bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anisotropic phantom measurements for quality assured use of diffusion tensor imaging in clinical practice
Authors: Berberat Jatta , Eberle Brigitte , Rogers Susanne , Boxheimer Larissa , Lutters Gerd , Merlo Adrian , Bodis Stephan , Remonda Luca 
Published: April 2013

Background Diffusion-weighted magnetic resonance imaging (MRI) is being increasingly applied in clinical practice, for example in neuronavigation and in modern radiation treatment planning. Quality assurance (QA) is therefore important to avoid clinical errors. Purpose To compare four analytical programs and a neuronavigation tool to evaluate our in-house diffusion-weighted imaging protocol in order to be able to implement diffusion tensor imaging (DTI) into clinical practice. Material and Methods A phantom containing crossing fibers was used for the QA. Fiber tracking and fractional anisotropy (FA) analyses were performed, and the geometrical resolution was verified using the phantom. Results FA results were reproducible within each program and no significant differences between programs were observed. Also, no significant differences in FA values were found when comparing the results between the four software programs. Geometrical resolution of the anatomical data-set was satisfactory; however the crossing of the fibers was not accurately represented by three of the four programs. Conclusion Phantom QA is necessary before using DTI for novel procedures to identify the uncertainties associated with DTI data. It is important to remember that the results are software-dependent and that representation of the tracts may vary between software products. We therefore recommend caution with regard to the application of fiber tracking results intraoperatively when dealing with abnormal fiber tract anatomy.
An imaging protocol for dynamic contrast-enhanced breast MRI with 3.0T: using sagittal sequence interleaved between axial sequences
Authors: Park Ji Eun , Lee Jee Eun , Hwang Ji-Young , Cha Eun Suk 
Published: April 2013

Background B1 transmission-field inhomogeneity has been reported at 3.0 Tesla (T) breast imaging. Enhancement measurements of breast cancers at 3.0T may be insufficient for some patients and improvements in imaging protocols are needed. Purpose To quantify B1 inhomogeneities in normal tissue and malignant masses at 3.0T breast MR imaging and to evaluate effect of an imaging protocol using an interleaved sagittal sequence in dynamic contrast-enhanced MRI (DCE-MRI). Material and Methods A total of 76 patients were included who underwent DCE-MRI of the breast at 3.0T with an imaging protocol consisting of 1st, 2nd, and 4–6th bilateral axial sequences, and 3rd and 7th unilateral sagittal sequences. Signal intensity (SI) of normal breast tissue was measured at nipple level in four bilateral locations (anterior, posterior, medial, and lateral). Mean whole breast and location specific SI were calculated and compared between right and left breast using a paired t-test. All malignant masses were classified into three groups according to tumor size on MRI (≤2 cm, 2–4 cm, >4 cm). SI of malignant masses was measured independently on axial and sagittal sequences. The axial–sagittal SI gap in each mass was calculated and difference between right and left breast was compared using the t test. Size of each malignant mass was compared with pathologic findings to assess performance of the imaging protocol. Results SI of normal breast tissue were lower for the right breast (R-L difference, −91.9; P < 0.0001) and in all four locations (anterior, P < 0.01; posterior, P < 0.01; medial, P < 0.0001; lateral, P < 0.0001). SI of malignant masses were lower for the right breast among same size of the lesions ( P < 0.0001), particularly < 4 cm ( P < 0.0001). Decreased right to left difference in SI was produced with an interleaved sagittal sequence, as axial–sagittal gap of malignant masses was significant when tumor locates on the right side ( P < 0.001). The concordance rate in predicting size of mass in this imaging protocol was 92.2%. Conclusion The interleaved sagittal sequence is helpful to adjust reduced SI of malignant masses on right breast at 3.0T. This imaging protocol is clinically applicable by adding a single sequence during DCE-MRI of the breast.
Concomitant findings and clinical significance of a fluid crescent between the iliacus muscle and iliac bone on MRI
Authors: Eshed Iris , Liberman Boaz , Inbar Yael , Amitai Michal , Portnoy Orith , Hertz Marjorie , Apter Sara 
Published: April 2013

Background Some routine magnetic resonance imaging (MRI) examinations show a thin line of fluid signal intensity along the iliac crest (“fluid crescent”) between the iliacus muscle and the iliac bone. This fluid crescent has not been described before. Purpose To evaluate the clinical context and significance of the fluid crescent. Material and Methods MRI examinations of the abdomen and pelvis performed over 1 year were retrospectively reviewed twice for the presence of a fluid crescent. The relationship between the presence of a fluid crescent and associated abnormal findings, including ascites, iliopsoas compartment, and bone and soft tissue pathologies, was evaluated. Results Forty-one out of 254 MRI studies (male:female ratio, 136:118; mean age, 42 years) demonstrated a fluid crescent (16%). Thirty-eight of them had associated MRI pathologies: edema of the hip muscles = 24, ascites = 11, iliac bone = 21, and iliopsoas compartment = 7. Correlations between the presence of a fluid crescent and pathological findings were highly significant ( P < 0.0001), except for the presence of fluid in the hip joint. Conclusion A fluid crescent is an abnormal MRI finding strongly associated with iliopsoas compartment pathology, ascites, hip muscle edema, and pelvic bone abnormalities. The nature of this fluid crescent is yet to be determined.
Improvement of SNR and acquisition acceleration using a 32-channel head coil compared to a 12-channel head coil at 3T
Authors: Reiss-Zimmermann Martin , Gutberlet Marcel , Köstler Herbert , Fritzsch Dominik , Hoffmann Karl-Titus 
Published: April 2013

Background Magnetic resonance imaging (MRI) techniques continue to improve in manifold ways. Besides field strength and sequence optimization, technical advances in coil design and sensitivity yield to increase the signal detection and therefore improve image quality. Purpose To evaluate the performance of signal-to-noise ratio (SNR) and parallel acquisition technique (PAT) acceleration of a dedicated 32-channel head coil compared with a standard 12-channel head coil. Material and Methods In a clinical 3T setting, spatial resolved SNR values for unaccelerated imaging and PAT with acceleration factors of 2–6 of a 32-channel head coil were evaluated in relation to a 12-channel head coil. SNR was determined quantitatively using proton-density-weighted in-vivo examinations in five healthy volunteers. Quantitative SNR maps for unaccelerated and PAT imaging were calculated using unfiltered MR raw data. Results Up to three-fold higher SNR values were achieved with the 32-channel head coil, which diminished towards the center to an increase of 40% compared with the 12-channel head coil. When using PAT, the 32-channel head coil resulted in a lower spatial-dependent quantitative noise enhancement, varying between 0% at R = 2 and 33% at R = 5. Conclusion The 32-channel head coil provided superior SNR both with and without PAT compared with a 12-channel head coil, especially close to the brain surface. Using PAT, the unavoidable noise enhancement is diminished up to acceleration factors of 6 for the 32-channel head coil. Therefore, the 32-channel head coil is considered as a preferable tool for high-resolution neuroradiological imaging.
Computed tomography-guided needle aspiration and biopsy of pulmonary lesions: a single-center experience in 1000 patients
Authors: Poulou Loukia S , Tsagouli Paraskevi , Ziakas Panayiotis D , Politi Dimitra , Trigidou Rodoula , Thanos Loukas 
Published: April 2013

Background Computed tomography (CT)-guided fine needle aspiration (FNA) and biopsies are well-established, minimally invasive diagnostic tools for pulmonary lesions. Purpose To analyze retrospectively the results of 1000 consecutive lung CT-guided FNA and/or core needle biopsies (CNB), the main outcome measures being diagnostic yield, and complication rates. Material and Methods Patients considered eligible were those referred to our department for lung lesions. The choice of FNA, CNB, or both was based upon the radiologist's judgment. Diagnostic yield was defined as the probability of having a definite result by cytology/histology. Results The study included 733 male patients and 267 female patients, with a mean (SD) age of 66.4 (11.4) years. The mean (SD) lesion size was 3.7 (2.4) cm in maximal diameter. Six hundred and forty-one (64%) patients underwent an FNA procedure, 245 (25%) a CNB, and 114 (11%) had been subjected to both. The diagnostic yield was 960/994 (96.6%); this decreased significantly with the use of CNB only (odds ratio [OR] 0.32; 95% CI 0.12–0.88; P = 0.03), while it increased with lesion size (OR 1.35; 95% CI 1.03–1.79; P = 0.03 per cm increase). In 506 patients (52.7%), a malignant process was diagnosed by cytopathology/histology. The complication rate reached 97/1000 (9.7%); complications included: hemorrhage, 62 (6.2%); pneumothorax, 28 (2.8%); hemorrhage and pneumothorax, 5 (0.5%); and hemoptysis, 2 (0.2%). It was not significantly affected by the type of procedure or localization of the lesion. The overall risk for complications was three times higher for lesions <4 cm (OR 3.26; 95% CI 1.96–5.42; P < 0.001). Conclusion CT-guided lung biopsy has a high diagnostic yield using FNA, CNB, or both. The CNB procedure alone will not suffice. Complication rates were acceptable and correlated inversely with lesion size, not localization or type of procedure.
Adrenal lesions: variability in attenuation over time, between scanners, and between observers
Authors: Hammarstedt Lilian , Thilander-Klang Anne , Muth Andreas , Wängberg Bo , Odén Anders , Hellström Mikael 
Published: April 2013

Background Measurements of attenuation (in Hounsfield units [HU]) and contrast wash-out are widely used to characterize adrenal lesions as benign or indeterminate/malignant at computed tomography (CT). Clinical experience suggests that such measurements of adrenal lesions may vary over time and between observers, making evaluation difficult. Purpose To investigate the change over time of adrenal lesion size, attenuation, and contrast wash-out at CT, to determine inter-observer variability, and to analyze other factors underlying the variability. Material and Methods In a cohort of patients, with or without malignant disease, undergoing CT, adrenal lesions were prospectively analyzed. Lesions with growth >20% or >5 mm over 6 months were excluded. Non-enhanced attenuation and contrast medium wash-out over 2-year follow-up were analyzed. An inter-observer analysis with five observers and a phantom study of eight different CT scanners were performed to assess measurement variability. Results Mean adrenal lesion non-enhanced attenuation values decreased by 0.5 HU/year during follow-up. Using 10 HU or 40% relative wash-out as threshold values for benign versus indeterminate lesions, 27 (20%) and 39 (29%) of 136 lesions, respectively, would be reclassified at some occasion during follow-up. In the observer analysis 37 of 40 lesions demonstrated agreement between all observers, using established threshold values. The phantom study showed an intra-scanner variability of 1–3 HU, but an inter-scanner variability of up to 8 HU for water. Conclusion The clinically widespread use of specific attenuation threshold values for characterizing adrenal lesions must be used with great caution, considering that multiple factors, related to patient, equipment, scanning technique, and observer influence the outcome.
Risk factors for high-altitude headache upon acute high-altitude exposure at 3700 m in young Chinese men: a cohort study
Authors: Bian Shi-Zhu , Zhang Ji-Hang , Gao Xu-Bin , Li Ming , Yu Jie , Liu Xi , Dong Jun-Qing , Chen Guo-Zhu , Huang Lan 
Published: April 2013

Abstract

Background
This prospective and observational study aimed to identify demographic, physiological and psychological risk factors associated with high-altitude headache (HAH) upon acute high-altitude exposure.

Methods
Eight hundred fifty subjects ascended by plane to 3700 m above Chengdu (500 m) over a period of two hours. Structured Case Report Form (CRF) questionnaires were used to record demographic information, physiological examinations, psychological scale, and symptoms including headache and insomnia a week before ascending and within 24 hours after arrival at 3700 m. Binary logistic regression models were used to analyze the risk factors for HAH.

Results
The incidence of HAH was 73.3%. Age (p =0.011), physical labor intensity (PLI) (p =0.044), primary headache history (p <0.001), insomnia (p <0.001), arterial oxygen saturation (SaO2) (p =0.001), heart rate (HR) (p =0.002), the Self-Rating Anxiety Scale (SAS) (p <0.001), and the Epworth Sleepiness Scale (ESS) (p <0.001) were significantly different between HAH and non-HAH groups. Logistic regression models identified primary headache history, insomnia, low SaO2, high HR and SAS as independent risk factors for HAH.

Conclusions
Insomnia, primary headache history, low SaO2, high HR, and high SAS score are the risk factors for HAH. Our findings will provide novel avenues for the study, prevention and treatment of HAH.
Codon pairs of the HIV-1 vif gene correlate with CD4+ T cell count
Authors: Bizinoto Maria Clara , Yabe Shiori , Leal Élcio , Kishino Hirohisa , de Oliveira Martins Leonardo , de Lima Mariana Leão , Morais Edsel Renata , Diaz Ricardo Sobhie , Janini Luiz Mário 
Published: April 2013

Abstract

Background
The human APOBEC3G (A3G) protein activity is associated with innate immunity against HIV-1 by inducing high rates of guanosines to adenosines (G-to-A) mutations (viz., hypermutation) in the viral DNA. If hypermutation is not enough to disrupt the reading frames of viral genes, it may likely increase the HIV-1 diversity. To counteract host innate immunity HIV-1 encodes the Vif protein that binds A3G protein and form complexes to be degraded by cellular proteolysis.

Methods
Here we studied the pattern of substitutions in the vif gene and its association with clinical status of HIV-1 infected individuals. To perform the study, unique vif gene sequences were generated from 400 antiretroviral-naïve individuals.

Results
The codon pairs: 78–154, 85–154, 101–157, 105–157, and 105–176 of vif gene were associated with CD4+ T cell count lower than 500 cells per mm3. Some of these codons were located in the 81LGQGVSIEW89 region and within the BC-Box. We also identified codons under positive selection clustered in the N-terminal region of Vif protein, between 21WKSLVK26 and 40YRHHY44 regions (i.e., 31, 33, 37, 39), within the BC-Box (i.e., 155, 159) and the Cullin5-Box (i.e., 168) of vif gene. All these regions are involved in the Vif-induced degradation of A3G/F complexes and the N-terminal of Vif protein binds to viral and cellular RNA.

Conclusions
Adaptive evolution of vif gene was mostly to optimize viral RNA binding and A3G/F recognition. Additionally, since there is not a fully resolved structure of the Vif protein, codon pairs associated with CD4+ T cell count may elucidate key regions that interact with host cell factors. Here we identified and discriminated codons under positive selection and codons under functional constraint in the vif gene of HIV-1.
Histone deacetylase inhibitors up-regulate LL-37 expression independent of toll-like receptor mediated signalling in airway epithelial cells
Authors: Liu Quan , Liu Juan , Roschmann Kristina Irene Lisolette , van Egmond Danielle , Golebski Korneliusz , Fokkens Wytske Johanna , Wang Dehui , van Drunen Cornelis Maria 
Published: April 2013

Abstract
HDAC inhibitors have been proposed as anticancer agents. However, their roles in innate genes expression remain not well known. Cathelicidin LL-37 is one of the few human bactericidal peptides, but the regulation of histone acetylation on LL-37 expression in airway epithelium remains largely unknown. Therefore, we investigated the effects of two non-selective HDACi, trichostatin A (TSA) and sodium butyrate (SB), on the expression of the cathelicidin LL-37 in human airway epithelial cells. LL37 in human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells(PNEC) in response to HDAC inhibitors with or without poly (I:C) stimulation was assessed using real-time PCR and western blot. In parallel, IL-6 expression was evaluated by ELISA. Our results showed that HDAC inhibitors up-regulated LL-37 gene expression independent of poly (I:C) stimulation in PNEC as well as in NCI-H292 cells. HDAC inhibitors increased LL37 protein expression in NCI-H292 cells but not in PNEC. In addition, HDAC inhibitors significantly inhibited poly (I:C)-induced IL-6 production in both of the epithelial cells. In conclusion, HDAC inhibitors directly up-regulated LL-37 gene expression in human airway epithelial cells.
A simple additive-free approach for the synthesis of uniform manganese monoxide nanorods with large specific surface area
Authors: Zheng Mingtao , Zhang Haoran , Gong Xuebin , Xu Ruchun , Xiao Yong , Dong Hanwu , Liu Xiaotang , Liu Yingliang 
Published: April 2013

Abstract
A simple additive-free approach is developed to synthesize uniform manganese monoxide (MnO) one-dimensional nanorods, in which only manganese acetate and ethanol were used as reactants. The as-synthesized MnO nanorods were characterized in detail by X-ray diffraction, scanning and transmission electron microscopy (TEM) including high-resolution TEM and selected-area electron diffraction, Fourier transform infrared spectrum, and nitrogen adsorption isotherm measurements. The results indicate that the as-synthesized MnO nanorods present a mesoporous characteristic with large specific surface area (153 m2 g−1), indicating promising applications in catalysis, energy storage, and biomedical image. On the basis of experimental results, the formation mechanism of MnO one-dimensional nanorods in the absence of polymer additives was also discussed.
Low prevalence of contraceptive counseling at Srinagarind hospital, Thailand among women of reproductive age with systemic lupus erythematosus
Authors: Kittisiam Thannaporn , Werawatakul Yuthapong , Nanagara Ratanavadee , Wantha Orathai 
Published: April 2013

AbstractObjectiveUnplanned pregnancy in women with SLE can have grave complications both for the child and the woman. We studied the prevalence of contraceptive counseling among women of reproductive age with SLE at a university hospital in Northeast Thailand.MethodsRecruited: 125 women with SLE, between 15 and 50 years, followed up at the Rheumatology Clinic. A questionnaire was administered and the results analyzed to identify the prevalence of contraceptive counseling.ResultsThe majority of women with SLE had had their reproductive goals evaluated (76.00%, 95% CI 66–83) and received contraceptive counseling (72%). Among the SLE patients at risk for pregnancy, only one-third used effective contraception and one-fifth of those did not have any background knowledge about SLE and pregnancy. Contraceptive counseling was more frequently given to women who had had a previous pregnancy or who were already concerned about SLE as related to pregnancy.ConclusionThe majority of SLE patients had at one time or other received contraceptive counseling, but some reported not grasping the gravity. The survey results presented herein suggest that a multidisciplinary team is needed to improve patient knowledge regarding SLE as it affects on pregnancy and relatedly contraceptive counseling.
Complete genome sequencing and analysis of six enterovirus 71 strains with different clinical phenotypes
Authors: Wen Hong-ling , Si Lu-ying , Yuan Xiao-jing , Hao Shu-bin , Gao Feng , Chu Fu-lu , Sun Cheng-xi , Wang Zhi-yu 
Published: April 2013

AbstractBackgroundHand, foot and mouth diseases (HFMD) caused by enterovirus 71(EV71) presents a broad spectrum of clinical manifestations ranging from mild febrile disease to fatal neurolocal disease. However, the mechanism of virulence is unknown.MethodsWe isolated 6 strains of EV71 from HFMD patients with or without neurological symptoms, and sequenced the whole genomes of the viruses to reveal the virulence factors of EV71.ResultsPhylogenetic tree based on VP1 region showed that all six strains clustered into C4a of C4 sub-genotype. In the complete polypeptide, 298 positions were found to be variable in all strains, and three of these positions (ValP814/IleP814in VP1, ValP1148/IleP1148in 3A and AlaP1728/CysP1728/ValP1728in 3C) were conserved among the strains with neurovirulence, but variable in strains without neurovirulence. In the 5′-UTR region, it showed that the first 10 nucleotides were mostly conserved, however from the 11th nucleotide, nucleotide insertions and deletions were quite common. The secondary structure prediction of 5′-UTR sequences showed that two of three strains without neurovirulence (SDLY11 and SDLY48) were almost the same, and all strains with neurovirulence (SDLY96, SDLY107 and SDLY153) were different from each other. SDLY107 (a fatal strain) was found different from other strains on four positions (CP241/TP241, AP571/TP571, CP579/TP579in 5′-UTR and TP7335/CP7335in 3′-UTR).ConclusionsThe three positions (ValP814/IleP814in VP1, ValP1148/IleP1148in 3A and AlaP1728/CysP1728/ValP1728in 3C), were different between two phenotypes. These suggested that the three positions might be potential virulent positions. And the three varied positions were also found to be conserved in strains with neurovirulence, and variable in strains without neurovirulence. These might reveal that the conservation of two of the three positions or the three together were specific for the strains with neurovirulence. Varation of secondary structure of 5′-UTR, might be correlated to the changes of viral virulence. SDLY107 (a fatal strain) was found different from other strains on four positions, these positions might be related with death.