Introduction of high-throughput measurement technologies combined with the increase of the scientific knowledge base, with respect to our understanding of cellular and biological processes, resulted in establishing computer and information science as an important and fundamental component of modern biology. High-throughput measurement technologies, such as microarray-based profiling, mass spectrometry screens, and high-throughput sequencing, give rise to several computational challenges. On one hand, they require a rigorous approach to assay design. Scientists and technology developers work on optimizing assay components so as to maximize the information obtained through the measurement. On the other hand, the use of high-throughput measurement gives rise to large quantities of data that needs to be pre-processed and analyzed to obtain meaningful knowledge. This processing and analysis is performed on various levels - from pre-processing the raw data, such as images from microarrays or raw sequence reads - to analyzing the data and to the discovery of biomarkers or other biologically meaningful characteristics. Measurement technology addresses several aspects of cellular processes such as DNA, RNA, proteomics, metabolomics, epigenetics and pathways. This increase in the scientific knowledge base also leads to a central role played by data analysis and modeling, strongly grounded in computational methods. Systems biology or integrative biology approaches and network analysis are of specific importance in this context.The above is even further emphasized in the context of cancer research. Samples are complex and heterogeneous, and cancer related mechanisms involve many layers of the process that leads from the genome to cellular function. One example of a specific need of cancer is the study of large scale aberrations in the genome. CNVs (copy number variations) were recently recognized as abundant in normal cell populations and as related to many other disease types but they are still a hallmark of cancer ,2. GenomComputational biologists focusing on cancer develop methods for the genome scale characterization of tumors, on various levels of the molecular process. Data analysis methods often rely on the analysis of high-throughput measurement data and they provide understanding of the relationship between various molecular characteristics of cells. For example - how do genome structural aberrations and changes in copy number, a result of increased genome instability in cancer, affect the expression of genes and other functional elements such as miRNA, and how do the latter changes affect the function of related proteins. Understanding of the association of genomic characteristics and clinical properties of primary tumor samples, xenografts or cell lines contributes to personalized cancer medicine through the development of predictive biomarkers of drug efficacy. Many research projects therefore aim to discover biomarkers, at either genome, transcriptome or proteome level that are prognostic of cancer progression or predictive of response to specific therapeutic agents ,7. Cancehttp://bioinfo.cs.technion.ac.il/people/zohar/recombccb2010/ took place in Oslo, Norway, adjacent to the biannual meeting of the European Association for Cancer Research (EACR). This meeting followed the first RCCB, which was held in San Diego in 2007. In 2011 RCCB will be held in conjunction with the main RECOMB conference in Vancouver; http://compbio.cs.sfu.ca/recomb2011/satellite/.RECOMB Cancer Computational Biology (RCCB) is a RECOMB satellite workshop that focuses on computational, statistical and algorithmic questions related to cancer. RCCB 2010 http://bioinfo.cs.technion.ac.il/people/zohar/recombccb2010/program.html. We will highlight three of the thematic foci of the meeting:Integrative computational biology in cancer research benefits from close collaboration among diverse disciplines - computational biology, cancer research, genomics, proteomics to name a few. This collaboration also manifested itself in the meeting, bringing together speakers and attendees from various disciplines. The full program and to video recordings of many of the talks are listed on the meeting's website Cancer and copy number instability. Chromosomal instability and changes in copy number are amongst the most important hallmarks of cancer. In many cases copy number differences drive differences in clinical behavior and in susceptibility to treatments. The understanding of the structure of chromosomal aberrations in cancer requires accurate measurement technologies coupled with data analysis and interpretation tools. Chris Greenman, from Wellcome Trust Sanger Institute, described an algorithmic approach to studying the evolution of genomic instability in cancer, through the analysis of sequencing data. In particular these methods attempt to infer orders of occurrence for observed aberrations, both mutations and copy number changes. Peter van Loo, from KU Leuven, described ASCAT - a tool for analyzing allele-specific copy number data, and discussed some results obtained for a breast cancer cohort. These include differences between various breast cancer subtypes. Basal-like samples were found to have significantly higher frequency of LOH compared to the other types. Hiroko Solvang, from Oslo University Hospital, talked about the relationship between copy number and expression levels [• n levels . Yinyin n levels . This apSystems biology approach to cancer. Three keynote talks addressed studies that consider the full system level properties of cancer and what can be learned from them. Joe Gray's Lab, at LBNL, worked with 50+ breast cancer cell lines and ~80 different compounds targeting the ERBB2 pathway, generating IC50 data for these combinations and inferring genomic determinants of treatment efficiency. Yossi Yarden's Lab, at the Weizmann Institute, studied the response to EGF stimulus, measuring both the transcriptome reaction and a comprehensive miRNA reaction. A talk at the meeting described some of these results in the context of previous studies of the EGF pathway. Special emphasis was put on miRNAs that are immediately down-regulated in response to the signal. Israel Steinfeld, from the Technion in Haifa, described a breast cancer study integrating miRNA and mRNA profiles that further expands our understanding of miRNA activity in cancer. This includes the association of processes such as proliferation and cell cycle to the activity of miRNAs and their target genes. High-throughput proteomics profiling, including the understanding of activation status, can be an important piece in the cancer system biology picture, including implications for direct targeted therapy. The realization of this potential requires accurate and high-throughput proteomics measurement technologies as well as data analysis techniques to support interpretation and inference. Gordon Mills, from MD Anderson Cancer Centre, described the ongoing work he and colleagues are doing on developing and optimizing Reverse Phase Protein Arrays (RPPAs), and on using them in cancer-related studies.• Networks. Understanding the relationship between various molecular elements can extend the understanding of larger scale processes and thereby expand the repertoire of molecules related to cancer. Anaise Baudot, from CNIO , presented her joint work with Enrico Glaab and others on extending functional annotation networks using information derived from protein-protein interaction networks [• networks . They manetworks .BMC Bioinformatics [The conference offered a full paper track, and in this thematic collection we present the papers that were presented as talks in Oslo and were also selected, through an additional co-ordinated review process, to be published by ormatics -25.


In osteoarthritis, articular cartilage degenerates and eventually wears out, resulting in pain and disability. It is a major challenge in health care to prevent osteoarthritis or slow down the progression of the disease. The onset of osteoarthritis may result from an altered stress and strain state in cartilage, for example, due to an injury of ligament, cartilage, or meniscus. However, the disease progression is patient specific and can hardly be predicted. In order to assess the articular cartilage function and possible failure sites in joints, and to evaluate the onset and progression of osteoarthritis patient-specifically, computational models may become useful tools. Although there has been significant progress over the last years, these models need to be further developed before they may eventually become of direct clinical value. For clinical, patient-specific application of a computer model, a realistic description of joint geometry, joint kinematics, and tissue loading is ultimately required. Geometrical data can be obtained from imaging modalities, such as MRI, which become increasingly more detailed. Still, meshing of such information and running computational simulations of such meshes is challenging. Simulation analysis of joint kinematics is computationally expensive and requires knowledge of the kinematic constraints as a consequence of muscles and ligaments, including, for instance, pre stresses and attachment sites of ligaments. In many cases, 3D and/or kinematic simulations are still more feasible in combination with simpler material models for cartilage. More advanced material descriptions are required for a more detailed investigation of mechanical conditions inside cartilage. However, these are essential to move forward in our understanding of the relationship between mechanical loading, cartilage damage, and osteoarthritis. A wide variety of cartilage models have been developed and employed to evaluate the mechanical behavior at the cell, tissue, and joint level. They have been used to evaluate static and dynamic tissue behavior, to explore effects of mechanical and biochemical loading, and even to predict tissue adaptation at the long time scale. The expectation is that such models may be taken to the next level, where patient-specific characteristics are incorporated in 3D kinematic joint models. Given the composite structure of cartilage with the collagen fibril network, proteoglycan matrix, and fluid, this special issue has a focus on the development and application of fibril-reinforced models at different scales. A review of the fibril-reinforced tissue models and their application in the cell level is presented . Practical considerations in modeling applications and model limitations are further discussed. A thorough review of recent advances in computational modeling of human knee joints is also presented . Creation of knee joint models starting from imaging data (such as MRI) is summarized, clinical applications of the models are discussed, and examples are given for patient-specific evaluation of knee joint mechanics. Furthermore, influence of the altered depth-dependent properties of cartilage in osteoarthritis on fluid pressurization in a knee joint is demonstrated (Y. Dabiri and L. P. Li). Since generation of computational finite element models of knee joints is time-consuming and model simulation times can be relatively long, a semiautomated method is presented to study tibiofemoral contact stresses of adult subjects . Combination of experimental measurements and modeling is reviewed and model validation in cell, tissue, and joint level is discussed . Specifically, experimental results on the depth-dependent microstructural response of cartilage under directly loaded and unloaded regions are presented (A. Thambyah and N. Broom). Loading-related changes in chondron aspect ratios at different zones are also shown. These results can be used for the validation and development of computational models incorporating higher degrees of structural realism. Further, experimentally measured chondrocyte deformation behavior under mechanical loading of the tissue is presented for normal and osteoarthritic cartilage . Computational multiscale modeling is applied to explain differences in the cell behavior between the aforementioned groups. Finally, potential future directions in the application of multiscale models for the evaluation of cell responses and disease progression in knee joints are addressed . Recent advances in the development of computational models of articular cartilage, as partially demonstrated in this special issue, and models of joints with realistic patient-specific material descriptions and joint kinematics have brought clinical application closer. More advanced adaptation models, likely combinations of models addressing different length scales, should ultimately lead to the prediction of altered tissue properties and wear, which strongly correlate to the development of osteoarthritis. Ultimately, computational modeling may become a clinical tool for identifying or optimizing patient-specific treatment strategies, such as rehabilitation and surgical interventions.Rami K. KorhonenPetro JulkunenLePing LiCorrinus C. van Donkelaar


Random sparse network architectures are intriguingly easy to construct, and, due to the lack of relevant structural studies, they have been difficult to disprove. Over the last decade, they have become the workhorse of computational studies of neuronal network dynamics. With the arrival of optical methods like channelrhodopsin and glutamate uncaging we can finally compare the predictions stemming from these architectures with responses measured in real cortical networks.Our model network is simulating L2/3 of a mouse barrel cortex column with three distinct neuronal populations: Excitatory pyramidal cells, fast-spiking inhibitory cells and non-fast-spiking inhibitory cells, modeled with biological plausible, cell-type specific adaptive exponential integrate and fire (AdEx) models . For thecannot capture the experimentally measured network responses.In parallel experiments and simulations, in which we stimulate groups of neurons and record the responses of the surrounding network, we can show that uniform random network models constructed from the statistics of pairwise recordings To improve the similarity between model and experiments, we investigate different ways to change the network architecture, for example by introducing correlations in the distribution of synaptic weights  or by mo


The absence of auditory input, particularly during development, causes widespread changes in the structure and function of the auditory system, extending from peripheral structures into auditory cortex. In humans, the consequences of these changes are far-reaching and often include detriments to language acquisition, and associated psychosocial issues. Much of what is currently known about the nature of deafness-related changes to auditory structures comes from studies of congenitally deaf or early-deafened animal models. Fortunately, the mammalian auditory system shows a high degree of preservation among species, allowing for generalization from these models to the human auditory system. This review begins with a comparison of common methods used to obtain deaf animal models, highlighting the specific advantages and anatomical consequences of each. Some consideration is also given to the effectiveness of methods used to measure hearing loss during and following deafening procedures. The structural and functional consequences of congenital and early-onset deafness have been examined across a variety of mammals. This review attempts to summarize these changes, which often involve alteration of hair cells and supporting cells in the cochleae, and anatomical and physiological changes that extend through subcortical structures and into cortex. The nature of these changes is discussed, and the impacts to neural processing are addressed. Finally, long-term changes in cortical structures are discussed, with a focus on the presence or absence of cross-modal plasticity. In addition to being of interest to our understanding of multisensory processing, these changes also have important implications for the use of assistive devices such as cochlear implants. A profound childhood hearing loss can have widespread, devastating consequences that impact a child and their family for a lifetime. Perhaps most importantly, hearing loss can prevent a child from acquiring spoken language, which has a number of subsequent developmental and psychosocial consequences . However, it is important to note that changes in the anatomy and function of peripheral and central auditory structures depend highly upon a number of factors, including the time of onset of hearing loss and the specific nature of the impairment. This review aims to address changes that occur in response to bilateral, congenital or early-onset deafness. Other forms of deafness  are associated with a wide variety of highly specific changes that are beyond the scope of this paper. Here we address the most common methods for acquiring deaf animal models, including some discussion surrounding whether the methods currently used to evaluate hearing impairment are sufficient. We then describe anatomical and physiological changes that occur following deafness, including structures within the cochlea, subcortical nuclei, and within auditory cortex. Finally, we discuss cross-modal reorganization that appears to follow hearing impairment with some consideration of potential mechanisms.Much of what we know about the changes to auditory structures that result from deafness, and how these changes have informed the design of cochlear prostheses, has come from studies in animal models. Fortunately, the subcortical auditory system is highly conserved among mammals  cause hereditary auditory-pigmentary disorders that mimic Waardenburg syndrome in humans  to define the endpoint of, or to measure the success of their deafening procedure. ABRs can be evoked using a variety of auditory stimuli. However, researchers typically rely on click-evoked ABRs to measure deafness in animal models , and a descending branch caudally into the posterior division (PVCN) of the ventral nucleus, which ultimately innervates the dorsal nucleus. These branches terminate in a variety of structures including endbulbs of Held, modified endbulbs, and terminal boutons which may be accompanied by a series of en passant swellings. In normal hearing animals, endbulbs of Held typically exhibit a complex arborization, with multiple branches that stem from a single, thick trunk. These endings typically contact up to half of the soma of a spherical bushy cell  cover the somata of bushy cells. These PSDs are punctate and tend to present as distinct convexities that indent the presynaptic membrane , lateral superior olive (LSO), and the medial nucleus of the geniculate body (MNTB), along with several smaller periolivary nuclei. In hearing animals, the MSO, LSO, and MNTB contribute to sound localization in the azimuth, and are tonotopically organized. Rough frequency gradients in these nuclei are established by the differential expression of ion channels  is comprised of dorsal and lateral cortices that collectively form a “rind” surrounding the central core Winer, . This ceWhile the number of projections to the IC appears unaffected by hearing loss, there appear to be substantial qualitative differences between IC neurons in hearing-deprived and normal hearing animals. The somata of IC neurons in bilaterally deafened animals undergo some degree of atrophy, resulting in a slight but significant decrease in soma area relative to normal hearing controls  is the auditory thalamic processing station between the inferior colliculus and the auditory cortex. Across species, the MGB is typically subdivided into multiple subsections, each of which contains several nuclei that process both afferent and efferent neural activity Winer, . DespiteThe primary auditory cortex (A1) is the most extensively studied area of auditory cortex. In congenitally deaf animals, A1 has a similar laminar structure to that of hearing animals  of the auditory cortex, which lies adjacent to the visual motion processing regions of the middle suprasylvian sulcus  underlying cross-modal plasticity are not yet fully understood. Thus, research using animal models will continue to inform our understanding of the far-reaching consequences of deafness as the field moves forward.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.


Esophageal adenocarcinoma is an aggressive malignancy with a poor prognosis. In Western countries, the incidence of esophageal adenocarcinoma has increased dramatically in the last three decades. To improve patient survival and reduce disease burden, early-stage detection, or better yet, preventing the progression of esophageal adenocarcinoma from its premalignant lesions, constitute the best short-term options. Barrett's esophagus is histologically characterized by the replacement of the normal stratified squamous epithelium of the esophagus with a columnar epithelium with intestinal differentiation  are a class of small non-coding endogenous RNAs, 18–25 nucleotides in length, and are capable of simultaneous regulation of genes by binding to target mRNAs, resulting in mRNA degradation or translational inhibition. miRNAs participate in many essential biological processes, including proliferation, differentiation, apoptosis, necrosis, autophagy, and stress responses  were found to show significantly higher expression in patients with progression to esophageal adenocarcinoma than in patients who did not show disease progression. Second, Saad et al. conducted a notable comprehensive microarray profiling for identifying the specific miRNA signature associated with esophageal adenocarcinoma  (Matsuzaki et al., miR-221 and miR-222 expressions are higher in esophageal adenocarcinoma than in the surrounding Barrett's esophagus. We also confirmed that the levels of p27Kip1 and CDX2 were lower in areas of esophageal adenocarcinoma than in those of Barrett's esophagus. Thus, we showed that the degradation of CDX2 was enhanced by upregulation of miR-221 and miR-222 on exposure to bile acids. Although bile acids are known to induce DNA damage, resistance to apoptosis through NF-κB activation, and resistance to autophagy (Fang et al., Since clinical predictors of increased risk of esophageal adenocarcinoma, namely, the length of Barrett's esophagus, male gender, older age, current tobacco smoking, alcohol consumption, central obesity, and bile reflux, have been established, the association between the expression levels of miRNA in Barrett's esophagus and these clinical risk factors would require further investigation. We had recently reported that expression levels of In conclusion, on the basis of clinical importance, better risk stratification biomarkers to determine the risk of progression from Barrett's esophagus to esophageal adenocarcinoma are expected. We should deepen our knowledge of miRNA using clinical materials, hopefully with more prospective approach. The fusion of basic science and clinical science research would also be required for identifying the upstream regulation and the downstream targets of miRNAs and understanding their mode of action. These will facilitate the development of miRNA-based prevention or therapeutic strategies for esophageal adenocarcinoma.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.


More than 40 years have passed since Kawasaki syndrome (KS) was first described. Yet KS still remains an enigmatic illness which damages the coronary arteries in a quarter of untreated patients and is the most common cause of childhood-acquired heart disease in developed countries. Many gaps exist in our knowledge of the etiology and pathogenesis of KS, making improvements in therapy difficult. In addition, many KS features and issues still demand further efforts to achieve a much better understanding of the disease. Some of these problem areas include coronary artery injuries in children not fulfilling the classic diagnostic criteria, genetic predisposition to KS, unpredictable ineffectiveness of current therapy in some cases, vascular dysfunction in patients not showing echocardiographic evidence of coronary artery abnormalities in the acute phase of KS, and risk of potential premature atherosclerosis. Also, the lack of specific laboratory tests for early identification of the atypical and incomplete cases, especially in infants, is one of the main obstacles to beginning treatment early and thereby decreasing the incidence of cardiovascular involvement. Transthoracic echocardiography remains the gold-standard for evaluation of coronary arteries in the acute phase and follow-up. In KS patients with severe vascular complications, more costly and potentially invasive investigations such as coronary CT angiography and MRI may be necessary. As children with KS with or without heart involvement become adolescents and adults, the recognition and treatment of the potential long term sequelae become crucial, requiring that rheumatologists, infectious disease specialists, and cardiologists cooperate to develop specific guidelines for a proper evaluation and management of these patients. More education is needed for physicians and other professionals about how to recognize the long-term impact of systemic problems related to KS. Kawasaki syndrome KS, OMIM 611775) is an acute necrotizing vasculitis of the medium and small-sized vessels, predominantly occurring in children aged 6 months-5 years, with a male-to-female ratio of 1.5-1.8 to 1 and a life-threatening predisposition to involve coronary arteries . KS is t11775 is Although reported all over the world, KS is most highly expressed among Asian populations, mainly of Japanese and Korean descent. In Japan, the 20th nationwide survey documented an annual incidence of 216.9 per 100,000 children aged 0-4 years. This incidence is remarkably greater than in Europe  or in the Caucasian population of the United States of America , supporting the speculation that both genetic predisposition and environmental factors are critical for KS pathogenesis ,12. A hoThough many etiological agents have been proposed, the exact cause of KS continues to be elusive. The rarity of the illness in the first months of life suggests a passive protection by maternal antibodies. Seasonality of cases, nationwide epidemics, and the self limited nature of KS favor an infectious trigger. Although the subject is still much debated, current research appears to indicate that the primum movens of KS might be an infectious agent with superantigenic activity, leading to a massive stimulation of the immune system and to the development of KS in a small subset of genetically predisposed individuals . The disLactobacillus casei cell wall extract-induced coronary arteritis, an animal model of KS [The immune response in KS encompasses both aspects of innate and adaptive immunity with a significant overproduction of different cytokines and activation of endothelial cells. Activation of both B and T cells has been detected together with increased proinflammatory cytokine production, including tumour necrosis factor (TNF)-α, interleukin-1 and interleukin-6 ,17. The el of KS . Many stel of KS ,20. Receel of KS . Geneticel of KS .Genome-wide association studies have been performed to identify novel loci modulating the susceptibility to KS and plausible candidate gene associations have been recognized, including apoptosis regulatory genes, genes implicated in the synthesis of transcription factors and interleukin inhibitors . A recenDiagnosing and treating both "atypical" and "incomplete" forms of KS remain major dilemmas for clinicians evaluating children, especially infants, with prolonged or refractory high fever. Even after 5 years of age, the diagnosis of KS can be very hard to establish. According to the American Heart Association and the American Academy of Pediatrics, "atypical" KS is defined as a child with high fever and symptoms and signs heralding the onset of the disease that are not included in the clinical major criteria of KS, such as acute abdominal pain, pulmonary signs, or gastrointestinal signs . The morConversely, the term "incomplete" KS refers to patients who lack the clinical findings of the disease to fulfill the classic criteria, but present fever, at least two of the typical clinical manifestations and CAA revealed by echocardiography . It is cThe primary goal for pediatricians should be early recognition and treatment of both atypical and incomplete cases before coronary arteries are damaged. Among all KS patients, atypical and incomplete cases have the highest risk of developing CAA if left untreated with IVIG ,28. In cAnother suggestive symptom in recognizing KS is the extreme irritability of the majority of pediatric patients, which is mainly related to aseptic meningitis and is uncommon in other febrile diseases . An inteSince no criteria have been developed that can reliably identify children at higher risk for severe disease at the time of initial presentation, all children diagnosed with KS must be treated at the time of diagnosis. Since both KS etiology and pathogenesis are not completely clarified, the general aims of treatment are to rapidly diminish the inflammation within the vascular system and specifically in the coronary arteries, minimize the incidence and progression of CAA, and prevent arterial thrombosis by inhibiting platelet aggregation . The curIVIG and aspirin therapy should be instituted as soon as possible when KS is diagnosed. If CAA are detected in a child prior to the child's fulfilling all KS diagnostic criteria, treatment with IVIG and aspirin should also be initiated then. When the KS diagnosis is delayed but inflammatory parameters are still high, it is however recommended to treat patients aggressively with IVIG and aspirin, especially young infants, even though the efficacy of this early treatment in preventing coronary artery injuries is uncertain . ApproxiAlthough corticosteroids are the treatment of choice in most vasculitides of adulthood, their role as a first-choice treatment for KS is controversial. A multicenter prospective randomized trial of corticosteroids in primary KS showed that the combination of IVIG and corticosteroids improves clinical course and coronary artery outcome, without causing side effects . HoweverNo specific guidelines are available for the management of refractory KS patients in whom inflammatory parameters do not subside and fever persists or recurs 24 to 48 hours after IVIG infusion, with the possible increased risk of coronary damage. Most of these patients will respond to a second infusion of IVIG , but up to one third of non-responders remain febrile with a persistently high serum CRP level ,48. BecaInfliximab, a chimeric mouse-human monoclonal antibody targeting soluble and membrane-bound TNF-alpha, has been successfully used in patients refractory to IVIG and corticosteroids, even with severe coronary artery involvement, without substantial side effects ,53. NoneThe major sequelae of KS, such as CAA leading to potential occlusion and cardiac ischemia, are dramatically decreased as a significant result of therapy with IVIG. Coronary artery damage is regarded as the hallmark of KS and is the single risk factor that contributes the most to an increase in the mortality risk of this disease in any patient . Other csaccular, if axial and lateral diameters are nearly equal, or fusiform, if symmetric dilation with gradual proximal and distal tapering is seen. When a coronary artery is larger than normal without a segmental aneurysm, it is considered "ectatic". In addition, according to the last American Heart Association statement, aneurysms can be classified as "small" , "medium"  or "giant"  [Aneurysms are usually classified as iameter) .Abnormal endothelial function might persist for many years after the resolution of the acute phase of KS, even in patients without detectable coronary artery damage. Patients with this abnormal endothelial function might display subclinical vasculitis many years after KS . EndotheThe long-term outcome of adults who have recovered from KS without CAA is considered excellent, though longitudinal studies are required before confirming this speculation. A heart-healthy lifestyle is recommended for all patients with a history of KS, including avoidance of smoking, low fat diet, control of blood pressure and lipid panels, and regular physical activity, unless contraindicated ,69. LongRoutine vaccinations are recommended for all individuals with KS. The schedule for administration of inactivated childhood vaccines should not be interrupted. As the passively transmitted antibodies in IVIG can block the specific immune response, it may be necessary to reschedule live viral vaccines  to at least 9 months after IVIG administration. In Japan an interval of 6 to 11 months is recommended between IVIG infusion and live vaccine administration, but there is no final agreement for IVIG-non responders who received a second or a third IVIG infusion; if the child's risk of exposure to measles or varicella is high, the child should be immunized and then reimmunized at least 11 months after administration of IVIG . The admAlthough our understanding of KS has increased enormously and many facts about KS have been elucidated, numerous dilemmas remain unsolved. The first concern is the need for the discovery of the causative agent that may allow more appropriate treatment for affected children. Secondly, there is urgency to identify specific laboratory tests to shorten the gap between the appearance of the first clinical manifestations and the diagnosis, with the possibility of reducing the occurrence of coronary damage or cardiac complications in adulthood. A critical point is related to infants younger than 3-6 months who frequently display an atypical or incomplete form of the disease, often sharing signs and symptoms with other infantile febrile illnesses mimicking KS. Therefore, it is crucial to perform early transthoracic echocardiography in all patients with suspected or established KS, and introduce the appropriate therapy even in the absence of all typical findings.Patients with giant aneurysms require aggressive anticoagulation with lifelong follow-up, including stress tests and multi-slice computed tomography or magnetic resonance imaging. The degree to which KS is a cardiovascular risk factor for progression to atherosclerosis is under debate and long term evolution and consequences of the disease are still unknown, despite many efforts of researchers worldwide. The available data suggest that all KS patients, including those without CAA, should remain connected to their medical system, even in their transition to adult medical care, with the hope that collaborative scientific research among various centers will help define the cause and eventual prevention of the syndrome and the optimal management of current KS patients.KS: Kawasaki syndrome; CAA: coronary artery aneurysms; IVIG: intravenous immunoglobulins; TNF: tumour necrosis factor; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein.The authors declare that they have no competing interests.FF (submitting author) primarily created and drafted the manuscript and revised it based on co-authors' suggestions; SC and DR have been involved in the critical revision of the manuscript, giving the final approval of this final version.


Piano performance involves a large repertoire of highly skilled movements. The acquisition of these exceptional skills despite innate neural and biomechanical constraints requires a sophisticated interaction between plasticity of the neural system and organization of a redundant number of degrees of freedom (DOF) in the motor system. Neuroplasticity subserving virtuosity of pianists has been documented in neuroimaging studies investigating effects of long-term piano training on structure and function of the cortical and subcortical regions. By contrast, recent behavioral studies have advanced the understanding of neuromuscular strategies and biomechanical principles behind the movement organization that enables skilled piano performance. Here we review the motor control and biomechanics literature, introducing the importance of describing motor behaviors not only for understanding mechanisms responsible for skillful motor actions in piano playing, but also for advancing diagnosis and rehabilitation of movement disorders caused by extensive piano practice. In this review, we focus on behavioral studies that probed motor control and learning of skilled piano performance in order to better understand the mechanisms of accomplished musical performance. Of specific interest is the distinct organization of the redundant number of degrees of freedom (DOFs) in the upper limb allowing the production of fast, accurate, and efficient piano performance by expert players. Furthermore, as an example of maladaptive neuroplasticity, we briefly mention focal dystonia in pianists, a neurological disorder characterized by a degradation of fine motor control of highly overlearned skilled movements.Outstanding musical performance has fascinated people over centuries. It is built on exceptional sensory, cognitive, and motor abilities, which include fast, accurate, dexterous, and efficient movements, production of rich repertoires of complex motions, quick correction of erroneous actions, sensory-motor coordination, and memory that stores vast musical repertoires and is recalled quickly. In the past years, researchers have attempted to clarify the neural mechanisms and neuroplasticity subserving the virtuosity of musicians by using neuroimaging techniques, such as fMRI, PET, MEG, and EEG. These “top–down” studies have demonstrated functional and structural neuroplastic changes at cortical and subcortical regions associated with sensory, cognitive, and motor abilities  . Second, a given motion at the fingertip can emerge as a consequence of a variety of possible spatio-temporal coordinative movements across multiple joints (kinematic redundancy). Third, a given rotation at a joint can be generated by complex interactions of different joint torques  originating from muscular, gravitational, inter-segmental and reaction forces (kinetic redundancy). Fourth, muscular torque emerges as a balance of forces generated by agonist and antagonist muscles surrounding a joint (muscular redundancy). The redundancy of the motor system therefore provides infinite possible ways of organizing the upper limb movements even for a single tone production Figure .The problem of endpoint redundancy indicates that loudness and duration of a single tone cannot define a unique waveform of the fingertip force. For instance, both impulsive force production via hitting a key and progressive force production during depressing a key can elicit the same target velocity of a key  affect joint kinetics , kinematic and kinetic redundancy problems are to some extent associated. During simultaneous keystrokes with the thumb and little finger  at a certain loudness, the arm downswing motion was characterized by a sequence of joint rotations in an order from proximal to distal for the expert pianists, but not for the novice players , muscles need to generate a joint torque that counteracts with this interfering dynamics . A comparison of hand movements elicited by TMS over the primary motor cortex between pianists, violinists and non-musicians identified distinct movement features associated with the trained movement repertoire . This involves not only parametric modulation of spatial and temporal features of movements, but also movement reorganization of the motor system. Plasticity of the nervous system allows through extensive piano training the optimization of movement control involved in adjustment of the individual elements of music. For example, to manipulate the loudness of a piano tone, skilled pianists and unskilled individuals reorganized the upper limb movements and muscular coordination in a distinct manner. In order to increase the velocity of elbow rotation during the hand downswing for a louder tone production, the experts elicited larger inter-segmental dynamics by increasing the amount of the shoulder joint deceleration, whereas the novices simply generated lager elbow muscular torque , an increase in tempo yielded increases in rotational velocity at both elbow and finger  and between the key and key-bed (bottom noise) (Goebl et al., The hand and arm movements in piano performance differ even across skilled pianists. The individual differences can manifest themselves from numerous intrinsic and extrinsic factors including anatomical and physiological properties of the musculoskeletal system, structure and function of the nervous system, practice regime, history of education, and neural and biomechanical strategies. Neuroimaging studies demonstrated that the structure of cortical and subcortical regions predicted speed and accuracy of skilled finger movements in individual players (Amunts et al., Musicians have a neural mechanism that integrates auditory and motor information (Bangert and Altenmüller, Focal hand dystonia is a neurological disorder characterized by involuntary movements, twisting, abnormal postures and co-contraction of antagonist muscles frequently in a task-specific context. In the general population it is most common as writer's cramp, however, prevalence in pianist is relatively high with about 1–2% of pianists becoming affected. Involuntary flexion of fingers, abnormal muscular contractions Figure , and detWe have highlighted movement features specific to skilled piano performance. These unique motor skills can be associated with idiosyncratic demands of the various, highly elaborated motor tasks. For example, repetitive motion of the arm and hand for a prolonged time period, -uncommon in daily life motor tasks,—can lead to movement reorganization that facilitates physiological efficiency. Similarly, spatio-temporal constraints on motions of the individual fingers, which are specific to musical performance, can necessitate individuated finger movements. In this way, long-term piano training endows pianists with specialized organizations of redundant DOFs in arm and hand movements in piano playing. This, in turn facilitates speed, accuracy, and efficiency of the dexterous motor actions. Differences in movement organization between skilled pianists, unskilled pianists, and pianists with focal dystonia suggest that complex interactions between neuroplasticity and redundancy in the motor system via extensive piano practice yield skillful, but also disordered motor behaviors. It is therefore of importance to identify factors that influence this interaction in future studies, which should include motor learning experiments. For example, a paradigm that assesses intramanual and intermanual transfer effects of practice (Koeneke et al., A significant implication of studies of behavioral movement science will aid musicians both in acquisition of complex motor skill efficiently and in prevention of playing-related neuromuscular disorders such as focal dystonia (Furuya et al., 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.


Obesity and metabolic syndromes are examples whereby excess energy consumption and energy flux disruptions are causative agents of increased fatness. Because other, as yet elucidated, cellular factors may be involved and because potential treatments of these metabolic problems involve systemic agents that are not adipose depot-specific in their actions, should we be thinking of adipose depot-specific (cellular) treatments for these problems? For sure, whether treating obesity or metabolic syndrome, the characteristics of all adipose depot-specific adipocytes and stromal vascular cells should be considered. The focus of this paper is to begin to align metabolic dysfunctions with specific characteristics of adipocytes. Our modern lifestyle has led to the diminished use of consumed energy and to an increasing population of obese individuals. Obesity is costly , 2, can White adipose tissue is critical for the deposition of excessive fatty acids. Surgical implantation of adipose cells into transgenic, adipose-devoid mice reinstated insulin sensitivity, decreased plasma glucose levels, and normalized insulin concentrations . AdipocyAdipose tissue development is characterized by both adipocyte hyperplasia and hypertrophy. Limiting adipocyte hyperplasia leads to accumulation of lipids in existing adipocytes, resulting in hypertrophy. The proteins downstream of tyrosine kinases-1 (Dok1) are important for adipogenic differentiation and adipocyte hyperplasia. Dok1 activates p120 Ras GTPase-activating proteins, which inhibit the proliferation of preadipocytes and promote their differentiation and lipid accumulation, resulting in hypertrophy of existing adipocytes .β-cells and Type II diabetes [In summary, adipose tissue functions as a sink for excessive fatty acids, and the impairment of fatty acid storage function of adipose tissue results in the deposition of fatty acids in other tissues, such as key insulin responsive tissues, muscle and liver, leading to insulin resistance. If metabolic syndromes  are undiagnosed and allowed to progress, patients will experience persistent hyperinsulinemia, resulting in detectable apoptosis of pancreatic diabetes .While visceral adipose tissue appears primarily involved in metabolic syndromes, there are three other major adipose depots that also may have a role in the etiology of obesity and/or metabolic syndrome, including visceral, subcutaneous, intermuscular, and intramuscular (including intramyocellular lipid) depots. Not all adipose depots possess the same physiology, and the distribution of adipocytes within the four major adipose depots plays a role in the severity of obesity and ultimately metabolic syndromes. This is probably due to the inherently different responses by the collective populations of different types of adipocytes in the distinct adipose depots. per se may adversely influence both the capillary and adipocyte ECM stability. All components of adipose tissue depots must be considered as being potentially involved in adipose tissue-related disease. Obtaining knowledge of how cell populations in depot-specific adipose tissue manage the dynamics of energy partitioning is of growing importance , 24. HowIncreasing energy utilization via exercise or weight loss provides a transient opportunity for energy storage in existing adipose cells, improves insulin sensitivity, and allows consumed, but as yet unused glucose, to be stored as lipid. However, if exercise/weight loss is inefficient, what becomes of the unutilized glucose? Moreover, is the manifestation of type II diabetes or hypercholesterolemia an indication of where feedback inhibition of depot-specific cellular metabolic processes exists? Also, is the hypercholesterolemia seen in metabolic syndrome caused by the inability of the body to synthesize lipid from acetate? Moreover, is the manifestation of type II diabetes or hypercholesterolemia an indication of where feedback inhibition of depot-specific cellular metabolic processes exists? Careful scrutiny of adipocytes may well address these questions and will provide knowledge about specific populations of adipocytes in the development of obesity/metabolic syndromes.Collectively, knowledge gained in any of these areas will aid us in finding a possible regulatory point for combating energy flux-related dysfunctions. Similarly, the observations contained in Can adipose tissue become the major regulator of body composition? Why is it that one of the most benign/banal tissues, adipose tissue, has become an amazing source of stem cells and systemic regulatory agents and, therefore, controls of a variety of systemic and local physiological and pathological variables of growth, development, and metabolism? In the light of current research, this once thought innocuous tissue has emerged as a true organ system, and these are issues that have to be addressed in the near future to gain more understanding regarding obesity, metabolic syndromes, and adipocytes.The author declares that there is no conflict of interests.


The optimal care of persons with diabetes by general practitioners and family physicians (GP/FP) is complex and requires multiple competencies. This is a fairly unrecognized key challenge in the healthcare systems. In some cases, local and national Continuous Professional Development (CPD) initiatives target these challenges; however there have been few international initiatives, possibly because challenges emerging from different studies have not been linked across national boundaries. In this context, the authors have compiled data about gaps and/or barriers inherent to GP/FP care of persons with type 2 diabetes from Austria, Canada, Germany and the United Kingdom.Secondary analyzes of pre-existing studies were conducted to identify challenges in the care of patients with type 2 diabetes as faced by GPs/FPs. Two sources of data were reviewed: unpublished research data from collaborating organizations and articles from a literature search (in English and German). Articles retrieved were scanned by the research team for relevance to the study objectives and to extract existing gaps and barriers. The identified challenges were then categorized along three major axes: (1) phase of the continuum of care {from screening to management}; (2) learning domain {knowledge, skills, attitudes, behavior, context}; and (3) by country/region. Compilation and categorization were performed by qualitative researchers and discrepancies were resolved through discussion until concordance was achieved.Thirteen challenges faced by GPs/FPs in the care for patients with type 2 diabetes were common in at least 3 of the 4 targeted countries/regions. These issues were found across the entire continuum of care and included: pathophysiology of diabetes, diagnostic criteria, treatment targets assessment, drugs' modes of action, decision-making in therapies, treatment guidelines, insulin therapy, adherence, management of complications, lifestyle changes, team integration, bureaucracy and third-party payers. The issues reported were not restricted to the physicians' knowledge, but also related to their skills, attitudes, behaviours and context.This study revealed challenges faced by GPs/FPs when caring for patients with diabetes, which were similar across international and health system borders. Common issues might be addressed more efficiently through international educational designs, adapted to each country's healthcare system, helping develop and maintain physicians' competencies. An estimated 260 million people are affected by type 2 diabetes worldwide and a further 7 million people develop diabetes each year . SeriousIn addition, the cost of diabetes to the health care system is increasingly important. The International Diabetes Federation (IDF)  reports The high prevalence/incidence of type 2 diabetes and its substantive effects on quality of life, social impact, and economic costs point to the importance of assuring that this disease is screened, diagnosed and managed expeditiously and effectively. Currently, the majority of persons with diabetes are diagnosed, treated, and managed by General Practitioners (GPs) and Family Physicians (FPs) as front line providers of care , rather A large study covering 13 countries, including Germany and the United Kingdom, found health care providers lacked resources  for commonly reported psychosocial problems amongst diabetes patients .Additional studies have suggested that FPs/GPs experience challenges in treating and managing diabetes . One stuContinuing Professional Development (CPD) programs are fundamental to the development and maintenance of physician competencies  and haveThe organizations represented by the authors of this manuscript formed an international collaborative with the goal of developing and disseminating international educational initiatives to FPs and GPs, and of addressing gaps and challenges in the care of persons with diabetes. The collaborative regroups organizations from Canada, Austria, Germany, and the United Kingdom. The overall objective of this research, which represents the first step of the international collaborative project, was to identify similarities in the gaps and barriers of the four regions that could be used to develop an international educational program. In order to achieve that, the following two steps were undertaken:: firstly, international data characterizing gaps and/or barriers inherent to FPs and GPs care of persons with type 2 diabetes was compiled; and secondly, the identified gaps and/or barriers were categorized according to the phases in the continuum of care  and the adapted domains of Bloom's taxonomy of learning   and unpublished research data from the co-authors' organizations. The three studies of the co-authors were developped and deployed independently, and each used its own methodology, described later in this section.The English-language literature review included three databases: Medline , EMBase Deutsches Institut für Medizinische Dokumentation und Information (DIMDI) , Germany [BMJ-GAP] [EIMSED-NA], and Canada [AXDEV-NA]. It was found that FPs/GPs lacked exact knowledge of the diagnostic criteria and cut-off points. According to the AXDEV-NA study, diagnosis guidelines are perceived to change often because of frequent updates, leading each Canadian health care organization to develop their own cut-off points. This result shows that the application of diagnosis guidelines can not be related solely to knowledge, but that attitudes have an impact as well.It was found that treatment targets for risk factors  were not being adequately tested in the UK and Germany , in Austria [EIMSED-NA], as well as in Canada [AXDEV-NA]. In Canada, physicians overestimate the level at which the targets are achieved, a tendency that, when combined with the perception that such testing is expensive, impractical and time consuming, leads FPs/GPs to test less regularly [AXDEV-NA]. Studies report that in Germany, HbA1c is tested in only 68% of patients . FurtherIn Austria, Germany and the United Kingdom, it was reported that FPs/GPs lack the exact knowledge of the mode or mechanism of action of the different drugs they prescribe [EIMSED-NA]. Additionally, the BMJ-GAP analysis showed, for the UK and Germany, that FPs/GPs lack the ability to give clear explanations to the patients of how the substances work.When treating persons with type 2 diabetes, FPs/GPs in all four targeted countries lacked the knowledge, skills and attitude to optimize their decision-making related to therapies . Notably, FPs/GPs lacked knowledge about new treatment strategies recently added to guidelines , and didThe use of insulin therapy was expressed as a challenge for FPs/GPs in the three European countries [EIMSED-NA]. More specifically, FPs/GPs did not feel competent with insulin therapy, lacked knowledge on when to initiate insulin therapy, and had challenges in maintaining and adjusting insulin therapy [BMJ-GAP]. In Germany, they were challenged in initiating an insulin therapy after failure of the treatment with oral anti-diabetics  and theyIn the management and monitoring of type 2 diabetes, FPs/GPs from all four countries were found to lack formal training in counseling and coaching the patient [AXDEV-NA] [EIMSED-NA] , a gap wFPs/GPs from the three European countries found it challenging to manage the complications of diabetes on a long-term basis particularly neuropathies, pancreas pathologies, diabetic foot , and retinopathy . In GermResults  alsoSuboptimal integration of the diabetic team during the referral process was also reported in the United Kingdom, Canada and Germany. More precisely, a gap was found in the United Kingdom and Germany, relating to the suboptimal use of the diabetic team, especially in referral to other team members, e.g., specialist diabetic nurse, podiatrist and dietician [BMJ-GAP]. In Germany, a lack of resources and support for diabetic teams was reported as a barrier, even though the potential of the paramedical personnel is high, which could mean that the resources are there, but underutilized ,45. In CContext-related issues were also identified in all four countries; more specifically, bureaucracy was named as a barrier to optimal care. The high level of documentation and effort required to update records were perceived as problematic [EIMSED-NA]. Furthermore, FPs/GPs in diabetes care play many roles for which they were not formally trained, including carrying out administrative tasks [AXDEV-NA].Additionally, third party payers were identified as context-related issues in Austria, Germany and the United Kingdom [EIMSED-NA]. Limitations set by health insurance bodies/cost carriers on the prescribing of newer  drugs are perceived as a barrier to optimal treatment by physicians [EIMSED-NA].The consensus approach used for this research identified needs, gaps and challenges that are similar in four different countries/regions. Issues identified as common to the targeted countries/regions might also be found in other countries, but further research is required to confirm this. These issues represent potential barriers to optimal healthcare that could be addressed by international educational design. Although the international collaborative has limited its efforts to four countries/regions in its first phase of activity, subsequent phases will be gradually enlarged to include additional countries, and assess the feasibility of using the same approach at a larger and more global level.Education researchers designing needs assessments in diabetes in these and other countries should be aware of the most common gaps and barriers presented here, and assure that they are included in future research designs.International educational design would potentially enable important economies of scale for education providers. The potential economies related to CME internationalization could be very important in optimizing resource utilization in healthcare performance improvement, therefore evolving the applied standards in the CME field. Reaching those highest standards is required to help physicians and other health care providers achieve patient outcomes compliant with the current best evidence, while respecting existing healthcare budgets.Cultural differences and different health system contexts will require tailoring to ensure international applicability. Nonetheless, education providers and designers should verify the comparability of educational activities and look for similarities that could be included in internationally deployed programs. Reviews such as this one could be instrumental in tailoring programs to local and regional needs.The approach presented here could also be used to identify common gaps across countries in other therapeutic areas where internationalization of CPD activities could also be beneficial.We acknowledge that our approach has some limitations. Firstly, only recent manuscripts indexed in Medline, EmBase, ERIC, DIMDI, ZDB or ccMED were included, providing a selected sample of the literature. To supplement our review, we drew upon three relevant sources of data known to us. Secondly, needs, gaps and barriers that were not identified in at least three of the four targeted countries/regions were excluded from further analysis/discussion and some of these issues could still hold international value. However our approach was designed to identify issues clearly relevant to multiple countries. Needs, gaps and barriers identified in less than three of the targeted countries/regions, require more exploration to determine if they are unique to one or two countries or if they are international issues that have not yet been identified in the other targeted countries. Thirdly, it cannot be assumed that care is optimal in other areas where gaps and barriers were not identified because emphasis was put on detecting common challenges, at the expense of areas in which care is excellent. Finally, cultural differences and different health system contexts might limit the generalisability of the findings so these issues should be investigated before designing local educational interventions in other areas.Following the literature-based needs assessment presented in this manuscript, the international collaborative initiative is pursuing its objective of internationalizing CME activities in the field of Diabetes, as it extends its efforts to additional countries. An international educational program is being developed to address five of the gaps and barriers revealed by this review. This activity will focus on diagnostic criteria, suboptimal integration of diabetic teams, assessment of treatment targets, modes of action of drugs and treatment guidelines. Those five gaps were selected during a face-to-face meeting with all members of the international collaborative, where members discussed and ranked each of the 13 gaps identified according to their reported importance and impact on patients' outcomes. Evaluation of the international educational program, including the selection process of the five gaps to be targeted, will be submitted for a separate publication.A consensus approach identified needs, gaps and challenges faced by GPs/FPs when caring for persons with type 2 diabetes that are similar in Austria, Canada, Germany and the United Kingdom. These issues represent potential barriers to optimal healthcare that could be addressed by international educational design. CPD internationalization could quickly evolve the applied standards in medical education, leading to the optimization of resource utilization in healthcare performance improvement. Elevation of the CPD standards will ultimately elevate the physicians' performance in providing care to their diabetes patients, and consequently contribute to better patient outcomes.SM is president and founder of AXDEV Group Inc., Brossard, Canada. PL is a researcher at AXDEV Group Inc., Brossard, Canada. SS is employed by BMJ Group which provides online learning resources for health professionals and regularly undertakes research on the behalf of BMJ Group. PJL is a Medical Scientific Liaison Manager at EIMSED, Vienna, Austria. PP is CEO at QUAIME AG in Flüelen, Switzerland. TK is leader of the Global Medical Education Strategy at Merck, New Jersey, United States. RDJ is a medical education advisor to onExamination and Editor-in-chief of BMJ Case Reports.SM conducted the AXDEV Diabetes Needs Assessment [AXDEV-NA] and presented the findings to the other members of the collaborative. SM and PL carried out the English literature review, compiled and classified the gaps, and wrote the first draft of this manuscript. SS and RDJ conducted the gap analysis of the data from the DNAT trial [BMJ-GAP] and presented the findings to the other members of the collaborative. PJL conducted the EIMSED needs assessment [EIMSED-NA] and presented the findings to the other members of the collaborative. PP carried out the German literature review. All authors contributed to the final analysis of common gaps, critically revised the first draft of the manuscript, and read and approved the final version of the manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2296/12/27/prepub


Cx43 hemichannels are also required for the release of prostaglandins and ATP by osteocytes, and for cell survival induced by mechanical stimulation in vitro. Moreover, they are required for the anti-apoptotic effect of parathyroid hormone in osteoblastic cells. This review summarizes the current knowledge on the presence and function of undocked connexons, and the role of hemichannel regulation for the maintenance of bone cell viability and, potentially, bone health.Cell function and survival are controlled by intracellular signals, and modulated by surrounding cells and the extracellular environment. Connexin channels participate in these processes by mediating cell-to-cell communication. In bone cells, gap junction channels were detected in the early 1970s, and are present among bone resorbing osteoclasts, bone forming osteoblasts, and osteocytes - mature osteoblasts embedded in the mineralized matrix. These channels are composed mainly by Cx43, although the expression of other connexins  has also been reported. It is now believed that undocked Cx43 hemichannels (connexons) formed in unopposed cell membranes facing the extracellular environment participate in the interaction of bone cells with the extracellular environment, and in their communication with neighboring cells. Thus, we and others demonstrated the presence of active hemichannels in osteoblastic and osteocytic cells. These hemichannels open in response to pharmacological and mechanical stimulation. In particular, preservation of the viability of osteoblasts and osteocytes by the anti-osteoporotic drugs bisphosphonates depends on Cx43 expression  The amount of bone and its strength is maintained throughout life by the concerted actions of osteoblasts, the bone forming cells, and osteoclasts, the bone removing cells Figure . The actin vitro and in vivo in all type of bone cells: osteoblasts, osteocytes and osteoclasts , a condition with skeletal malformation that include craniofacial abnormalities and broad long bones , we examined whether inhibition of connexin channels affected the protective response to the bisphosphonate alendronate. We found that inhibiting connexin channels with 18 α-glycyrrhetinic acid (AGA) abolished the anti-apoptotic effect of alendronate, whereas the inactive analog of AGA, glycyrrizic acid (GA), did not modify this response    is the only FDA-approved treatment to increase bone mass. Cx43 expression appears to be required to obtain a full anabolic response to intermittent PTH administration in mice (Castro et al., In vitro mechanistic studies showed that, indeed, PTH does not prevent apoptosis in osteoblastic cells lacking Cx43, whereas overexpression of wild type Cx43 rescues the survival effect of the hormone (Figure e Figure  (Bivi ete Figure . A simile Figure . On the In addition, the interaction of Cx43 with β-arrestin modulates the response of osteoblasts to PTH Figure  Bivi et. Thus, PWe found that PTH does not increase the expression of cAMP-target genes in osteoblastic cells lacking Cx43 (Bivi et al., in vitro and in vivo. Moreover, the role of the Cx43 hemichannels in vivo has begun to be unveiled. Indeed, while studies with genetically modified mice appear to agree that sustained opening of Cx43 hemichannels is deleterious for bone (Dobrowolski et al., Since the first description of gap junction channels at the structural level in bone cells, substantial advances on our understanding of the role of connexins on bone cell physiology have been made (Civitelli, The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


In the last decade, tissue engineering is a field that has been suffering an enormous expansion in the regenerative medicine and dentistry. The use of cells as mesenchymal dental stem cells of easy access for dentist and oral surgeon, immunosuppressive properties, high proliferation and capacity to differentiate into odontoblasts, cementoblasts, osteoblasts and other cells implicated in the teeth, suppose a good perspective of future in the clinical dentistry. However, is necessary advance in the known of growth factors and signalling molecules implicated in tooth development and regeneration of different structures of teeth. Furthermore, these cells need a fabulous scaffold that facility their integration, differentiation, matrix synthesis and promote multiple specific interactions between cells. In this review, we give a brief description of tooth development and anatomy, definition and classification of stem cells, with special attention of mesenchymal stem cells, commonly used in the cellular therapy for their trasdifferentiation ability, non ethical problems and acceptable results in preliminary clinical trials. In terms of tissue engineering, we provide an overview of different types of mesenchymal stem cells that have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDs), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs), and stem cells from apical papilla (SCAPs), growth factors implicated in regeneration teeth and types of scaffolds for dental tissue regeneration. Key words:Dental stem cells, regenerative dentistry, mesenchymal stem cells, tissue engineering, stem cells. The formation of the tooth is determined by the cells of which it is composed, the buccal epithelial cells that form the enamel organ and the mesenchymal cells that form the dental papilla. The enamel is formed by the enamel organ, and the dentin is formed by the dental papilla. Cells from the neural crest also take part in tooth formation. These cells originate in the nervous system and later migrate to the maxilla and mandible, where they interact with mesenchymal cells to form the enamel organ and the dental papilla ,2.The tooth has two anatomical parts. The crown is the part of the tooth which is covered with enamel and it is the part usually visible in the mouth. The root is the part embedded in the jaw. It anchors the tooth in its bony socket and is normally not visible. The tissues of tooth are enamel, dentin, cementum and pulp. The pulp contains blood vessels and nerves that enter the tooth from a hole at the apex of the root and cementum Fig.. Around -Dental Pulp TissueDental pulp is a loose connective tissue that occupies the pulp chamber of the tooth and originates in the embryonic dental papilla ; it is the mature form of the papilla and the only smooth tissue of the tooth. The principal cell of this tissue is the odontoblast, also referred to as the dentinoblast. The dental pulp also contains fibroblasts, undifferentiated mesenchymal cells or stem cells, macrophages, and lymphocytes .-Periodontal ligament (PDL)The periodontal ligament (PDL) is a vascularised, cellular soft connective tissue that surrounds the teeth and joins the root cementum with the hard sheet of the alveolar bone . Most ofThe term stem cell was proposed for scientific use by Russian histologist Alexander Maksimov in 1909. Alexander Maximov was the first to suggest the existence of hematopoietic stem cells (HSC) with the morphological appearance of a lymphocyte, capable of migrating throughout the blood to microecological niches that would allow them to proliferate and differentiate along specific . While rStem cells can be classified according to their abilities to differentiate as totipotent, pluripotent, or multipotent. Totipotent stem cells are those that can be implanted in the uterus of a living animal and give rise to a full organism. Pluripotent stem cells are those that can give rise to every cell of an organism except its extra-embryonic tissues, such as the placenta. This limitation re-stricts pluripotent stem cells from developing into a full organism. Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are pluripotent stem cells. Multipotent stem cells are adult stem cells which only generate specific lineages of cells ,12.Embryonic stem cells have both moral and technical problems; because these cells will later develop into a human being, taking these cells will require destruction of an embryo. Technically these cells are difficult to control and grow and they might as well form tumors after their injection . DiffereA very recent development, with potentially a profound significance for clinical therapy has been the generation of induced pluri-potent stem (iPS) cells from somatic cells. The method for iPS cell induction is “ground-breaking” because somatic cells are converted directly into pluripotent cells through introduction of four genes: Oct-4, Sox2, c-Myc and Klf4 . iPS celTo date, AS cells provide a promising tool for clinical applications in the near future due to their accessibility, despite their reduced plasticity . Althoug-Mesenchymal Stem CellsAlexander Friedenstein was the first to evidence the presence of a population of nonhematopoietic cells that were capable of autorenovation and bone differentiation in the bone marrow . SubsequAt present, any cell population which meets the following characteristics, irrespective of its tissue source, is generally referred as MSC: morphologically, they adhere to plastic and have a fibroblast-like appearance; functionally, they have the ability of self-renewal and could differentiate into cells of the mesenchymal lineage , also into cells of the endoderm (hepatocytes) and ectoderm (neurons) lineages under proper cell culture conditions; phenotypically, they express more than 95% of the population express the CD105, CD73,CD90 surface antigens and that less than 2% of the population ex-press the pan-leukocyte marker CD45, the primitive hematopoietic progenitor and endothelial cell marker CD34, the monocyte and macrophage markers CD14 and CD11, the B cell markers CD79 and CD19, or HLA class II .-Tissue Engineering in Dentistry with Mesenchymal dental stem cellsTissue engineering is an interdisciplinary field of study that applies the principles of engineering to biology and medicine toward the development of biological substitutes that restore, maintain, and improve normal function . The emeGrowth factorsGrowth factors and signaling molecules have the ability to stimulate cellular proliferation and cellular differentiation. Bone morphogenetic proteins (BMPs) family members are used sequentially and repeatedly throughout embryonic tooth development, initiation, morphogenesis, cytodifferentiation and matrix secretion . Six difCell Source: Mesenchymal dental stem cells (MDSCs) To date, several types of adult stem cells have been isolated from teeth, including dental pulp stem cells (DPSCs) , stem ceMDSCs are multipotent cells that proliferate extensively (maintained for at least 25 passages), can be safely cryopreserved, pos-sess immunosuppressive properties, and express mesenchymal markers. MSDSCs can be isolated using explant cultures or enzy-matic digestion. In addition, the stem cells derived from teeth are large spindle-shaped cells with a large central nucleus abundant cytoplasm, and cytoplasmic extensions in culture Fig. . MDSCs cIn 2000, Gronthos et al.  discoverScaffoldActually, investigators search the “ideal scaffold” to facilitate the growth, integration and differentiation of stem cells. The scaffold should be biocompatible, non-toxic and have optimal physical features and mechanical properties. Experiments with cell-free scaffolds are especially attractive because of an easier handling process that eliminates the issues associated with the use of stem cells and their expansion in vitro, with storage and shelf-life, cost aspects, immunoresponse of the host and transmission of diseases . HoweverMany materials have been designed and constructed for tissue engineering approaches, namely natural and synthetic polymers or inorganic materials and composites, which have been fabricated into porous scaffolds, nanofibrous materials, microparticles and hydrogels. Natural materials include collagen, elastin, fibrin, alginate, silk, glycosaminoglycans such as hyaluronan, and chitosan . They ofMesenchymal Dental Stem cells derived from teeth are easily accessible multipotent cells with the capacity to differentiate into distinct cell types. This new source of stem cells could be of benefit in cellular therapy and the eventual development of techniques for use in regenerative dentistry and degenerative diseases. Future studies will probably focus on subpopulations of stem cells derived from teeth characterized by specific surface markers, their distinctive properties and their use in clinical applications.


The use of different NGS platforms and their sequencing error profiles are compared in the context of various applications of diversity estimation, ranging from the detection of single nucleotide variants (SNVs) to the reconstruction of whole-genome haplotypes. We describe the statistical and computational challenges arising from these technical artifacts, and we review existing approaches, including available software, for their solution. Finally, we discuss open problems, and highlight successful biomedical applications and potential future clinical use of NGS to estimate viral diversity.Many viruses, including the clinically relevant RNA viruses HIV (human immunodeficiency virus) and HCV (hepatitis C virus), exist in large populations and display high genetic heterogeneity within and between infected hosts. Assessing intra-patient viral genetic diversity is essential for understanding the evolutionary dynamics of viruses, for designing effective vaccines, and for the success of antiviral therapy. Next-generation sequencing (NGS) technologies allow the rapid and cost-effective acquisition of thousands to millions of short DNA sequences from a single sample. However, this approach entails several challenges in experimental design and computational data analysis. Here, we review the entire process of inferring viral diversity from sample collection to computing measures of genetic diversity. We discuss sample preparation, including reverse transcription and amplification, and the effect of experimental conditions on diversity estimates due to  Many viruses, in particular RNA or single-stranded DNA viruses, exhibit extreme evolutionary dynamics. They have very high mutation rates, up to six orders of magnitude higher than in humans, short generation times, and large population sizes  technologies, the experimental analysis of viral genetic diversity has changed dramatically. Rather than using labor-intensive limiting dilution and individual cloning of viruses followed by traditional Sanger sequencing, NGS now allows for sampling the virus population in a highly parallel fashion in a single experiment. However, the novel high-throughput approach has several pitfalls associated with both the experimental protocol and the statistical analysis of the data. We address both aspects in this review and discuss several successful applications of NGS to viral diversity studies, including drug resistance, immune escape, and epidemiology.The usefulness of NGS for viral diversity estimation depends crucially on the quality of the sample and on the procedure to prepare the sample. NGS sequence reads mirror the accumulation of errors, some of them preventable others unavoidable. To minimize the error rate, each step requires careful handling, starting with biological sample retrieval and storage up to the last steps of the NGS procedure itself Figure .Viral genomes are usually protected by the viral capsid and some of them additionally by an envelope, for instance, HIV and HCV. However, retrieval and storage conditions of biological specimens are especially important when studying RNA viruses due to the fragility of RNA  The virus is known and an amplicon approach is chosen for NGS. Here, the specificity of the primers might allow for amplifying the viral genome without any upstream enrichment. Nevertheless, it is often beneficial to eliminate contaminating DNA or RNA by DNase or RNase treatment. For instance, investigating HIV RNA genomes requires the elimination of proviral DNA genomes  long fragments  are error-prone enzymes, because of the lack of any proof-reading activity  nucleotide misincorporation due to the inaccuracy of DNA polymerases, and (iv) resampling due to, for instance, too low amounts of input DNA copies  biased amplification due to primer mismatches, (ii) Overall, sample preparation is a critical issue in the process of NGS. If unrecognized, errors during sample preparation can lead to an artificially increased diversity of the investigated virus population. To avoid such misinterpretation, the pitfalls of sample preparation need to be identified and properly addressed.In the last decade, many NGS technologies have been developed and several are commercially available today or about to become available in the near future Mardis, . Due to All NGS technologies involve the steps of template preparation, sequencing, and imaging, followed by data analysis, but they differ in the realization of each step. 454/Roche pyrosequencing has been the first NGS method commercially available and until today it is the most commonly used technology for the analysis of viruses  are the most common type of errors. They occur predominantly in homopolymeric regions of the target sequence, where the linear relationship between signal intensity and number of incorporated nucleotides starts to fail. Remaining nucleotides after washing can give rise to insertions or carry forward errors, while deletion errors can result from incomplete extension  calling, haplotype reconstruction, diversity estimation, and data integration . For read mapping, local alignment using dynamic programming may be applied  graph-based methods that first aggregate the reads in a read graph and then search for a minimum set of paths through this graph, (2) probabilistic clustering models based on mixture models, and (3) Read graph-based global haplotype reconstruction consists in aggregating the reads in a read graph and subsequently identifying haplotypes as paths in this graph. The concept of a read graph has been independently introduced by Eriksson et al.  and WestEvery path in the read graph connecting source and sink is a potential haplotype, and the problem of estimating the haplotypes present in a certain sample might be restated as finding a set of such source-sink paths that explains the reads well. Different formalizations of this problem lead to different optimization problems. One example is the search for the minimum set of paths that covers all reads implemented in ShoRAH . The other 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.


Glenoid hypoplasia is a relatively rare alteration that in most cases involves the pectoral girdle in a bilateral and symmetrical manner. In general, glenoid hypoplasia is associated with skeletal changes such as hypoplasia of the humeral head or changes in the morphology of the acromion and of the coracoid. We describe a rare case of unilateral glenoid hypoplasia without instability and not involving humeral head. The patient was managed effectively with nonoperative measures that featured specific rehabilitation exercises for the shoulder. The term congenital and primary glenoid hypoplasia refers to an uncommon condition characterized by incomplete ossification of the lower two-thirds of the cartilaginous glenoid and adjacent neck of the scapula . Since i To our knowledge, in the largest series so far by Wirth et al, three groups of patients were identified: (1) those who had bilateral glenoid hypoplasia without instability of the shoulder, (2) those who had bilateral glenoid hypoplasia with instability of the shoulder, and (3) those who had unilateral glenoid hypoplasia and severe deformity of the humeral head . The purpose of this report is to describe a rare case of unilateral glenoid hypoplasia without instability of the shoulder and not involving the humeral head. The patient was managed effectively with nonoperative measures that featured specific rehabilitation exercises for the shoulder.A twenty-one-year-old male barber, right hand dominant, was seen at our hospital with six-year history of discomfort and mild pain in the left shoulder that had occurred with repeated overhead activity related to his occupation. No significant birth, family, medical, or surgical history could be obtained.Physical examination revealed limitation of overhead abduction without any instability of the shoulder. Forward flexion was to 130 degrees on the left and to 140 degrees on the right, abduction to 80 degrees on the left and to 90 degrees on the right. Strength and tone examination revealed normal muscle strength. Muscle atrophy was absent and the examination was negative for ligamentous laxity. Laxity and stability examination revealed anterior apprehension to be negative, relocation test was negative, load and shift test was normal, the inferior sulcus sign was normal, and posterior load shift was normal as was adduction load. No generalized ligament laxity like hyperextension of metacarpophalangeal, knee, and elbow joint could be found.Imaging studies (X-rays and CT scan) revealed hypoplastic glenoid fossa, prominent coracoid process, large acromion process, hooking of distal aspect of clavicle, and normal humeral head Figures .Investigations including levels of creatine kinase, vitamin C, vitamin D, liver, and renal function tests, EMG-NCV, were found to be normal.Contralateral shoulder was found to be normal on history, physical examination, and imaging studies .The patient was managed conservatively using anti-inflammatory medications, moist heat application, life style modifications, rehabilitation exercises like rubber therabands, pulley kit and weight exercise, shoulder shrugs and push-ups  to strengthen deltoid, internal rotators, external rotators, and scapular stabilising muscles and he fared well.The aetiology and inheritance of glenoid hypoplasia are poorly understood. The pathogenesis appears to be a failure of ossification of the inferior glenoid cartilage . The und Samilson  suggest  Glenoid hypoplasia is often diagnosed as an incidental finding on chest radiographs as many patients with this disorder are asymptomatic. Edelson reported the incidence of posterior glenoid dysplasia in over 11.000 cadaveric specimens studied. As many as 35% of the specimens had deficiencies in the posterior-inferior aspect of the glenoid  found th The treatment of glenoid hypoplasia is controversial, with most authors advocating conservative measures , 12. If  Smith and Bunker  noted th In a review of the literature, Glenoid hypoplasia is usually bilateral and symmetric with only eight cases described in whom the findings were unilateral , 15, 17.


R0), and the mechanisms of dispersal that allow ticks and tick-borne pathogens to invade suitable environments. Using the expanding geographic distribution of the vectors and agent of Lyme disease as an example we then investigate what could be expected of the diversity of tick-borne pathogens during the process of range expansion, and compare this with what is currently being observed. Lastly we explore how historic population and range expansions and contractions could be reflected in the phylogeography of ticks and tick-borne pathogens seen in recent years, and conclude that combined study of currently changing tick and tick-borne pathogen ranges and diversity, with phylogeographic analysis, may help us better predict future patterns of invasion and diversity.The geographic ranges of ticks and tick-borne pathogens are changing due to global and local environmental (including climatic) changes. In this review we explore current knowledge of the drivers for changes in the ranges of ticks and tick-borne pathogen species and strains via effects on their basic reproduction number ( Ixodes scapularis and I. ricinus and the pathogens they transmit . We show that many current hypotheses are supported by observations, which gives confidence that in the future we may, by combined study of the ecology of tick and tick-borne pathogen invasion, their genetic diversity and their phylogeography, be better able to predict future patterns of invasion and diversity.Change in geographic range is one process whereby infectious diseases emerge or re-emerge  is an index of the rate of reproduction of a species or strain under the conditions occurring at a particular point in space and time. Therefore, R0 provides an index of the fitness of species and strains at locations where they occur, or in new locations into which ticks and tick-borne pathogens are invading. In this section we review the key variables affecting the basic reproduction number (R0) of tick-borne pathogens using the simplified equation of Randolph  and vertebrate host-to-tick], p = vector daily survival probability, n = development duration for ticks , r = daily rate of loss of infectivity of host, h = host daily mortality rate, f = probability tick feeds on an individual of a host species, F = tick birth rate.Where I. ricinus, I. persulcatus and I. scapularis), some ticks are host specialists that are often nest-living . The density of hosts for the latter, the specialists, will in most cases be lower than for the former in most locations. Both feeding ticks and free-living ticks  suffer mortality. Apart from host densities, rates of mortality of ticks that are not feeding on hosts are likely the main determinant as to whether a particular habitat is suitable for tick population invasion, establishment and maintenance. The capacity of a habitat to provide non-feeding ticks with refugia from extreme temperatures, desiccation, drowning or perhaps predation, within the limits provided by climate, will determine the mortality rates of ticks in that habitat  and (if it occurs) transovarial transmission (βt−v and then βt−t) are functions of the pathogen-tick interaction and key determinants of the basic capacity of the tick-borne pathogen to invade: if a tick-borne pathogen is poorly adapted to ticks in regions in which it is invading, these transmission coefficients will be lower, reaching zero if the vector is completely incompetent. Therefore, the geographic occurrence of competent tick vector species absolutely impacts the geographic range of tick-transmitted pathogens, although genetic change by random mutations can mean that tick-borne pathogens become adapted to transmission by new tick vector species  of transstadial transmission , depends on the innate susceptibility of individuals of the host community to infection, i.e., the capacity of the innate immune response of the host to kill the pathogen at the point of infection , the less impact tick seasonality will have.Host-to-tick transmission coefficients are usually highest in early acute stages of infection, and then decline to low levels (assuming the pathogen is capable of more long-term immune evasion and persistence in the host) or to zero if host immunity is complete , and the fecundity of individual female ticks, which depends on the quality and quantity of the female tick's meal. The latter will be determined by the community of adult tick hosts and their innate and acquired immune responses to the ticks  becomes a more meaningful index of the abundance of ticks and pathogens, host acquired immunity  becomes a more crucial determinant of In summary, the main factors that determine the capacity for tick and tick-borne pathogen populations to expand and drive invasion, and the suitability of any one location for invasive ticks and tick-borne pathogens to become established are (i) climate ; (ii) habitat; and (iii) host species range and density, and (iv) for tick-borne pathogens the presence of, and adaptation to competent vector species. Generalist exophilic tick vectors and generalist pathogens will have greater capacity to invade new regions than specialist ticks and tick-borne pathogens that have a narrow, specialized niche breadth. Climate, habitat and host species range and abundance are highly linked, and together affect suitability for tick invasion; changes in one factor alone is unlikely to drive population or range expansion while one of the other factors is limiting. The rate of range expansion would, however, be expected to vary according to how many limiting factors must change. For example, if habitat and host abundance are suitable, responses to a warming climate may be more rapid than if the warming climate must also drive changes in habitat and host densities for these to become suitable for tick and pathogen invasion. Changes in just one of these factors that are detrimental to tick and tick-borne pathogen persistence would, however, drive range contraction even if the other two factors remain within parameter ranges suitable for tick and tick-borne pathogen persistence. As described above, superimposed on these three main drivers of tick and tick-borne pathogen range change, is the possibility of tick-borne pathogens expanding their populations subsequent to genetic changes that produce novel strains that are capable of exploiting new, or enhancing transmission amongst existing, tick vectors and reservoir host species.For a location to be a source, the ticks and pathogens must be sufficiently abundant, and the effective reproduction number sufficiently high, that export of ticks and pathogens (i) is precisely balanced by immigration from elsewhere, (ii) is precisely balanced by the rate of reproduction, or (iii) merely releases the ticks and pathogens from density-dependent regulation. If these criteria are not met then ticks and pathogens will die out in the source location. In most circumstances this means that source tick and pathogen populations are undergoing expansion or that tick and pathogen densities are constrained at equilibrium by density-dependent regulation mechanisms.I. scapularis into Canada which has been predicted on the basis of dispersion by migratory passerines  of housekeeping genes that show neutral variation is being recognized as a highly useful tool for phylogeographic studies  have become more stable, adaptive radiation of B. burgdorferi s.s., leading to multiple niche polymorphism, has been suggested  arisen from isolated founder events  gene of B. burgdorferi s.s. have also been found in Canada  and north (Mafra) of Lisbon using MLST   populations of I. ricinis and I. persulcatus  occur sympatrically  while some Borrelia species are not or rarely detectable in I. persulcatus suggesting vector incompetence for those  has important implications for historic dispersal and the colonization of the American continent by this species. It suggests that B. burgdorferi s.s. and related species either originated in North America  have been associated exclusively with I. persulcatus while ospA type 4 (the European variant of B. bavariensis) are transmitted by I. ricinus (Fingerle et al., B. bavariensis adapted to a different vector and was subsequently able to spread into a new geographic region (Margos et al., A further determinant of the phylogeography of I. scapularis and B. burgdorferi s.s. populations in the USA and Canada we now we have the opportunity to study these processes in real time. Amongst the three key drivers of range change, climate and to some extent habitat are quantifiable, categorisable and measurable allowing some prediction of invasion probabilities (see for example Ogden et al., B. burgdorferi s.l. associated with current environmental changes. Confidence in such predictions would depend on validation, which is difficult to do prospectively. However, the phylogeographic record may allow us to validate models by hindcasting past population expansions and contractions associated with glacial and interglacial periods, and comparing expected results against currently observed phylogeography. More precise estimates of the molecular clock of selectively neutral loci would be particularly useful for this purpose.Courtesy of current expansion of B. burgdorferi s.l. suggest that the phylogeographic and ancestral patterns held within the genome of tick-borne pathogens may depend closely on host behavior and dispersion, and provide clues as to how their populations expanded and contracted associated with past climatic changes. Study of host dispersion and current range expansions may help us to develop better predictive models of effects of current climate change on patterns of invasion and diversity of ticks and tick-borne pathogens, while the phylogeographic record of past population expansions and contractions may allow us to validate these models.Here we have outlined processes involved in the expansion and invasion of tick and tick-borne pathogen populations and identified changes in climate, habitat and hosts as key factors in range changes for ticks and tick-borne diseases. Host movements are the main mechanism of dispersal of ticks and tick-borne pathogens that permits invasions. We have also reviewed expected patterns of diversity of ticks and tick-borne pathogens in zones of emergence and geographic spread and we identify that for the Lyme borreliosis spirochaetes and vectors many observed patterns are consistent with the patterns expected from theoretical studies or studies of other species. Studies of the agent of Lyme disease 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.