For over two decades a significant proportion of neuroscience research has been dedicated to understanding the normal function of neural stem and progenitor cells, as well as developing novel ways to use them to achieve nervous system repair. These therapeutic stem and progenitor cell-based strategies can be broadly divided into three categories: activating endogenous neural stem/progenitor cells, cell transplantation, and the use of stem or progenitor cells to model disease. The progress being made in each of these key areas is addressed briefly within this review and by key contributions to this special issue.Within the adult mammalian brain, including the human brain, neural stem cells (NSCs) are found in the subventricular zone and hippocampal dentate gyrus, where they divide and give rise to new neurons, in a process termed adult neurogenesis. These newly generated neurons are highly plastic and are important for many brain functions including learning and memory and mood. NSCs in the subventricular zone are also capable of generating astrocytes and oligodendrocytes , 2, and Studies in rodents have shown that behavioural interventions such as environmental enrichment and cognitive training and exercise can promote neurogenesis , and som in vitro and retain their ability to differentiate into each of the major neural cell types. However, the benefits observed in response to stem cell transplantation in mouse models of neurodegenerative disease are often not the result of the transplanted cells differentiating into functional neurons or glia on a large scale. Instead they appear to promote neural regeneration by the secretion of paracrine factors. Neural and mesenchymal stem cells that are transplanted into mouse models of Alzheimer's dementia produce beneficial neurotrophins, which have an anti-inflammatory effect and reduce both amyloid and tau pathologies. Similarly, NSCs transplanted into rodents with experimental autoimmune encephalomyelitis, a model of inflammatory-mediated demyelinating disease, have been shown to attenuate inflammation and promote functional recovery [The second major avenue of cell-based neural repair research is stem cell transplantation, which has been used for other clinical purposes since the 1960s. Stem cells from a variety of sources have been proposed and tested for the treatment of neurodegenerative disease. While mesenchymal stem cells have a limited ability to generate neural cell types, human embryonic stem cells can be expandedrecovery . The pas in vitro.The final way in which neural stem and progenitor cells are being utilized to treat nervous system disorders is through the development of cell culture-based models of disease. For example, neural stem and progenitor cells can be differentiated into neurons, astrocytes, and oligodendrocytes in order to study specific human genetic mutations associated with neurodevelopmental or neurodegenerative disorders or expanded for the large-scale screening of novel pharmacotherapies. Human neural progenitor cells are ideally suited for these studies but are difficult to obtain. However, in this special issue, H. Fukusumi et al. (2016) demonstrate that human induced pluripotent stem cells can be derived from multiple sources, including dermal fibroblasts, cord blood cells, and peripheral blood mononuclear cells and readily differentiated into human neural progenitor cells. Moreover, N. Gunewardene et al. (2016) report that human induced pluripotent stem cells can be differentiated into neurons that are able to innervate cochlear hair cells, allowing them to be used to model auditory neuron replacement therapiesThis special issue highlights the rapid progress being made in neural stem and progenitor cell biology.


The advanced developments in external beam radiation therapy (EBRT) over the past few decades have improved dose conformity to the target while minimizing dose to the surrounding organs at risk (OAR). Intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) are two commonly used EBRT techniques to treat cancer. In sliding window (SW) or dynamic IMRT, each radiation beam is modulated by continuously moving multileaf collimators (MLC), whereas in step-and-shoot (SS) or static IMRT, the MLC divide each radiation beam into a set of smaller segments of differing MLC shape, and the radiation beam is switched off between the segments.2The advanced developments in external beam radiation therapy (EBRT) over the past few decades have improved dose conformity to the target while minimizing dose to the surrounding organs at risk (OAR). Intensity modulated radiation therapy (IMRT) and volumetric intensity-modulated arc therapy (VMAT) are two commonly used EBRT techniques to treat cancer. In sliding window (SW) or dynamic IMRT, each radiation beam is modulated by continuously moving multileaf collimators (MLC), whereas in step-and-shoot (SS) or static IMRT, the MLC divide each radiation beam into a set of smaller segments of differing MLC shape, and the radiation beam is switched off between the segments.2–20) was higher in the VMAT plans than in the IMRT plans.20 of normal lung.8Recently, there has been increased interest in treating cancer using VMAT. Several authors have done the treatment planning studies comparing IMRT versus VMAT for different tumour sites,2The inconsistency in the results among different planning studies may have been due to difference in selection of beam parameters, dose calculation algorithm, plan optimization technique, and delivery technique of the treatment machine. In comparison to the VMAT plan with one arc, the VMAT plan with multiple arcs has more control points that give higher degree of freedom for possible MLC positions. This could result in higher degree of modulation and better plan quality, especially for a complex-shaped target volume. However, a higher degree of modulation generally increases the planning time due to longer plan optimization and dose calculation processes. Thus, treatment planning personnel may be required to make a compromise between planning time and plan quality depending on the physician requirements and available planning resources. The dosimetric results of the OAR can also be affected by the design of the treatment machine as dose to the OAR is dependent on the secondary collimator transmission and scatter radiation of the machine.Another factor that may affect the quality of the IMRT and VMAT plans is the dose calculation algorithm. Several studies have shown that dose calculation algorithms employed within commercially available treatment planning system (TPS) are not consistent in predicting doses, especially when heterogeneous media are involved along the photon beam path. The difference in beam modelling within dose calculation algorithms may result in different dosimetric results. If the treatment plan includes a small lung tumour, dose calculation algorithms must apply tissue heterogeneity corrections that will account accurately for the electronic disequilibrium effect near the air/tissue interfaces. The International Commission on Radiation Units (ICRU) recommends the dose to be delivered with an error of less than 5%. This implies that necessary accuracy for the dose calculation on treatment plans should be on the order of 2–3%. However, photon dose calculation algorithms could have dose prediction error more than 3% depending on the field size of a photon beam and tissue heterogeneities.The quality of treatment plan is also dependent on the dose–volume (planning) objectives and planner's familiarity with certain algorithms/interfaces. For example, during the treatment plan optimization in the Eclipse TPS, a planner has the flexibility of selecting dose–volume objectives and weight factor to generate an optimum treatment plan. Additionally, a planner who has worked with IMRT for several years will likely be better in creating IMRT plans than VMAT plans, if the controls and/or optimization parameters are different. Direct comparison between different studies using IMRT and VMAT is also not straightforward because of the differences in prescription dose, planning target volume definitions, and plan optimization algorithms.There is no doubt that the dosimetric results in the treatment plan play an important role in selecting the treatment technique; however, it is important to note that the quality assurance (QA) result of a patient treatment plan could also impact the selection of IMRT or VMAT technique. The choice of measurement device is also equally important to verify the patient-specific QA. For instance, the MapCHECK 2D diode array is typically used for the IMRT technique, whereas the ArcCHECK 3D diode array is used for the VMAT technique. Sanghangthum et al.In the recent years, the development of new treatment delivery methods, dose calculation engines, and plan optimization algorithms has led to an increased number of planning comparison studies, which are mainly based on the statistical analysis of dose–volume histogram data. Furthermore, the treatment planning studies typically report the average results of a group of patients, and patient-specific results are usually not discussed. It is important to note that the difference in tumour location in patients with different anatomy may also provide different dosimetric results. As clinical protocols may include the data from different centres with different TPS/algorithm, it is essential to have a database that includes the patient characteristics, treatment planning and optimization parameters, delivery technique, and patient follow-up information. This could provide us some guidelines to compare the treatment plans generated by different planning techniques. However, it may not be possible to completely eliminate the planner bias among different planning studies. Due to dependency of dosimetric quality of IMRT and VMAT on different factors mentioned in this article, the results from the treatment planning studies must be interpreted with caution.


The study of large-scale functional interactions in the human brain with functional magnetic resonance imaging (fMRI) extends almost to the first applications of this technology. Due to historical reasons and preconceptions about the limitations of this brain imaging method, most studies have focused on assessing connectivity over extended periods of time. It is now clear that fMRI can resolve the temporal dynamics of functional connectivity, like other faster imaging techniques such as electroencephalography and magnetoencephalography . However, the indirect nature of fMRI measurements can hinder the interpretability of the results. After briefly summarizing recent advances in the field, we discuss how the simultaneous combination of fMRI with electrophysiological activity measurements can contribute to a better understanding of dynamic functional connectivity in humans both during rest and task, wakefulness, and other brain states. KEY CONCEPT 1. Functional connectivityThis concept refers to signals of neural origin that co-vary over time, for instance, two regions showing similar temporal patterns of spontaneous activity fluctuations. In fMRI signals, functional connectivity is commonly measured by linear correlation. Functional connectivity does not imply a causal mechanism between the signals.However, until recently functional magnetic resonance imaging KEY CONCEPT 2. fMRI and BOLDFunctional Magnetic Resonance Imaging (fMRI) is a non-invasive technique used to detect changes in magnetic susceptibility, which may correlate with oxygen consumption, and therefore with neural (synaptic) activity. The measured signal is termed Blood Oxygen Level Dependent (BOLD).KEY CONCEPT 3. ElectroencephalographyElectroencephalography is a non-invasive method routinely used to measure changes in voltage at the scalp, which can be originated by synchronous assemblies of neurons. EEG measures changes in voltage resulting from the flow of ions implicated in the generation of action potentials. While EEG can be measured with very high temporal resolution, it is difficult to pinpoint where in the brain the voltages originate.KEY CONCEPT 4. Convolution and de-convolutionBecause of the indirect nature of fMRI measurements, precisely localized neural activity (in the time domain) is measured by fMRI as widespread and lagged. Formally, neural activity time series are said to be convoluted, i.e., blurred by a moving average weighted by a kernel . The (difficult) operation of inverting this process is termed de-convolution.Are temporal changes in connectivity related to respiration or heart rate fluctuations? Since fMRI measures blood flow, physiological changes could impact directly on BOLD measurements .Are temporal changes in connectivity related to head motion? It has been shown that movements inside the scanner can strongly influence connectivity estimates .Do apparent temporal changes in functional connectivity appear spuriously (by chance) or by meaningful neurophysiological fluctuations? Computation of short-term correlations between random noise signals can give rise to apparently complex dynamics , 11.Are changes in functional connectivity related to cognition or behavior or do they represent changes in vigilance and arousal? The question of how ubiquitous is sleep during the resting-state is closely related to this issue .Leaving these assumptions aside, recent studies revealed meaningful changes in functional connectivity over time. Furthermore, the analysis of single volume co-activation patterns emerged , 7, thusIn this focused review we discuss how, when faced with such questions, the combination of fMRI with other neuroimaging methods (such as EEG and MEG) can help prove or disprove the neurophysiological relevance of dynamic changes in functional connectivity. This strategy was fundamental for validating the neurophysiological origin of spontaneous activity fluctuations in resting-state fMRI measurements , 14 and Extensive reviews already cover with detail the recent developments in the field , 16. HerA natural starting point is the work of Chang and Glover  and SakoKEY CONCEPT 5. Sliding windowsFunctional connectivity can be computed over a relatively short period or window of time (in the order of seconds for fMRI time series). In a sliding window analysis, this computation is repeated many times while displacing the window forward in time (either by one or many samples), therefore estimating temporal changes in functional connectivity. The window size and the overlap between windows are free parameters to be decided.Aside from establishing the existence of fluctuations in functional connectivity, others attempted to evaluate whether short-term patterns of connectivity can be accurately classified or clustered into a discrete set of states. Clustering via k-means revealed short-term patterns of connectivity diverging from results obtained from whole recordings , whereasMost of the analyses outlined above were carried out using sliding windows, basically an extension of standard linear correlation and therefore inheriting its bivariate nature. Higher order correlations, however, are ubiquitous in brain activity  and a fuThe human brain is inherently dynamic and variable, with oscillations over different frequencies paralleling changes in brain states . Non-staA relevant finding is the correlation between changes in functional connectivity of the DMN and stimulus-independent thought, as demonstrated in . AuthorsIn another study, spatiotemporal ICA was introduced to capture the temporal evolution of networks in task fMRI data . This anOne natural question is whether spontaneous fluctuations in connectivity can bias perception and action. This question has an affirmative answer for the amplitude of BOLD signals. For instance, when showing ambiguous images to subjects (faces being one of two possible interpretations) researchers found that increased activity in the fusiform face area predicted the perception of the stimulus as a face . How areMultimodal imaging  can offer insights on the functional role of spontaneous fluctuations in functional connectivity. A rich literature demonstrates how band-specific spontaneous changes in EEG oscillatory power can bias behavior and perception. Following the previous example, pre-stimulus gamma band in the lateral part of the occipital cortex can predict conscious awareness . As discIn line with the possibility of connectivity indexing fluctuations of attention and perception, we recently suggested that temporal changes of functional connectivity track more radical departures from wakefulness, i.e., toward drowsiness and sleep .Implicit to the use of single connectivity estimates over extended resting-state sessions is the assumption that the brain state of subjects will be homogeneous and will not depart from an idealized “resting-state wakefulness.” While the existence of the latter is disputed , brain states associated with considerable neurophysiological changes (such as sleep) should be monitored and avoided. This is supported by many reports showing different BOLD functional connectivity and dynamics during drowsiness and sleep –47.Dynamical changes in functional connectivity can be used to decode sleep stages [as defined by AASM rules ]. This wOne lesson of these studies is that temporal fluctuations in functional connectivity can be accounted  by changes in vigilance levels and sleep stages. Vigilance shifts indeed occur during rest, therefore it is in the interest of researchers to maintain a steady brain state during fMRI acquisition  in order to avoid sleep-related confounds. This is of particular importance when comparing different clinical populations 61). In tCorrelations between both functional connectivity and BOLD signal amplitude  with EEGTo overcome the limitations of volume conduction, concurrent direct electrophysiological recordings and BOLD signals were obtained in the somatosensory cortex of rats . The resThe studies mentioned in the preceding section do not directly relate measures of electrophysiological synchronization  to BOLD functional connectivity between pairs of regions. For this purpose is necessary to source localize the EEG/MEG scalp sensor data, allowing more accurate estimation of the coordinates from where time series are extracted. To study the correlation between static BOLD functional connectivity and electrophysiological coherence is not necessary to perform simultaneous combined measurements, instead, both metrics can be obtained during two different offline recordings and subsequently correlated. This approach was followed by Brookes and colleagues  using noBrainMap, www.brainmap.org)   were ablmap.org) , 7. ThusIt is yet necessary to establish the electrophysiological signatures of these spontaneous activation patterns. Besides the need to distinguish meaningful neuroelectrical activity from other confounds due to brain vasculature, head motion, etc., there is a rich history in cognitive neuroscience assigning band-specific frequencies and Evoked Reponse Potentials (ERPs) to particular tasks which, in turn, could be associated with these patterns of spontaneous co-activations. To the present day, average activity in RSN was linked to characteristic distributions of EEG frequencies , but temThe study of such correlations corresponds to an fMRI-informed EEG analysis, which is exactly the opposite of the most common strategy . The main difficulty is the relative temporal imprecision of fMRI recordings, which complicates EEG analysis triggered by fMRI events. The improvement of fMRI sampling rates could reveal stable electrophysiological signatures of RSN in the temporal domain, by averaging temporal EEG data temporally locked to the spontaneous activation of different RSN. However, the use of scanning sequences with shorter TRs  has intrinsic limitations (such as hemodynamic convolution and the possibility of heterogeneous hemodynamic coupling throughout the cortex).Two inter-related problems arise when studying temporal changes in BOLD functional connectivity. First, how to adequately define states which through their temporal progression can be used to characterize dynamics. Second, the problem of spurious results when sliding windows is used to obtain temporally evolving connectivity.Due to poor temporal sampling it is difficult to naturally divide an fMRI resting-state session into segments of different connectivity. Interesting advances have been made by means of different analytical methods  or withGiven the limited temporal resolution of fMRI data, the study of single volume co-activation patterns is of substantial interest. At the core of this method is the realization that patterns appearing on average are also manifest “instantaneously” as groups of jointly activated voxels. The study of these patterns holds promise to map the spontaneous cognitive processes underlying the resting-state. The combination with simultaneous EEG could reveal signatures disentangling transient artifacts from real cognitive processes. Also, observing a correlation between different conscious contents and rapidly shifting patterns of co-activated regions could strengthen the observation that functional connectivity reflects mind wandering or day-dreaming .We want to note that simultaneous EEG–fMRI acquisition can pose difficult challenges . WhIn summary, the reviewed articles show widespread evidence that: (i) functional connectivity fluctuates over time in short temporal windows, (ii) these fluctuations are neural in origin and paralleled by electrophysiological changes, and (iii) these electrophysiological correlates in humans are consistent with their purported role in binding/inhibitory processes. While some studies suggest that MEG and EEG are in general terms superior for tracking functional connectivity changes over time, the use of fMRI is still more common due to its ability to consistently map stable, high-resolution large-scale networks. Ideally, the advantages of both methods (and not their disadvantages) will be combined in the future to gain a deeper understanding of dynamic functional connectivity.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.


Translational research is an evolving discipline that is intended to bridge the gaps between basic science research, clinical research, and implementation in clinical practice. It is a fluid, multidirectional process that requires strong interdisciplinary collaboration to produce research that is relevant to end-users.This review summarizes current perspectives on translational research and outlines its relevance and importance to kidney transplantation research.Sources of information used for this review include published reports, articles, and research funding websites.Tissue typing is used as an in-depth example of how translational research has been applied in the field of kidney transplant medicine, and how it has resulted in successful implementation of diagnostic and management options for sensitized individuals undergoing kidney transplantation. The value of actively involving kidney transplant stakeholders  in setting research priorities and determining relevant outcomes for future investigation is also discussed.This is a narrative review of the literature which has been partly influenced by the perspectives and experiences of its authors.Translational and patient-oriented research practices should be incorporated into future research endeavours in the field of kidney transplantation in order to create beneficial change in clinical practice and improve patient outcomes.Translational research which engages patients in the investigative process can enhance the likelihood that medical discoveries will have a meaningful impact at the bedside.This article applies current perspectives on translational research and patient engagement to the field of kidney transplantation, illustrating how these approaches have led to significant advancements in the field. It provides further justification for deliberate, targeted efforts to cross-collaborate and incorporate the patient voice into kidney transplant research. A kidney transplant is the best treatment for patients with end-stage renal disease. This review highlights the importance of translational research in bridging the gaps between basic and clinical research and promoting evidence implementation in the field of kidney transplantation. It also reviews the key role of patient engagement in the research process.The example of tissue typing is provided to illustrate the application of translational research in kidney transplantation. Patient-oriented research, including the involvement of kidney transplant stakeholders in determining research priorities and outcomes, may enhance the relevance and implementation of research findings into practice.Translational research fosters multidisciplinary and multi-stakeholder collaboration and can improve translation of findings into practice. This strategy lends itself to many opportunities to enhance patient care and quality of life post-kidney transplant.A Medline search exploring the term “translational research” reveals titles published as early as the 1990s . The conThe National Institutes of Health initially defined translational research as two separate areas of research: the first involving the application of discoveries from the laboratory or “bench” to the clinical setting, and the second aimed at adapting “best practices” in the community. It was thought to exist along a unidirectional continuum . Over ththe decreased capacity to translate the results of discoveries generated by basic biomedical research in the laboratory to the bedside or careside …”, and Valley 2 refers to the “limited capacity to synthesize, disseminate and integrate research results more broadly into health care decision-making and clinical practice” [Some of the benefits of translational research include an increased number of individuals participating in research and a more patient-centered approach . Obstaclractice” . In thiscellular, biochemical, molecular or genetic alteration by which a biological process can be recognized and/or monitored and has diagnostic or prognostic utility” [A kidney transplant is the preferred treatment for patients with end-stage renal disease (ESRD). Despite improvements in graft survival, long-term management post-transplant is still challenging. The constant risk of rejection and the long-term side effects of immunosuppressive medications remain obstacles. Early acute rejection affects 10 % of kidney transplants –18. Measutility” . Urine iutility” .Halawa reviews some of the biomarkers that have been considered in kidney transplantation in an attempt to detect kidney injury earlier . One of there is currently insufficient evidence to guide treatment for acute ABMR”. This area of research highlights an example of Valley 2, as the clinical studies that have been performed in this area lack the size and quality to provide compelling evidence needed to make standardized practice recommendations.Acute antibody-mediated rejection (ABMR) is another form of rejection that occurs in 5–7 % of transplants and causes 10–48 % of acute rejection episodes post-kidney transplant . ABMR isThe knowledge sharing and collaboration that has occurred across the valleys in the field of tissue typing exemplify how translational research has led to improved patient outcomes. This process began with a series of early discoveries in the laboratory. In the 1930s, P.A. Gorer, a physician, studied a possible link between blood group antigens and rejection of allogeneic tumor transplants in mice and observed that the rejection reaction of tumor grafts resembled the reaction to incompatible blood transfusions. Meanwhile, G. Snell, a geneticist, studied the genetics of the histocompatibility loci. The two established that the blood group antigens and the histocompatibility H locus were the same, and termed the locus H2 . Jean DaThe initial serological assays included complement-dependent cytotoxicity (CDC). CDC-based methods, where recipient serum is mixed with donor cells, were the first tests used to identify circulating antibodies . Their iThe sensitivity and specificity of histocompatibility testing needed to be improved to enable rapid translation to the entire transplant population. This process was partly facilitated by International Histocompatibility Workshops, which helped standardize research techniques to enable collaboration between different researchers and laboratories . ImproveWhile these advances improved the ability to describe a patient’s immunologic risk, solutions were still needed to translate better risk stratification into improved outcomes that matter to patients. This challenge was accepted by clinical and health service researchers, who could now properly assess the benefits and risks of innovative transplant options for sensitized patients. Three protocols for sensitized patients now exist: acceptable mismatch, kidney paired donation, and desensitization, with the choice based primarily on an individual patient’s antibody profile , 42.The first two options take advantage of HLA technology to avoid donor specific antibodies that would elicit an immune response. Acceptable mismatch programs use large donor pools to identify HLA antigens toward which a recipient has never formed antibodies , 43, 44.Patients with rare HLA phenotypes who are not suitable for acceptable mismatch programs may still find a donor through kidney paired exchange. Kidney paired donation programs match incompatible donor-recipient pairs to each other, leading to compatible pairs and avoidance of donor-specific antibodies . These pDesensitization remains an option to enable transplantation of a mismatched kidney for those who cannot access a kidney in either of the previous programs –51. DeseIn Canada, both a living donor paired exchange and highly sensitized patient program exist . The latHow did histocompatibility testing successfully translate from knowledge to practice and create several transplant options for the sensitized patient? This question is difficult to answer with certainty, but interdisciplinary collaboration appears to have played a major role. One excellent example is the Banff initiative, which is an ongoing interdisciplinary effort to standardize definitions of rejection involving elements from both histocompatibility and pathology , 58. PatThere are also several histocompatibility clinical observations that may be candidates for reverse translation from the bedside back to the bench. Firstly, solid phase assays sometimes identify donor specific antibodies despite a negative CDC crossmatch , 59, theThe HLA story demonstrates how translational research is a fluid process that requires collaboration between basic scientists and clinical researchers. It describes one example of successful translational research in kidney transplantation, where basic science discoveries resulted in specialized treatment options depending on an individual patient’s antibody profile. As a consequence, kidney transplant patients can receive the transplant option most appropriate to their own circumstances, leading to better health outcomes at the population level.One of the key barriers to bridging the research-to-practice valleys identified by the CIHR is the limited role of patients in research . While tTraditionally, approaches to defining research priorities have not involved patients, which can make it challenging to bridge either of the death valleys along the translational research continuum. Each year, up to $240 billion is spent funding biomedical research, of which up to 85 % is considered wasted . This waFew evidence-based methods for involving patients and other stakeholders in determining research priorities exist. The Cochrane Agenda and Priority Setting Methods Group has identified three such processes: the health equity lens model , the diaWhile studies on research prioritization in kidney disease in general provide valuable information that will help guide future research, patients who have received a kidney transplant represent a separate population with likely different concerns and priorities. Little work has been done on patient involvement in kidney transplant-related research prioritization. A recent systematic review evaluating approaches to research prioritization in kidney disease found only four studies that identified research priorities in kidney transplantation . These freports coming directly from patients about how they feel or function in relation to a health condition and its therapy without interpretation by healthcare professionals or anyone else” [In addition to involving patients in research priority setting, there has been a growing recognition of the importance of using patient-reported outcomes (PROs) to ensure treatments lead to meaningful health improvements for patients. PROs have been defined as “ne else” . Not onlPROs have been used in kidney transplant research for various purposes. One salient example has been to address medication non-adherence among kidney transplant recipients. Medication non-adherence is a prevalent issue in kidney transplant patients , which iAnother example of PRO use is in the growing field of geriatric transplantation, where quality-of-life outcomes hold particular significance. Research has demonstrated that elderly transplanted patients experience better HRQoL than elderly patients on dialysis, but they also score more poorly than normative age-matched populations in some HRQoL-related domains such as functional status –97. OldeDespite their demonstrated potential to lead to meaningful improvements in patient wellbeing, PROs currently occupy a small proportion of the outcome literature in kidney transplantation. For example, a systematic review which examined the use of PRO measures in immunosuppressive regimen trials concluded that very few randomized controlled trials had used HRQoL outcomes. Efforts to incorporate PROs into research have also often been minimized by various challenges - the same review found that when PROs such as HRQoL were included in such trials, the validity of the measures used or the clinical relevance of the results were often not considered . PRO-focThis review has provided an overview of translational research and highlighted examples of translational research in the field of kidney transplantation. Translational research is an evolving discipline that emphasizes fluidity between the different phases of research and requires strong interdisciplinary collaboration among researchers and clinicians.The example of histocompatibility testing, and how translational research has played a role in improving management options for sensitized individuals, demonstrates how focused efforts to bridge gaps between basic science research, clinical research, and implementation in clinical practice can lead to improved patient outcomes. Further, involving patients and stakeholders in establishing and monitoring research agendas increases the likelihood that research will be produced that is meaningful and relevant to patients and those who care for them. Potential rich areas for translational research efforts include non-invasive diagnostic test development for acute rejection, novel immunosuppression strategies, and improving medication adherence. Future use of established, transparent research prioritization initiatives involving key Canadian kidney transplantation stakeholders and evaluation of these processes will be not only important but also necessary to ensure that the concerns of research end-users are being addressed and that research findings are being implemented in practice. The future of translational research in kidney transplantation and beyond will require the deliberate fostering of partnerships to ensure that scientists, clinicians, and patients are working towards common goals.


The extent to which animal studies can be relevant to military posttraumatic stress disorder (PTSD) continues to be a matter of discussion. Some features of the clinical syndrome are more easily modeled than others. In the animal literature, a great deal of attention is focused on modeling the characteristics of military exposures and their impact on measurable behaviors and biological parameters. There are many issues to consider regarding the ecological validity of predator, social defeat or immobilization stress to combat-related experience. In contrast, less attention has been paid to individual variation following these exposures. Such variation is critical to understand how individual differences in the response to military trauma exposure may result to PTSD or resilience. It is important to consider potential differences in biological findings when comparing extremely exposed to non-exposed animals, versus those that result from examining individual differences. Animal models of military PTSD are also critical in advancing efforts in clinical treatment. In an ideal translational approach to study deployment related outcomes, information from humans and animals, blood and brain, should be carefully considered in tandem, possibly even computed simultaneously, to identify molecules, pathways and networks that are likely to be the key drivers of military PTSD symptoms. With the use novel biological methodologies  in the animal models, critical genes and pathways can be tuned up or down (rather than over-expressed or ablated completely) in discrete brain regions. Such techniques together with pre-and post-deployment human imaging will accelerate the identification of novel pharmacological and non-pharmacological intervention strategies. Prior to exposure to trauma, soldiers who will participate in a combat theater are selected according to fitness criteria and undergo training, which is designed to prepare them. Nonetheless, the probability of posttraumatic stress disorder (PTSD) after combat exposure is high (approximately 40%); higher than after a natural disaster (approximately 4%) but lower than after rape (approximately 65%)  dependent differences  the This model has been proven to be sensitive to manipulations of single genes  paradigm  sub jected to chronic social defeat stress escape most of the above symptoms. These mice are referred to as “unsusceptible” compared to the majority that is referred to as “susceptible” . Here, the test mouse witnesses another test mouse of the same strain undergoing physical defeat, and then spends the rest of the day with that aggressor behind the same screen. Ten days of this witnessed stress results in nearly as robust behavioral sequelae as physical defeat, with roughly the same fraction of animals showing susceptibility vs. resilience. Such witnessed defeats seem particularly relevant to combat-related PTSD, and analogous to battlefield exposures, wherein many troops suffer severe psychological syndromes by witnessing death or maiming of their colleagues without sustaining injury themselves. Actually, exposures to human atrocities tend to even have greater impact than self-exposures  are in sensory contact with trained aggressors for 6 h daily session that include one to three (unpredictable) daily physical contact periods for 5 or 10 days. During aggressor exposure, mice display less territorial behavior, increased weight, and increased body temperature. One day after the last aggressor exposure, inflammatory cardiac histopathologies are present; after 10 days, mild myocardial degeneration with fibrosis or fibroplasias are evident, while control mice show almost no cardiac abnormalities at any time. After 4 weeks, the medial frontal cortex of control mice show increased dendritic spine density, but aggressor-exposed mice showed no increase. For up to 6 weeks after the last aggressor exposure, subjects display prolonged grooming, freezing, retarded locomotion and no tail rattling, the traits of fear response to contexual cues. Activated gene modules (across blood and various brain regions) were identified in these social defeated mice . The It is critical to determine sex differences in critical pathways and phenotypes related to deployment and deployment-related responses. Social stress models with females are challenged by the virtual rarity of male-typical aggression among female rodents , to model PTSD-like behavior in mice  is highly expressed in central amygdala (CeA) whereas its expression in other brain regions is relatively low. Oprl1 mRNA was significantly up-regulated in the IMO-exposed animals compared to the control-fear condition, compared to prior IMO exposed animals demonstrating an amygdala-specific dysregulation of Oprl1 gene expression after fear conditioning and extinction in IMO mice. Finally, OPRL1 agonists, administered in CeA, could inhibit fear consolidation in mice and a DNA polymorphism within the human OPRL1 gene was associated with PTSD, altered fear learning and amygdala-insula co-activation  history, and not fear conditioning Fear conditioning and immobilization stress could represent quite different dimensions of combat-related experience. On the one hand, soldiers will often argue that the inability to act, for example when being bombarded is far more stressful than being able to use the skills which they have acquired and have a high sense of self-effectiveness, which they can utilize in active combat. On the other hand, there are many triggers and stimuli in the combat environment that could lead to fear conditioning.Advanced techniques that are available in animal models can enhance the time, brain-site and cell-type resolution of our understanding of gene–environment interactions relevant for PTSD susceptibility , biological sampling before and after stress , and repeated phenotyping .This review presents and discusses recent studies using animal models that could be relevant for military PTSD. Based on these studies, we designed an experimental setup  that wilThe biomarker identification using exposure-based animal models will be facilitated by the use of multiple stress models that resemble different dimensions of military experience. Studying them together will permit the dissection of common neuronal and molecular networks associated with the behavioral response to traumatic events from those that might pertain to specific types of exposures or behaviors  that increase susceptibility to develop PTSD after stress exposure in persons who are behaviorally no different from anyone else at baseline conditions. Focusing on discriminating biological differences between animals showing more impairment and behavioral disruption and those demonstrating less impairment, it is possible to identify biomarkers associated with vulnerability (posttrauma illness) vs. resilience  to similar exposures.The use of genetically modified mice (or rats), viral gene transfer and optogenetic approaches to manipulate identified biomarkers, biochemical pathways, and neural circuits, provide an unprecedented advantage of highly specific and nuanced alterations of biological activity.We propose the following five principles for developing animal models of military PTSD:


The vast majority of environmental bacteria and archaea remain uncultivated, yet their genome sequences are rapidly becoming available through single cell sequencing technologies. Reconstructing metabolism is one common way to make use of genome sequences of ecologically important bacteria, but molecular evolutionary analysis is another approach that, while currently underused, can reveal important insights into the function of these uncultivated microbes in nature. Because genome sequences from single cells are often incomplete, metabolic reconstruction based on genome content can be compromised. However, this problem does not necessarily impede the use of phylogenomic and population genomic approaches that are based on patterns of polymorphisms and substitutions at nucleotide and amino acid sites. These approaches explore how various evolutionary forces act to assemble genetic diversity within and between lineages. In this mini-review, I present examples illustrating the benefits of analyzing single cell genomes using evolutionary approaches. Single cell genome sequencing technology  has been widely used to unravel the metabolism of uncultivated microbes in the past 5 years, and this trend is expected to continue in that 99% of the environmental microbes remain uncultivated. Analyses of single-cell amplified genomes (SAGs) from the uncharted branches of the tree of life have allowed reconstruction of metabolic potential of ecological key players in various marine and terrestrial environments , extensiProchlorococcus showed that a small volume of seawater contains 100s of ecologically distinct subpopulations differing mainly at the SNP level and linked to a limited diversity of flexible genes  and thus are significantly affected by acquisition of divergent alleles through recombination, among which the urease gene cluster might be used to resist acidic stress in the bee gut. The underlying principle is that nucleotide substitutions at synonymous site are largely “invisible” to natural selection. Consequently, the variation of Sd among genes largely reflects stochasticity of mutations and some unusually large values are most likely to arise from recombination. In a third approach, the ratio of probabilities that a given site is altered through recombination versus mutation (r/m) was measured, and the finding of a higher r/m ratio associated with a lineage in G. apicola validated the distinct pattern of Sd in this lineage. Finally, 15% of the genes were found to have intragenic recombination . In another study of homologous recombination in an uncultivated free-living bacterial lineage LD12 represented by 10 SAGs, Homologous recombination is an important evolutionary mechanism shaping the genetic diversity of asexual populations. Understanding homologous recombination rate and pattern requires analyzing closely related sequences varying at the strain level, and this has been done for uncultivated microbes as intraspecific SAGs are becoming available. By analyzing four closely related SAGs of betaproteobacterial Sd estimate for homologous recombination, analyses are usually based on the orthologous genes that are present in every member of the taxa under study. In the case of gene tree – genome tree comparison, missing taxa in the gene trees are tolerable, since these missing taxa can be dropped from the genome tree so that the gene tree and genome tree under comparison have the same set of taxa.Single-cell amplified genomes are often incomplete, and hence it is useful to check the completeness requirement of the above approaches. In the r/m measurement and the Figure 1A) per non-synonymous site (dN) to the number of synonymous substitutions  per synonymous site (Sd). Theory predicts that a genome-wide inflation of ω is a result of reduced efficiency of selection  of the number of non-synonymous substitutions  between the two amino acids in replacement . Further, rates of these two types of non-synonymous substitutions, that is, the number of radical non-synonymous substitutions per radical non-synonymous site (dR) and the number of conservative non-synonymous substitutions per conservative non-synonymous site (dC), are measurable  is substantially lower than that of cultured Roseobacters (60 ± 4%). Although an inflated genome-wide dR to dC ratio was found in SAG-O19 compared to any cultured Roseobacter lineage, ascription of this inflation to inefficient selection on the SAG-O19 clade requires additional evidence  presented here for comparing selection efficiency both use a statistical approach (paired t-test or sign test) to compare the mean or median values of the genome-wide orthologous genes among multiple lineages. These statistical approaches allow missing data, thus making SAGs suitable for the analyses of selection efficiency.Often, closely related genomes are not available, as is the case of an uncultivated Roseobacter lineage (named SAG-O19) exclusively represented by three divergently related single cells . In thisasurable . Theory  program  cannot aevidence . The twoVariation at single nucleotide site could also be generated by sequencing errors. Indeed, using benchmark SAGs, an error frequency of 5–200 bases per Mb has been estimated . HoweverGene flux analysis has been used in a number of microbial genome evolutionary studies. It adds significant insights into evolutionary changes of genome content through reconstructing the number of gene gains and losses during the history of a group of related organisms. It, however, becomes less applicable to partial single cell genomes, since missing genes can be either truly absent, or simply not amplified and sequenced. In their gene flux analysis of the marine SAR11 lineages and its uncultivated freshwater relative LD12 lineage represented by 10 SAGs, In some lineages, ecological subpopulations associated with distinct habitats co-occur with phylogenetic differentiation, and identification of a few ecologically relevant genes that are specific to each subpopulation may be linked to the adaptive mechanism in these habitats. One example is the rarely cultivated marine Thaumarchaeota. Single marker gene  analyses consistently showed that they fall into two phylogenetically distinct groups corresponding to shallow- and deep-water clades. This depth distribution has been hypothesized to be related to photoinhibition . PhylogeA few SAGs are associated with certain uncharted branches of the tree of life, and phylogenetic placement based on a concatenated sequence of multiple proteins is a common practice. For instance, On the other hand, many SAGs are members of well-studied lineages with cultured isolates, but genomic traits of these SAGs do not necessarily match their cultivated relatives. This has been well documented in various surface ocean bacterial lineages . Among tFigure 2B; Figure 2A) or when a node-discrete composition heterogeneity (NDCH) model in the P4 software  is another long-standing issue encountered in various phylogenetic analyses, leading to artificial grouping of lineages with accelerated and parallel changes of molecular sequences. Since genome streamlining is often associated with long branches , and sinSingle cell genome sequencing has been extensively used to reconstruct the metabolism of uncultivated microbes, but its potential in molecular evolutionary analyses has not been fully explored. SAG sequences differentiate strains at single nucleotide site, and such intra- and inter-specific variations are the key information that various population genetic approaches look for. It is useful to compare the level of polymorphism contained in the population to the estimated amount of sequencing errors, since single cell genome sequencing may have a greater error rate compared to conventional genome sequencing. The major limitation of using SAGs for evolutionary analyses is its incompleteness, which limits gene flux analysis and ancestral genome reconstruction. In addition, theoretical studies demonstrated that missing a significant amount of genes in the concatenated sequences may be detrimental to phylogenetic inferences . More siThe Editor Brandon K. Swan declares that, despite having collaborated with author Haiwei Luo, the review process was handled objectively and no conflict of interest exists. 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.


Since birth of the first “test tube” baby—Louise Brown—in 1978, pioneered by physiologist Robert G. Edwards and surgeon Patrick C. Steptoe, there was a great advance in reproductive biomedicine made by amazing people, who insisted on this path in spite of pressure from society. In vitro fertilization procedure indeed became an established way to treat couples with severe infertility problems, and until today more than four million babies have been born worldwide in this way. The field of assisted conception is a fast-developing domain at both the basic and clinical level. This is reflected in the 31 papers in this special issue, spanning a wide range of topics including female and male infertility, gametes, embryos, pregnancy, and babies born after assisted conception.There are some new aspects to study and think about female (in)fertility. The methodology of proteomics was exposed to be important in potential linking oxidative stress and female infertility . One of the main tasks in the in vitro fertilization program remains to better elucidate oocyte quality. This can be facilitated by novel proteomic and secretome tools as have been used in animal models, although some obstacles still need to be resolved before these can be applied to human cells (I. Virant-Klun and J. Krijgsveld). The quality of oocytes also depends on mutual interactions with surrounding granulosa cells; therefore, global profiling of gene expression of follicular cumulus cells using microarrays and next generation sequencing (NGS) may lead to establishment of new reliable biomarkers to select oocytes with the highest developmental potential (E. Chronowska). Oocyte maturity is a prerequisite for successful fertilization and pregnancy. Time-lapse dynamics of oocyte chromatin organisation during meiotic resumption was observed in a mouse model, providing a pathway of transition from the GV to the MII stage oocyte . In vitro maturation (IVM) of human oocytes is still a suboptimal procedure resulting in impaired oocyte developmental potential. However, results on bovine oocytes showed that addition of hyaluronan (HA) to the IVM medium improved the quality of in vitro derived embryos-blastocysts, which expressed less DNA fragmentation . Oocyte quality can be influenced by female infertility factors. In nonoverweight women with polycystic ovary syndrome (PCOS), the association between follicular fluid leptin and serum insulin was confirmed . It was proposed that lower levels of leptin in follicular fluid may explain the lower oocyte quality and fertilization in these women and this may be related to the level of insulin and/or insulin resistance.2+) is extensively involved in almost every step. Modern proteomic analyses have identified several sperm proteins, and therefore these findings might provide further insight into understanding the Ca2+ influx, protein functions, and regulation of fertility .Most instances of severe infertility in men cannot be explained. A special concern is represented by male and couple fertility impairment due to human papilloma virus (HPV) DNA sperm infection . The question of potential negative impact of HPV infection on semen quality is still open, despite high prevalence of infection (37.1%) in men from infertile couples . In nonobstructive azoospermia, the increase in volume density of both the CD 68-positive macrophages and vacuolated Leydig cells and a positive correlation between the volume densities of these cell types were observed; it was proposed that overstimulation of Leydig cells, together with a negative paracrine action of macrophages, could result in the damage of steroidogenesis and lower levels of testosterone in situ . The fertilization potential of spermatozoa depends on appropriate and time-dependent process of hyperactivation, chemotaxis, capacitation, and the acrosome reaction, where calcium . Furthermore, a special concern are also the paternal, sperm-borne mitochondria (mt) that are selectively degraded inside the fertilized oocytes. Assisted reproductive therapies (ART) such as intracytoplasmic sperm injection (ICSI) for male infertility treatment include the injection of the entire sperm into oocytes including mitochondria and mtDNA; therefore, sperm mitochondrial degradation mechanisms may play a crucial role with implications to health, fitness and fertility, and development and health of ART babies .Array comparative genomic hybridization (aCGH) for comprehensive screening of all chromosomes is becoming a new tool for selection of euploid embryos to be transferred in the in vitro fertilization program  and can improve the clinical outcome—pregnancy rate—in women with repeated implantation failure . Yet, some caution is needed, because embryo biopsy is an invasive procedure, and less invasive procedures to distinct normal and abnormal embryos need to be developed (T. Vladimirova Milachich). Not only embryo but also the endometrium plays an important role in successful implantation. One of the first studies confirmed that the infusion of granulocyte colony-stimulating factor (G-CSF) leads to the improvement in endometrium thickness and the chance to achieve pregnancy in women with treatment-resistant thin endometrium . In a clinical study, tissue Doppler imaging (TDI) based elastography was used for assessment of cervical stiffness during all three trimesters of pregnancy and a correlation with gestational age, cervical length, and parity was found . Fetal middle cerebral artery (MCA) circulation was followed after defined prenatal acoustical stimulation (PAS), correlating the role of cilia in hearing and memory in fetus to signal transduction . The authors suggest that fetuses are getting used to sound, developing a kind of memory patterns, considering acoustical and electromagnetic waves . Further, BACs-on-beads technology represents a new and reliable test for rapid detection of fetal aneuploidies and microdeletions in prenatal diagnostics . Quantitative proteomics analysis revealed the altered protein expression in the placental villous tissue of early pregnancy loss using isobaric tandem mass tags and may represent a new diagnostic tool in the future .Besides in vitro fertilization itself, cryopreservation of embryos, gametes, and reproductive tissues represents an extremely important part of assisted conception to preserve the potential of life and fertility, as reviewed by J. Konc et al. Advanced experimental data were provided on new approaches to human ovarian tissue cryopreservation in young cancer patients, showing vitrification with good preservation of stromal cells without apoptosis in human ovarian tissue  and an effective in vitro perfusion of ovine intact ovaries with vascular pedicle by freezing medium, important for development of whole ovary cryopreservation in humans . An option in cancer patients is also to cryopreserve the oocytes, if ovarian stimulation is safe and possible, but this is not an easy task and was thoroughly reviewed in bovine oocytes (I.-S. Hwang and S. Hochi). The data also show that superoxide dismutase (SOD) represents a good predicting factor for boar semen characteristics after short-term cryostorage  and may be applied in human medicine.Each birth of a baby after in vitro fertilization still represents a great effort and a “miracle.” During the last years, several studies have shown that babies after assisted conception are healthy and do not differ from other babies. Nevertheless, permanent concern is needed for both mother and baby to be safe and healthy. In a clinical study, singleton pregnancy and neonate outcomes after in vitro fertilization with fresh or frozen-thawed embryo transfer were followed in a large group of women .The perspectives and challenges of pluripotent and induced pluripotent stem cells as new agents for treatment of infertility are discussed by V. Volarevic et al. Moreover, stem cells from follicular aspirates in infertile women were successfully cultured in vitro. They expressed several genes related to mesenchymal stem cells and were successfully differentiated into cells of all three germ layers . These cells may be interesting for both the reproductive  and regenerative medicine. Also spermatogonial stem cells were further researched by generating gene expression profiles for human spermatogonia both after short- and long-term culture .In this special issue, it is also reported that full reimbursement of in vitro fertilization with repeated attempts can provide a notable success considering cumulative delivery rate and should thus be proposed to public health systems . All great efforts summarized in this special issue not only bring several scientific and clinical answers but also open some new questions, which are an important task and an exciting challenge for the future.Irma Virant-KlunJeroen KrijgsveldJohn HuntrissRaymond J. Rodgers


Oncolytic virotherapy for cancer is an innovative therapeutic option where the ability of a virus to promote cell lysis is harnessed and reprogrammed to selectively destroy cancer cells. Such treatment modalities exhibited antitumor activity in preclinical and clinical settings and appear to be well tolerated when tested in clinical trials. However, the clinical success of oncolytic virotherapy has been significantly hampered due to the inability to target systematic metastasis. This is partly due to the inability of the therapeutic virus to survive in the patient circulation, in order to target tumors at distant sites. An early study from various laboratories demonstrated that cells infected with oncolytic virus can protect the therapeutic payload form the host immune system as well as function as factories for virus production and enhance the therapeutic efficacy of oncolytic virus. While a variety of cell lineages possessed potential as cell carriers, copious investigation has established stem cells as a very attractive cell carrier system in oncolytic virotherapy. The ideal cell carrier desire to be susceptible to viral infection as well as support viral infection, maintain immunosuppressive properties to shield the loaded viruses from the host immune system, and most importantly possess an intrinsic tumor homing ability to deliver loaded viruses directly to the site of the metastasis—all qualities stem cells exhibit. In this review, we summarize the recent work in the development of stem cell-based carrier for oncolytic virotherapy, discuss the advantages and disadvantages of a variety of cell carriers, especially focusing on why stem cells have emerged as the leading candidate, and finally propose a future direction for stem cell-based targeted oncolytic virotherapy that involves its establishment as a viable treatment option for cancer patients in the clinical setting. Oncolytic virotherapy is an uprising approach for treating human malignancy. Such treatments either utilize genetically engineered virus or virus with natural tropism towards transformed cells to induce targeted destruction of tumor burden by replication-mediated killing ,2. EvoluMost cancers that lack therapeutic options usually presented with disseminated metastasis, and thus require systemic therapy. In ideal conditions, treatments for patients with metastatic cancers would give targeted therapy such as oncolytic virotherapy systemically, allowing the injected viruses to locate and destroy tumor cells at distant sites without affecting healthy tissues. However, significant challenges remain in targeting systemic disease with “naked” (unprotected therapeutic virus particles in the circulation) therapeutic viruses administered into the patient’s circulation. Host immune system-mediated neutralization is evoked during the first week of therapy and ablates the delivery of repeated systemic administration of naked therapeutic virons . AdditioSince clinical applications of OV have issues in targeting systemic diseases, a “Trojan Horse” strategy was proposed to shield therapeutic payloads in the circulation while they home toward tumor beds,10. Thisex vivo with one leading objective: to package as many OV onto or into the carrier system as possible. This objective is crucial, as the loading dose is typically directly proportional to the therapeutic dose available at the tumor sites. Moreover, loading of the therapeutic virus must occur rapidly, as any premature initiation of OV replication will not only reduce the viability of the cell carrier, but will also increase the likelihood of untimely presentation of the viral antigen at the surface of the cell carrier and thus the virus will be eliminated by the host immune system.Therapeutic virus loading on a carried system is usually carried out Secondly, a complete cell carrier must have some degree of ability to defend the therapeutic payload from the host’s immune system. Oncolytic virotherapy has the greatest potential to be successful in the clinical setting if such therapy can be administered systemically to target the metastatic tumor burden effectively. This approach holds a significant challenge, as unprotected “naked” viral particles in the circulation are highly vulnerable to immune recognition . The immMost importantly, an effective carrier system must possess some degree of intrinsic tumor homing ability. Once the OVs are delivered into patient circulation, cell carriers must be able to navigate through the hostile environment to locate tumors at distant sites and selectively deliver the therapeutic cargo. Recently, different cell systems have been evaluated as cell carriers--with a few of them exhibiting varying magnitudes of tumor homing capacity  in the immunocompetent cotton rat model to protect oncolytic adenovirus and demonstrated that virus loaded MSCs can persist longer in tumors as compared to naked viruses since the host’s antiviral immune response is significantly dampened . The ex and MCP1 . Howeverand MCP1 ,34,50. TStem cells from various sources have been investigated as cell carriers for oncolytic virotherapy, including mesenchymal stem cells (MSCs), neural stem cells (NSCs) and adipose-derived stem cells. Each type of stem cell has its advantages and disadvantages with respect to their ability to function as a cell carrier. The approaches for testing the efficiency of stem cell carriers can vary, yet the conclusion asserts that the stem cell-based cell carrier approach is a viable approach to deliver OVs for treatment of tumors. Here we focus on the two most widely used stem cells, MSCs and NSCs  that can be isolated from the developing and adult CNS . Our labIn search for the optimal cell carrier for anti-glioma oncolytic virotherapy, we performed a preclinical compression of NSC and MSC using CRAd-S-pk7 virus in the orthotopic GBM xenograft model . Our datex vivo is fairly well established [ex vivo loading capacities. Moreover, intra-patient variability for the amount and the quality of MSCs that can be isolated depend on patient age and current health status. In planning for a clinical trial, Mader et al. recently demonstrated that MSCs isolated from healthy donors and MSCs isolated from patients with new and recurrent ovarian cancer show very similar phenotypes and doubling times [ex vivo to generate the amount of cells required for a clinical trial. However, the fact that about 20% of isolated MSCs show abnormal karyotypes is somewhat concerning, even though these MSCs were not tumorigenic in the immunocompromised animals. Additional studies characterizing freshly isolated heterogeneous MSCs with respect to their behavior post implantation would be beneficial in order to use these cells in the clinical setting.MSCs freshly isolated from patients are an attractive candidate for oncolytic virotherapy carrier system because the feasibility of using autologous cells may allow us to avoid allograft rejection. MSCs can be isolated from the bone marrow, adipose tissues and other tissues very efficiently, and the protocol to expand these cells ablished ,79. Howeng times . Within On the other hand, NSCs have been evaluated as a carrier system to target malignancies in the CNS due to their origin and their inherent tumor tropism ,77,80,81With difficulties involving the delivery of the OV via the blood stream, the possible search of a new cellular vehicle for OV can raise hopes in improving the current status of oncolytic virotherapy. A lot of clinical data regarding the use of stem cells as cell replacement therapy has been recently generated . These dUpgrading the GPS system: The ability of stem cells to travel a great distance and home to systemic metastases and disseminated tumor burdens is fundamental to their utility as cell carriers for oncolytic virotherapy. Even though sufficient pre-clinical data in the rodent model demonstrate such characteristics, the distance that implanted stem cells have to travel in patient circulation may be considerably further than in any rodent system. Moreover, only 20%–30% of implanted NSCs were able to home to distant tumor sites [or sites . The migor sites . By utilAllogeneic stem cell line, iPS and personalized cell carrier: An ex vivo culture technology that has the capacity to isolate large quantities of autologous stem cells from a patient with the shortest amount of time would be ideal to avoid allogeneic implantation of stem cell-based cell carrier that might be subject to rapid rejection by the host immune system [in vivo, their application in cell therapies has been limited [in vivo and can express high levels of engineered transgene [e system . Howevere system . iPS-dere system . Systemi limited . One alt limited ,88. Moreransgene ,88,89. IReduce premature cell lysis in the carrier cells: One of the important characteristics to function as cell carriers for oncolytic virotherapy is the support of the therapeutic virus replication. This is challenging, as the loading of a replication competent virus can destroy the cell carrier. Such processes could be counterproductive, as any premature carrier cell lysing can drastically reduce the dose of therapeutic virus at the tumor sites. Even though the kinetics of oncolytic adenovirus replication is much slower in the NSC-based cell carrier as compared to tumor cells, at a higher loading dose the therapeutic virus can significantly reduce the viability of NSC-based cell carriers [carriers ,50. One carriers . Howevercarriers . Chioccacarriers . Such apNon-invasive imaging to monitor stem cells in real time: Finally, real-time dynamic determination of carrier cells’ migratory and distribution kinetics will be critical in optimizing stem cell-based oncolytic virotherapy treatment protocol in the clinical setting. The utilization of non-invasive imaging techniques such as magnetic resonance imaging (MRI) for cellular tracking is a rapidly growing field [ex vivo tissue reconstruction, we have demonstrated that OV loaded NSCs have very similar intratumoral distribution to unloaded NSCs, both displaying about 31% coverage of intracranial tumors in the orthotropic patient-derived glioma xenograft model [ng field ,91. Protng field ,91. By cft model . DevelopThe conjugal between OV and cell-based carrier concept is an evadible one and has opened up many new avenues for developing a selective approach to target systemic metastasis without affecting normal tissue. Establishing a stem cell-based carrier system with intrinsic tumor homing ability would be the “icing on the cake”, which would allow us to install a GPS system in this anit-cancer biotherapeutic in order to precisely track systemic diseases as well as invasive cancer cells that left their original sites. Establishing a carrier system with immunosuppressive properties will allow us to shield the therapeutic payload in the patient bloodstream. Their capacity to guide the therapeutic cargo toward the tumor burden at the distant site will allow us to effectively target the systemic metastasis. As discussed in this review, the early results from the preclinical setting are optimistic, but certain future advancement will be the key for the successful translation of the stem cell-based oncolytic virotherapy in the clinic. The first issue that needs to be addressed is the limited tumor homing ability of the currently available stem cell-based cell carrier. Our understanding of molecular mechanisms governing the intrinsic tumor homing ability of stem cells is limited and thus must be expanded. Knowledge from such research must be cultivated to develop the next generation stem cell-based cell carrier with enhanced tumor tracking ability. Secondly, the OV-mediated toxicity towards the carrier cells needed be circumvented. This is critical for achieving a therapeutic dose of viral payload at the distant tumor sites that can generate a clinically relevant therapeutic efficacy. An inducible system should be considered to regulate replication-mediated oncolysis of the carrier cells so that an adequate number of therapeutic cargos can reach the distant tumor sites. Finally, carrier cell engraftment efficiency must be improved. The use of reprogramming technology to generate autologous stem cells from the patients’ somatic cells may avoid the use of allogeneic stem cell lines that can be rejected very quickly after implantation. However, the reprogramming technology is in its infancy and such technology needs to be further optimized in order to be ready for the clinic. With these advancements, one might envision in the near future oncologists being able to offer personalized, targeted stem cell-based oncolytic virotherapy to their cancer patients with metastatic diseases.


There is an increasing demand to determine the clinical implication of experimental findings in molecular biomedical research. Survival (or failure time) analysis methodologies have been adapted to the analysis of genomics data to link molecular information with clinical outcomes of interest. Genome-wide molecular profiles have served as sources for discovery of predictive/prognostic biomarkers as well as therapeutic targets in the past decade. In this review, we overview currently available software, web applications, and databases specifically developed for survival analysis in genomics research and discuss issues in assessing clinical utility of molecular features derived from genomic profiling. With the increasing capability to perform genome-wide molecular characterization of clinical specimens, making clinical implication of genomic aberrations has become a more relevant topic. The decreasing cost of the assays has facilitated accumulation of genomic profiles of sizable clinical cohorts, with which more reliable molecular prognostic analysis has become possible. Also, expanding clinical contexts covered by the studies/datasets has enabled exploration of clinically more relevant predictive/prognostic biomarkers from genomic data . Here, tClinical outcome especially prognosis is often presented as the time period between the start and end of the clinical observation in combination with a binary status information, indicating whether or not each patient had a clinical event of interest, e.g., death, cancer recurrence, and drug response. In contrast to laboratory experiment-derived data, clinical outcome data are generally incomplete because of the missing observation of the clinical event. For example, in the case of analyzing time to cancer recurrence after surgery, some patients who are still recurrence free during the study period may develop recurrence later, i.e., it is uncertain whether the patient should be classified into recurrence-positive or recurrence-negative group. Such situation, where a true outcome is still unknown, is treated as a censored observation, and the observation time is incorporated in the analysis. This type of analysis is called “survival” or “failure time” analysis, for which various biostatistical analysis methodologies are already available. These methodologies have been adapted for the analysis of genomic datasets with modifications to accommodate the high-dimensional data structure by utilizing correction methods for highly multiple hypothesis testing .in silico discovery and/or validation of predictive/prognostic molecular biomarkers. In this article, we overview currently available software, web applications, and databases specifically developed for integrative analysis of survival and genomic data. We also discuss current limitations mostly residing on the clinical study design side and how we could methodologically overcome these challenges to facilitate the development of molecular biomarkers with clinical utility.The accumulated genomic datasets with clinical outcome information have led to a new paradigm of biomarker research, i.e., The major tasks of survival analysis in genomics research include 1) survey/identify genomic feature(s) correlated with survival data and 2) evaluate/validate survival data correlation for predefined genomic feature(s). There are several freely available tools to complete the tasks for users with a wide range of informatics capability and fluency  in electronic health record (EHR) may help resolve these issues and eventually facilitate clinical translation of genome-based prognostic biomarkers.Clinically applicable molecular biomarkers must yield reproducible and robust measurements in real-world clinical setting with clinically acceptable logistical complexity and cost to justify their use. The lack of reproducibility of the measurement especially for transcript-based biomarkers has been the major technical obstacle in clinical deployment of genome-based biomarkers . Recent


Visual processing depends on computations performed by complex neural circuits. Although the circuitry in the retina has been extensively characterized, common "functional" models of how ganglion cell spike trains represent visual stimuli typically rely on linear descriptions of their receptive field . DiffereHere, we describe a new nonlinear model framework designed to represent key elements of the retinal circuit, which can predict recorded retinal ganglion cell spike trains with high temporal precision. We used recordings of both synaptic currents (via voltage-clamp recordings) and spike (via loose patch recordings) from the same ON Alpha ganglion cells in the mouse retina in order to build a two-stage nonlinear model. This model describes ganglion cell computation as sums and products of excitatory and inhibitory inputs . Model pWe found that excitatory synaptic currents to the ganglion cell are well described by an excitatory input combined with divisive suppression, both elements described by LN models fit to intracellular data. Using stimuli with center-surround structure, we demonstrate that this divisive suppression arises from the surround, and is the likely result of presynaptic inhibition mediated by amacrine cells , rather The resulting model had unprecedented ability to predict both synaptic current and spike trains (with >90% of the explainable variance) at one millisecond resolution on cross-validation datasets, capturing both fast transient responses in synaptic current, as well as the high precision of spike train responses. Furthermore, the model output automatically "adapted" to contrast, and could predict the responses across contrast levels with similar accuracy without any change in model parameters. Notably, the nonlinear structure of the model was particular to ON Alpha ganglion cells, and other retinal ganglion cell types had distinct computational structures, likely corresponding to different underlying connectivity within the retina governing their processing of vision.Thus, by targeting a nonlinear model based on the specific computations performed by retinal circuit elements, we uncovered an extremely accurate description of retinal processing, and identified two-stage computational properties that can be linked to elements of the retinal circuit. In addition to providing an accurate description of ON Alpha cells, such computational framework also sets a foundation for understanding the different roles of the ~20 ganglion cell types that comprise the input to the rest of the visual system.


As the main theme of this special issue, CRP not only is an inflammatory marker but also has diverse biological functions associated with different diseases. To investigate CRP's physiologies and their relationship with human pathological significance, it is essential to use appropriate animal models for translational research. The most popular models for the study of CRP are transgenic mice. However, researchers should be careful when extrapolating the findings derived from these animal models. This review will discuss the current concerns on CRP transgenic mice and rabbits. More than 30 epidemiological studies have demonstrated a significant association between elevated serum or plasma CRP concentration and the prevalence of atherosclerotic vascular disease, the risk of recurrent cardiovascular events among those with established disease, or the incidence of first cardiovascular events among those at risk . This stμg/mL levels , 3332, 3Rabbits have been used as an excellent model for the study of human atherosclerosis because their lipoprotein metabolism and cardiovascular system are similar to those of humans . Unlike To elucidate whether high levels of plasma CRP participate in the development of atherosclerosis, our laboratory generated 2 lines of transgenic (Tg) rabbits expressing human CRP (hCRP) transgene in the liver . Plasma Using double balloon-injury models of the femoral arteries in Tg rabbits, we demonstrated that high expression of hCRP led to enhanced thrombosis formation on the injured smooth muscle cell-rich neointima by upregulating tissue factor expression , suggestβ-VLDLs, which may complicate the evaluation of hCRP pathophysiological functions in these models [The major concern about using cholesterol-fed Tg animals is that transgenic proteins  are exogenous to animals and the atherogenic lipoproteins are remnant lipoproteins, so-called e models . To overIn conclusion, rabbits are a suitable model for the investigation of CRP physiology because they resemble humans in many aspects, compared with mice. Cholesterol-fed rabbits along with WHHL rabbits and hCRP transgenic rabbits offer another opportunity to elucidate CRP functions that cannot be conducted in mice. After a decade's effort using these unique models, it is time to draw a conclusion regarding the true role of CRP in atherosclerosis. Is CRP a marker or mediator of atherosclerosis? Do we still need to continue the debate? Should we treat CVD patients who have a high level of CRP? The answers are becoming clearer and clearer: without doubt, plasma CRP levels are indeed increased and CRP is intimately present in the lesions of atherosclerosis. However, the net effect exerted by CRP is not proatherogenic, while we cannot rule out the possibility that CRP is antiatherogenic or participates in other diseases. These experimental observations are also in support of the human studies reported recently –51. Thes


Aging involves a deterioration of cell functions and changes that may predispose the cell to undergo an oncogenic transformation. The carcinogenic risks following radiation exposure rise with age among adults. Increasing inflammatory response, loss of oxidant/antioxidant equilibrium, ongoing telomere attrition, decline in the DNA damage response efficiency, and deleterious nuclear organization are age-related cellular changes that trigger a serious threat to genomic integrity. In this review, we discuss the mechanistic interplay between all these factors, providing an integrated view of how they contribute to the observed age-related increase in radiation sensitivity. As life expectancy increases and so it does the medical intervention, it is important to highlight the benefits of radiation protection in the elderly. Thus, a deep understanding of the mechanistic processes confining the threat of aging-related radiosensitivity is currently of foremost relevance. Individuals exposed at early ages are the most radiosensitive as the primary damage has a longer latent phase to outbreak into cancer. After that, sensitivity to radiation decreases until maturity, but it increases again at older ages. Epidemiological evidence for such age-dependent radiosensitivity variation has been reported in different studies. In the Life Span Study cohort of the Japanese atomic bomb survivors, the excess relative risks (ERRs) for radiation-induced cancers as a function of age at exposure were examined  can be endogenously generated by the normal cellular metabolism or exogenously originated by exposure to radiation and chemical compounds , which made glioma cells more sensitive to radiation , for fighting against these threats. These mechanisms detect the DNA damage and mediate its repair while arresting the cell cycle to avoid DNA replication or segregation  that causes changes in gene expression, heterochromatin organization, and failure of proper DNA repair  can also contribute to the DDR deterioration. Dysfunction of the nuclear pore complexes can result in the loss of essential proteins to maintain the chromatin organization and DNA repair. NPCs work as nuclear gatekeepers, allowing the free diffusion of small molecules and tightly regulating the transport of macromolecules (Fernandez-Martinez & Rout, et al., et al., et al., Age-related changes described above, such as nuclear lamina decay and leaking NPCs, hamper the proper repair of radiation-induced DNA lesions. Hence, the increased radiosensitivity observed in aging cells may be a consequence of already dysfunctional systems trying to cope with the damage raised by IR. As stated before, ionizing radiation does not only induce DNA lesions, but also disturbs the nuclear organization by ROS production Fig.. Indeed,There are many factors that contribute to the close relationship that exists between radiation sensitivity and age. These factors provide several plausible and nonexclusive explanations for the increased carcinogenic risk of radiation in the elderly, as reported by epidemiological studies in different cohorts. It is possible that the age-related oxidative stress accumulation disturbs the nuclear organization, which in turn may impede a proper repair. Because nuclear organization is also disturbed by ionizing radiation, aging cells become an easy target for suffering enhanced effects after irradiation. DDR impairment together with telomere attrition can result in the accumulation of genomic rearrangements that may contribute to the increased incidence of radiation-induced carcinogenesis in the elderly. Nevertheless, the intricate interplay between these aging-related defects acts as a confounding factor making it very difficult to study the contribution of each factor independently. Thus, studies that provide an integrated view of how radiosensitivity affects aging organisms are necessary for a better understanding and improvement of experimental designs. We conclude that aging must be seen as a convoluted scenario, where radiation is a bump in the road of preserving genome integrity. Because radiosensitivity increases with age and life expectancy rises steadily, there is a need for improving radiation protection measures to ensure the safety of the elderly.


In this article we first point at the expansion of associative cortical areas in primates, as well as at the intrinsic changes in the structure of the cortical column. There is a huge increase in proportion of glutamatergic cortical projecting neurons located in the upper cortical layers (II/III). Inside this group, a novel class of associative neurons becomes recognized for its growing necessity in both inter-areal and intra-areal columnar integration. Equally important to the changes in glutamatergic population, we found that literature data suggest a 50% increase in the proportion of neocortical GABAergic neurons between primates and rodents. This seems to be a result of increase in proportion of calretinin interneurons in layers II/III, population which in associative areas represents 15% of all neurons forming those layers. Evaluating data about functional properties of their connectivity we hypothesize that such an increase in proportion of calretinin interneurons might lead to supra-linear growth in memory capacity of the associative neocortical network. An open question is whether there are some new calretinin interneuron subtypes, which might substantially change micro-circuitry structure of the primate cerebral cortex. Figure 1). There are novel neuronal elements that appear in the human cerebral cortex making organization of microcircuitry  substantially different when compared to non-primate mammals  cortico-cortical projecting neurons, as well as a possible functional significance of those changes regarding increase in cognitive capabilities. We also found that present comparative anatomical data suggest a distinct role in reorganization of cortical microcircuitry for one of the GABAergic local circuit neuron classes, the calretinin expressing neurons that in primates have much higher proportion. We propose a possible mechanism how calretinin neurons might contribute to reorganization of microcircuitry in the human associative cortex and how this might be related to an increase of cognitive capabilities.It is well recognized that upper layer pyramids  are cortPyramidal neurons located in upper layers of the primate prefrontal cortex also provide rich intracortical projections. From large layer III pyramids 80% of synaptic output belongs to local connections coming from axonal side branches . They exHuman brain evolution is characterized by an increase in the number and width of minicolumns, but also in the increase of space available for interconnectivity between neurons, especially in the human prefrontal cortex where associative layer III pyramidal neurons are particularly abundant . Except Table 1A). It is curious that only rarely the same group performed a systematic analysis of several species, using the same methodology, making it difficult to conclude about interspecies differences. Most of the studies performed in rat and mouse found that cortical GABAergic neurons represent around 15% (14–16%) of the overall population. In monkey and human their proportion mostly exceeds 20% (20–29%) suggesting an increase in proportion for about 30–50%.In parallel with evolutionary changes in connectivity of cortico-cortical network, significant changes appear in the organization of GABAergic network. This network acts as intrinsic modulator of cortical output since it is composed of local circuit neurons . This large increase in proportion of GABAergic neurons seems to be principally caused by increase in number of neurons containing calretinin. Another two main classes, those containing parvalbumin and somatostatin, do not show such a robust increase in proportion . In rodeFor efficient functioning of the human cerebral cortex with its complex areal subdivision and increased number of cortical columns, there is a need for enhanced inter-areal and intra-areal integration . AppearaBased on electrophysiological properties, two main types of calretinin interneurons can be distinguished in rodents: accommodating and non-adapting non-fast spiking cells . These eDifferent types of calretinin neurons can be identified based on their morphological features, particularly on the postsynaptic domain targeted by their axon. Double bouquet cells have vertically oriented axons which project mainly to basal dendrites of pyramidal cells , while bParvalbumin neurons are mostly basket cells, which exert strong inhibitory control over pyramid’s soma . OptogenThis group of cells, including calretinin neurons, their somatostatin targets, parvalbumin neurons, and their pyramidal targets, can be collectively called a neuronal assembly . The sigPresent evidence suggests that the evolutionary path of the primate cortico-cortical network seems to have been an expansion in two aspects. First, there is an increase in proportion of principal neurons located in layers II and III, which would be a way to create the basic excitatory architecture for inter-areal processing. Second, there is an increase in proportion of calretinin expressing GABAergic interneurons, which would be a way to create a gain in synchrony and parallel processing between disparate cortical areas. An open question is whether this jump in proportion of calretinin neurons is based on a simple expansion of already preexistent subtypes of these cells found in the rodents or do we have some new cellular subtypes. If so, this might produce a more profound changes then simple supra-linear increase in their number, similar to changes occurring with appearance of associative principal neurons. These two might have been converging processes, making structure of microcircuitry in the primate neocortex substantially different when compared to other non-primate mammals.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.