMG, MRI, CT, and US for the diagnosis of carpal tunnel syndrome with the use of clinical findings as the gold standard.

Methods:

Patients suspected to have CTS on presentation to the outpatient clinic were evaluated. The tests were performed after a detailed physical examination. Both wrists of the 69 patients in the study were investigated.

Results:

The diagnostic accuracies of all the tests were found to be sufficient. Although EMG seemed to have the highest sensitivity and specificity, there was no statistically significant difference between the tests.

Conclusion:

EMG or US could be used as the first-step test in most cases. If they are both available, EMG should be the first choice. They may be performed together when diagnosis is challenging. CT may especially be preferred for bone-related pathological conditions, whereas MRI may be preferred for soft tissue-related pathological conditions. Even though imaging studies have been proven to be powerful diagnostic tools for CTS, no conclusive information currently exists to support replacing EMG with imaging studies.
Comparative Evaluation of Percutaneous Retrogasserian Glycerol Rhizolysis and Radiofrequency Thermocoagulation Techniques in the Management of Trigeminal Neuralgia
Authors: Udupi Bidkar Prasanna , Chouhan Rajendra S. , Dash Hari H. , Bithal Parmod K. , Prabhakar Hemanshu
Published: October 2011

BACKGROUND:

Among the percutaneous procedures for the treatment of trigeminal neuralgia, percutaneous anhydrous glycerol rhizolysis (PRGR) and radiofrequency (RF) ablation of trigeminal neuralgia have stood the test of time.

OBJECTIVE:

A prospective study was conducted to compare PRGR and RF ablation techniques in patients with trigeminal neuralgia in terms of (1) efficacy of pain relief, (2) duration of pain relief and (3) side effects.

METHODS:

All patients presenting to our pain clinic for the first time for the treatment of trigeminal neuralgia were enrolled to receive either PRGR or RF ablation; the treatment was chosen by the patient. Demographic data, magnetic resonance imaging scan, relevant medical disease, amount of anhydrous glycerol, lesion temperature, and total duration of RF were noted. The presence or absence of cerebrospinal fluid egress, immediate pain relief, duration of pain-free period, need for repeat injection or additional peripheral nerve block, and recurrence of pain were also noted. The degree of pain relief was recorded every 3 months. Any complications during the procedure and side effects were also recorded.

RESULTS:

Seventy-nine patients underwent either PRGR (n = 40) or RF thermocoagulation (n = 39). A total of 23 patients (58.9%) in the PRGR group and 33 patients (84.6%) in the RF group experienced excellent pain relief. The mean duration of excellent pain relief in the PRGR and RF groups was comparable. By the end of the study period, 39.1% patients in the PRGR group and 51.5% patients in the RF group experienced recurrence of pain.

CONCLUSION:

Both PRGR and RF techniques can achieve acceptable pain relief with minimal side effects.
Risk Factors for Posttreatment Edema in Patients Treated With Stereotactic Radiosurgery for Meningiomas
Authors: Unger Keith R. , Lominska Christopher E. , Chanyasulkit June , Randolph-Jackson Pamela , White Robert L. , Aulisi Edward , Jacobson Jeffrey , Jean Walter , Gagnon Gregory J.
Published: October 2011

Background:

Peritumoral edema is a recognized complication following stereotactic radiosurgery (SRS).

Objective:

To evaluate the risk of posttreatment peritumoral edema following SRS for intracranial meningiomas and determine predictive factors.

Methods:

Between 2002 and 2008, 173 evaluable patients underwent CyberKnife or Gamma Knife SRS for meningiomas. Eighty-four patients (49%) had prior surgical resections, 13 patients had World Health Organization grade II (atypical) meningiomas, and 117 patients had a neurological deficit before SRS. Sixty-two tumors were in parasagittal, parafalcine, and convexity locations. The median tumor volume was 4.7 mL (range, 0.1–231.8 mL). The median prescribed dose and median prescribed biologically equivalent dose were 15 Gy (range, 9–40 Gy) and 67 Gy (range, 14–116 Gy), respectively. Ninety-seven patients were treated with single-fraction SRS, 74 received 2 to 5 fractions, and 2 received >5 fractions.

Results:

The median follow-up was 21.0 months. Thirteen patients (8%) developed symptomatic peritumoral edema, with a median onset time of 4.5 months (range, 0.2– 9.5 months). The 3-, 6-, 12-, and 24-month actuarial symptomatic edema rates were 2.9%, 4.9%, 7.7%, and 8.5%, respectively. The crude tumor control rate was 94%. On univariate analysis, large tumor volume (P = .01) and single-fraction SRS (P = .04) were predictive for development of posttreatment edema.

Conclusion:

SRS meningioma treatment demonstrated a low incidence of toxicity; however, large tumor volumes and single-fraction SRS treatment had an increased risk for posttreatment edema. Risk factors for edema should be considered in meningiomas treatment.
Carotid Endarterectomy With Primary Closure: Analysis of Outcomes and Review of the Literature
Authors: Zenonos Georgios , Lin Ning , Kim Albert , Kim Jeong Eun , Governale Lance , Friedlander Robert Max
Published: October 2011

Background:

Despite abundant published support of patch angioplasty during carotid endarterectomy (CEA), primary closure is still widely used. The reasons underlying the persistence of primary closure are not quite evident in the literature.

Objective:

To present our experience with primary closure in CEA, and provide a rationale for its persistent wide use.

Methods:

Medical records of all patients undergoing CEA by the senior author (R.F.) were retrospectively reviewed. Follow-up was supplemented with a telephone interview and completion of a structured questionnaire. A review of the current literature was performed.

Results:

From 1998 to 2010, the senior author performed 111 CEAs. Average cross-clamp time was 33 ± 11 minutes. Postoperative complications included 1 non– ST-elevation myocardial infarction and 2 strokes. No deaths, cranial-nerve deficits, or acute reocclusions were observed. After a mean follow-up of 64.6 months (7170.6 case-months), there were 3 contralateral strokes and 7 deaths. There were no ipsilateral strokes or restenoses >50%. Follow-up medication compliance was 94.6% for anti-platelet agents and 91.9% for statins. The outcomes of the current study were comparable to those of the available trials comparing patch angioplasty with primary closure. A careful evaluation of the literature revealed a number of reasons potentially explaining the persistent use of patch angioplasty.

Conclusion:

In conjunction with contemporary medical management, primary closure during CEA may yield results comparable or superior to patch angioplasty. Advantages of primary closure include shorter cross-clamp times and elimination of graft-specific complications.
Image-Guided Thoracoscopic Resection of Thoracic Dumbbell Nerve Sheath Tumors
Authors: Ghostine Samer , Vaynman Shoshanna , Schoeb James Scott , Cambron Helen , King Wesley A. , Samudrala Srinath , Johnson J. Patrick
Published: October 2011

BACKGROUND:

Surgical removal of dumbbell nerve sheath tumors (NSTs) remains challenging because these neoplasms occupy ≥ 2 spinal and extraspinal spaces. The presence of intraspinal extension, tumor dimension, and/or its location within the thoracic cavity have previously made the resection of these types of neoplasms difficult.

OBJECTIVE:

To describe the feasibility of performing minimally invasive thoracoscopic surgery, as facilitated by an image guidance system (IGS), to achieve gross total resection of select dumbbell NSTs located in the thoracic spine.

METHODS:

The 3 cases presented here contained small intraspinal or foraminal components. Preoperative symptoms included Horner syndrome and back and chest wall pain. We used IGS to help guide the complete thoracoscopic resection of select dumbbell NSTs, consisting of extradural, intraforaminal, and paravertebral tumor components, which previously would have been challenging with only a thoracoscopic approach.

RESULTS:

IGS provided continuous intraoperative anatomic orientation to achieve gross total resection in all 3 cases. All surgical and postsurgical outcomes were satisfactory; preoperative symptoms improved or resolved; and no adverse events were observed.

CONCLUSION:

Thoracic dumbbell NSTs that have small intraspinal or foraminal components could be resected thoracoscopically when facilitated by IGS. Image-guided thoracoscopic resection of such dumbbell tumors may not only improve the precision of resection, reduce recurrence, and avoid the need for spinal reconstruction but also obviate the need for more invasive or simultaneous posterior procedures. The IGS enhances the accuracy and safety of 2-dimensional thoracoscopic surgery and may reduce its learning curve.
Informal Taxation
Authors: Olken Benjamin A , Singhal Monica
Published: October 2011

Informal payments are a frequently overlooked source of local public finance in developing countries. We use microdata from ten countries to establish stylized facts on the magnitude, form, and distributional implications of this “informal taxation.” Informal taxation is widespread, particularly in rural areas, with substantial in-kind labor payments. The wealthy pay more, but pay less in percentage terms, and informal taxes are more regressive than formal taxes. Failing to include informal taxation underestimates household tax burdens and revenue decentralization in developing countries. We discuss various explanations for and implications of these observed stylized facts. (JEL H24, H27, O12, O17, O23)
Climate Change, Mortality, and Adaptation: Evidence from Annual Fluctuations in Weather in the US
Authors: Deschênes Olivier , Greenstone Michael
Published: October 2011

Using random year-to-year variation in temperature, we document the relationship between daily temperatures and annual mortality rates and daily temperatures and annual residential energy consumption. Both relationships exhibit nonlinearities, with significant increases at the extremes of the temperature distribution. The application of these results to “business as usual” climate predictions indicates that by the end of the century climate change will lead to increases of 3 percent in the age-adjusted mortality rate and 11 percent in annual residential energy consumption. These estimates likely overstate the long-run costs, because climate change will unfold gradually allowing individuals to engage in a wider set of adaptations. (JEL I12, Q41, Q54)
Subsidized Farm Input Programs and Agricultural Performance: A Farm-Level Analysis of West Bengal's Green Revolution, 1982–1995
Authors: Bardhan Pranab , Mookherjee Dilip
Published: October 2011

We examine the role of delivery of subsidized seeds and fertilizers in the form of agricultural minikits by local governments in three successive farm panels in West Bengal spanning 1982–1995. These programs significantly raised farm value added per acre, accounting for almost two-thirds of the observed growth. The estimates are robust to possible endogeneity of program placement, controls for farm and year effects, other programs of agricultural development, local weather, and price shocks. The effects of the kits delivery program overshadowed the effects of other rural development programs, including the tenancy registration program Operation Barga. (JEL O13, Q12, Q16, Q18)
Health Capital and the Prenatal Environment: The Effect of Ramadan Observance During Pregnancy
Authors: Almond Douglas , Mazumder Bhashkar
Published: October 2011

This paper uses the Islamic holy month of Ramadan as a natural experiment in diurnal fasting and fetal health. Among births to Arab parents in Michigan, we find prenatal exposure to Ramadan results in lower birth weight. Exposure in the first month of gestation also reduces the number of male births. Turning to long-term “fetal origins” effects, we find Muslims in Uganda and Iraq are 20 percent more likely to be disabled as adults if early pregnancy overlapped with Ramadan. Estimated effects are larger for mental (or learning) disabilities. Our results suggest that relatively mild prenatal exposures can have persistent effects. (JEL I12, J16, O15, O17, Z12)
The Consumption Response to Seasonal Income: Evidence from Japanese Public Pension Benefits
Authors: Stephens Melvin , Unayama Takashi
Published: October 2011

Japanese public pension benefits, which were distributed quarterly through February 1990, and every other month since then, induce substantial but predictable income fluctuations. The relative magnitude of the payments combined with the delay between payments yields a stronger test of the Life-Cycle/Permanent Income Hypothesis than in prior studies. Applying two identification strategies to monthly household panel data, we find that consumption significantly responds to quarterly benefit receipt. Additional analysis suggests that our findings cannot be explained by either liquidity constraints or precautionary savings motives. (JEL D12, D91, E21, H55)
Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging
Authors: Sipola Petri , Leinonen Ville , Niemeläinen Riikka , Aalto Timo , Vanninen Ritva , Manninen Hannu , Airaksinen Olavi , Battié Michele C
Published: October 2011

Background

Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal.

Purpose

To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI).

Material and Methods

Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular ( n = 188) and foraminal zones ( n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen.

Results

The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively.

Conclusion

Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study.
Detection of pulmonary nodules by C-arm CT using a phantom lung: comparison with CT
Authors: Higashihara Hiroki , Osuga Keigo , Azuma Takeo , Nakazawa Tetsuro , Yanagawa Masahiro , Kikuyama Ayano , Maeda Noboru , Tomiyama Noriyuki
Published: October 2011

Background

Evaluation of detection of lung nodules by C-arm CT (CACT) is important before this procedure can be used to guide percutaneous lung interventions.

Purpose

To compare the efficacy of CACT with CT in the detection of pulmonary nodules using a phantom lung.

Material and Methods

A phantom lung containing 12 phantom nodules in four sizes(5mm/8mm/10mm/12mm) and three CT values (one solid nodule, +100 HU; two ground glass nodules, -630 and -800 HU) was used. Six sessions of CACT (slice thickness 4.5 mm) and CT (slice thickness 5 mm) were performed. In each session, the locations of nodules were arbitrarily changed in the phantom. Three radiologists assessed the detection of atotal of 72 nodules. Statistical analysis was performed for the sensitivity and positive predictive value of lung nodules between CACT and CT by the McNemar test and paired t-test ( P < 0.05).

Results

Sensitivity did not differ between CACT and CT, respectively (reader 1, 82% vs. 88%, P = 0.22; reader 2, 82% vs. 78%, P = 0.37; reader 3, 79% vs. 83%, P = 0.48). For nodules of 8mm or larger, the sensitivity increased for each reader and showed no significant difference between CACT vs. CT. The positive predictive value did not differ between CACT and CT.

Conclusion

In this phantom study, CT and CACT show similar sensitivity for the detection of pulmonary nodules. CACT could be used in percutaneous interventional procedures in the lungs.