bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphofunctional transformations of the yolk syncytial layer during zebrafish development
Authors: Kondakova Ekaterina Alexandrovna A. , Efremov Vladimir Ivanovich I.
Published: October 2013

The yolk syncytial layer (YSL) is a provisory extraembryonic structure of teleost fishes and representatives of some other taxa with meroblastic cleavage. The YSL of teleosts is a symplast with polymorphous polyploid nuclei. It is known to perform nutritional, morphogenetic, immune, and, probably, other functions. Data about the YSL organization, functioning and regulation is fragmentary. Although gene expression patterns and other aspects of YSL functioning have been studied in Danio rerio, the morphology of its YSL has not been described in detail. The study of zebrafish YSL structure on sequential developmental stages is necessary to recognize specific features of this important polyfunctional system in this model organism and to extend our knowledge about provisory systems. The thickness of the YSL and the distribution of its nuclei are not uniform on each stage and change during development. During oblong and sphere stages the internal YSL (I‐YSL) is filled with yolk inclusions; interphase yolk syncytial nuclei (YSN) and mitotic asters can be seen. During doming and epiboly the external YSL (E‐YSL) is thicker than I‐YSL. On the subsequent stages the YSL is thickened caudally. The dorsal YSL part is thickened during early segmentation stages and becomes the thinnest YSL region later. The anterior part of the YSL is thin, but enlarges during larval period. The YSN of different size and diverse forms, from regular to lobed, are present and form clusters. The number of irregular‐shaped nuclei increases during development. The YSL thickens in the end of endotrophic and in the course of endo‐exotrophic period, and its cytoplasm contains numerous yolk inclusions. After yolk exhaustion the YSL is flat. As the YSL degrades, the YSN become pycnotic, and the YSL remnant probably is cleared by phagocytes. J. Morphol. 275:206–216, 2014. © 2013 Wiley Periodicals, Inc.
Magnetic resonance elastography of liver in healthy asians: Normal liver stiffness quantification and reproducibility assessment
Authors: Venkatesh Sudhakar K. , Wang Gang , Teo Lynette L.S. , Ang Bertrand W.L.
Published: October 2013

Purpose

To determine normal liver stiffness values evaluated with magnetic resonance elastography (MRE) in healthy normal Asian volunteers and assess its reproducibility.

Materials and Methods

Liver stiffness was evaluated with MRE in 41 healthy Asians (23 females, 18 males; mean age, 41.8 years, and mean body mass index [BMI], 23.4 kg/m2) on a 1.5T clinical scanner. The correlations between mean liver stiffness and age, gender, BMI, and fat fraction percentage of the liver were studied. Another 12 volunteers underwent liver MRE exams on two separate days 4–6 weeks apart under similar conditions for reproducibility assessment. Intraclass correlation coefficient (ICC) analysis was performed and within‐subject coefficient of variation (CV) of stiffness was estimated.

Results

The mean ± standard deviation (SD) of liver stiffness in normal healthy Asian subjects was 2.09 ± 0.22 kPa (95% confidence interval [CI], 2.04–2.15 kPa; range 1.68–2.48 kPa). The mean liver stiffness did not significantly correlate with age, gender, BMI, or fat content of the liver. The ICC for mean liver stiffness was 0.90 (95% CI, 0.78–0.96) and CV ranged from 2.2%–11.4%.

Conclusion

The liver stiffness in normal Asians is not affected by age, gender, BMI, or fat content. Liver stiffness with MRE is highly reproducible. J. Magn. Reson. Imaging 2014;39:1–8. © 2013 Wiley Periodicals, Inc.
Clinical evaluation of CAIPIRINHA: Comparison against a GRAPPA standard
Authors: Wright Katherine L. , Harrell Michael W. , Jesberger John A. , Landeras Luis , Nakamoto Dean A. , Thomas Smitha , Nickel Dominik , Kroeker Randall , Griswold Mark A. , Gulani Vikas
Published: October 2013

Purpose

To evaluate image quality when using a CAIPIRINHA sampling pattern in comparison to a standard GRAPPA sampling pattern in patients undergoing a routine three‐dimensional (3D) breathheld liver exam. CAIPIRINHA uses an optimized phase encoding sampling strategy to alter aliasing artifacts in 3D acquisitions to improve parallel imaging reconstruction.

Materials and Methods

Twenty patient volunteers were scanned using a 3D VIBE acquisition with an acceleration factor of four using a CAIPIRINHA and standard GRAPPA sampling pattern. CAIPIRINHA and GRAPPA images were evaluated by three radiologists in a two alternative forced choice test, and the Wilcoxon signed rank test was performed.

Results

The CAIPIRINHA sampling pattern was preferred in an average of 68% of the comparisons, and the Wilcoxon signed rank test showed a significant improvement in CAIPIRINHA images (P = 0.014). This analysis indicates that in the given sample set, CAIPIRINHA preference over the GRAPPA standard was statistically significant.

Conclusion

This work shows that for an acceleration factor of four, a CAIPIRINHA accelerated VIBE acquisition provides significantly improved image quality in comparison to the current GRAPPA standard. This allows a further reduction in imaging time for similar spatial resolutions, which can reduce long breathhold requirements in abdominal imaging, and may be particularly helpful in patients who cannot provide requisite breathholds with current protocols. J. Magn. Reson. Imaging 2014;39:189–194. © 2013 Wiley Periodicals, Inc.
Double inversion recovery MR imaging of the breast: Efficacy in detection of breast cancer
Authors: Kim Jeoung Hyun , Ryu Jung Kyu , Jahng Geon‐Ho , Song Jeong Yoon
Published: October 2013

Purpose

To investigate the efficacy of the double inversion recovery sequence (DIR) in breast cancer detection.

Materials and Methods

Fifty‐six patients with biopsy‐proven breast cancers underwent preoperative breast MRI, including sagittal DIR and contrast‐enhanced T1‐weighted images (CE‐T1WI). Twenty‐four of the 56 patients additionally underwent sagittal T1WI and T2WI. The signal intensities of the lesion (L) and ipsilateral normal breast tissue (N) were measured. The lesion‐to‐normal ratio (LNR) was defined as LNR = 100(L‐N)/N. We compared LNRs among the four sequences, and then assessed the differences of LNRs between CE‐T1WI and DIR in each pathologic subgroup (IDC and non‐IDC group). Multiple regression analysis was performed to identify predictors of the signal‐to‐noise ratios (SNR) of the normal tissue or lesion and LNRs.

Results

The mean LNR did not differ significantly between DIR (58.65 ± 71.55) and CE‐T1WI (59.78 ±31.04), nor did the LNRs between DIR and CE‐T1WI in the two subgroups. The LNRs of DIR did not differ significantly between the two subgroups (P = 0.247). The SNR of lesions in DIR was correlated with the intraductal component percentage (r2 = 0.485, P = 0.037).

Conclusion

DIR and CE‐T1WI showed similar tumor detection efficacy, and DIR could complement dynamic MRI for detecting breast cancer without a contrast agent. J. Magn. Reson. Imaging 2014;39:51–58. © 2013 Wiley Periodicals, Inc.
Improved motion correction in PROPELLER by using grouped blades as reference
Authors: Liu Zhe , Zhang Zhe , Ying Kui , Yuan Chun , Guo Hua
Published: October 2013

Purpose

To develop a robust reference generation method for improving PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) reconstruction.

Materials and Methods

A new reference generation method, grouped‐blade reference (GBR), is proposed for calculating rotation angle and translation shift in PROPELLER. Instead of using a single‐blade reference (SBR) or combined‐blade reference (CBR), our method classifies blades by their relative correlations and groups similar blades together as the reference to prevent inconsistent data from interfering the correction process. Numerical simulations and in vivo experiments were used to evaluate the performance of GBR for PROPELLER, which was further compared with SBR and CBR in terms of error level and computation cost.

Results

Both simulation and in vivo experiments demonstrate that GBR‐based PROPELLER provides better correction for random motion or bipolar motion comparing with SBR or CBR. It not only produces images with lower error level but also needs less iteration steps to converge.

Conclusion

A grouped‐blade for reference selection was investigated for PROPELLER MRI. It helps to improve the accuracy and robustness of motion correction for various motion patterns. J. Magn. Reson. Imaging 2014;39:700–707. © 2013 Wiley Periodicals, Inc.
Quantitative measurement of femoral condyle cartilage in the knee by MRI: Validation study by multireaders
Authors: Fujinaga Yasunari , Yoshioka Hiroshi , Sakai Toshinori , Sakai Yoko , Souza Felipe , Lang Philipp
Published: October 2013

Purpose

To determine reproducibility of the femoral condyle cartilage volume (CV) in cross‐sectional and longitudinal studies using various 3D imaging techniques at 1.5 T and 3 T.

Materials and Methods

In 21 subjects with osteoarthritis, magnetic resonance imaging (MRI) including four different sequences (sagittal 3D fat suppressed spoiled gradient‐echo [SPGR] at 1.5 T, fat suppressed fast low angle shot [FLASH] at 3 T, water‐excitation dual echo steady state [DESS] at 3 T, and water‐excitation multiecho data image combination [MEDIC] at 3 T) were acquired at baseline and ∼1 year later. The CV measured using semiautomated segmentation software by three readers was analyzed.

Results

The mean of the interclass correlation coefficient between each reader from SPGR, FLASH, DESS, and MEDIC was 0.899, 0.948, 0.943, and 0.954, respectively. The mean CV (×104 mm3) measured by each reader from SPGR/FLASH/DESS/MEDIC sequences was the following in this order: 1.34/1.52/1.50/1.35, 1.21/1.43/1.40/1.27, 1.22/1.37/1.36/1.22, and 1.17/1.36/1.35/1.21 by readers 1, 2, 3 (first analysis), and 3 (second analysis), respectively. There was no statistically significant difference in CV between any readers in any sequences. The CV measured on FLASH and DESS tended to be greater than that on SPGR or MEDIC.

Conclusion

Inter‐ and intraobserver reproducibility of cartilage segmentation using semiautomated software was validated. Although there was no statistical significance, there was a tendency of under‐ or overestimating CV by each sequence. J. Magn. Reson. Imaging 2014;39:972–977. © 2013 Wiley Periodicals, Inc.
Improved anatomical reproducibility in quantitative lower‐limb muscle MRI
Authors: Fischmann Arne , Morrow Jasper M. , Sinclair Christopher D.J. , Reilly Mary M. , Hanna Michael G. , Yousry Tarek , Thornton John S.
Published: October 2013

Purpose

To compare the influence of two limb positions and slice prescription using scout‐image–based and surface‐anatomy–based methods on the reproducibility of quantitative MRI of lower‐limb muscles.

Materials and Methods

Ten healthy subjects were scanned at 3 Tesla with a two‐dimensional turbo spin‐echo T1‐weighted acquisition. Imaging was performed at thigh and calf level in two subject limb positions and independently repeated by a second operator. Regions‐of‐interest (ROI) were drawn on three muscles at thigh and calf levels on axial slices at fixed distance from the knee joint and at a level determined by surface anatomy.

Results

Test–retest reliability of muscle cross‐sectional area and ROI area overlap were similar for both limb positioning methods. Changing limb position between scans reduced ROI overlap (P < 0.01). Scout‐image–based slice prescription resulted in narrower limits of agreement and higher intraclass correlation coefficients compared with surface‐anatomy–based slice prescription.

Conclusion

Slice prescription based on fixed distance from the knee joint provided superior reproducibility of slice location than a surface anatomy‐based method and should be used for longitudinal quantitative MRI studies. Exact subject positioning will depend on scanner and coil configuration, but should be consistent through a longitudinal study. J. Magn. Reson. Imaging 2014;39:1033–1038. © 2013 Wiley Periodicals, Inc.
Probably benign breast MRI lesions: Frequency, lesion type, and rate of malignancy
Authors: Lourenco Ana P. , Chung Michelle Tsang Mui , Mainiero Martha B.
Published: October 2013

Purpose

To determine the frequency, malignancy rate, and imaging characteristics of BI‐RADS (Breast Imaging Reporting and Data System) 3 MRI detected lesions.

Materials and Methods

A total of 4370 consecutive contrast‐enhanced breast MRI exams from March 1, 2004, to March 1, 2009, were retrospectively reviewed. The study was HIPAA (Health Insurance Portability Accountability Act) compliant and Institutional Review Board approved. The frequency of BI‐RADS 3 MRI interpretations and lesion type, as well as malignancy rate at follow‐up were calculated.

Results

There were 348/4370 (8%) BI‐RADS 3 exams performed on 345 patients. There were 125 foci (35.9%), 52 non‐masslike enhancements (14.9%), and 171 masses (49.1%). There were 207 lesions with biopsy or imaging follow‐up of at least 24 months (mean, 32 months; range, 6–77 months) of the BI‐RADS 3 lesion. Five of these 207 (2.4%) lesions were found to be malignant.

Conclusion

Rate of malignancy among BI‐RADS 3 MRI exams with follow‐up was 2.4%. Types of lesions assigned as probably benign were 35.9% foci, 14.9% non‐masslike enhancements, and 49.1% masses. J. Magn. Reson. Imaging 2014;39:789–794. © 2013 Wiley Periodicals, Inc.
Sex dimorphism in the white matter: Fractional anisotropy and brain size
Authors: Takao Hidemasa , Hayashi Naoto , Ohtomo Kuni
Published: October 2013

Purpose

To examine sex differences in fractional anisotropy of the white matter across the whole brain, controlling for head size variation.

Materials and Methods

A total of 238 normal subjects aged 40–49 years were included in this study. Diffusion tensor images were acquired at 3 Tesla using a single‐shot spin‐echo echo‐planar sequence. With use of tract‐based spatial statistics (TBSS), sex differences in fractional anisotropy of the white matter were examined across the whole brain, without and with adjustment of total intracranial volume. Voxelwise analyses of the processed fractional anisotropy data were performed using permutation‐based, voxelwise nonparametric testing.

Results

TBSS analysis without adjustment for total intracranial volume showed several regions with a significant effect of sex on fractional anisotropy; these included the splenium of the corpus callosum, bilateral superior corona radiata, and posterior limbs of the internal capsule, midbrain, and cerebellum. Significantly higher fractional anisotropy was seen in males compared with females in these regions. TBSS analysis with adjustment for total intracranial volume, however, showed a greatly reduced number of such regions.

Conclusion

The results of our study suggest that sex differences in fractional anisotropy of the white matter reported by previous studies may partly reflect differences in head size, not microscopic differences. J. Magn. Reson. Imaging 2014;39:917–923. © 2013 Wiley Periodicals, Inc.
Assessing patients with hepatocellular carcinoma meeting the milan criteria: Is liver 3 tesla MR with gadoxetic acid necessary in addition to liver CT?
Authors: Cha Dong Ik , Lee Min Woo , Kim Young Kon , Kim Seong Hyun , Park Hyun Jeong , Rhim Hyunchul , Lim Hyo K.
Published: October 2013

Purpose

To determine the added value of 3 Tesla liver MR in patients with hepatocellular carcinoma (HCC) within the liver computed tomography (CT) ‐based Milan criteria.

Materials and Methods

Liver CT and MR images of 130 patients with HCC within the Milan criteria based on liver CT were retrospectively reviewed. The number of MR‐diagnosed HCCs and that of high risk hypervascular nodules (HRHNs), the effect of obtaining MR on patient management and CT appearances of MR‐diagnosed HCCs and those of HRHNs were evaluated. Independent predictor for diagnosing additional HCCs on liver MR was analyzed.

Results

A total of 18.5% (24/130) of patients had additional 39 HCCs on MR, with a 5.4% (7/130) dropout rate from the Milan criteria. 28.5% (37/130) of patients had additional 78 HRHNs. Overall, 39.2% (51/130) of patients required changes in management. The common CT appearances of MR‐diagnosed HCCs were arterial enhancing lesions ≥ 0.5cm (38.4%, 15/39), low density nodules < 1.5 cm (30.8%, 12/39) and invisibility (28.2%, 11/39). For MR‐diagnosed HRHNs, 55.1% (43/78) were invisible on CT. The presence of inconclusive lesions on CT was an independent predictor for diagnosing additional HCCs on MR.

Conclusion

For patients with HCCs within the Milan criteria on liver CT, liver MR may be necessary to detect additional HCCs and HRHNs. J. Magn. Reson. Imaging 2014;39:842–852. © 2013 Wiley Periodicals, Inc.
CMR reference values for left ventricular volumes, mass, and ejection fraction using computer‐aided analysis: The Framingham Heart Study
Authors: Chuang Michael L. , Gona Philimon , Hautvast Gilion L.T.F. , Salton Carol J. , Breeuwer Marcel , O'Donnell Christopher J. , Manning Warren J.
Published: October 2013

Purpose

To determine sex‐specific reference values for left ventricular (LV) volumes, mass, and ejection fraction (EF) in healthy adults using computer‐aided analysis and to examine the effect of age on LV parameters.

Materials and Methods

We examined data from 1494 members of the Framingham Heart Study Offspring cohort, obtained using short‐axis stack cine SSFP CMR, identified a healthy reference group (without cardiovascular disease, hypertension, or LV wall motion abnormality) and determined sex‐specific upper 95th percentile thresholds for LV volumes and mass, and lower 5th percentile thresholds for EF using computer‐assisted border detection. In secondary analyses, we stratified participants by age‐decade and tested for linear trend across age groups.

Results

The reference group comprised 685 adults (423F; 61 ± 9 years). Men had greater LV volumes and mass, before and after indexation to common measures of body size (all P = 0.001). Women had greater EF (73 ± 6 versus 71 ± 6%; P = 0.0002). LV volumes decreased with greater age in both sexes, even after indexation. Indexed LV mass did not vary with age. LV EF and concentricity increased with greater age in both sexes.

Conclusion

We present CMR‐derived LV reference values. There are significant age and sex differences in LV volumes, EF, and geometry, whereas mass differs between sexes but not age groups. J. Magn. Reson. Imaging 2014;39:895–900. © 2013 Wiley Periodicals, Inc.
Liver dynamic contrast‐enhanced MRI for staging liver fibrosis in a piglet model
Authors: Zhou Li , Chen Tian‐wu , Zhang Xiao‐ming , Yang Zhi , Tang Hong‐jie , Deng Dan , Zeng Nan‐lin , Wang Li‐ying , Chen Xiao‐li , Li Hang , Li Chun‐ping , Li Li , Xie Xian‐yong , Hu Jiani
Published: October 2013

Purpose

To determine whether dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) could monitor progression of liver fibrosis in a piglet model, and which DCE‐MRI parameter is most accurate for staging this disease.

Materials and Methods

Sixteen piglets were prospectively used to model liver fibrosis and underwent liver DCE‐MRI followed by biopsy on the 0, 5th, 9th, 16th, and 21st weekends after modeling of fibrosis. Time of peak (TOP), time to peak (TTP), positive enhancement integral (PEI), maximum slope of increase (MSI), and maximum slope of decrease (MSD) were measured and statistically analyzed for the monitoring and staging.

Results

As fibrosis progresses, TOP and TTP tended to increase, whereas MSI, MSD, and PEI tended to decrease (all P < 0.05). TOP, TTP, and MSI could discriminate fibrosis stage 0 from 1–4, 0–1 from 2–4, 0–2 from 3–4, and 0–3 from 4; PEI could distinguish the above‐mentioned stages except 0–3 from 4; and MSD could distinguish stage 0–3 from 4, and 0 from 1–4 (all P < 0.05). For predicting stage ≥1, ≥2, and ≥3, the area under receiver operating characteristic curve (AUC) of MSI was largest among all parameters; for stage 4 AUC of TTP was largest.

Conclusion

DCE‐MRI has the potential to dynamically stage progression of liver fibrosis. J. Magn. Reson. Imaging 2014;39:872–878. © 2013 Wiley Periodicals, Inc.
Real‐time flow MRI of the aorta at a resolution of 40 msec
Authors: Joseph Arun , Kowallick Johannes T. , Merboldt Klaus‐Dietmar , Voit Dirk , Schaetz Sebastian , Zhang Shuo , Sohns Jan M. , Lotz Joachim , Frahm Jens
Published: October 2013

Purpose

To evaluate a novel real‐time phase‐contrast magnetic resonance imaging (MRI) technique for the assessment of through‐plane flow in the ascending aorta.

Materials and Methods

Real‐time MRI was based on a radial fast low‐angle shot (FLASH) sequence with about 30‐fold undersampling and image reconstruction by regularized nonlinear inversion. Phase‐contrast maps were obtained from two (interleaved or sequential) acquisitions with and without a bipolar velocity‐encoding gradient. Blood flow in the ascending aorta was studied in 10 healthy volunteers at 3 T by both real‐time MRI (15 sec during free breathing) and electrocardiogram (ECG)‐synchronized cine MRI (with and without breath holding). Flow velocities and stroke volumes were evaluated using standard postprocessing software.

Results

The total acquisition time for a pair of phase‐contrast images was 40.0 msec (TR/TE = 2.86/1.93 msec, 10° flip angle, 7 spokes per image) for a nominal in‐plane resolution of 1.3 mm and a section thickness of 6 mm. Quantitative evaluations of spatially averaged flow velocities and stroke volumes were comparable for real‐time and cine methods when real‐time MRI data were averaged across heartbeats. For individual heartbeats real‐time phase‐contrast MRI resulted in higher peak velocities for values above 120 cm s−1.

Conclusion

Real‐time phase‐contrast MRI of blood flow in the human aorta yields functional parameters for individual heartbeats. When averaged across heartbeats real‐time flow velocities and stroke volumes are comparable to values obtained by conventional cine MRI. J. Magn. Reson. Imaging 2014;40:206–213. © 2013 Wiley Periodicals, Inc.
Susceptibility to cytomegalovirus, parvovirus B19 and age‐dependent differences in levels of rubella antibodies among pregnant women
Authors: Barlinn Regine , Vainio Kirsti , Samdal Helvi Holm , Nordbø Svein Arne , Nøkleby Hanne , Dudman Susanne G.
Published: October 2013

Infections caused by cytomegalovirus (CMV), parvovirus B19 (B19), and rubella can lead to serious complications in pregnant women. The aim of this study was to determine the susceptibility to CMV, B19, and rubella antibodies in pregnant women in Norway. Consecutive sera samples were collected from pregnant women in two different regions in Norway. Sera were collected from age groups; ≤19, 20–24, 25–29, 30–34, 35–39, and ≥40 years old. Of the 2,000 pregnant women tested, anti‐CMV IgG was positive in 62.8% anti‐parvovirus B19 IgG in 59.7% and anti‐rubella IgG in 94.4%. CMV IgG susceptibility has decreased in pregnant women less than 30 years of age, from 60% in a study conducted in 1973–1974 to 37.2% in present study. There was a significant difference in CMV IgG seropositivity rate between the two regions (58.6% and 67.1%). Serum levels of rubella IgG was lowest in age group 25–29 years with a positivity rate of 91.0%. Women born before vaccination with two doses of MMR started, had both a higher positivity rate and significantly higher levels of rubella antibody titre, 96.1% and 82.2 IU/ml compared to those born after 92.9% and 41.7 IU/ml. Significantly lower anti‐rubella IgG titre found in the youngest age groups highlights the need for continued antenatal screening. A considerable increase in anti‐CMV‐IgG seropositivity rate was observed and might be associated with higher rate of breastfeeding and a higher percentage attending day‐care centres. J. Med. Virol. 86:820–826, 2014. © 2013 Wiley Periodicals, Inc.
Immunopathogenesis of dengue hemorrhagic fever: Contribution to the study of human liver lesions
Authors: Pagliari Carla , Quaresma Juarez Antonio Simões , Fernandes Elaine Raniero , Stegun Felipe Weisshaupt , Brasil Roosecelis Araújo , de Andrade Heitor Franco , Barros Vera , Vasconcelos Pedro Fernando C. , Duarte Maria Irma Seixas
Published: October 2013

Dengue infection is an important tropical disease worldwide. The host immune response has been studied in order to better understand lesion mechanisms. It was performed an immunohistochemical study in 14 specimens of liver from patients with dengue hemorrhagic fever (DHF) to characterize cytokines and some factors present in liver lesions and their possible role in the pathogenesis of hepatic injury. Portal tract and hepatic acinus presented high expression of TLR2, TLR3, IL6, and granzyme B. Hepatic acinus also presented iNOS, IL18, and TGF‐beta. Cells expressing IL12, IL13, JAk1, STAT1, and NF‐κB were rarely visualized. Treg cells foxp3+ were absent. TLR2 and TLR3 seem to participate in cellular activation and cytokine production. Cytotoxic response seems to play a role. Although TGF‐beta promotes the activation of Foxp3+ regulatory T cells, IL6 can significantly suppresses their generation. The expression of Treg cells is diminished probably as a result of the high frequency of these cytokines. Both cytokines play a role in the increased vascular permeability and edema observed in dengue liver specimens, with consequent plasma leakage and severity of the disease. It was observed a regular expression of IL‐18 in hepatocytes and lymphocytes of the inflammatory infiltrate in portal tract, which reflects the acute inflammatory response that occurs in the liver and contributes to hepatic injury. At least in part, the increased number of cells expressing IL‐18 could play a role of “up” regulation of FasL and correlate to the phenomenon of apoptosis, a mechanism of destruction of hepatocytes in DHF. J. Med. Virol. 86:1193–1197, 2014. © 2013 Wiley Periodicals, Inc.
Burden of respiratory viruses in patients with acute respiratory failure
Authors: Schnell David , Gits‐Muselli Maud , Canet Emmanuel , Lemiale Virginie , Schlemmer Benoît , Simon François , Azoulay Elie , Legoff Jérôme
Published: October 2013

Respiratory viruses (RVs) are ubiquitous pathogens that represent a major cause of community‐acquired pneumonia and chronic pulmonary diseases exacerbations. However, their contribution to acute respiratory failure events requiring intensive care unit admission in the era of rapid multiplex molecular assay deserves further evaluation. This study investigated the burden of viral infections in non immunocompromised patients admitted to the intensive care unit for acute respiratory failure using a multiplex molecular assay. Patients were investigated for RVs using immunofluoresence testing and a commercial multiplex molecular assay, and for bacteria using conventional culture. Half the patients (34/70, 49%) had a documented RVs infection. No other pathogen was found in 24 (71%) patients. Viral infection was detected more frequently in patients with obstructive respiratory diseases (64% vs. 29%; P = 0.0075). Multiplex molecular assay should be considered as an usefull diagnostic tool in patients admitted to the intensive care unit with acute respiratory failure, especially those with acute exacerbations of chronic obstructive pulmonary disease and asthma. J. Med. Virol. 86:1198–1202, 2014. © 2013 Wiley Periodicals, Inc.
Unusual presentation of Epstein–Barr virus hepatitis treated successfully with valganciclovir
Authors: Cauldwell Katrine , Williams Roger
Published: October 2013

Described is the case of a 21‐year‐old male patient who presented with a severe Epstein–Barr virus (EBV) hepatitis. The initial diagnosis was challenging, as the patient did not have the typical features of the mononucleosis syndrome and despite the severity of the hepatitis, the initial serology was negative. In addition the liver biopsy did not show the mononuclear cell infiltration typically seen in EBV hepatitis. Later, measurements of EBV DNA showed high titers and the patient received a course of oral valganciclovir, following which he made a rapid clinical and serological response. This case describes an unusual presentation of EBV hepatitis, and adds to the body of evidence supporting its treatment with valganciclovir. J. Med. Virol. 86:484–486, 2014. © 2013 Wiley Periodicals, Inc.
Clinical implications of the titer of serum hepatitis B surface antigen during the natural history of hepatitis B virus infection
Authors: Suh Sang Jun , Bae Song‐I , Kim Ji Hoon , Kang Keunhee , Yeon Jong Eun , Byun Kwan Soo
Published: October 2013

Although there are some differences in hepatitis B surface antigen (HBsAg) titers in infection with different hepatitis B virus (HBV) genotypes, the HBsAg titers for each HBV genotype have not been evaluated extensively. The aim of this study was to investigate HBsAg titers during the natural history of patients infected with HBV in Korea, where the HBV genotype C is endemic exclusively. Four hundred fifteen patients were enrolled retrospectively and classified according to definitions of the natural phases of HBV infection. In total, 73, 118, 147, and 77 patients were classified in the immune tolerance, immune clearance, low replicative, and HBeAg‐negative hepatitis phases, respectively. HBsAg titers (4.35 ± 0.67, 3.74 ± 0.68, 2.39 ± 1.23, and 3.29 ± 0.64 log10 IU/ml) were significantly different in the immune tolerance, immune clearance, low replicative, and HBeAg‐negative hepatitis phases, respectively (P < 0.001). The ratio of HBsAg to HBV DNA was highest in the low replicative phase (1.13 ± 0.71, all P < 0.001) and second highest in the HBeAg‐negative hepatitis phase (0.58 ± 0.18, all P < 0.05). In multivariate analysis of all patients, the HBsAg titers did not correlate with alanine aminotransferase. However, the HBsAg titers correlated with age (P = 0.038), platelet count (P < 0.001) and HBV DNA (P < 0.001). In subgroup analysis, the HBsAg titers correlated with HBV DNA in all phases (P < 0.001), except for the HBeAg‐negative hepatitis phase. HBsAg titers were significantly different across the four phases of the natural history of the infection and correlated significantly with HBV DNA titer in genotype C chronic hepatitis B patients. The HBsAg titer could be used as a biomarker to differentiate the natural history of HBV infection. J. Med. Virol. 86:117–123, 2014. © 2013 Wiley Periodicals, Inc.
Norovirus infection in immunocompromised children and children with hospital‐acquired acute gastroenteritis
Authors: Munir Naeemah , Liu Pengbo , Gastañaduy Paul , Montes Julia , Shane Andi , Moe Christine
Published: October 2013

Norovirus (NoV) is a leading cause of acute viral gastroenteritis among children, yet its burden of disease among immunocompromised hosts and its role in hospital acquired infections (HAI) is not well characterized. To determine the prevalence, genotypes, and NoV loads among immunocompromised children and children with HAI, residual stool samples, and clinical data were collected at two major pediatric hospitals in metropolitan Atlanta from 92 children that were immunocompromised and/or had a hospital acquired acute gastroenteritis. NoV was identified in 16.3% (15/92) of all stool specimens; 23.4% (11/47) in immunocompromised only children, and 13.3% (4/30) in children with HAI. All NoV positive cases were genogroup II (GII), and GII.4 was the predominant strain followed by GII.3, GII.12, and GII.13. The average NoV load for immunocompromised patients was 6.3 ± 1.4 log genome equivalent copies (GEC) per gram of stool compared to 5.8 ± 1.1 log GEC among patients with HAI. NoV infections are common among immunocompromised children and children with hospital‐acquired gastroenteritis, underscoring the urgent need for rapid NoV detection system, and highlighting the importance of strict hospital hygiene practices. J. Med. Virol. 86:1203–1209, 2014. © 2013 Wiley Periodicals, Inc.
Dried blood spots for HIV‐1 drug resistance genotyping in decentralized settings in Senegal
Authors: Diouara Abou Abdallah Malick , Diop‐Ndiaye Halimatou , Kebe‐Fall Khady , Tchiakpè Edmond , Ndiaye Ousseynou , Ayouba Ahidjo , Peeters Martine , Mboup Souleymane , Kane Coumba Toure
Published: October 2013

The aim of this study was to evaluate the use for HIV‐1 drug resistance testing dried blood spots collected in remote areas and sent under field conditions to a reference laboratory and also to document virological failure in patients with suspected treatment failure. Samples were collected from patients receiving first line ART at 11 hospital sites around country, kept at room temperature (<37°C) and sent within 15 days maximum to the reference laboratory. Viral nucleic acids were obtained by magnetic extraction with NucliSENS (bioMérieux, Marcy l'Etoile, France). Genotyping of HIV‐1 pol gene was performed using the ANRS protocol. Drug resistance mutations were analyzed according to the Stanford University HIV database version 6.0.8. Two hundred thirty one HIV‐infected adults' on HAART first line regimen composed study population. The median time on ART was 18 months (range 6–68). Regardless of the treatment duration, the overall rate of virological failure (VL ≥ 3 log10 cp/ml) was 23.8% (n = 55/231). HIV genotypes were obtained successfully in 94.5% (n = 52/55). Drug resistance mutation was found in 41/52 patients in virological failure, for 17.7% (n = 41/231) an overall rate of drug resistance mutations. M184V/I was the most frequent mutation occurring, followed by K103N. Phylogenetic analysis of the 52 genotyped viral isolates showed the predominance of CRF02_AG with 62% (n = 32/52). Use of a DBS specimen is suitable to assist national programs for monitoring in remote areas HIV drug resistance in resources limited‐settings. J. Med. Virol. 86:45–51, 2014. © 2013 Wiley Periodicals, Inc.
Correlation between hepatitis B virus surface antigen level and alpha‐fetoprotein in patients free of hepatocellular carcinoma or severe hepatitis
Authors: Akuta Norio , Suzuki Fumitaka , Kobayashi Mariko , Hara Tasuku , Sezaki Hitomi , Suzuki Yoshiyuki , Hosaka Tetsuya , Kobayashi Masahiro , Saitoh Satoshi , Ikeda Kenji , Kumada Hiromitsu
Published: October 2013

Alfa‐fetoprotein (AFP) is used as a marker of early hepatocarcinogenesis. However, the impact of hepatitis B virus surface antigen (HBsAg) on this relationship in patients with HBV infection is not clear. The present study evaluated the relation between HBsAg and AFP levels at the initial visit in 1,610 untreated HBV patients, free of hepatocellular carcinoma (HCC) or severe hepatitis. The cumulative rate of HCC was significantly lower in patients with a low AFP level (≤10 µg/L; below the upper limit of normal) than in those with a high AFP level (≥11 µg/L) at the initial visit. In patients with HBsAg levels more than 500 IU/ml, HBsAg levels correlated significantly and negatively with AFP levels, and significantly with platelet count. Multivariate analysis of data of patients with HBsAg more than 500 IU/ml identified HBsAg (<7,000 IU/ml), albumin (<3.9 g/dl), platelet count (<20.0 × 104/mm3), gamma‐glutamyl transpeptidase (≥50 IU/L), aspartate aminotransferase (≥34 IU/L), HBeAg (positive), and HBV core‐related antigen (≥3.0 log U/ml) as determinants of a high AFP. Especially, in patients with HBsAg more than 500 IU/ml and low transaminase levels (below the upper limit of normal), HBsAg was identified as significant determinant of a high AFP. On the other hand, in patients with HBsAg less than 500 IU/ml, multivariate analysis identified albumin, gamma‐glutamyl transpeptidase, and HBV core‐related antigen as determinants of a high AFP. The results indicated that HBsAg level seems to affect, at least in part, the AFP levels, and that it can be used as a surrogate marker of early hepatocarcinogenesis. J. Med. Virol. 86:131–138, 2014. © 2013 Wiley Periodicals, Inc.
Distribution of JC virus genotypes among serbian patients infected with HIV and in healthy donors
Authors: Karalic Danijela , Lazarevic Ivana , Knezevic Aleksandra , Cupic Maja , Jevtovic Djordje , Jovanovic Tanja
Published: October 2013

Certain factors lead to increased reactivation of JC virus (JCV) and immunodeficiency seems to be the most important. JCV isolates can be classified into eight different genotypes and several subtypes based on nucleotide difference in the VP1 gene. JCV genotypes are strongly associated with particular ethnic groups and frequently used as genetic markers for human evolution and migration. The aim of this study was to determine the frequency of JCV urinary shedding and genotype distribution in Serbia among patients infected with HIV and healthy donors. Urine samples from 107 healthy donors and 93 patients infected with HIV were collected. PCR followed by sequence analysis was carried out using primers specific for VP1 and NCRR of the virus genome. Excretion rate of JCV‐DNA in urine was higher in patients infected with HIV than in healthy donors (44.1% vs. 31.7%) although statistical significance was not found. Within the group infected with HIV, the degree of immunosuppression (measured by CD4+ cell count) did not influence JCV excretion rate. Sequence analysis of JCV NCRR from both patients infected with HIV and healthy donors showed a pattern identical to archetype structure. In healthy Serbian donors the predominant genotype was 1 (41.2%), followed by 4 (32.4%) and 2 (26.4%). On the other hand, genotype distribution pattern was different in patients infected with HIV: 2 (43.9%), 1 (31.7%), and 4 (24.4%). This study showed that European, Eurasian, and Indian types are circulating in Serbia and that distribution corresponds to the origin of the inhabitants of Serbia. J. Med. Virol. 86:411–418, 2014. © 2013 Wiley Periodicals, Inc.
HIV, HBV, and HCV molecular epidemiology among trans (transvestites, transsexuals, and transgender) sex workers in Argentina
Authors: Carobene Mauricio , Bolcic Federico , Farías María Sol Dos Ramos , Quarleri Jorge , Ávila María Mercedes
Published: October 2013

Commercial sex work is frequent among male‐to‐female transvestites, transsexuals and transgenders in Argentina, leading to high susceptibility to HIV, HBV, and HCV among other sexually transmitted infections. In a global context of scarce data on the trans sex workers population, this study was aimed to study the genomic characterization of these viruses. Plasma presence of HIV, HBV, and HCV genomic material was evaluated in samples from 273 trans sex workers. Genomic sequences of HIV‐gag, pol, and vif‐vpu genes, HBV‐S gene, and HCV‐5′UT and NS5B genes were obtained. Molecular characterization involved phylogenetic analysis and several in silico tools. Resistance‐associated mutations in HIV and HBV pol genes were also analyzed. The HIV genomic characterization in 62 trans sex workers samples showed that 54.8% of the isolates corresponded to BF intersubtype recombinants, and 38.7% to subtype B. The remaining were classified as subtypes C (4.8%) and A (1.6%). HBV and HCV co‐infection prevalence among HIV positive trans sex workers yielded rates of 3.2% and 6.5% respectively. Drug resistance‐associated mutations were found in 12/62 (19%) HIV pol sequences, but none among HBV. Based on phylogenetic relationships, HIV isolates characterized as subtypes BF and B appeared intermingled with those from other high‐risk groups. Despite trans sex workers declared not to have received antiviral treatment, complex drug resistance‐associated mutation patterns were found in several HIV isolates. Planned prevention, screening, and treatment are needed to reduce further transmission and morbidity. J. Med. Virol. 86:64–70, 2014. © 2013 Wiley Periodicals, Inc.
Nonlinear modeling of LDMOS transistors for high‐power FM transmitters
Authors: Bosi Gianni , Crupi Giovanni , Vadalà Valeria , Raffo Antonio , Giovannelli Antonello , Vannini Giorgio
Published: October 2013

In this paper, a nonlinear model of a commercial 10‐W laterally diffused metal oxide semiconductor (LDMOS) transistor for FM transmitters is identified. It is based on high‐frequency small‐signal measurements for the identification of both the parasitic network and the strictly nonlinear dynamic effects, whereas low‐frequency large‐signal measurements are exploited for the description of the dynamic I/V characteristics of the device above the cut‐off of low‐frequency dispersion. A validation of the proposed model is provided by using time‐domain nonlinear measurements carried out at 40 MHz and 100 MHz. Copyright © 2013 John Wiley & Sons, Ltd.
Ischemia, immunosuppression, and SSEA‐1‐negative cells all contribute to tumors resulting from mouse embryonic stem cell‐derived neural progenitor transplantation
Authors: Guan Yunqian , Zou Haiqiang , Chen Xiaocong , Zhao Chunsong , Wang Jiayin , Cai Yanning , Chan Piu , Chen Ling , Zhang Y. Alex
Published: October 2013

Neural progenitor cells (NPCs) derived from mouse embryonic stem (mES) cells can lead to tumors after transplantation. The cellular source of such tumors remains under debate. We investigated the tumor formation resulting from mES cell‐derived NPCs in a rat stroke model and in nude mice. After 2 hr of ischemia and 48 hr of reperfusion, the NPCs were transplanted into the ischemic core of the xenogeneic rats. Four weeks after transplantation, the grafted cells were found to be viable at the border of the necrosis and had differentiated into neurons. Transplanted rats did not exhibit any behavioral improvement, because tumor formed in 90% of the animals. Immunosuppression facilitated tumor formation. Tumors were observed in 40% of normal rats after NPC transplantation when cyclosporin A was administered. Meanwhile, no tumor formation was observed without cyclosporin A. Ischemic damage also facilitated tumor formation, because NPCs gave rise to tumors in 90% of ischemic rats, a percentage significantly higher than that in intact rats, which was 40%. The SSEA‐1‐positive cells isolated from stage 4 are not exactly undifferentiated ES cells. They exhibited a marker gene transcription profile different from that of ES cells and did not form tumors in transplanted nude mice. The undifferentiated ES cells remaining after differentiation did not contribute to tumors either. First, the tumor formation rate resulting from undifferentiated ES cells in the brains of normal rats is 0%, significantly lower than that of NPCs. Second, transplanted NPCs that led to 100% tumors in nude mice contained approximately 1.5 × 103 Oct‐4‐positive cells; however, even 5 × 105 undifferentiated ES cells formed neoplasm only in 40% nude mice. © 2013 Wiley Periodicals, Inc.
Zebrafish brain proteomics reveals central proteins involved in neurodegeneration
Authors: Gebriel Mohammed , Prabhudesai Shubhangi , Uleberg Kai‐Erik , Larssen Eivind , Piston Dominik , Bjørnstad Anne Hjelle , Møller Simon Geir
Published: October 2013

Understanding the complex biology of the brain requires analyzing its structural and functional complexity at the protein level. The large‐scale analysis of the brain proteome, coupled with characterization of central brain proteins, provides insight into fundamental brain processes and processes linked to neurodegenerative diseases. Here we provide a map of the zebrafish brain proteome by using two‐dimensional gel electrophoresis (2DE), followed by the identification of 95 brain proteins using mass spectrometry (LC‐ESI MS/MS). Our data show extensive phosphorylation of brain proteins but less prominent glycosylation. Furthermore, ∼51% of the identified proteins are predicted to have one or more ubiquitination sites whereas ∼90% are predicted to have one or more SUMOylation sites. Our findings provide a valuable proteome map of the zebrafish brain and associated posttranslational modifications demonstrating that zebrafish proteomic approaches can aid in our understanding of proteins central to important neuronal processes and those associated with neurodegenerative disorders. © 2013 Wiley Periodicals, Inc.
Developing a passion for work passion: Future directions on an emerging construct
Authors: Perrewé Pamela L. , Hochwarter Wayne A. , Ferris Gerald R. , McAllister Charn P. , Harris John N.
Published: October 2013

Although the passion that people demonstrate at work would appear to be a topic of considerable interest and importance to organizational scholars and practitioners, we know virtually nothing about it. In response, we introduce the work passion construct, discuss what we currently understand, and provide needed directions for future research. Copyright © 2013 John Wiley & Sons, Ltd.
Release of feruloylated oligosaccharides from wheat bran through submerged fermentation by edible mushrooms
Authors: Xie Chunyan , Wu Zhiyan , Guo Hongzhen , Gu Zhenxin
Published: October 2013

Wheat bran, a by‐product of the flour industry, is believed to be a raw material for the production of feruloylated oligosaccharides (FOs) because of its high content of conjiont ferulic acid (FA). Studies were carried out to identify edible mushrooms that are able to release FOs from wheat bran. All the six tested mushrooms (Pleurotus ostreatus, Hericium erinaceum, Auricularia auricula, Cordyceps militaris, Agrocybe chaxingu, and Ganoderma lucium) were found to release FOs, and Agrocybe chaxingu had the highest yield, reaching 35.4 µM in wheat bran broth. Enzymes detection showed that these species secreted extracellular enzymes during fermentation, including cellulase and xylanase. Agrocybe chaxingu secreted the significant amount of xylanase (180 mU ml−1), which was responsible for the release of FOs from wheat bran, while Hericium erinaceum secreted FA esterase which could disassemble FOs.
Oral vaccination with inhibin DNA delivered using attenuated Salmonella choleraesuis for improving reproductive traits in mice
Authors: Han Li , Zhen Yan‐Hong , Liang Ai‐Xin , Zhang Jian , Riaz Hasan , Xiong Jia‐Jun , Guo Ai‐Zhen , Yang Li‐Guo
Published: October 2013

The objective of this study was to examine the efficacy and safety of a novel inhibin vaccine containing inhibin α (1–32) fragments in mice. A recombinant plasmid pVAX‐asd‐IS was constructed by inserting recombinant inhibin α (1–32) and the hepatitis B surface antigen S into the plasmid in which the asd gene, rather than the kanamycin gene, was a selection marker. Ninety Kuming mice were divided into six groups consisting of 15 mice each. First group was (C1) injected with 200 µl of PBS, second (C2) received 1 × 1010 CFU of crp−/asd− C500/pVAX‐asd and served as vector control, third did not receive any treatment (C3), while fourth, fifth, and sixth group received 1 × 1010, 1 × 109, 1 × 108 CFU of the recombinant inhibin vaccine crp−/asd− C500/pVAX‐asd‐IS (group T1, T2, T3), respectively. Western blotting demonstrated that recombinant expressed inhibin protein possessed immune function and that this plasmid could replicate for up to 40 generations stably. Vaccination with this strain at a dose of 1 × 1010 CFU/200 µl per mouse induced high anti‐inhibin antibody levels, significantly increased large‐follicle production in T1 group (p < 0.05) and average litter size (p > 0.05) compared with control groups. Integration studies showed no evidence of inhibin fusion gene integrated into mice's genome 2‐month after immunization. These results suggest that the vaccine described in the present study may provide a safe method to improve reproductive traits in animals. A trend towards increased litter size and significant increase in large follicle population depict that this vaccine may have direct application in large animal industry.