bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypercytolytic activity of hepatic natural killer cells correlates with liver injury in chronic hepatitis B patients
Authors: Zhang Zheng , Zhang Shuye , Zou Zhengsheng , Shi Jianfei , Zhao Juanjuan , Fan Rong , Qin Enqiang , Li Baosen , Li Zhiwei , Xu Xiangsheng , Fu Junliang , Zhang Jiyuan , Gao Bin , Tian Zhigang , Wang Fu-Sheng
Published: September 2010

Natural killer (NK) cells are abundant in the liver and serve as a major innate immune component against microbial infection. Although NK cells have been implicated in inducing hepatocellular damage in patients with chronic hepatitis virus infections, the roles that hepatic NK cells play in chronic hepatitis B virus (HBV) infections remain obscure. In this study, we comprehensively characterized intrahepatic and peripheral NK cells and investigated their impact on liver pathology in a cohort of HBV-infected individuals; this cohort included 51 immune-activated (IA) patients, 27 immune-tolerant (IT) carriers, and 26 healthy subjects. We found that NK cells expressing NK receptors (activation receptors) preferentially accumulated in the livers of IA patients, in which they were activated and skewed toward cytolytic activity but without a concomitant increase in interferon-γ production, in comparison with those of IT carriers and healthy subjects. Further analysis showed that the livers of IA patients, in comparison with those of IT and healthy subjects, expressed higher levels of interleukin-12 (IL-12), IL-15, and IL-18

in situ

and lower levels of IL-10, which

in vitro

can induce the activation and degranulation of NK cells from healthy individuals. Finally, hepatic NK cells displayed more cytolytic activity than peripheral NK cells, and this was found to be positively correlated with the liver histological activity index and serum alanine aminotransferase levels in these IA patients.

Conclusion:

In IA patients, hepatic NK cells are activated and preferentially skew toward cytolytic activity, which depends on an imbalanced cytokine milieu and correlates with liver injury during chronic HBV infection. (Hepatology 2011)
Ablation of the tumor suppressor histidine triad nucleotide binding protein 1 is protective against hepatic ischemia/reperfusion injury
Authors: Martin Juliette , Romanque Pamela , Maurhofer Olivier , Schmitter Karin , Hora Caroline , Ferrand Gisèle , Dufour Jean-François
Published: September 2010

The identification of cellular pathways capable of limiting ischemia/reperfusion (I/R) injury remains a frontier in medicine, and its clinical relevance is urgent. Histidine triad nucleotide binding protein 1 (HINT1) is a tumor suppressor that influences apoptosis. Because apoptotic pathways are a feature of I/R injury, we asked whether Hint1 influences hepatic I/R injury.

Hint1

−/− and C57BL/6 mice were subjected to 70% liver ischemia followed by reperfusion for 3 or 24 hours or to a sham operation. The serum aminotransferase levels, histological lesions, apoptosis, reactive oxygen species, and expression of B cell lymphoma 2–associated X protein (Bax), heme oxygenase 1 (HO-1), interleukin-6 (IL-6), IL-10, tumor necrosis factor-
a

, Src, nuclear factor kappa B (p65/RelA), and c-Jun were quantified. The responses to toll-like receptor ligands and nicotinamide adenine dinucleotide phosphate oxidase activity in Kupffer cells were compared in

Hint1

−/− mice and C57BL/6 mice. After I/R, the levels of serum aminotransferases, parenchymal necrosis, and hepatocellular apoptosis were significantly lower in

Hint1

−/− mice versus control mice. Furthermore, Bax expression decreased more than 2-fold in

Hint1

−/− mice, and the increases in reactive oxygen species and HO-1 expression that were evident in wild-type mice after I/R were absent in

Hint1

−/− mice. The phosphorylation of Src and the nuclear translocation of p65 were increased in

Hint1

−/− mice, whereas the nuclear expression of phosphorylated c-Jun was decreased. The levels of the protective cytokines IL-6 and IL-10 were increased in

Hint1

−/− mice. These effects increased survival after I/R in mice lacking Hint1.

Hint1

−/− Kupffer cells were less activated than control cells after stimulation with lipopolysaccharides.

Conclusion:

The Hint1 protein influences the course of I/R injury, and its ablation in Kupffer cells may limit the extent of the injury. (Hepatology 2011)
Incorporating contaminant bioavailability into sediment quality assessment frameworks
Authors: Maruya Keith A , Landrum Peter F , Burgess Robert M , Shine James P
Published: September 2010

The recently adopted sediment quality assessment framework for evaluating bay and estuarine sediments in the state of California incorporates bulk sediment chemistry as a key line of evidence (LOE) but does not address the bioavailability of measured contaminants. Thus, the chemistry-based LOE likely does not provide an accurate depiction of organism exposure in all cases, nor is it particularly well suited for assessment of causality. In recent years, several methods for evaluating the bioavailability of sediment-associated contaminants have emerged, which, if optimized and validated, could be applied to improve the applicability and broaden the scope of sediment quality assessment. Such methods include equilibrium-based biomimetic extractions using either passive sampling devices (PSDs) or measures of rapidly desorbing contaminant pools, which provide information compatible with existing mechanistic approaches. Currently, these methods show promise in relating bioaccessible chemicals to effects endpoints, including bioaccumulation of hydrophobic organic compounds and/or toxicity due to metals. Using these methods, a bioavailability LOE for organics is proposed based on PSD and equilibrium partitioning theory that can be employed as an independent LOE or in assessing causality in tiered toxicity identification evaluations. Current and future research should be aimed at comparing the performance of PSDs and their relationships with effects concentrations, field validation of the most promising methods, addressing contaminant mixtures, further developing the parameterization of the proposed bioavailability LOE, and providing a better understanding of the underlying diagenetic cycling of metal contaminants that lead to exposure, affect bioavailability, and drive adverse outcomes. Integr Environ Assess Manag 2012; 8: 659–673. © 2010 SETAC
Biomass or growth rate endpoint for algae and aquatic plants: Relevance for the aquatic risk assessment of herbicides
Authors: Bergtold Matthias , Dohmen Gerhard Peter
Published: September 2010

Ecotoxicological studies with algae and aquatic plants are essential parts of the aquatic risk assessment for crop protection products (CPP). Growth rate is used as a response variable and in addition the effects on biomass and/or yield (in the following biomass) can be measured. The parameter biomass generally provides a lower numerical value compared with the growth rate for systematic and mathematical reasons. Therefore, some regulators prefer to use the EbC50 value (i.e., the concentration at which 50% reduction of biomass is observed) rather than ErC50 (the concentration at which a 50% inhibition of growth rate is observed) as the endpoint for ecotoxicological risk assessment. However, the parameter growth rate is scientifically more appropriate and robust against deviations in test conditions, permitting better interpretation of, and comparison between, studies. The aim of the present work is to evaluate the growth rate and biomass parameters with regard to their protectiveness and suitability for environmental risk assessment of CPP. It has been shown for a number of herbicides that the use of the EC50 value (without distinction between growth rate and biomass endpoints) from laboratory studies in combination with an assessment factor of 10 is sufficiently protective for aquatic plants (except for the herbicide 2,4-D). In this paper we evaluated EbC50 and ErC50 values seperately. Data on 19 different herbicides were compiled from the literature or GLP reports. The EbC50 and ErC50 values obtained in laboratory studies were compared with effect concentrations in ecosystem studies (mainly mesocosm). This comparison of laboratory and field data shows that the overall aquatic risk assessment using ErC50 values in combination with the currently applied assessment factor of 10 is sufficient to exclude significant risk to aquatic plants in the environment. Integr Environ Assess Manag 2011;7:237–247. © 2010 SETAC
Changes in the two‐dimensional electrophoresis pattern of the Parkinson's disease related protein DJ‐1 in human SH‐SY5Y neuroblastoma cells after dopamine treatment
Authors: Alberio Tiziana , Colapinto Monica , Natale Massimo , Ravizza Raffaella , Gariboldi Marzia B. , Bucci Enrico M. , Lopiano Leonardo , Fasano Mauro
Published: September 2010

DJ‐1 is a mitochondrial protein linked to Parkinson's disease. DJ‐1 has been suggested to have several possible functions, although it has been mainly associated to oxidative stress defence. Changes in the two‐dimensional electrophoresis pattern have been thoroughly described as a consequence of oxidative modification of the Cys106 residue. There is accumulating evidence supporting a specific role of DJ‐1 in protecting dopaminergic neurons from dopamine itself. By exposing SH‐SY5Y human neuroblastoma catecholaminergic cells to dopamine, we observed a specific increase in the most acidic forms in the DJ‐1 two‐dimensional electrophoresis pattern together with a significant decrease of the most basic spot. Unlike cells exposed to generic oxidative conditions, no additional shift was observed. The results are corroborated by a meta‐analysis of the literature showing that in the absence of dopamine treatment the specific acidic form is underrepresented. © 2010 IUBMB IUBMB Life, 62(9): 688–692, 2010
IGF-1 and bone: New discoveries from mouse models
Authors: Yakar Shoshana , Courtland Hayden-William , Clemmons David
Published: September 2010

Insulin-like growth factor-1 (IGF-1) plays a central role in cellular growth, differentiation, survival, and cell cycle progression. It is expressed early during development and its effects are mediated through binding to a tyrosine kinase receptor, the insulin-like growth factor-1 receptor (IGF-1R). In the circulation, the IGFs bind to IGF-binding proteins (IGFBPs), which determine their bioavailability and regulate the interaction between the IGFs and IGF-1R. Studies in animal models and in humans have established critical roles for IGFs in skeletal growth and development. In this review we present new and old findings from mouse models of the IGF system and discuss their clinical relevance to normal and pathological skeletal physiology. © 2010 American Society for Bone and Mineral Research.
Microscopical evaluation of extracellular matrix and its relation to the palatopharyngeal muscle in obstructive sleep apnea
Authors: Molina Fernando D. , Santos Fernanda C.A. , Falleiros Luis R. , Goloni‐Bertollo Eny M. , Felisbino Sérgio L. , Justulin Luis A. , Maniglia José V. , Taboga Sebastião R.
Published: September 2010

Obstructive sleep apnea hypopnea syndrome (SAHS) is a complex disease of the upper respiratory airways. SAHS physiopathology is multifactorial in which airway compliance is a very important component. To evaluate the tissue changes in the palatopharyngeal muscle by morphometric, histochemical, immunohistochemical, and stereological quantification, with special attention to extracellular matrix associated with this muscle at the structural and ultrastructural levels. Thirty patients with SAHS were divided into groups of 10 according to disease severity: mild, moderate, and severe SAHS. In addition, the control group consisted of 10 patients. Fragments of palatopharyngeal muscle removed from patients with SAHS and tonsillectomies from patients in the control group were histopathologically submitted to light microscopy and transmission electron microscopy. Histopathological evaluations by light and transmission electron microscopes showed differences in analyzed groups, such as reduction of the muscle fiber diameter in patients with SAHS, taking disease severity into consideration. In contrast, stereological analysis showed a gradual increase of the collagen and elastic system fibers relative frequencies, proportionally to SAHS seriousness. MMP‐2 and MMP‐9 immunostaining also showed an increased reaction in the muscle fiber cytoplasm and endomisium during SAHS progression. The ultrastructural analysis showed that palatopharyngeal muscle fibers presented cytoplasmic residual corpuscles, a sign of early cell aging. In conclusion, the increase of tissue compliance in individuals with SAHS can be, in addition to other factors, consequence of diminished contractile activity of the muscle fibers, which exhibited clear signs of early senescence. Moreover, extracellular matrix components changes may contribute to muscle myopathy during SAHS progression. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Human odontoblasts express transient receptor protein and acid‐sensing ion channel mechanosensor proteins
Authors: Solé‐Magdalena Antonio , Revuelta Enrique G. , Menénez‐Díaz Ivan , Calavia Marta G. , Cobo Teresa , García‐Suárez Olivia , Pérez‐Piñera Pablo , De Carlos Felix , Cobo Juan , Vega Jose A.
Published: September 2010

Diverse proteins of the denegerin/epithelial sodium channel (DEG/ENa+C) superfamily, in particular those belonging to the acid‐sensing ion channel (ASIC) family, as well as some members of the transient receptor protein (TRP) channel, function as mechanosensors or may be required for mechanosensation in a diverse range of species and cell types. Therefore, we investigated the putative mechanosensitive function of human odontoblasts using immunohistochemistry to detect ENa+C subunits (α, β, and γ) and ASIC (1, 2, 3, and 4) proteins, as well as TRPV4, in these cells. Positive and specific immunoreactivity in the odontoblast soma and/or processes was detected for all proteins studied except α‐ENa+C. The intensity of immunostaining was high for β‐ENa+C and ASIC2, whereas it was low for ASIC1, ASIC3, γ‐ENa+C, and TRPV4, being absent for α‐ENa+C and ASIC4. These results suggest that human odontoblasts in situ express proteins related to mechanosensitive channels that probably participate in the mechanisms involved in teeth sensory transmission. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Convergence in dental histology between the late Triassic semionotiformSargodon tomicus(Neopterygii) and a late cretaceous (Turonian) pycnodontid (Neopterygii: Pycnodontiformes) species
Authors: Andreev Plamen Stanislavov
Published: September 2010

Microstructural scanning electron microscope investigation was performed on sectioned and surface‐etched isolated, prehensile teeth of the Late Triassic semionotiform speciesSargodon tomicusand Pycnodontidaeincertae sedisfrom the Late Cretaceous. The teeth of both taxa display a system of vascular canals penetrating the dentine and the overlying hypermineralized acrodin cap; small tubules are radiating at an angle to the long axis of the canals, interpreted as residual spaces left by odontoblast cell processes. This is the first detailed account of vascular acrodin encountered in a pycnodont species. New information is revealed also aboutSargodondental histology in the shape of mineralized remnants of the basal lamina at the acrodin–dentine junction. This implies that deposition of the acrodin organic matrix proceeded centrifugally by the cells of the inner dental epithelium, probably with minor collagen contribution from odontoblasts. This is contrary to the more typical centripetal formation (beneath the basal lamina) of the acrodin layer implied for the studied pycnodontid teeth. The rare occurrences of vascular acrodin within Actinopterygii, and the demonstrated differences in its histogenesis, do not suggest the usefulness of the tissue as systematic character but rather point to its adaptive significance. The superficial increase in the order of acrodin bundle orientation, observed in both species, is similarly regarded as convergently acquired mechanical adaptation. The observed uneven shape of crystallite rows and lesser degree of mineralization of the inner collariform ganoin, compared to its outer portion, is indicative of epithelial‐ectomesenchymal interaction and qualifies the tissue as enameloid. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Virtual communication, transformational leadership, and implicit leadership
Authors: Salter Charles , Green Mark , Duncan Phyllis , Berre Anne , Torti Charles
Published: September 2010

This research was designed to test the theoretical relationship among personality, implicit leadership, and transformational leadership in a setting devoid of face‐to‐face communication, which we entitled virtual communication. Specifically, the study was designed to link, by using the International Personality Item Pool (IPIP), traits from the 5‐factor model of personality (the Big 5) to followers' perception of the leadership style of a virtual leader on the basis of Bass and Avolio's MLQ‐5X (1994). A voluntary sample consisted of undergraduate and graduate students from two universities in the south Texas area (N = 306). Respondents to the virtual communication rated Leader 1's communication, which used previously identified transformational language (Salter, Carmody‐Bubb, Duncan, & Green, 2007), as significantly more transformational than Leader 2's communication, using words not associated with transformational leaders. Participants who scored high in the Big 5 personality traits of agreeableness, openness to experience, conscientiousness, and extraversion rated the leader as more transformational while those high in neuroticism rated the leader as less transformational.
Indicators of leadership development in undergraduate military education
Authors: Shepherd Rebecca S. , Horner Donald H.
Published: September 2010

Despite the reputation of service academies and military colleges for producing leaders of character who serve as commissioned officers in America's armed forces, little is known about the actual effects these institutions have on the leadership development of their students. A two‐step process, this cross‐sectional study sought to investigate leadership development through the lens of the leadership identity development model as measured by the aptitude for commission grade. From a review of the military leadership curriculum at American service academies and military colleges, the initial phase of research established that leadership development occurred. The second phase used quantitative methods and a cross‐sectional design to investigate the effects of peer ranking, cumulative grade point average, leadership grades, and varsity athletic participation on leadership development throughout four years of undergraduate education. Findings indicated that company ranking by peers was significant regardless of gender or ethnicity. Mixed significant findings resulted for grade point average, leadership grades, and varsity athletic participation when based on gender and self‐identified minority status.
Initial assessment and validation of an instrument to measure student perceptions of leadership skills
Authors: Zula Ken , Yarrish Karen , Christensen Stephen D.
Published: September 2010

This article reports on development and validation of an instrument for use in measuring student perceptions of leadership skills. The article describes the development process of an instrument through use of subject matter experts for measuring leadership skill perception among students and use of an exploratory factor analysis technique to validate the resulting instrument. These data were obtained from a survey of 214 students in a small liberal arts college of business. The article presents an instrument for assistance with measuring leadership skill perception, development, and importance as well as further reports on the initial validity and reliability measures resulting from the analysis. In addition, the usefulness of the instrument for educators and workplace trainers is explored.
Undermanaged and not yet led: Reconciling management gap and leadership challenge for the new nature of the Chinese firm
Authors: Jelen Jonatan , Schmidt Thomas
Published: September 2010

The People's Republic of China is already the world's largest social system. It is now well on its way to becoming the world's largest national economy. This rapid economic development of the last 30 years is a result of the economic reforms carefully architected since 1978 by the former Paramount Leader Deng Xiaoping. There are several remarkable characteristics of this uniquely Chinese experience. First, it was not conceived as a paradigmatic shift. The Chinese transition to market‐economic models is closely controlled, incremental, selective, seemingly harmonious, and yet sustainable. Second, it was conceived as a paradox. The scope of these reforms deliberately did not extend to institutional reform. The famous characterization “One Country, Two Systems” captures this almost un‐Western idea of disassociating the evolution of the two spheres and allowing the co‐existence of two competing ideologies. Third, it was conceived as a pragmatic transformation, without proper ontological grounding as to how this dissonance will eventually be reconciled. At this point, the main actors caught between the two fronts (markets and institutions), the firms, will have to rise to the occasion and provide change leadership autonomously. The purpose of this conceptual article is to identify the required changes in nature of the Chinese firms navigating this dualist system, in particular with respect to their leadership component by exploring the presence of antecedents that will allow leadership to emerge. In the alternative we tentatively suggest carefully transferring some of our Western leadership wisdom, but we have to carefully evaluate to what extent existing conditions may also prevent us from doing so.
Non‐invasive visualization of basilar artery perforators with 7T MR angiography
Authors: Kang Chang‐Ki , Park Chan‐A , Kim Kyoung‐Nam , Hong Suk‐Min , Park Cheol‐Wan , Kim Young‐Bo , Cho Zang‐Hee
Published: September 2010

Purpose:

To visualize the perforating arteries originating from basilar artery (BA) by using ultra‐high resolution 7T MR angiography (MRA) and optimizing MR parameters as well as radio frequency (RF) coils, which may provide important information for neurosurgery and understanding diseases of the pons, but was unable to clearly visualize with conventional MRA techniques.

Materials and Methods:

Seven healthy volunteers (five males and two females, age [mean ± SD] = 28.71 ± 7.54 years) were scanned using optimized MR parameters to obtain images of pontine arteries (PAs) originating from the main trunk of BA. Two different volume coils and a phased array coil were designed and compared for this study. The images obtained at 7T MRA were compared with those at 1.5T and 3T MRA.

Results:

The results showed that PA imaging at 7T MRI consistently provided clearly identifiable vessels, which were difficult to visualize in MR angiograms obtained at 1.5T and 3T MRIs. Volume RF coils had higher sensitivity for the center of the brain, which enhanced PA imaging compared to phased array coil. The average number of PA branches in all seven subjects observable by 7T MRA was 7.14 ± 2.79, and the visualized PA branches were found to mainly propagating on the surface of the pons.

Conclusion:

We have demonstrated that ultra‐high resolution 7T MRA could delineate the PAs using optimized imaging parameters and volume RF coils compared to commercially available 1.5T and 3T MRIs. J. Magn. Reson. Imaging 2010;32:544–550. © 2010 Wiley‐Liss, Inc.
Common data elements in radiologic imaging of traumatic brain injury
Authors: Haacke E. Mark , Duhaime Ann Christine , Gean Alisa D. , Riedy Gerard , Wintermark Max , Mukherjee Pratik , Brody David L. , DeGraba Thomas , Duncan Timothy D. , Elovic Elie , Hurley Robin , Latour Lawrence , Smirniotopoulos James G. , Smith Douglas H.
Published: September 2010

Traumatic brain injury (TBI) has a poorly understood pathology. Patients suffer from a variety of physical and cognitive effects that worsen as the type of trauma worsens. Some noninvasive insights into the pathophysiology of TBI are possible using magnetic resonance imaging (MRI), computed tomography (CT), and many other forms of imaging as well. A recent workshop was convened to evaluate the common data elements (CDEs) that cut across the imaging field and given the charge to review the contributions of the various imaging modalities to TBI and to prepare an overview of the various clinical manifestations of TBI and their interpretation. Technical details regarding state‐of‐the‐art protocols for both MRI and CT are also presented with the hope of guiding current and future research efforts as to what is possible in the field. Stress was also placed on the potential to create a database of CDEs as a means to best record information from a given patient from the reading of the images. J. Magn. Reson. Imaging 2010;32:516–543. © 2010 Wiley‐Liss, Inc.
Sealed‐off spontaneous perforation of a pyometra diagnosed preoperatively by magnetic resonance imaging: A case report
Authors: Kim Jonghyun , Cho Dong‐Hyu , Kim Young‐Kon , Lee Jeong‐Heon , Jeong Young‐Ju
Published: September 2010

:

Spontaneous perforation is a very rare complication of pyometra. The clinical findings of perforated pyometra usually mimic perforation of the gastrointestinal tract. In most cases a correct diagnosis can be made only by laparotomy. In our case, the patient's pyometra was sealed and she complained only of mild abdominal pain and showed no signs of peritonitis. Ultrasonography and computed tomography (CT) findings were not suggestive of uterine rupture. However, T2‐weighted magnetic resonance imaging (MRI) demonstrated a full thickness defect of the myometrium. We discuss the CT and MRI findings that confirmed a correct diagnosis of perforated pyometra. J. Magn. Reson. Imaging 2010;32:697–699. © 2010 Wiley‐Liss, Inc.
Reversed laminar appearance of articular cartilage by T1‐weighting in 3D fat‐suppressed spoiled gradient recalled echo (SPGR) imaging
Authors: Xia Yang , Zheng Shaokuan
Published: September 2010

Purpose:

To investigate the reversed intensity pattern in the laminar appearance of articular cartilage by 3D fat‐suppressed spoiled gradient recalled echo (FS‐SPGR) imaging in magnetic resonance imaging (MRI).

Materials and Methods:

The 3D SPGR experiments were carried out on canine articular cartilage with an echo time (TE) of 2.12 msec, a repetition time (TR) of 60 msec, and various flip angles (5° to 80°). In addition, T1, T2, and T2* in cartilage were imaged and used to explain the laminar appearance in SPGR imaging.

Results:

The profiles of T2 and T2* in cartilage were similar in shape. However, the T2 values from the multigradient‐echo imaging sequence were about 1/3 of those from single spin‐echo sequences at a pixel resolution of 26 μm. While the laminar appearance of cartilage in spin‐echo imaging is caused mostly by T2‐weighting, the laminar appearance of cartilage in fast imaging (ie, short TR) at the magic angle can have a reversed intensity pattern, which is caused mostly by T1‐weighting.

Conclusion:

The laminar appearance of articular cartilage can have opposite intensity patterns in the deep part of the tissue, depending on whether the image is T1‐weighted or T2‐weighted. The underlying molecular structure and experimental protocols should both be considered when one examines cartilage images in MRI. J. Magn. Reson. Imaging 2010;32:733–737. © 2010 Wiley‐Liss, Inc.
Multiple‐bolus dynamic contrast‐enhanced MRI in the pancreas during a glucose challenge
Authors: Naish J.H. , Hutchinson C.E. , Caunce A. , Roberts C. , Waterton J.C. , Hockings P.D. , Taylor C.J. , Parker G.J.M.
Published: September 2010

Purpose:

To assess the feasibility of multiple‐bolus dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) in the pancreas; to optimize the analysis; and to investigate application of the method to a glucose challenge in type 2 diabetes.

Materials and Methods:

A 4‐bolus DCE‐MRI protocol was performed on five patients with type 2 diabetes and 11 healthy volunteers during free‐breathing. Motion during the dynamic time series was corrected for using a model‐driven nonlinear registration. A glucose challenge was administered intravenously between the first and second DCE‐MRI acquisition in all patients and in seven of the healthy controls.

Results:

Image registration improved the reproducibility of the DCE‐MRI model parameters across the repeated bolus‐acquisitions in the healthy controls with no glucose challenge (eg, coefficient of variation for Ktrans improved from 38% to 28%). Native tissue T1 was significantly lower in patients (374 ± 68 msec) compared with volunteers (519 ± 41 msec) but there was no significant difference in any of the baseline DCE‐MRI parameters. No effect of glucose challenge was observed in either the patients or healthy volunteers.

Conclusion:

Multiple bolus DCE‐MRI is feasible in the pancreas and is improved by nonlinear image registration but is not sensitive to the effects of an intravenous glucose challenge. J. Magn. Reson. Imaging 2010;32:622–628. © 2010 Wiley‐Liss, Inc.
Real‐time noise cancellation for speech acquired in interactive functional magnetic resonance imaging studies
Authors: Zvyagintsev Mikhail , Klasen Martin , Mathiak Krystyna A. , Weber René , Edgar J. Christopher , Mathiak Klaus
Published: September 2010

Purpose:

To present online scanner noise cancellation for speech acquired in functional magnetic resonance imaging (fMRI) studies.

Materials and Methods:

An online active noise cancellation method for speech acquired in fMRI studies was developed. The approach consists of two automated steps: 1) creation of an MR noise template in a short “test” fMRI scan; 2) application of the template for automatic recognition and subtraction of the MR noise from the acquired microphone signal during an fMRI study. The method was applied in an experimental paradigm where a subject and an investigator communicated in an interactive verbal generation task during fMRI.

Results:

By applying online active noise cancellation, the quality of the subject's speech was substantially improved. The present approach was found to be flexible, reliable, and easy to implement, providing a method for fMRI studies that investigate the neural correlates of interactive speech communication.

Conclusion:

Using online noise cancellation it is possible to improve the quality of acquired speech in fMRI. This approach may be recommended for interactive fMRI studies. J. Magn. Reson. Imaging 2010;32:705–713. © 2010 Wiley‐Liss, Inc.
Use of time resolved magnetic resonance imaging in the diagnosis of pelvic congestion syndrome
Authors: Pandey Tarun , Shaikh Raja , Viswamitra Sanjaya , Jambhekar Kedar
Published: September 2010

We describe the efficacy of time‐resolved MR angiography in diagnosing a case of pelvic congestion syndrome (PCS). MR angiography, using four‐dimensional (4D) TRAK (Time‐Resolved Angiography using Keyhole) technique was used in an 81‐year‐old woman presenting with low backache, pelvic pain, and left pelvic fullness. Dynamic images were obtained in multiple vascular phases including arterial, arteriovenous, and venous phases. The high temporal resolution of 4D TRAK could demonstrate early retrograde left ovarian vein filling as well as multiple dilated pelvic varices, allowing the prospective diagnosis of PCS to be made. Although uncommon in this age group, the diagnosis was subsequently confirmed on conventional catheter venography with symptomatic relief after successful embolization of the incompetent left ovarian vein. The MRA and correlative catheter venography images are presented in this case report. J. Magn. Reson. Imaging 2010;32:700–704. © 2010 Wiley‐Liss, Inc.
Negative predictive value of normal adenosine‐stress cardiac MRI in the assessment of coronary artery disease and correlation with semiquantitative perfusion analysis
Authors: Pilz Guenter , Eierle Susanne , Heer Tobias , Klos Markus , Ali Eman , Scheck Roland , Wild Michael , Bernhardt Peter , Hoefling Berthold
Published: September 2010

Purpose:

To prospectively determine the negative predictive value of normal adenosine stress cardiac MR (CMR) in routine patients referred for evaluation of coronary artery disease (CAD), predominantly with intermediate to high pretest risk.

Materials and Methods:

Consecutive patients referred for coronary angiography were examined in a 1.5 Tesla whole‐body scanner before catheterization. A total of 158 patients with normal CMR on qualitative assessment were included, and semiquantitative perfusion analysis was performed. Significant CAD was regarded as luminal narrowing of ≥70% in coronary angiography.

Results:

In the 158 study patients, negative predictive value of normal adenosine‐stress CMR for significant CAD was 96.2% (for stenosis ≥90%: 98.1%). True‐negative and false‐negative patients were comparable regarding clinical presentation, risk factors, and CMR findings. Semiquantitative perfusion analysis gave significantly prolonged arrival time index and peak time index in the false‐negative group. Using cutoff values >1.8 for arrival time index or >1.2 for peak time index, the CMR negative predictive value increased to 98.7% (for stenosis ≥90%: to 100%).

Conclusion:

The very high negative predictive value for CAD supports CMR‐based decision making for the indication to coronary angiography. Semiquantitative perfusion analysis seems promising to identify the small group of CAD patients not detectable by qualitative CMR assessment. J. Magn. Reson. Imaging 2010;32:615–621. © 2010 Wiley‐Liss, Inc.
Comparison between areas with Gd‐EOB‐DTPA uptake and without in hepatocellular carcinomas on Gd‐EOB‐DTPA‐enhanced hepatobiliary‐phase MR imaging: Pathological correlation
Authors: Lee Sanghee , Kim Seong Hyun , Park Cheol Keun , Kim Young‐sun , Lee Won Jae , Lim Hyo K.
Published: September 2010

Purpose:

To determine histological and MR imaging differences between areas with Gd‐EOB‐DTPA (gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid) uptake and without in hepatocellular carcinomas (HCCs) as seen on Gd‐EOB‐DTPA‐enhanced hepatobiliary‐phase MR images.

Materials and Methods:

This study included nine patients with nine histopathologically proven HCCs (mean size, 1.9 cm) that consisted of two portions of a non‐hypointense (Gd‐EOB‐DTPA uptake) and hypointense area (no Gd‐EOB‐DTPA uptake) in one tumor as depicted on hepatobiliary‐phase MR images. Two radiologists and one pathologist compared the histological and MR finding differences between the two portions in consensus.

Results:

In eight specimens, non‐hypointense areas of six specimens showed a green color and two specimens did not show a green color. Microscopically, two of nine showed a higher percentage of bile pigments in the non‐hypointense area as compared to the hypointense area and the remaining seven showed no difference. Six were homogeneous Edmondson‐Steiner grade II, and one was grade I. In two, non‐hypointense areas were grade II and hypointense areas were grade I. No difference between the two portions was found for necrosis, hemorrhage, fibrosis, and a fibrous capsule. Seven on T1/T2‐weighted images and eight on arterial and portal phase images showed no different signal intensity between the two portions.

Conclusion:

Although macroscopically, a non‐hypointense area of an HCC seen on GD‐EOB‐DTPA‐enhanced hepatobiliary‐phase images may be associated with the area with a green color, no definite microscopic and MR imaging findings that could discriminate a non‐hypointense from a hypointense area of an HCC was found. J. Magn. Reson. Imaging 2010;32:719–725. © 2010 Wiley‐Liss, Inc.
Functional connectivity in blood oxygenation level‐dependent and cerebral blood volume‐weighted resting state functional magnetic resonance imaging in the rat brain
Authors: Magnuson Matthew , Majeed Waqas , Keilholz Shella D.
Published: September 2010

Purpose:

To directly compare functional connectivity and spatiotemporal dynamics acquired with blood oxygenation level‐dependent (BOLD) and cerebral blood volume (CBV)‐weighted functional magnetic resonance imaging (fMRI) in anesthetized rats.

Materials and Methods:

A series of BOLD images were acquired in 10 rats followed by CBV‐weighted images created by injection of ultrasmall iron oxide particles. Functional connectivity, spectral information, and spatiotemporal dynamics were compared for the BOLD and CBV‐weighted resting state scans.

Results:

BOLD scans exhibited higher cross‐correlation values compared to CBV‐weighted scans, but the spatial patterns of correlation were similar. The BOLD spectrum contains power evenly distributed throughout the low‐frequency range while the CBV power spectrum exhibited a high power peak localized to ≈0.2 Hz. Both BOLD and CBV resting state scans showed similar propagating waves of activity along the cortex from the SII toward MI; however, these waves were detected more often in BOLD scans than in CBV scans.

Conclusion:

While the power spectrum of the CBV signal is different from that of the BOLD signal, both connectivity maps and spatiotemporal dynamics are similar for the two modalities. Further experiments should address the relationship between spontaneous neural activity, local changes in metabolism, and hemodynamic fluctuations to elucidate the origins of the BOLD and CBV signals. J. Magn. Reson. Imaging 2010;32:584–592. © 2010 Wiley‐Liss, Inc.
Interobserver and intraobserver variability of the apparent diffusion coefficient in treated malignant hepatic lesions on a 3.0T machine: Measurements in the whole lesion versus in the area with the most restricted diffusion
Authors: Lu Tri‐Linh C. , Meuli Reto A. , Marques‐Vidal Pedro M. , Bize Pierre , Denys Alban , Schmidt Sabine
Published: September 2010

Purpose:

To assess the inter/intraobserver variability of apparent diffusion coefficient (ADC) measurements in treated hepatic lesions and to compare ADC measurements in the whole lesion and in the area with the most restricted diffusion (MRDA).

Materials and Methods:

Twenty‐five patients with treated malignant liver lesions were examined on a 3.0T machine. After agreeing on the best ADC image, two readers independently measured the ADC values in the whole lesion and in the MRDA. These measurements were repeated 1 month later. The Bland–Altman method, Spearman correlation coefficients, and the Wilcoxon signed‐rank test were used to evaluate the measurements.

Results:

Interobserver variability for ADC measurements in the whole lesion and in the MRDA was 0.17 × 10−3 mm2/s [−0.17, +0.17] and 0.43 × 10−3 mm2/s [−0.45, +0.41], respectively. Intraobserver limits of agreement could be as low as [−0.10, +0.12] 10−3 mm2/s and [−0.20, +0.33] 10−3 mm2/s for measurements in the whole lesion and in the MRDA, respectively.

Conclusion:

A limited variability in ADC measurements does exist, and it should be considered when interpreting ADC values of hepatic malignancies. This is especially true for the measurements of the minimal ADC. J. Magn. Reson. Imaging 2010;32:647–653. © 2010 Wiley‐Liss, Inc.
A new open tubular capillary microextraction and sweeping for the analysis of super low concentration of hydrophobic compounds
Authors: Xia Zhining , Gan Tingting , Chen Hua , Lv Rui , Wei Weili , Yang Fengqing
Published: September 2010

A sample pre‐concentration method based on the in‐line coupling of in‐tube solid‐phase microextraction and electrophoretic sweeping was developed for the analysis of hydrophobic compounds. The sample pre‐concentration and electrophoretic separation processes were simply and sequentially carried out with a (35%‐phenyl)‐methylpolysiloxane‐coated capillary. The developed method was validated and applied to enrich and separate several pharmaceuticals including loratadine, indomethacin, ibuprofen and doxazosin. Several parameters of microextration were investigated such as temperature, pH and eluant. And the concentration of microemulsion that influences separation efficiency and microextraction efficiency were also studied. Central composite design was applied for the optimization of sampling flow rate and sampling time that interact in a very complex way with each other. The precision, sensitivity and recovery of the method were investigated. Under the optimal conditions, the maximum enrichment factors for loratadine, indomethacin, ibuprofen and doxazosin in aqueous solutions are 1355, 571, 523 and 318, respectively. In addition, the developed method was applied to determine loratadine in rabbit blood sample.
Enantioseparation of racemic paroxol on an amylose‐based chiral stationary phase by supercritical fluid chromatography
Authors: Bao Zongbi , Su Baogen , Xing Huabin , Yang Yiwen , Ren Qilong
Published: September 2010

The separation of racemic paroxol, a key precursor of trans‐(−)‐paroxetine, on Chiralpak AD‐H, an amylose‐based chiral stationary phase, by supercritical fluid chromatography was studied. Pulse experiments were investigated using supercritical carbon dioxide modified with methanol (MeOH), ethanol and 2‐propanol at 35°C and 15 MPa. Retention and separation factors were determined under analytical conditions for different mobile phase compositions. Among the modifiers used, MeOH was shown to be the best additive, and 5% v/v of MeOH was the preferable concentration at which selectivity of 1.14 and resolution of 3.0 was obtained. In order to evaluate the potential with respect to preparative separations, the adsorption isotherms of individual enantiomers of paroxol were estimated using the elution by characteristic point method. Isotherm parameters were determined from the overloaded elution profiles that were collected at pressure ranging from 15 to 24 MPa. The isotherms obtained were further validated by comparing experimentally recorded elution profiles with the predictions based on the equilibrium‐dispersive model. The results are important to the process design and optimization of preparative supercritical fluid chromatography application.
The relationship between managers' environmental perceptions, environmental management and firm performance in Spanish hotels: a whole framework
Authors: López‐Gamero María D. , Molina‐Azorín José F. , Claver‐Cortes Enrique
Published: September 2010

The examination of the possible direct link between environmental protection and firm performance has generally produced mixed results. This paper contributes to the literature by considering the antecedents of hotel managers' environmental attitudes to check whether perceptions of the external and internal factors are behind the adoption of a proactive environmental management. The study also tests whether or not the resource‐based view of the hotel mediates the positive relationships of proactive environmental management and improved environmental performance with competitive advantage and financial performance. This contribution is original because this study develops a comprehensive whole picture of this path process, which has previously only been partially discussed in the literature. Copyright © 2010 John Wiley & Sons, Ltd.
Three-dimensional computed tomography scan analysis of hepatic vasculatures in the donor liver for living donor liver transplantation
Authors: Uchida Koichiro , Taniguchi Masahiko , Shimamura Tsuyoshi , Suzuki Tomomi , Yamashita Kenichiro , Ota Minoru , Kamiyama Toshiya , Matsushita Michiaki , Furukawa Hiroyuki , Todo Satoru
Published: September 2010

Because hepatic vasculatures exhibit variations, a preoperative evaluation of the vascular anatomy and an estimation of the volume of the liver graft are essential for successful adult living donor liver transplantation. Using 3-dimensional (3D) computed tomography (CT), we analyzed the volumetric and anatomical relationship of the hepatic vasculatures of liver grafts. The livers of 223 potential donors were analyzed by 3D CT. Volumetric analysis was performed for each hepatic vein and its tributaries. The anatomy of the portal vein and hepatic artery was assessed along with the biliary system via intraoperative cholangiography in 110 recipients. On the basis of the anatomical presentation of the inferior right hepatic vein (IRHV), the hepatic veins were classified as follows: in type I, the IRHV was absent; in type II, the IRHV was smaller than the right hepatic vein (RHV); and in type III, the IRHV was greater than or equal to the RHV in size. The drainage volume of the middle hepatic vein (MHV) and especially its tributaries in the right lobe increased with the size of the IRHV (P < 0.001). In type III hepatic veins with a large IRHV (17% of the donors), the MHV tributaries had the largest drainage volume in the right lobe (41.2% ± 11.8%). Furthermore, type III hepatic veins typically exhibited biliary variations in 75% of the donors. No correlation was observed between variations in the hepatic artery and portal vein. In conclusion, a right lobe graft with a large IRHV is accompanied by a large drainage volume via the MHV and by bile duct variations in 17% of livers. Therefore, anatomical and volumetric analysis is important for preoperative evaluations. Liver Transpl 16:1062-1068, 2010. © 2010 AASLD.
Distribution‐based anomaly detection in 3G mobile networks: from theory to practice
Authors: D'Alconzo Alessandro , Coluccia Angelo , Romirer‐Maierhofer Peter
Published: September 2010

The design of anomaly detection (AD) methods for network traffic has been intensively investigated by the research community in recent years. However, less attention has been devoted to the issues which eventually arise when deploying such tools in a real operational context. We designed a statistical based change detection algorithm for identifying deviations in distribution time series. The proposed method has been applied to the analysis of a large dataset from an operational 3G mobile network, in the perspective of the adoption of such a tool in production. Our algorithm is designed to cope with the marked non‐stationarity and daily/weekly seasonality that characterize the traffic mix in a large public network. Several practical issues emerged during the study, including the need to handle incompleteness of the collected data, the difficulty in drilling down the cause of certain alarms, and the need for human assistance in resetting the algorithm after a persistent change in network configuration (e.g. a capacity upgrade). We report on our practical experience, highlighting the key lessons learned and the hands‐on experience gained from such an analysis. Finally, we propose a novel methodology based on semi‐synthetic traces for tuning and performance assessment of the proposed AD algorithm. Copyright © 2010 John Wiley & Sons, Ltd.