bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative diffusion tensor imaging in amyotrophic lateral sclerosis: Revisited
Authors: Sage Caroline A. , Van Hecke Wim , Peeters Ronald , Sijbers Jan , Robberecht Wim , Parizel Paul , Marchal Guy , Leemans Alexander , Sunaert Stefan 
Published: April 2009

AbstractVoxel‐based analyses (VBA) are increasingly being used to detect white matter abnormalities with diffusion tensor imaging (DTI) in different types of pathologies. However, the validity, specificity, and sensitivity of statistical inferences of group differences to a large extent depend on the quality of the spatial normalization of the DTI images. Using high‐dimensional nonrigid coregistration techniques that are able to align both the spatial and orientational diffusion information and incorporate appropriate templates that contain this complete DT information may improve this quality. Alternatively, a hybrid technique such as tract‐based spatial statistics (TBSS) may improve the reliability of the statistical results by generating voxel‐wise statistics without the need for perfect image alignment and spatial smoothing. In this study, we have used (1) a coregistration algorithm that was optimized for coregistration of DTI data and (2) a population‐based DTI atlas to reanalyze our previously published VBA, which compared the fractional anisotropy and mean diffusivity maps of patients with amyotrophic lateral sclerosis (ALS) with those of healthy controls. Additionally, we performed a complementary TBSS analysis to improve our understanding and interpretation of the VBA results. We demonstrate that, as the overall variance of the diffusion properties is lowered after normalizing the DTI data with such recently developed techniques (VBA using our own optimized high‐dimensional nonrigid coregistration and TBSS), more reliable voxel‐wise statistical results can be obtained than had previously been possible, with our VBA and TBSS yielding very similar results. This study provides support for the view of ALS as a multisystem disease, in which the entire frontotemporal lobe is implicated. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Neural correlates of the females' susceptibility to negative emotions: An insight into gender‐related prevalence of affective disturbances
Authors: Yuan Jiajin , Luo Yuejia , Yan Jin H. , Meng Xianxin , Yu Fengqiong , Li Hong 
Published: April 2009

AbstractConsiderable studies reported that females are more susceptible to affective disturbances such as depression, anxiety disorder, and phobia compared to males. Based on the close relation between emotional sensitivity and liability to affective disturbances (Hofer et al. [2006]: NeuroImage 32, 854–862; Spearing [2001]: Bipolar disorder, 2nd ed. Bethesda (MA): National institute of Mental Health), this study investigated the neural mechanism underlying the females' liability to affective disturbances by hypothesizing that females are more susceptible to negative emotions than males. Event‐related potentials (ERPs) were recorded for highly negative (HN), moderately negative (MN), and neutral images in Experiment 1, and for highly positive, moderately positive, and neutral images in Experiment 2, whereas subjects (15 males and 15 females) performed a standard/deviant distinction task, irrespective of the emotional valence of deviants in both experiments. In addition to the prominent emotional reactions evoked by HN stimuli in both genders, Experiment 1 displayed conspicuous emotional responses of females to MN stimuli across N2 and P3 components, which were absent in males. In contrast, Experiment 2 demonstrated neither significant valence effect, nor significant valence by gender interaction effect at these components. Thus, although both genders are sensitive to HN stimuli, females, instead of males, are particularly susceptible to negative stimuli of lesser salience, and this female specific susceptibility does not exist to the positive stimuli. Therefore, females must be more susceptible to negative emotions in life settings, which may be one important mechanism underlying their higher prevalence of affective disturbances. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Management of squamous cell carcinoma of the base of tongue with chemoradiation and brachytherapy
Authors: Cano Elmer R. , Lai Stephen Y. , Caylakli Fatma , Johnson Jonas T. , Ferris Robert L. , Carrau Ricardo L. , Snyderman Carl H. , Gooding William E. , Simenthal Alfred A. , Myers Eugene N. 
Published: April 2009

AbstractBackground.Treatment of base of tongue (BOT) squamous cell carcinoma (SCC) has traditionally been associated with poor prognosis and significant morbidity. We report a program consisting of concurrent chemoradiation followed by brachytherapy for these patients.Methods.We reviewed all patients in our institution with previously untreated BOT SCC (1996–2004) who received this treatment program.Results.In 88 patients (median age, 60.2 years; 37 T1/T2; 51 T3/T4), cervical lymph node metastases were present in 71 patients (80.7%). Six patients had residual/subsequent cervical metastases requiring 7 neck dissections. Local recurrence occurred in 16 patients (18.2%) and distant metastases occurred in 9 patients (10.2%). Median follow‐up time was 3.1 years (range, 0.5–7.8 years). Three‐year overall survival was 80.9% (95% CI: 69.6% to 88.3%). Locoregional control rate was 79.9% and disease‐specific survival was 69.5% at 3 years.Conclusions.Concurrent chemoradiotherapy followed with brachytherapy is a safe and effective method of treatment of SCC of the BOT. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Image‐guided surgery in an occult neck metastasis
Authors: Mierzwa Kathleen , Mueller Andreas 
Published: April 2009

AbstractBackground.We report a case of a squamous cell carcinoma of the right tonsillar region with 5 metastatic lymph nodes and a retropharyngeal metastasis, the latter detected in the preoperative MRI scan.Methods and Results.The treatment consisted of excision of the tumor in the oral cavity and the bilateral neck dissection. Despite careful exploration, a retropharyngeal metastasis was not identifiable during this procedure. This failure encouraged us to use navigation‐guided surgery in a second step. The difficulty in using navigation in soft tissue of the neck is the fixation of the neck. Therefore, a thermoplastic head mask, normally indicated in radiation therapy, was used for both the preoperative CT and navigation‐guided surgery. The retropharyngeal metastasis was successfully excised with this method.Conclusion.This is the first reported attempt to use navigation‐guided surgery in the soft tissue of the neck. It reveals new opportunities for navigation in the future. © 2009 Wiley Periodicals, Inc. Head Neck, 2010
Elevated parathyroid hormone levels after parathyroidectomy for primary hyperparathyroidism
Authors: Mizrachi Aviram , Gilat Hanna , Bachar Gideon , Feinmesser Raphael , Shpitzer Thomas 
Published: April 2009

AbstractBackground.Curative parathyroidectomy is associated with elevated levels of parathyroid hormone (PTH) with eucalcemia. This study sought to determine the frequency, clinical significance, and risk factors of this finding.Methods.Seventy‐six consecutive patients surgically treated for primary hyperparathyroidism due to a single parathyroid adenoma in 2006 to 2007 were monitored for 1 month postoperatively; those with elevated PTH levels (>70 pg/mL) were monitored for 18 months.Results.Nineteen patients (25%) had high postoperative PTH levels with normal calcium levels. Compared with the remaining patients, this group had a significantly higher average preoperative PTH level (224.89 vs 156.86 pg/mL) and a lesser intraoperative decrease in PTH.Conclusions.About 25% of eucalcemic patients may have elevated PTH levels after parathyroidectomy. A high preoperative PTH level (>225 pg/mL) may predict a persistently high postoperative level. Evaluation of blood and urine calcium, bone density, and cardiac function should be considered in affected patients. Head Neck, 2009
Initial clinical experience with helical tomotherapy for head and neck cancer
Authors: Chen Allen M. , Jennelle Richard L. S. , Sreeraman Radhika , Yang Claus C. , Liu Tianxiao , Vijayakumar Srinivasan , Purdy James A. 
Published: April 2009

AbstractBackground.To report a single‐institutional experience with the use of helical tomotherapy (HT)‐based intensity‐modulated radiotherapy (IMRT) for head and neck cancer.Methods.Seventy‐seven consecutive patients were treated with HT for squamous cell carcinoma of the head and neck to a median dose of 66 Gy (range, 60 to 72 Gy). Megavoltage CT scans were obtained as part of an image‐guided registration protocol for patient alignment before each treatment. Concurrent chemotherapy was administered to 48 patients (62%).Results.The 2‐year estimates of overall survival, local‐regional control, and disease‐free survival were 82%, 77%, and 71%, respectively. Spatial evaluation of local‐regional failures revealed that 16 of the 18 patients who progressed in the primary site or neck failed in the high‐dose planning target volume (PTV).Conclusions.HT appears to achieve clinical outcomes comparable to contemporary series reporting on IMRT for head and neck cancer. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Move it or lose it—Is stimulation of the vestibular system necessary for normal spatial memory?
Authors: Smith Paul F. , Darlington Cynthia. L. , Zheng Yiwen 
Published: April 2009

AbstractStudies in both experimental animals and human patients have demonstrated that peripheral vestibular lesions, especially bilateral lesions, are associated with spatial memory impairment that is long‐lasting and may even be permanent. Electrophysiological evidence from animals indicates that bilateral vestibular loss causes place cells and theta activity to become dysfunctional; the most recent human evidence suggests that the hippocampus may cause atrophy in patients with bilateral vestibular lesions. Taken together, these studies suggest that self‐motion information provided by the vestibular system is important for the development of spatial memory by areas of the brain such as the hippocampus, and when it is lost, spatial memory is impaired. This naturally suggests the converse possibility that activation of the vestibular system may enhance memory. Surprisingly, there is some human evidence that this may be the case. This review considers the relationship between the vestibular system and memory and suggests that the evolutionary age of this primitive sensory system as well as how it detects self‐motion (i.e., detection of acceleration vs. velocity) may be the reasons for its unique contribution to spatial memory. © 2009 Wiley‐Liss, Inc.
Establishing a relationship between activity reduction in human perirhinal cortex and priming
Authors: Voss Joel L. , Hauner Katherina K.Y. , Paller Ken A. 
Published: April 2009

AbstractPerirhinal neurons exhibit reduced firing rates with stimulus repetition, a phenomenon termed “repetition suppression.” However, relationships between perirhinal repetition suppression and behavioral expressions of memory remain unclear. We used anatomically constrained functional magnetic resonance imaging (fMRI) to assess relationships between perirhinal activity and priming, a type of implicit memory. Priming was expressed as speeded animacy judgments for old versus new words. Concurrently, old words elicited less neural activity in bilateral perirhinal cortex. The magnitude of the left perirhinal activity reduction selectively predicted the magnitude of behavioral priming in an across‐subjects hierarchical linear regression analysis. These findings have implications for considering how perirhinal cortex may contribute to different neurocognitive functions, possibly including both implicit memory and familiarity‐based recognition. This study documents the first evidence linking behavioral measures of priming to information processing in perirhinal cortex. © 2009 Wiley‐Liss, Inc.
The hippocampus contributes to memory expression during transitive inference in mice
Authors: DeVito Loren M. , Kanter Benjamin R. , Eichenbaum Howard 
Published: April 2009

AbstractThere is substantial evidence that the hippocampus plays a role in transitive inference, the capacity to link overlapping memories and subsequently make novel judgments between elements of those memories that are only indirectly related. However, it is unclear whether the hippocampus is involved primarily during the original acquisition of the overlapping memories, or additionally during the flexible expression of those memories during transitive judgments. Here, we demonstrated that selective hippocampal damage produced after acquisition of the overlapping memories resulted in a severe impairment in subsequent transitive inference judgments, indicating that the hippocampus does play an important role beyond the initial learning phase. Furthermore, this study extends to mice a role for the hippocampus in transitive inference, as previously observed in other species. © 2009 Wiley‐Liss, Inc.
Low‐frequency‐induced synaptic potentiation: A paradigm shift in the field of memory‐related plasticity mechanisms?
Authors: Habib Diala , Dringenberg Hans C. 
Published: April 2009

AbstractLong‐term potentiation (LTP) and long‐term depression (LTD) are two forms of synaptic plasticity thought to play functional roles in learning and memory processes. It is generally assumed that the direction of synaptic modifications (i.e., up‐ or down‐regulation of synaptic strength) depends on the specific pattern of afferent inputs, with high frequency activity or stimulation effectively inducing LTP, while low‐frequency patterns often elicit LTD. This dogma (“high frequency‐LTP, low frequency‐LTD”) has recently been challenged by evidence demonstrating low frequency stimulation (LFS)‐induced synaptic potentiation in the rodent hippocampus and amygdala. Extensive work in the past decades has focused on deciphering the mechanisms by which high frequency stimulation of afferent fiber systems results in LTP. With this review, we will compare and contrast the well‐known synaptic and cellular mechanisms underlying classical, high‐frequency‐induced LTP to those mediating the more recently discovered phenomena of LFS‐induced synaptic enhancement. In addition, we argue that LFS protocols provide a means to more accurately mimic some endogenous, oscillatory activity patterns present in hippocampal and extra‐hippocampal (especially neocortical) circuits during periods of memory consolidation. Consequently, LFS‐induced synaptic potentiation offers a novel and important avenue to investigate cellular and systems‐level mechanisms mediating the encoding, consolidation, and transfer of information throughout multiple forebrain networks implicated in learning and memory processes. © 2009 Wiley‐Liss, Inc.
Oxidative stress status and RNA expression in hippocampus of an animal model of Alzheimer's disease after chronic exposure to aluminum
Authors: Garcia Tania , Esparza José L. , Nogués M. Rosa , Romeu Marta , Domingo José L. , Gómez Mercedes 
Published: April 2009

AbstractIt is well established that aluminum (Al) is a neurotoxic agent that induces the production of free radicals in brain. Accumulation of free radicals may cause degenerative events of aging such as Alzheimer's disease. On the other hand, melatonin (Mel) is a known antioxidant, which can directly act as free radical scavenger, or indirectly by inducing the expression of some genes linked to the antioxidant defense. In this study, AβPP female transgenic (Tg2576) (Tg) and wild‐type mice (5 months of age) were fed with Al lactate supplemented in the diet (1 mg Al/g diet). Simultaneously, animals received oral Mel (10 mg/kg) dissolved in tap water until the end of the study at 11 months of age. Four treatment groups were included for both Tg and wild‐type mice: control, Al only, Mel only, and Al+Mel. At the end of the period of treatment, hippocampus was removed and processed to examine the following oxidative stress markers: reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), and thiobarbituric acid reactive substances (TBARS). Moreover, the gene expression of Cu‐ZnSOD, GR, and CAT was evaluated by real‐time RT‐PCR. Aluminum concentration in hippocampus was also determined. The biochemical changes observed in this tissue suggest that Al acts as a pro‐oxidant agent. Melatonin exerts an antioxidant action by increasing the mRNA levels of the antioxidant enzymes SOD, CAT, and GR evaluated in presence of Al and Mel, with independence of the animal model. © 2009 Wiley‐Liss, Inc.
Parametric surface modeling and registration for comparison of manual and automated segmentation of the hippocampus
Authors: Shen Li , Firpi Hiram A. , Saykin Andrew J. , West John D. 
Published: April 2009

AbstractAccurate and efficient segmentation of the hippocampus from brain images is a challenging issue. Although experienced anatomic tracers can be reliable, manual segmentation is a time consuming process and may not be feasible for large‐scale neuroimaging studies. In this article, we compare an automated method, FreeSurfer (V4), with a published manual protocol on the determination of hippocampal boundaries from magnetic resonance imaging scans, using data from an existing mild cognitive impairment/Alzheimer's disease cohort. To perform the comparison, we develop an enhanced spherical harmonic processing framework to model and register these hippocampal traces. The framework treats the two hippocampi as a single geometric configuration and extracts the positional, orientation, and shape variables in a multiobject setting. We apply this framework to register manual tracing and FreeSurfer results together and the two methods show stronger agreement on position and orientation than shape measures. Work is in progress to examine a refined FreeSurfer segmentation strategy and an improved agreement on shape features is expected. © 2009 Wiley‐Liss, Inc.
Selective effect of age, Apo e4, and Alzheimer's disease on hippocampal subfields
Authors: Mueller Susanne G. , Weiner Michael W. 
Published: April 2009

AbstractHistopathological studies and animal models suggest that different physiological and pathophysiological processes exert different subfield specific effects on the hippocampus. High‐resolution images at 4T depict details of the internal structure of the hippocampus allowing for in vivo volumetry of hippocampal subfields. The aims of this study were (1) to determine patterns of hippocampal subfield volume loss due to normal aging and Apo e4 carrier state, (2) to determine subfield specific volume losses due to preclinical (MCI) and clinical Alzheimer's disease (AD) and their modification due to age and Apo e4 carrier state. One hundred fifty seven subjects (119 cognitively healthy elderly controls, 20 MCI and 18 AD) were studied with a high resolution T2 weighted imaging sequence obtained at 4T aimed at the hippocampus. Apo e4 carrier state was known in 95 subjects (66 controls, 14 MCI, 15 AD). Subiculum (SUB), CA1, CA1‐CA2 transition zone (CA1‐2 transition), CA3‐ dentate gyrus (CA3&DG) were manually marked. Multiple linear regression analysis was used to test for effects of age, Apo e4 carrier state and effects of MCI and AD on different hippocampal subfields. Age had a significant negative effect on CA1 and CA3&DG volumes in controls (P < 0.05). AD had significantly smaller volumes of SUB, CA1, CA1‐2 transition, and MCI had smaller CA1‐2 transition volumes than controls (P < 0.05). Apo e4 carrier state was associated with volume loss in CA3&DG compared to non‐Apo e4 carriers in healthy controls and AD. Based on these findings, we conclude that subfield volumetry provides regional selective information that allows to distinguish between different normal and pathological processes affecting the hippocampus and thus for an improved differential diagnosis of neurodegenerative diseases affecting the hippocampus. © 2009 Wiley‐Liss, Inc.
Automated segmentation of hippocampal subfields from ultra‐high resolution in vivo MRI
Authors: Van Leemput Koen , Bakkour Akram , Benner Thomas , Wiggins Graham , Wald Lawrence L. , Augustinack Jean , Dickerson Bradford C. , Golland Polina , Fischl Bruce 
Published: April 2009

AbstractRecent developments in MRI data acquisition technology are starting to yield images that show anatomical features of the hippocampal formation at an unprecedented level of detail, providing the basis for hippocampal subfield measurement. However, a fundamental bottleneck in MRI studies of the hippocampus at the subfield level is that they currently depend on manual segmentation, a laborious process that severely limits the amount of data that can be analyzed. In this article, we present a computational method for segmenting the hippocampal subfields in ultra‐high resolution MRI data in a fully automated fashion. Using Bayesian inference, we use a statistical model of image formation around the hippocampal area to obtain automated segmentations. We validate the proposed technique by comparing its segmentations to corresponding manual delineations in ultra‐high resolution MRI scans of 10 individuals, and show that automated volume measurements of the larger subfields correlate well with manual volume estimates. Unlike manual segmentations, our automated technique is fully reproducible, and fast enough to enable routine analysis of the hippocampal subfields in large imaging studies. © 2009 Wiley‐Liss, Inc.
Prolonged voluntary wheel‐running stimulates neural precursors in the hippocampus and forebrain of adult CD1 mice
Authors: Bednarczyk Matthew R. , Aumont Anne , Décary Simon , Bergeron Raynald , Fernandes Karl J.L. 
Published: April 2009

AbstractVoluntary wheel‐running induces a rapid increase in proliferation and neurogenesis by neural precursors present in the adult rodent hippocampus. In contrast, the responses of hippocampal and other central nervous system neural precursors following longer periods of voluntary physical activity are unclear and are an issue of potential relevance to physical rehabilitation programs. We investigated the effects of a prolonged, 6‐week voluntary wheel‐running paradigm on neural precursors of the CD1 mouse hippocampus and forebrain. Examination of the hippocampus following 6 weeks of running revealed two to three times as many newly born neurons and 60% more proliferating cells when compared with standard‐housed control mice. Among running mice, the number of newly born neurons correlated with the total running distance. To establish the effects of wheel‐running on hippocampal precursors dividing during later stages of the prolonged running regime, BrdU was administered after 3 weeks of running and the BrdU‐retaining cells were analyzed 18 days later. Quantifications revealed that the effects of wheel‐running were maintained in late‐stage proliferating cells, as running mice had two to three times as many BrdU‐retaining cells within the hippocampal dentate gyrus, and these yielded greater proportions of both mature neurons and proliferative cells. The effects of prolonged wheel‐running were also detected beyond the hippocampus. Unlike short‐term wheel‐running, prolonged wheel‐running was associated with higher numbers of proliferating cells within the ventral forebrain subventricular region, a site of age‐associated decreases in neural precursor proliferation and neurogenesis. Collectively, these findings indicate that (i) prolonged voluntary wheel‐running maintains an increased level of hippocampal neurogenesis whose magnitude is linked to total running performance, and (ii) that it influences multiple neural precursor populations of the adult mouse brain. © 2009 Wiley‐Liss, Inc.