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We have characterized the cellular content and some antibody reactivities in synovial fluid (SF) from DA rats with CIA. Since CIA is widely used as a model for RA, in which many studies concerning immune responses are performed on SF samples, we considered it important to describe the local, disease-causing immune reactions in CIA. At the peak of disease (day 22 after immunization), the major cell population in CIA SF was granulocytes (72%), but macrophages (17.9%), plasma cells (2.6%) and lymphocytes (7.7%) were also present. The CIA synovial membrane (SM) obtained at the same time was mainly infiltrated by monocytes, with granulocytes, lymphocytes and plasma cells also present. Cell populations in blood did not differ between arthritic and normal DA rats. Equally, high anti-collagen type II (CII) and rheumatoid factor (RF) levels could be detected both in SF and in sera. Notably, RF levels were also increased in normal DA rats. Moderate levels of anti-heat shock protein 65 kD (hsp) antibodies were recorded systemically in both normal and diseased animals. In conclusion, the cellular composition in SF and in SM are similar in rat CIA and in RA. The morphological differences between SF and SM that are characteristic for RA could also be demonstrated in CIA. The antibody data indicate systemic production of anti-CII and anti-hsp antibodies as well as RF. but they give no support for local production of these antibodies in the joints, which is the case in RA. [ABSTRACT FROM AUTHOR]

More than 10 million Europeans show signs of mild cognitive impairment (MCI), a transitional stage between normal brain aging and dementia stage memory disorder. The path MCI takes can be divergent; while some maintain stability or even revert to cognitive norms, alarmingly, up to half of the cases progress to dementia within 5 years. Current diagnostic practice lacks the necessary screening tools to identify those at risk of progression. The European patient experience often involves a long journey from the initial signs of MCI to the eventual diagnosis of dementia. The trajectory is far from ideal. Here, we introduce the AI-Mind project, a pioneering initiative with an innovative approach to early risk assessment through the implementation of advanced artificial intelligence (AI) on multimodal data. The cutting-edge AI-based tools developed in the project aim not only to accelerate the diagnostic process but also to deliver highly accurate predictions regarding an individual's risk of developing dementia when prevention and intervention may still be possible. AI-Mind is a European Research and Innovation Action (RIA H2020-SC1-BHC-06-2020, No. 964220) financed between 2021 and 2026. First, the AI-Mind Connector identifies dysfunctional brain networks based on high-density magneto- and electroencephalography (M/EEG) recordings. Second, the AI-Mind Predictor predicts dementia risk using data from the Connector , enriched with computerized cognitive tests, genetic and protein biomarkers, as well as sociodemographic and clinical variables. AI-Mind is integrated within a network of major European initiatives, including The Virtual Brain, The Virtual Epileptic Patient, and EBRAINS AISBL service for sensitive data, HealthDataCloud, where big patient data are generated for advancing digital and virtual twin technology development. AI-Mind's innovation lies not only in its early prediction of dementia risk, but it also enables a virtual laboratory scenario for hypothesis-driven personalized intervention research. This article introduces the background of the AI-Mind project and its clinical study protocol, setting the stage for future scientific contributions., Competing Interests: CH-H was employed by BrainSymph AS. VAy, JP, and LP were employed by Lurtis Rules S.L. EC was employed by Pre Diagnostics AS. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Haraldsen, Hatlestad-Hall, Marra, Renvall, Maestú, Acosta-Hernández, Alfonsin, Andersson, Anand, Ayllón, Babic, Belhadi, Birck, Bruña, Caraglia, Carrarini, Christensen, Cicchetti, Daugbjerg, Di Bidino, Diaz-Ponce, Drews, Giuffrè, Georges, Gil-Gregorio, Gove, Govers, Hallock, Hietanen, Holmen, Hotta, Kaski, Khadka, Kinnunen, Koivisto, Kulashekhar, Larsen, Liljeström, Lind, Marcos Dolado, Marshall, Merz, Miraglia, Montonen, Mäntynen, Øksengård, Olazarán, Paajanen, Peña, Peña, Peniche, Perez, Radwan, Ramírez-Toraño, Rodríguez-Pedrero, Saarinen, Salas-Carrillo, Salmelin, Sousa, Suyuthi, Toft, Toharia, Tveitstøl, Tveter, Upreti, Vermeulen, Vecchio, Yazidi and Rossini.)

New biomarkers are urgently needed for many brain disorders; for example, the diagnosis of mild traumatic brain injury (mTBI) is challenging as the clinical symptoms are diverse and nonspecific. EEG and MEG studies have demonstrated several population-level indicators of mTBI that could serve as objective markers of brain injury. However, deriving clinically useful biomarkers for mTBI and other brain disorders from EEG/MEG signals is hampered by the large inter-individual variability even across healthy people. Here, we used a multivariate machine-learning approach to detect mTBI from resting-state MEG measurements. To address the heterogeneity of the condition, we employed a normative modeling approach and modeled MEG signal features of individual mTBI patients as deviations with respect to the normal variation. To this end, a normative dataset comprising 621 healthy participants was used to determine the variation in power spectra across the cortex. In addition, we constructed normative datasets based on age-matched subsets of the full normative data. To discriminate patients from healthy control subjects, we trained support-vector-machine classifiers on the quantitative deviation maps for 25 mTBI patients and 20 controls not included in the normative dataset. The best performing classifier made use of the full normative data across the entire age and frequency ranges. This classifier was able to distinguish patients from controls with an accuracy of 79%. Inspection of the trained model revealed that low-frequency activity in the theta frequency band (4-8 Hz) is a significant indicator of mTBI, consistent with earlier studies. The results demonstrate the feasibility of using normative modeling of MEG data combined with machine learning to advance diagnosis of mTBI and identify patients that would benefit from treatment and rehabilitation. The current approach could be applied to a wide range of brain disorders, thus providing a basis for deriving MEG/EEG-based biomarkers., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Itälinna et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: Chronic pain associates with various sleep problems. Patients with complex regional pain syndrome (CRPS) often report impaired sleep, but objective measurements of sleep in CRPS patients are scarce. Neuromodulation with repetitive transcranial magnetic stimulation (rTMS) can alleviate pain and improve sleep. Secondary somatosensory cortex (S2) is a possible rTMS target for the treatment of chronic pain, but the effect of S2-targeted rTMS on sleep is unknown., Methods: This randomized, sham-controlled trial assessed the effect of S2-targeted rTMS on sleep in patients with CRPS. Patients (n = 31) received either S2-targeted rTMS (10 Hz) or sham stimulation for 3 weeks. The effect of treatment on sleep was assessed with validated questionnaires, with a sleep and pain diary, and with a consumer-grade sleep tracker, the Oura ring. In addition to an ordinary univariate analysis of the results, we conducted multivariate testing of the Oura data using linear discriminant analysis (LDA)., Results: S2-targeted rTMS decreased sleep restlessness that significantly differed between the rTMS and sham stimulation patient groups (p = .028). In the multivariate analysis of the Oura data, LDA classification accuracy to separate the rTMS and sham groups exceeded 95% confidence level in four out of the seven tested models. In the subjective evaluation of sleep, the effect of rTMS and sham did not differ., Conclusion: S2-targeted rTMS influenced sleep in patients with CRPS. Improved sleep may enhance CRPS symptom alleviation and be of clinical importance. A univariate analysis could separate the rTMS and sham treatments. The multivariate analysis revealed that including multiple sleep-related parameters can be beneficial when analyzing rTMS effects on sleep. As sleep is related both to pain and quality of life, and sleep rTMS can be directly affected by rTMS, objective monitoring of sleep in various future rTMS trials could be fruitful., (© 2023 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

Different neuroimaging methods can yield different views of task-dependent neural engagement. Studies examining the relationship between electromagnetic and hemodynamic measures have revealed correlated patterns across brain regions but the role of the applied stimulation or experimental tasks in these correlation patterns is still poorly understood. Here, we evaluated the across-tasks variability of MEG-fMRI relationship using data recorded during three distinct naming tasks (naming objects and actions from action images, and objects from object images), from the same set of participants. Our results demonstrate that the MEG-fMRI correlation pattern varies according to the performed task, and that this variability shows distinct spectral profiles across brain regions. Notably, analysis of the MEG data alone did not reveal modulations across the examined tasks in the time-frequency windows emerging from the MEG-fMRI correlation analysis. Our results suggest that the electromagnetic-hemodynamic correlation could serve as a more sensitive proxy for task-dependent neural engagement in cognitive tasks than isolated within-modality measures., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Mononen, Kujala, Liljeström, Leppäaho, Kaski and Salmelin.)

Exaggerated subthalamic beta oscillatory activity and increased beta range cortico-subthalamic synchrony have crystallized as the electrophysiological hallmarks of Parkinson's disease. Beta oscillatory activity is not tonic but occurs in 'bursts' of transient amplitude increases. In Parkinson's disease, the characteristics of these bursts are altered especially in the basal ganglia. However, beta oscillatory dynamics at the cortical level and how they compare with healthy brain activity is less well studied. We used magnetoencephalography (MEG) to study sensorimotor cortical beta bursting and its modulation by subthalamic deep brain stimulation in Parkinson's disease patients and age-matched healthy controls. We show that the changes in beta bursting amplitude and duration typical of Parkinson's disease can also be observed in the sensorimotor cortex, and that they are modulated by chronic subthalamic deep brain stimulation, which, in turn, is reflected in improved motor function at the behavioural level. In addition to the changes in individual beta bursts, their timing relative to each other was altered in patients compared to controls: bursts were more clustered in untreated Parkinson's disease, occurring in 'bursts of bursts', and re-burst probability was higher for longer compared to shorter bursts. During active deep brain stimulation, the beta bursting in patients resembled healthy controls' data. In summary, both individual bursts' characteristics and burst patterning are affected in Parkinson's disease, and subthalamic deep brain stimulation normalizes some of these changes to resemble healthy controls' beta bursting activity, suggesting a non-invasive biomarker for patient and treatment follow-up., Competing Interests: Declaration of Competing Interest Jukka Nenonen is employed by MEGIN Oy, the producer of the MEG device used for measurements. Eero Pekkonen has received lecturing fees from Abbott, the producer of the DBS stimulation device, and is the Finnish PI for the ‘Abbott DBS Registry of Outcomes for Indications over Time’. Apart from that, the authors declare no other potential competing interests., (Copyright © 2022. Published by Elsevier Inc.)

Beta rhythm modulation has been used as a biomarker to reflect the functional state of the sensorimotor cortex in both healthy subjects and patients. Here, the effect of reduced alertness and active attention to the stimulus on beta rhythm modulation was investigated. Beta rhythm modulation to tactile stimulation of the index finger was recorded simultaneously with MEG and EEG in 23 healthy subjects (mean 23, range 19-35 years). The temporal spectral evolution method was used to obtain the peak amplitudes of beta suppression and rebound in three different conditions (neutral, snooze, and attention). Neither snooze nor attention to the stimulus affected significantly the strength of beta suppression nor rebound, although a decrease in suppression and rebound strength was observed in some subjects with a more pronounced decrease of alertness. The reduction of alertness correlated with the decrease of suppression strength both in MEG (left hemisphere r = 0.49; right hemisphere r = 0.49, *p < 0.05) and EEG (left hemisphere r = 0.43; right hemisphere r = 0.72, **p < 0.01). The results indicate that primary sensorimotor cortex beta suppression and rebound are not sensitive to slightly reduced alertness nor active attention to the stimulus at a group level. Hence, tactile stimulus-induced beta modulation is a suitable tool for assessing the sensorimotor cortex function at a group level. However, subjects' alertness should be maintained high during recordings to minimize individual variability., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Reliable paradigms and imaging measures of individual-level brain activity are paramount when reaching from group-level research studies to clinical assessment of individual patients. Magnetoencephalography (MEG) provides a direct, non-invasive measure of cortical processing with high spatiotemporal accuracy, and is thus well suited for assessment of functional brain damage in patients with language difficulties. This MEG study aimed to identify, in a delayed picture naming paradigm, source-localized evoked activity and modulations of cortical oscillations that show high test-retest reliability across measurement days in healthy individuals, demonstrating their applicability in clinical settings. For patients with a language disorder picture naming can be a challenging task. Therefore, we also determined whether a semantic judgment task ('Is this item living?') with a spoken response ("yes"/"no") would suffice to induce comparably consistent activity within brain regions related to language production. The MEG data was collected from 19 healthy participants on two separate days. In picture naming, evoked activity was consistent across measurement days (intraclass correlation coefficient (ICC)>0.4) in the left frontal (400-800 ms after image onset), sensorimotor (200-800 ms), parietal (200-600 ms), temporal (200-800 ms), occipital (400-800 ms) and cingulate (600-800 ms) regions, as well as the right temporal (600-800 ms) region. In the semantic judgment task, consistent evoked activity was spatially more limited, occurring in the left temporal (200-800 ms), sensorimotor (400-800 ms), occipital (400-600 ms) and subparietal (600-800 ms) regions, and the right supramarginal cortex (600-800 ms). The delayed naming task showed typical beta oscillatory suppression in premotor and sensorimotor regions (800-1200 ms) but other consistent modulations of oscillatory activity were mostly observed in posterior cortical regions that have not typically been associated with language processing. The high test-retest consistency of MEG evoked activity in the picture naming task testifies to its applicability in clinical evaluations of language function, as well as in longitudinal MEG studies of language production in clinical and healthy populations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Inc.)

Modulation of the ~20-Hz brain rhythm has been used to evaluate the functional state of the sensorimotor cortex both in healthy subjects and patients, such as stroke patients. The ~20-Hz brain rhythm can be detected by both magnetoencephalography (MEG) and electroencephalography (EEG), but the comparability of these methods has not been evaluated. Here, we compare these two methods in the evaluating of ~20-Hz activity modulation to somatosensory stimuli. Rhythmic ~20-Hz activity during separate tactile and proprioceptive stimulation of the right and left index finger was recorded simultaneously with MEG and EEG in twenty-four healthy participants. Both tactile and proprioceptive stimulus produced a clear suppression at 300-350 ​ms followed by a subsequent rebound at 700-900 ​ms after stimulus onset, detected at similar latencies both with MEG and EEG. The relative amplitudes of suppression and rebound correlated strongly between MEG and EEG recordings. However, the relative strength of suppression and rebound in the contralateral hemisphere (with respect to the stimulated hand) was significantly stronger in MEG than in EEG recordings. Our results indicate that MEG recordings produced signals with higher signal-to-noise ratio than EEG, favoring MEG as an optimal tool for studies evaluating sensorimotor cortical functions. However, the strong correlation between MEG and EEG results encourages the use of EEG when translating studies to clinical practice. The clear advantage of EEG is the availability of the method in hospitals and bed-side measurements at the acute phase., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Despite the high prevalence of mild traumatic brain injury (mTBI), current diagnostic tools to objectively assess cognitive complaints after mTBI continue to be inadequate. Our aim was to identify neuronal correlates for cognitive difficulties in mTBI patients by evaluating the possible alterations in oscillatory brain activity during a behavioral task known to be sensitive to cognitive impairment after mTBI. We compared oscillatory brain activity during rest and cognitive tasks (Paced Auditory Serial Addition Test [PASAT] and a vigilance test [VT]) with magnetoencephalography between 25 mTBI patients and 20 healthy controls. Whereas VT induced no significant differences compared with resting state in either group, patients exhibited stronger attenuation of 8- to 14-Hz oscillatory activity during PASAT than healthy controls in the left parietotemporal cortex ( p  ≤ 0.05). Further, significant task-related modulation in the left superior frontal gyrus and right prefrontal cortex was detected only in patients. The ∼10-Hz (alpha) peak frequency declined in frontal, temporal, and parietal regions during PASAT compared with rest ( p  < 0.016) in patients, whereas in controls it remained the same or showed a tendency to increase. In patients, the ∼10-Hz peak amplitude was negatively correlated with behavioral performance in the Trail Making Test. The observed alterations in the cortical oscillatory activity during cognitive load may provide measurable neurophysiological correlates of cognitive difficulties in mTBI patients, even at the individual level.

Communication between brain regions is thought to be facilitated by the synchronization of oscillatory activity. Hence, large-scale functional networks within the brain may be estimated by measuring synchronicity between regions. Neurophysiological recordings, such as magnetoencephalography (MEG) and electroencephalography (EEG), provide a direct measure of oscillatory neural activity with millisecond temporal resolution. In this paper, we describe a full data analysis pipeline for functional connectivity analysis based on dynamic imaging of coherent sources (DICS) of MEG data. DICS is a beamforming technique in the frequency-domain that enables the study of the cortical sources of oscillatory activity and synchronization between brain regions. All the analysis steps, starting from the raw MEG data up to publication-ready group-level statistics and visualization, are discussed in depth, including methodological considerations, rules of thumb and tradeoffs. We start by computing cross-spectral density (CSD) matrices using a wavelet approach in several frequency bands (alpha, theta, beta, gamma). We then provide a way to create comparable source spaces across subjects and discuss the cortical mapping of spectral power. For connectivity analysis, we present a canonical computation of coherence that facilitates a stable estimation of all-to-all connectivity. Finally, we use group-level statistics to limit the network to cortical regions for which significant differences between experimental conditions are detected and produce vertex- and parcel-level visualizations of the different brain networks. Code examples using the MNE-Python package are provided at each step, guiding the reader through a complete analysis of the freely available openfMRI ds000117 "familiar vs. unfamiliar vs. scrambled faces" dataset. The goal is to educate both novice and experienced data analysts with the "tricks of the trade" necessary to successfully perform this type of analysis on their own data.

Reconfigurations of synchronized large-scale networks are thought to be central neural mechanisms that support cognition and behavior in the human brain. Magnetoencephalography (MEG) recordings together with recent advances in network analysis now allow for sub-second snapshots of such networks. In the present study, we compared frequency-resolved functional connectivity patterns underlying reading of single words and visual recognition of symbol strings. Word reading emphasized coherence in a left-lateralized network with nodes in classical perisylvian language regions, whereas symbol processing recruited a bilateral network, including connections between frontal and parietal regions previously associated with spatial attention and visual working memory. Our results illustrate the flexible nature of functional networks, whereby processing of different form categories, written words vs. symbol strings, leads to the formation of large-scale functional networks that operate at distinct oscillatory frequencies and incorporate task-relevant regions. These results suggest that category-specific processing should be viewed not so much as a local process but as a distributed neural process implemented in signature networks. For words, increased coherence was detected particularly in the alpha (8-13 Hz) and high gamma (60-90 Hz) frequency bands, whereas increased coherence for symbol strings was observed in the high beta (21-29 Hz) and low gamma (30-45 Hz) frequency range. These findings attest to the role of coherence in specific frequency bands as a general mechanism for integrating stimulus-dependent information across brain regions.

Current cardiac drug safety assessments focus on hERG channel block and QT prolongation for evaluating arrhythmic risks, whereas the optogenetic approach focuses on the action potential (AP) waveform generated by a monolayer of human cardiomyocytes beating synchronously, thus assessing the contribution of several ion channels on the overall drug effect. This novel tool provides arrhythmogenic sensitizing by light-induced pacing in combination with non-invasive, all-optical measurements of cardiomyocyte APs and will improve assessment of drug-induced electrophysiological aberrancies. With the help of patch clamp electrophysiology measurements, we aimed to investigate whether the optogenetic modifications alter human cardiomyocytes' electrophysiology and how well the optogenetic analyses perform against this gold standard. Patch clamp electrophysiology measurements of non-transduced stem cell-derived cardiomyocytes compared to cells expressing the commercially available optogenetic constructs Optopatch and CaViar revealed no significant changes in action potential duration (APD) parameters. Thus, inserting the optogenetic constructs into cardiomyocytes does not significantly affect the cardiomyocyte's electrophysiological properties. When comparing the two methods against each other (patch clamp vs. optogenetic imaging) we found no significant differences in APD parameters for the Optopatch transduced cells, whereas the CaViar transduced cells exhibited modest increases in APD-values measured with optogenetic imaging. Thus, to broaden the screen, we combined optogenetic measurements of membrane potential and calcium transients with contractile motion measured by video motion tracking. Furthermore, to assess how optogenetic measurements can predict changes in membrane potential, or early afterdepolarizations (EADs), cells were exposed to cumulating doses of E-4031, a hERG potassium channel blocker, and drug effects were measured at both spontaneous and paced beating rates (1, 2 Hz). Cumulating doses of E-4031 produced prolonged APDs, followed by EADs and drug-induced quiescence. These observations were corroborated by patch clamp and contractility measurements. Similar responses, although more modest were seen with the I Ks potassium channel blocker JNJ-303. In conclusion, optogenetic measurements of AP waveforms combined with optical pacing compare well with the patch clamp gold standard. Combined with video motion contractile measurements, optogenetic imaging provides an appealing alternative for electrophysiological screening of human cardiomyocyte responses in pharmacological efficacy and safety testings.

Language production is a complex neural process that requires the interplay between multiple specialized cortical regions. We investigated modulations in large-scale cortical networks underlying preparation for speech production by contrasting cortico-cortical coherence for overt and silent picture naming in an all-to-all connectivity analysis. To capture transient, frequency-specific changes in functional connectivity we analyzed the magnetoencephalography data in two consecutive 300-ms time windows. Within the first 300 ms following picture onset beta frequency coherence was increased for overt naming in a network of regions comprising the bilateral parieto-temporal junction and medial cortices, suggesting that overt articulation modifies selection processes involved in speech planning. In the late time window (300-600 ms after picture onset) beta-range coherence was enhanced in a network that included the ventral sensorimotor and temporal cortices. Coherence in the gamma band was simultaneously reduced between the ventral motor cortex and supplementary motor area, bilaterally. The results suggest functionally distinct roles for beta (facilitatory) and gamma (suppressive) band interactions in speech production, with strong involvement of the motor cortex in both frequency bands. Overall, a striking difference in functional connectivity between the early and late time windows was observed, revealing the dynamic nature of large-scale cortical networks that support language and speech. Our results demonstrate that as the naming task evolves in time, the global connectivity patterns change, and that these changes occur (at least) on the time-scale of a few hundred milliseconds. More generally, these results bear implications for how we view large-scale neural networks underlying task performance., (© 2014 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.)

It is often implicitly assumed that the neural activation patterns revealed by hemodynamic methods, such as functional magnetic resonance imaging (fMRI), and electrophysiological methods, such as magnetoencephalography (MEG) and electroencephalography (EEG), are comparable. In early sensory processing that seems to be the case, but the assumption may not be correct in high-level cognitive tasks. For example, MEG and fMRI literature of single-word reading suggests differences in cortical activation, but direct comparisons are lacking. Here, while the same human participants performed the same reading task, analysis of MEG evoked responses and fMRI blood oxygenation level-dependent (BOLD) signals revealed marked functional and spatial differences in several cortical areas outside the visual cortex. Divergent patterns of activation were observed in the frontal and temporal cortex, in accordance with previous separate MEG and fMRI studies of reading. Furthermore, opposite stimulus effects in the MEG and fMRI measures were detected in the left occipitotemporal cortex: MEG evoked responses were stronger to letter than symbol strings, whereas the fMRI BOLD signal was stronger to symbol than letter strings. The EEG recorded simultaneously during MEG and fMRI did not indicate neurophysiological differences that could explain the observed functional discrepancies between the MEG and fMRI results. Acknowledgment of the complementary nature of hemodynamic and electrophysiological measures, as reported here in a cognitive task using evoked response analysis in MEG and BOLD signal analysis in fMRI, represents an essential step toward an informed use of multimodal imaging that reaches beyond mere combination of location and timing of neural activation.

Podosomes and invadopodia are actin-based structures at the ventral cell membrane, which have a role in cell adhesion, migration and invasion. Little is known about the differences and dynamics underlying these structures. We studied podosome-like structures of oral squamous carcinoma cells and invadopodia of their invasive variant that has undergone a spontaneous epithelial-mesenchymal transition (EMT). In 3D imaging, podosomes were relatively large structures that enlarged in time, whereas invadopodia of invasive cells remained small, but were more numerous, degraded more extracellular matrix (ECM) and were morphologically strikingly different from podosomes. In live-cell imaging, highly dynamic, invadopodia-embedded actin tails were frequently released and rocketed through the cytoplasm. Resembling invadopodia, we found new club-ended cell extensions in EMT-experienced cells, which contained actin, cortactin, vinculin and MT1-matrix metalloproteinase. These dynamic cell extensions degraded ECM and, in field emission scanning electron microscopy, protruded from the dorsal cell membrane. Plectin, alphaII-spectrin, talin and focal adhesion kinase immunoreactivities were detected in podosome rings, whereas they were absent from invadopodia. Tensin potentially replaced talin in invadopodia. Integrin alpha(3)beta(1) surrounded both podosomes and invadopodia, whereas integrin alpha(v)beta(5) localized only to invadopodia heads. Pacsin 2, in conjunction with filamin A, was detected early in podosomes, whereas pacsin 2 was not found in invadopodia and filamin A showed delayed accumulation. Fluorescence recovery after photobleaching indicated faster reorganization of actin, cortactin and filamin A in podosomes compared to invadopodia. In conclusion, EMT affects the invasion machinery of oral squamous carcinoma cells. Non-invasive squamous carcinoma cells constitutively organize podosomes, whereas invasive cells form invadopodia. The club-ended cell extensions, or externalized invadopodia, are involved in ECM degradation and maintenance of contact to adhesion substrate and surrounding cells during invasion.

Most neuroimaging studies are performed using one imaging method only, either functional magnetic resonance imaging (fMRI), electroencephalography (EEG), or magnetoencephalography (MEG). Information on both location and timing has been sought by recording fMRI and EEG, simultaneously, or MEG and fMRI in separate sessions. Such approaches assume similar active areas whether detected via hemodynamic or electrophysiological signatures. Direct comparisons, after independent analysis of data from each imaging modality, have been conducted primarily on low-level sensory processing. Here, we report MEG (timing and location) and fMRI (location) results in 11 subjects when they named pictures that depicted an action or an object. The experimental design was exactly the same for the two imaging modalities. The MEG data were analyzed with two standard approaches: a set of equivalent current dipoles and a distributed minimum norm estimate. The fMRI blood-oxygen-level dependent (BOLD) data were subjected to the usual random-effect contrast analysis. At the group level, MEG and fMRI data showed fairly good convergence, with both overall activation patterns and task effects localizing to comparable cortical regions. There were some systematic discrepancies, however, and the correspondence was less compelling in the individual subjects. The present analysis should be helpful in reconciling results of fMRI and MEG studies on high-level cognitive functions., ((c) 2009 Wiley-Liss, Inc.)

Objective: To test if the pannus tissue is characterized by a high receptor activator of nuclear factor kappaB ligand to osteoprotegerin (RANKL:OPG) ratio, which could explain local osteoclastogenesis and formation of bony erosions., Methods: Messenger RNA and protein expressions of RANKL and OPG in rheumatoid and osteoarthritic tissue samples were measured using quantitative real-time RT-PCR and Western blot/densitometry. Pannus and synovitis fibroblasts explanted from tissue samples were cultured in vitro without and with TNF-alpha, IL-1Beta or IL-17 and analyzed quantitatively for RANKL expression. The ability of pannus fibroblasts to induce formation of multinuclear osteoclast-like cells from human monocytes, with macrophage-colony stimulating factor (M-CSF) but without RANKL added, was tested. Histochemical staining was used to assess the eventual presence of RANKL and tartrate resistant acid phosphatase positive osteoclast-like cells at the pannus-bone interface., Results: RANKL:OPG ratios of messenger RNA (p<0.05) and protein level were high in pannus (2.06+/-0.73 and 2.2+/-0.65) compared to rheumatoid (0.62+/-0.13 and 1.31+/-0.69) and osteoarthritis (0.62+/-0.32 and 0.52+/-0.16) synovial membranes. Resting and stimulated (p dependent on the cytokine used) pannus fibroblasts produced RANKL in excess (p=0.0005) and unstimulated pannus fibroblasts also effectively induced osteoclast-like cell formation from monocytes in vitro without any exogenous RANKL added. Compatible with these findings, multinuclear osteoclasts-like cells were frequent in the fibroblast- and macrophage-rich pannus tissue at the soft tissue-to-bone interface., Conclusion: The high RANKL:OPG ratio, together with close fibroblast-to-monocyte contacts in pannus tissue, probably favor local generation of bone resorbing osteoclasts at the site of erosion in rheumatoid arthritis.

Objective: Synovial inflammation in rheumatoid arthritis (RA) leads to pannus tissue invasion and destruction of cartilage/bone matrix by proteinases. Our intention was to analyze some of the key matrix metalloproteinases (MMPs) in pannus tissue overlying evolving cartilage erosions in RA., Methods: Frozen tissue samples of pannus and synovium from advanced RA and synovium from osteoarthritic patients were used for immunohistochemical, western blotting and quantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis of MMP-1, -3, -13 and -14. Synovial fibroblast cultures, stimulated with tumour necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta), were analyzed with enzyme-linked immunosorbent assays (ELISA) and quantitative RT-PCR., Results: MMP-3 was highly expressed in pannus tissue compared with significantly lower expression levels of MMP-1, -13 and -14. In fibroblast cultures IL-1beta was a potent stimulus for MMP-3, whereas TNF-alpha was more potent for MMP-1., Conclusion: This is the first study to demonstrate quantitatively in real time that MMP-3 mRNA expression is clearly higher in advanced RA pannus tissue compared to parallel RA or osteoarthritic synovium. MMP-3 mRNA levels were also clearly overexpressed in RA pannus compared to MMP-1, -13 and -14. Advanced RA has previously been found to overexpress IL-1beta. The high expression of MMP-3 in pannus and IL-1beta, mediated stimulation of MMP-3 suggest that MMP-3 plays a significant role in the progression of erosions through the proteoglycan-rich cartilage matrix.

Objective: To study tumor necrosis factor alpha (TNFalpha) -308 gene promoter polymorphism and circulating levels of TNFalpha and soluble TNF receptor type I (sTNFRI) in rheumatoid arthritis (RA) patients with and without reactive amyloidosis., Methods: In a retrospective study, we examined 55 RA patients with biopsy-proven reactive amyloidosis and 55 control RA patients without amyloidosis (matched for age, sex, rheumatoid factor titer, and RA duration). Inflammatory activity was assessed by measuring the erythrocyte sedimentation rate and C-reactive protein level. TNFalpha gene promoter polymorphism was studied using polymerase chain reaction-restriction fragment length polymorphism assay. Cytokine and receptor levels were measured by enzyme-linked immunoassays., Results: Patients with RA and amyloidosis had significantly higher TNFalpha and sTNFRI levels than did the control RA patients. The increased circulating levels of TNFalpha correlated with interleukin-18 levels, but not with the serum amyloid A protein levels or with TNFalpha -308 gene promoter polymorphism (reported to be associated with high TNFalpha levels and certain disease susceptibilities). In the patients with RA and amyloidosis, those with anemia had significantly higher TNFalpha and sTNFRI levels than did those without anemia, and circulating TNFalpha and sTNFRI levels correlated negatively with hemoglobin concentrations. In the patients with RA and amyloidosis, those with nephropathy had significantly higher TNFalpha and sTNFRI levels than did those without nephropathy; in patients with isolated proteinuria (but no creatinine elevation) the TNFalpha level was also significantly increased, indicating that the TNFalpha elevation was not merely a consequence of impaired renal function., Conclusion: This study shows that circulating levels of TNFalpha and sTNFRI are significantly increased in RA patients with amyloidosis as compared with control RA patients without amyloidosis and that the increased levels may be implicated in the pathogenesis of certain disease manifestations, including anemia of chronic disease and renal pathology in reactive amyloidosis.

Objective: To measure cartilage pH in patients with osteoarthritis (OA) and to analyze the presence of cathepsin K, the recently discovered acidic endoproteinase, in phenotypically altered chondrocytes., Methods: Intraoperative measurements of the pH of clinically normal, fibrillated, superficially fissured, and deeply fissured cartilage surfaces (grades 0-3, respectively) in OA patients undergoing primary hip replacement surgery were performed with the use of a sting electrode sterilized with microbicidic plasma. Fluorescent pH probes were used for in situ assessment of cartilage matrix pH. Cathepsin K was assessed using quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry methods., Results: The pH of grade 0 cartilage surfaces was 7.1 +/- 0.4 (mean +/- SD), compared with 6.2 +/- 0.9 (P < 0.05), 5.7 +/- 1.0 (P < 0.001), and 5.5 +/- 1.0 (P < 0.001) for grades 1-3 cartilage surfaces, respectively. Fluorescent pH probes and acid-dependent autocatalytic conversion of cathepsin K into its active, low molecular weight form in cartilage confirmed these findings. Cathepsin K messenger RNA levels increased in relation to the severity of OA, and the number of cathepsin K-containing chondrocytes increased from a mean +/- SD of 12 +/- 3 in grade 0 cartilage surfaces to 47 +/- 7, 50 +/- 6, and 100 +/- 12 in grades 1-3 cartilage surfaces, respectively (P < 0.001 for all comparisons)., Conclusion: Acid-activated, but pharmacologically inhibitable, cathepsin K is induced in phenotypically altered chondrocytes in OA. The findings suggest that cathepsin K, rather than neutral matrix metalloproteinases, degrades the superficial gliding surfaces of the articular hyaline cartilage in OA.

Objective: To investigate the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in the synovial membrane of patients with rheumatoid arthritis (RA) and osteoarthritis (OA)., Methods: Mouse monoclonal antibody against human EMMPRIN was applied according to an avidin-biotin-peroxidase complex method to reveal EMMPRIN expression. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to check for the presence of EMMPRIN protein and messenger RNA (mRNA)., Results: EMMPRIN immunoreactivity was more intense in RA than in OA synovial membrane (P < 0.01). EMMPRIN staining was more widespread in RA than in OA, especially in association with macrophage infiltrates. RT-PCR of synovial membrane samples disclosed the presence of EMMPRIN mRNA. Nucleotide sequencing of the PCR amplification products confirmed the identity of the amplified bands. Immunoblot analysis revealed 55-kd glycosylated EMMPRIN bands, which were particularly prominent in RA samples., Conclusion: The expression of EMMPRIN is upregulated in the rheumatoid synovial membrane. EMMPRIN can induce local production of at least MMPs 1, 2, and 3, and can thereby play a role in joint destruction in RA.