Protein glycosylation, as an important post-translational modification, is implicated in a number of ailments. Applying proteomic approaches, including mass spectrometry (MS) analyses that have played a significant role in biomarker detection and early diagnosis of diseases, to the study of glycoproteins or glycopeptides will facilitate a deeper understanding of many physiological functions and biological pathways involved in cancer, inflammatory and degenerative diseases. The abundance of glycopeptides and their ionization potential are relatively lower compared to those of non-glycopeptides; therefore, sample enrichment is necessary for glycopeptides prior to MS analysis. The application of nanotechnology in the past decade has been rapidly penetrating into many diverse scientific research disciplines. Particularly in what we now refer to as the “glycoproteomics area”, nanotechnologies have enabled enhanced sensitivity and specificity of glycopeptide detection in complex biological fluids, which are critical for disease diagnosis and monitoring. In this review, we highlight some recent studies that combine the capabilities of specific nanotechnologies with the comprehensive features of glycoproteomics. In particular, we focus on the ways in which nanotechnology has facilitated the detection of glycopeptides in complex biological samples and enhanced their characterization by MS, in terms of intensity and resolution. These studies reveal an increasingly important role for nanotechnology in helping to overcome certain technical challenges in biomarker discovery, in general, and glycoproteomics research, in particular. Protein glycosylation is one of the most common post-translational modifications (PTMs) in living cells ,2. GlycoThus far, analytical methods of identifying (sometimes subtle) changes in disease-relevant glycoproteins can be divided into two main groups: glycoprotein- or glycopeptide-based analysis. We illustrate the workflow of these two approaches in Figure In the past decade, we have witnessed an enormous growth in the application of nanotechnology to solve biological and biomedical problems. Due to some of these (nano) technological advances, we can now identify and analyze biomolecules at a speed and resolution never seen before. Compared to conventional macro-scale materials, nano materials, such as nanoparticles, nanowires, nanotubes, nanorods, and thin films with meso-scale pores, have unique transport properties , better optical excitation and high detection efficiency. Nanomaterials also impart to their fabricated platforms higher surface-to-volume ratio with reduced dimensionality, which are key features that often enhance the physical and chemical properties of materials. In addition, materials with lower dimensionality are conducive to extremely high unit-density integration on arrays and lab-on-a-chip platforms for point-of-care devices for high-throughput biodetection. Miniaturized devices composed of nanomaterials have the advantage of low cost, good portability, and potential use in minimally invasive instrumentation . In FiguGlycoproteins are not as amenable to isolation and identification due confounding factors such as complex glycan structures, glycan isomers, and amino acid residues attached to the oligosaccharide chains. The most commonly employed technique for the analysis of protein glycosylation  is MS, albeit with still a few existing technical challenges . In thisA nanomaterial is a natural, incidental or manufactured material containing particles in an unbound, aggregate or agglomerate state, where one or more external dimensions is in the size range 1–100 nanometers. Due to their smaller size, nanomaterials possess incredibly larger surface areas than bulky materials. This feature provides more activated sites for glycopeptide enrichment and unique optical properties, in the context of rapid and sensitive detection. Perhaps the most attractive characteristic of nanomaterials is the degree to which their size, shape and morphology can be precisely controlled to enhance the optical, electronic, or magnetic capabilities typically desired in certain applications. Several nano-platforms exist for the isolation of glycopeptides in complex samples with improved sensitivity and specificity, and we discuss them in more details in the following Subsections.Nanoparticles are arguably the most widely used nanomaterial to assemble chips for biomolecule enrichment because: 1) nanoparticles can be synthesized with various size distributions, and morphologies; 2) nanoparticles can be modified and diversified by numerous reagents for specific uses; and 3) they exhibit unique optical and electrochemical features. When attempting to enrich glycopeptides in complex samples, researchers often adopt core-shell structured nanoparticles with a magnetic core within a thin layer of compatible material. The magnetic core, which provides a strong magnetic force, would be simply attracted by magnets and the outer layer would be easily modified by various organic or inorganic reagents to recognize the biomarker of interest.Using a version of the above approach, Zhou et al. fabricated aminophenyl boronic acid-functionalized magnetic nanoparticles and used them to selectively capture glycopeptides and glycoproteins from mixtures containing non-glycomoleculars . Other gPolysaccharides can also be used as a surface-modifying component for glycopeptide enrichment. Xiong et al. reported a layer-by-layer approach to synthesize magnetic nanoparticles (MNPs) that are coated with multilayered polysaccharide shells, and then used these hydrophilic materials for selective enrichment of glycopeptides from biological samples. These investigators identified 605 unique N-glycosylation sites in 616 distinct glycopeptides, corresponding to 350 glycosylated proteins in 20 μg mouse liver protein sample. Their results indicated that exploiting specific sugar-sugar interactions shows promise as a design strategy for characterizing protein glycosylation .Rather than using boronic acid as a surface-modifying reagent for nanoparticles, Tran et al. developed a new kind of gold nanoparticles, functionalized with ultra-small hydrazide groups, with a core diameter of 1.2 nm. The assembly process involves an oxidation step and covalent coupling, whereby the carbohydrate moiety of the glycoproteins are oxidized into aldehydes by periodate and the oxidized glycoproteins are covalently coupled to hydrazide resin. No glycoproteins are removed by washing. They successfully utilized these nanoparticles to isolate 90% of the glycopeptides from complex biological samples. The nanoparticle stability in biological solution, unique solubility, and large capacity for peptide capturing provide great application potential in glycoproteomics studies .Isolating glycopeptides via their lectin moiety is another common approach, and commercialized solutions are now available in the market. Tsutsumi and colleagues conjugated gold nanoparticles (GNPs) with monosaccharide-modified peptides as optical probes for lectin detection. The aggregation of the glycopeptide-modified GNPs with concanavalin A (ConA) causes an absorption shift from 534 nm to 620 nm, an apparent color change that can be detected by the naked eye .Ligand-modified nanoparticles have been proven to be an excellent platform for glycopeptide enrichment, but ligand-free nanoparticles are emerging as good candidates for glycoproteins or glycopeptides isolation. A research group in Fudan University developed ligand-free silver nanoparticles coated with magnetic nanoarchitecture for selective enrichment of glycopeptides by taking advantage of the reversible interaction of glycans with silver nanoparticles. The investigators could easily and quickly (only 1 min incubation time) extract glycopeptides at a low molar ratio of glycopeptides: non-glycopeptides (1:100) using these silver-nanoparticle magnetic beads. Moreover, they mapped 127 unique glycopeptides mapped to 51 different glycoproteins from a very small sample volume (only 1 μL rat serum) .Particle-based materials are the most widely adopted for isolating and separating glycosylated peptides due to their nano dimensionality, tightly controlled size, and unique optical and electrochemical properties. They will likely continue to play a prominent role in glyco-proteomics for biomarker detection and early diagnosis of diseases.Several classes of porous materials exist and group according to size. The International Union of Pure and Applied Chemistry (IUPAC) clarifies , micropoXu and colleagues first introduced mesoporous silica materials functionalized with boronic acid for the detection of glycosylated peptides. In Figure 2 species were highly dispersed on the surface of meso-structured cellular foam. Hydrogen bonding between the oxygen atoms of ZrO2 and the hydrogen atoms of glycans forms a relatively strong interaction, thus isolating the glycopeptides from complex samples. Since ZrO2 can also attract phosphopeptides, the investigators treated digested mixtures of the phosphoprotein, α-casein, and IgG with ZrO2/MPS HILIC SPE materials. The results demonstrated that glycopeptides could be effectively enriched with interference from Zirconia layer coated silica surface [Other than boronic acid, transition metal oxides can be coupled to mesoporous silica, as demonstrated by Wan and coworkers. These investigators coated mesoporous silica microspheres in a layer of zirconium dioxide to create a platform for hydrophilic interaction liquid chromatography (HILIC) solid phase extraction (SPE)  MS. Twenty four N-linked glycans derived from standard glycoproteins could be detected with high signal-to-noise (S/N) ratios and peak intensities. Thirty-two N-linked glycans were profiled in complex samples, five (4 core-fucosylated glycans) of which exhibited distinct patterns in liver cancer compared to healthy samples. Their results support the notion that precisely-sized mesoporous carbon materials could play a prominent role in clinical glycoproteomics .With such broad applicability and adaptability, we expect the use of mesoporous materials to continue leaving an impact on the glycoproteomics landscape. The large specific surface area, surface modification potential, size exclusion toward large molecular weight biomolecules, and support strong capillary force in nano scale are all characteristics that lend well to their wide-spread use.Two-dimensional (2D) crystalline materials have recently been identified and analyzed for use in glycopeptide enrichment . GraphenCarbon nanotubes (CNTs) are allotropes of carbon exhibiting a cylindrical nanostructure. These cylindrical carbon molecules have unusual properties that could be, and is currently, exploited by the electronics industry, optics industry, and other fields of materials science and technology. Zhang X. and colleagues constructed a novel lectin-based electrochemical biosensor of functionalized, multi-walled CNTs to capture glycans from living cells . They faThe two applications for functionalized CNTs, whether as a biosensing platform and biocomposite, allow enhanced glycan signal detection. The former  has demonstrated good analytical performance – high sensitivity, selectivity and rapid response – for the analysis of mannose in human lung cancer cells. This approach could be adapted for other indications by broadening the selection moiety  for biosensor development.Investigators have long recognized the significance of protein glycosylation in physiological processes and disease, as evidenced by the number of related publications that continue to accumulate. Furthermore, glycosylated proteins are increasing identified as biomarkers for early disease detection of diseases via proteomics methods. Although recent advances in mass spectrometry have made large-scale identification of proteins feasible, it is still very challenging to analyze protein glycosylation in complex samples owing to the fact that glycopeptides often constitute a minor portion of the total peptide mixture, whose signal intensities are often lower compared to non-glycosylated peptides and are suppressed in the presence of non-glycopeptides. Nanotechnology has undoubtedly contributed to the realization of glycoprotein/glycopeptide enrichment methods, particularly from enrichment from complex samples in preparation for MS characterization. The use of nanomaterials with various morphologies and characteristics  has enabled enhanced sensitivity and specificity of glycopeptides isolation.Challenges do remain in detecting post-translationally modified proteins/peptides, especially circulating glycopeptides. Characterizing glycosylated peptides is also difficult due to unique electrochemical properties, optical properties, and energy brand structure. By applying nano-scaled materials to tunable platforms, scientists have greatly enhanced the capabilities of traditional MS-based techniques, by increasing mass resolution, mass range, mass intensities, to name a few. We believe this significant progress blazes a trail for future efforts (and accomplishments) in the combined areas of nano-engineering, MS and glycoproteomics.The authors declare that they have no competing interests.HZ, YL and YH participated the drafting of the manuscript. All of the authors read and approved the final manuscript.


Cardiocondyla obscurior workers and thereby the pace of behavioral transitions. By challenging same-age young and older age cohorts to de novo establish DOL into nurse and foraging tasks and by forcing nurses to precociously become foragers and vice versa we studied expression patterns of one of the best known candidates for social insect worker behavior, the foraging gene. Contrary to our expectations we found that foraging gene expression correlates with age, but not with the task foraging per se. This suggests that this nutrition-related gene, and the pathways it is embedded in, correlates with physiological changes over time and potentially primes, but not determines task preference of individual workers.One of the fundamental principles of social organization, age polyethism, describes behavioral maturation of workers leading to switches in task preference. Here we present a system that allows for studying division of labor (DOL) by taking advantage of the relative short life of  Age or temporal polyethism in holometabolous insect societies describes the common transition from young workers performing brood/queen care to nest duties and finally to exploration of the environment and foraging later in life. Age polyethism profoundly shapes social organization but the proximate mechanisms for its formation are unknown. It has been suggested that intrinsic physiological changes of individuals could render their behavior with age . Alternaforaging (for) gene coding for a cyclic guanosine mono-phosphate (cGMP)-dependent kinase (PKG). The role of for variants has been shown to play a critical role in the regulation of foraging behavior and energy balance in flies ), two cGMP-binding domains (CAP_ED [cd00038]) and a regulatory domain (DD_cGKI-beta [cd12086]). The shorter Cobs_15824 only has one cGMP-binding domain and lacks the catalytical domain. Similar to previous studies in ants, we focused only on the former [Cofor. After manual correction of the gene model guided by draft genomes of five ant species , the cloned and Sanger-sequenced P. pallidula Ppfor T1 protein sequence, Apis mellifera (NP_001011581.1) and Drosophila (ACO44435.1), we designed a primer pair for a 143bp amplicon spanning the 1st and 3rd exon to avoid amplification of possible genomic DNA contamination . We used a single housekeeper, rps2 (Cobs_18295) because of limited input cDNA of the samples . A serial dilution starting with 50ng input cDNA showed similar efficiencies with 92.5% for Cofor and 87.8% for rps2, respectively.Fly allidula . Cobs_17e former ,16, here-ΔCq [For interpretation of the qPCR data we used the relative 2-ΔCq  method, Cofor expression compared to age-unknown foragers, respectively. In contrast, neither of the two age treatments (age-independent DOL) showed significant differences in foraging expression between task groups  and between task groups in the experiment challenging foragers to become reverted nurses  showed the predicted direction of differential expression with callows engaged in nursing behavior .Cofor expression levels than foragers, suggesting that C. obscurior follows an age-related behavioral trajectory with young nurses and older foragers. In social species without specialized morphological worker castes it has been suggested that old, disposable workers with low body-fat perform those exterior tasks with high mortality risks [for variants partly correlates with the insulin-signalling pathway, which responds to hemolymph blood sugar levels. Similarly, Cofor likely plays a role in nutrient-dependent physiological processes in C. obscurior, and its expression could relate to body-fat and carbohydrate levels, which are predicted to be higher in young workers.In line with previous studies on ants ,14, contty risks . Gene exCofor expression in control colonies clearly shows a correlation with behavioral phenotype, regardless whether nurses were less than two days old or age-unknown, there was no correlation of Cofor expression with task performance per se. Furthermore, workers readily switched tasks in the manipulated colonies, regardless of whether they were young or matured, or already performed a particular task previously. This implies that the absence of successful returning foragers or signals from hungry brood motivates individual workers to switch task and to revert to nursing or to become precociously explorative, independent of Cofor expression.While foraging could function in priming individuals for a particular task but that it is not indispensible for the establishment of DOL in social insects. It may thus be considered a textbook example for a gene that is a follower in many evolutionary processes [In general, the various contexts in which this gene is expressed in different taxa, genotypes, morphs, behavioral types, age stages, day times and cells, as well as conflicting expression direction between ants and bees , shows trocesses –22 and erocesses .C. obscurior system with an established draft genome [Ant workers appear to be capable of the full behavioral repertoire once they reach a certain age, although the genetic background in polyandric species can play a role in individual task preference ,24 and ct genome  and first genome  in combiS1 Data(ZIP)Click here for additional data file.


Treatments for neonatal hypoxic-ischemic encephalopathy (HIE) have been limited. The aim of this paper is to offer translational research guidance on stem cell therapy for neonatal HIE by examining clinically relevant animal models, practical stem cell sources, safety and efficacy of endpoint assays, as well as a general understanding of modes of action of this cellular therapy. In order to do so, we discuss the clinical manifestations of HIE, highlighting its overlapping pathologies with stroke and providing insights on the potential of cell therapy currently investigated in stroke, for HIE. To this end, we draw guidance from recommendations outlined in stem cell therapeutics as an emerging paradigm for stroke or STEPS, which have been recently modified to Baby STEPS to cater for the “neonatal” symptoms of HIE. These guidelines recognized that neonatal HIE exhibit distinct disease symptoms from adult stroke in need of an innovative translational approach that facilitates the entry of cell therapy in the clinic. Finally, new information about recent clinical trials and insights into combination therapy are provided with the vision that stem cell therapy may benefit from available treatments, such as hypothermia, already being tested in children diagnosed with HIE. Hypoxic-ischemic encephalopathy (HIE), cerebral palsy (CP), and periventricular leukomalacia (PVL) are mainly triggered by neonatal hypoxic-ischemic brain injury. Neurodevelopmental deficits such as learning disabilities, mental retardation, and hearing and visual impairments accompany children diagnosed with hypoxic-ischemic brain injury. Brain expression of systemic asphyxia characterizes HIE . PerinatAcademicians, industry partners, and regulators, which include both the National Institutes of Health (NIH) and the U.S. Food and Drug Administration (FDA), have jointly created Stem cell Therapeutics as an Emerging Paradigm for Stroke (STEPS). Together, they have provided guidelines to increase the successful outcome of cell therapy in stroke patients –31. The The animal species and strain should be specially considered in HIE modeling. Rodent models such as Vannucci’s model of neonatal hypoxic-ischemic brain injury parallel many pathological events that humans endure during neonate HIE . ResearcAnother equally important variable that should be controlled in the experimental HIE is the age of the animals. Younger animals have shown to be impervious against hypoxia. A 1–2-day-old postnatal rat needs to be exposed to more severe hypoxia as compared to its 7-day-old counterpart in order to attain efficacious HIE symptoms . AnotherGender should also be taken into consideration for models, in that HIE-induced female neonates displayed a much smaller infarct volume and improved sensorimotor task than their male counterparts after perinatal hypoxic-ischemic brain injury and treatment with erythropoietin . A possiThe approximation of the clinical pathology of HIE is a crucial goal in standardizing the animal models because a model that better mimics a human condition would allow for better evaluations of possible treatments in human patients. Rats along with many other species, which include non-human primate, sheep, lamb, puppy, piglet, and rabbit, have been employed as models to closely resemble some HIE pathological aspects in humans , 55–60. Lab-to-clinic translatable functional tests need to be developed to better assess the pathological improvements of experimental interventions for short and long-term outcomes that are species specific and mimic the human condition. Despite efforts of investigators to control many variables in experimental HIE models, characterizing the phenotype of encephalopathy in neonates has proven to be elusive. As opposed to adults, neonatal encephalopathy is prevented from implementation of timely interventions as there is a scarcity in studies determining the optimal supra-acute to chronic therapeutic window in laboratory models, thus presenting a major barrier to translating experimental treatments to clinical applications. Acknowledging this research gap is pivotal when designing therapeutic intervention studies for future clinical applications in neonates. In order to create well-designed translational studies, it is critical to optimize the dosage, delivery route, and timing of stem cell transplantation within applicable clinical parameters. Treating the laboratory as the clinical setting for cell therapy in HIE will enhance the translational potential of the stem cell product. In order to prevent any potential microembolism, the minimum therapeutic cell dosage must be determined. Finding minimally invasive procedures for cell delivery could prevent exacerbation of the already injured brain. For timing of cell delivery, consideration should be given to the neuroprotective phase (< 1 day of injury) and the neurorestorative phase (> 1 day after injury) , 64. WhiA detailed description of the distinguishable phenotypic features of stem cells is an integral component of understanding the biology and potential of stem cells –74. To dTo assess the safety and efficacy of the treatment group in HIE, specific behavioral and histological procedures are frequently used. These assays can determine motor and cognitive amelioration as well as provide insight to the biochemical processes that are undergoing in the brain , 78, 79.Two major modes of action are involved in stem cell-mediated functional recovery in ischemic brain injury: cell replacement and by-stander effect. Cellular and molecular neurorestorative mechanisms include neurogenesis, angiogenesis, synaptogenesis, immunomodulation, and trophic factor secretion , 31, 90.Preclinical trials on stem cells in cerebral palsy have been conducted and have shown significant improvement in animal models. However, results have been difficult to replicate in humans since most of the studies have been on acute hypoxic injury models, which are less similar to human cases compared to chronic models. So far, clinical trials on children with cerebral palsy (CP) have suggested that neural progenitor cells (NPC), umbilical cord mononuclear cells, and mesenchymal stem cells (MSC) transplants are safe, and could improve motor and cognitive functions . CurrentTwo of these clinical trials are currently being conducted in the United States, with the aim of testing the safety and efficacy of autologous cord blood cells. The primary outcomes should be expected by the year 2015. Although patient recruitment is not open, China intends to test the efficacy of umbilical cord MSC versus rehabilitation treatments on children with cerebral palsy. In Iran, two clinical trials have already been completed. These clinical trials studied the efficacy of multiple intrathecal bone marrow-derived CD133 cell transplantation in children with cerebral palsy. Results are not published yet .It is imperative to set the parameters defining safety and efficacy of stem cell therapy in neonatal HIE clinical trials. In the United States, the Medical College of Georgia and Duke University are assessing the safety and efficacy of umbilical cord blood transplants in CP pediatric patients. The long-term efficacy of intravenous transplantation of autologous cord blood in CP children remains to be determined , 104. SoThe current therapies for HIE attempt to interrupt the pathways activated by HIE. In neonates with HIE, the results have not been promising in regards to preventing the neuronal loss , 115. InN-methyl-d-aspartate (NMDA) and kainate, and quisqualate (K/Q)  and mitochondria sequester calcium when intracellular levels increase . Calciumte (K/Q) . In the te (K/Q) . In addite (K/Q) . This acte (K/Q) . Moreovete (K/Q) . Hypothete (K/Q) . The relte (K/Q) . Hypothete (K/Q) . Hypothete (K/Q) .Hypothermia exerts neuroprotection in HIE against aberrant stages of region-specific brain maturation , blood–bAs discussed above, accumulating experimental data have indicated the mobilization of bone marrow-derived stem cells, such as MSCs, in brain plasticity and therapy of HIE to the affected area . In the The observation that seizure onset beyond the first 12 h of life is not only common in newborns with HIE , but alsAs mentioned previously, combination therapy may be the best approach to treat neonatal HIE, especially when a definite therapeutic time frame has not been fully established. The use of other possible neuroprotective strategies has been studied and is believed to enhance the therapeutic effects of hypothermia by targeting different therapeutic windows and stages of HIE. Oxygen free radicals are usually elevated after hypoxic-ischemic injury. The use of antioxidants like superoxide dismutase, combined with polyethylene glycol to facilitate infiltration across the blood–brain barrier, can degrade reactive oxygen species to ameliorate the negative effects of hypoxia. Nonetheless, neuroprotection in newborn animals has only been seen when administered prior to injury. Xanthine oxidase inhibitors, like allopurinol and oxypurinol, have also shown to reduce concentrations of free radicals in infants when administered early during the recovery phase, while administration of lazeroids appears to inhibit iron-dependent lipid peroxidation in immature models of hypoxic-ischemic brain damage , 142. Epin vitro and in vivo disease models  condition, a model of hypoxic-ischemic injury, then incubated at 25°C (severe hypothermia), 34°C (moderate hypothermia), and 37°C (normothermia) with or without subsequent co-culture with MSCs. Combination treatment of moderate hypothermia and MSCs proved to be the optimal condition for preserving cell survival and mitochondrial activity after OGD exposure. Pharmacologic induction of hypothermia in human embryonic kidney cells (HEK293) via treatment with delta opioid peptide (DADLE) resembled moderate hypothermia’s attenuation of OGD-mediated cell alterations, which were much more pronounced in HEK293 cells overexpressing the delta opioid receptor. Further, the addition of DADLE to 34°C hypothermia and stem cell treatment in primary rat neurons showed synergistic neuroprotective effects against OGD which were significantly more robust than the dual combination of moderate hypothermia and MSCs, and were significantly reduced, but not completely abolished, by the opioid receptor antagonist naltrexone altogether implicating a ligand–receptor mechanism of neuroprotection. Investigations into other therapeutic signaling pathways revealed growth factor upregulation  and anti-apoptotic function accompanying the observed therapeutic benefits. These results support combination therapy of hypothermia and stem cells for hypoxic-ischemic injury, which may have direct impact on current clinical trials using stand-alone hypothermia or stem cells for treating neonatal hypoxic-ischemic brain injury.The use of delta opioid agonists may resemble certain physiological correlation of hibernation, including hypothermia , which me models . Our rece models  revealedThe use of hypothermia as a treatment strategy is not limited to neonates. In adults, hypothermia has been regarded as a therapeutic strategy to improve the patient’s survival and reduce neurologic injury after cardiac arrest . Small cIn addition, the use of stem cells as a therapeutic strategy in adults has obtained much attention due to the substantial beneficial data gathered in animal and clinical studies. For example, specific disease-relevant neurons can be obtained from induced pluripotent stem cells including dopaminergic neurons for Parkinson’s disease (PD), hippocampal and cholinergic neurons for Alzheimer’s disease, motor neurons for amyotrophic lateral sclerosis, and inhibitory interneurons for schizophrenia . EmbryonStem cell therapy has the potential to become a treatment method for neonatal hypoxic-ischemic brain injury, but it needs to be first implemented in the clinic on patients with neonatal hypoxic-ischemic brain injury. This will require further translational research studies so that stem cell therapy can be fully implemented. Stem cell therapy can also benefit from the ongoing trials of stem cell therapy in adult stroke due to the similarities in pathology. Neonatal hypoxic-ischemic injury, however, has distinct symptoms from adult stroke –159 thatCurrently, the use of stem cells for neonatal hypoxic-ischemic brain injury is still in its experimental phase. Although clinical trials are scheduled to be conducted using autologous umbilical cord blood cells on CP children, there still needs to be a sufficient amount of data demonstrating the safety and efficacy before transplantation therapy can be used in other neonatal diseases. It is a priority to obtain standardized experimental models with quantitative functional endpoints and predictive clinical outcomes so that translational research can be implemented. In addition, it is important to address and modify the following for an effective future use of stem cell therapy: the route of delivery, cell dose, and timing of transplantation after diagnosis of neonatal brain injury. It should also be noted that because it is difficult to detect encephalopathy in premature babies due to the lack of advanced imaging devices and sufficient studies, initial cell therapy clinical trials will consist of full term infants. Because it is agreed that HIE involves several cell death pathways, it is expected that more laboratory research on combination therapies will be conducted in the future. Specifically, incorporating clinical stage therapies, such as hypothermia and other neuroprotective strategies, with stem cell transplantation therapy will be of future focus. Moreover, the safety and efficacy of these combinatorial strategies for neonatal hypoxic-ischemic brain injury can be maximized by following pertinent translational research guidelines .Cesar V. Borlongan holds patents and has pending patent applications in stem cell biology and therapeutic applications.


Peripheral artery disease (PAD) is due to the blockage of the arteries supplying blood to the lower limbs usually secondary to atherosclerosis. The most severe clinical manifestation of PAD is critical limb ischemia (CLI), which is associated with a risk of limb loss and mortality due to cardiovascular events. Currently CLI is mainly treated by surgical or endovascular revascularization, with few other treatments in routine clinical practice. There are a number of problems with current PAD management strategies, such as the difficulty in selecting the appropriate treatments for individual patients. Many patients undergo repeated attempts at revascularization surgery, but ultimately require an amputation. There is great interest in developing new methods to identify patients who are unlikely to benefit from revascularization and to improve management of patients unsuitable for surgery. Circulating biomarkers that predict the progression of PAD and the response to therapies could assist in the management of patients. This review provides an overview of the pathophysiology of PAD and examines the association between circulating biomarkers and PAD presence, severity and prognosis. While some currently identified circulating markers show promise, further larger studies focused on the clinical value of the biomarkers over existing risk predictors are needed. Narrowing or blockage of the arteries supplying blood to the lower limbs, usually termed peripheral artery disease (PAD), is principally caused by athero-thrombosis. PAD is a leading cause of morbidity due to the associated functional decline and limb loss. Both asymptomatic and symptomatic PAD are significant predictors of cardiovascular disease (CVD) events and mortality . CurrentThe main recognized clinical presentations of PAD are intermittent claudication (IC) and critical limb ischemia (CLI). IC describes the symptoms of pain in the muscles of the lower limb brought on by physical activity which is rapidly relieved by rest. CLI is a more severe manifestation of PAD, which presents as rest pain, ischemic ulceration or gangrene of the foot. Patients with CLI have a high risk of limb loss and fatal or non-fatal vascular events, such as myocardial infarction (MI) and stroke . Acute lThe prevalence of PAD is estimated to be 10%–25% in people aged ≥55 years and increases to approximately 40% in community populations aged >80 years ,7,8. In versus Angioplasty in Severe Ischemia of the Leg  trial, the re-intervention rate in 216 patients with CLI treated by percutaneous transluminal angioplasty was 26% at 12 months [Recurrent CLI due to the failure of lower extremity revascularization is associated with a poor outcome ,25. In t2 months . Reasons2 months ,28. ImprApproximately 70% of PAD cases can be explained by established risk factors such as older age, hypertension, dyslipidemia, cigarette smoking and diabetes . It has PAD management focuses in part on the reduction of CVD risk factors ,35. A nuThere is current interest in the development of novel therapies to improve arteriogenesis  and/or angiogenesis (capillary formation) in patients with PAD . A numbein situ thrombosis related to hypercoagulable states. The pathophysiology of athero-thrombosis induced PAD is complex, and involves a large number of cells, proteins and pathways. Important cells contributing to or controlling the development of athero-thrombosis include vascular endothelial cells (ECs), vascular smooth muscle cells (SMCs), fibroblasts, platelets, resident stem cells, pericytes and inflammatory cells [PAD is mainly caused by atherosclerosis and associated thrombosis within the lower limb arteries leading to end organ ischemia. Other causes include vasculitis and ry cells ,44,45. Try cells ,47,48.Under healthy conditions the response to gradually progressive limb ischemia involves the promotion of angiogenesis and arteriogenesis in an attempt to increase the blood supply to the affected limb. Vascular remodeling, inflammation and apoptotic pathways are also implicated in the ischemic response and these may in part contribute to the resolution of tissue damage. In patients with CLI these compensatory responses to ischemia are ineffective. As a result, there is on-going inadequate perfusion of tissue, endothelial dysfunction, chronic inflammation and high levels of oxidative stress. All these changes lead to mitochondrial injury, free radical generation, muscle fibre damage, myofibre degeneration and fibrosis, and tissue damage, which may present as gangrene ,51,52,53Arteriogenesis is the process of enlargement of pre-existing collateral arteries to contribute to tissue perfusion . The priPotential therapies designed to accelerate arteriogenesis and angiogenesis during ischemia are under intense investigation although most of these interventions have not developed to a stage that they are ready for widespread clinical use ,60,61,62PAD is usually diagnosed using clinical assessment, ankle brachial pressure index (ABI) measurement or radiological imaging, or both, depending on the setting of the patient. Each of these approaches has advantages and disadvantages. ABI for example is a simple and cheap investigation to diagnose PAD but not applied frequently in routine practice ,64. PatiA range of circulating markers of atherosclerosis, arterial stiffness, inflammation, angiogenesis, vascular extra cellular matrix (ECM) remodeling, endothelial dysfunction and oxidative stress have been reported to be associated with PAD. Some of these biomarkers have also been suggested to be useful in predicting disease severity and prognosis.Case-control studies have reported the association of a number of circulating markers with PAD presence .It was previously reported that a combination of β-2-microglobulin (B2M), cystatin C, high-sensitivity C-reactive protein (hsCRP) and glucose was associated with PAD ,66. PlasThe levels of a number of lipids and fat related markers have also been reported to be differentially regulated in PAD patients. A recent lipidomic analysis comparing serum lipid profiles in 168 patients with PAD and 161 abdominal aortic aneurysm patients showed that a group of linoleic acid-containing triacylglycerols and diacylglycerols were negatively associated with PAD presence . FurtherRecently, a number of novel markers, such as Rho-kinase activity  and humaAn interesting observation was reported recently in relation to gender and racial differences in endothelial oxidative stress in patients with symptomatic PAD . Female A number of reports suggest that markers of oxidative stress ,98,99, sNicotinamide adenine dinucleotide phosphate oxidase (NOX)-2, is a multicomponent enzyme and the catalytic core of NADPH oxidase. NOX-2 mediates electron transfer from NADPH oxidase to molecular oxygen, and is the most important producer of ROS. Compared to controls, patients with PAD have been reported to have enhanced soluble NOX-2-derived peptides, isoprostanes and reduced serum levels of NO and flow mediated dilation . CLI patIn vitro and in vivo studies have suggested that recombinant human TSP-1 had a negative effect on angiogenesis. siRNA mediated TSP-1 inhibition has been reported to promote endothelial colony forming cells (ECFC) proliferation and recombinant human TSP-1 significantly enhanced ECFC adhesion [N-terminal part of TSP-1 named TSP-Hep-I also significantly enhanced the adhesion potential of ECFCs. Further work is needed to assess the value of circulating TSP-1 concentrations in identifying and providing prognostic information for PAD patients.Reduced circulating concentrations of a number of proteins involved in ECM remodeling, such as TGF-β1, have been reported in PAD patients . Anotheradhesion . Further(+) or CD133(+) circulated in lower numbers in PAD patients compared to healthy controls [(+) or CD133(+) are believed to represent bone marrow progenitors and studies in mice models have suggested they are involved in angiogenesis [(+) cells and augment ischemia induced angiogenesis in mice with hind limb ischemia [The number of circulating endothelial progenitor cells (EPC) has been reported to be associated with atherosclerosis and CVD however further work is needed to assess its value as a reliable biomarker for PAD . It has,controls . The celogenesis . A thermischemia .Overall, while several biomarkers have been associated with PAD presence currently none of these markers have been consistently demonstrated to improve detection of PAD. In this context, markers of oxidative stress and circulating progenitor cell populations warrant further attention. Further investigations in which markers are examined in large and repeated groups of patients are needed to better examine the potential of using these circulating markers in clinical practice.Biomarkers may not only be useful in determining the presence or absence of a disease, but could also be useful in predicting patient outcomes. A detailed analysis of a reliable biomarker when combined with established risk factors could assist in stratifying patients at high risk and for selecting optimal treatment. Many published studies have assessed the value of prognostic biomarkers in small groups of patients. However, data that available markers can lead to consistent improvements in clinical management is currently not convincing. It is important that the associations between markers and prognosis observed in smaller isolated studies are followed up by validation in larger cohort studies in independent populations. This section of the review focuses on the most commonly reported circulating biomarkers linked to inflammation, endothelial dysfunction, angiogenesis and vascular remodeling and their relationship with PAD severity and outcomes such as reduced ABI, amputation and mortality .n = 4787), elevated levels of hsCRP, fibrinogen, and leukocyte counts were associated with lower ABI values [n = 225, followed up for a median of 893 days). The study showed that the traditional risk factors and circulating markers of inflammation such as hsCRP, sVCAM-1, renal function, and nutrition had excellent discriminatory ability in predicting all-cause mortality in PAD patients [Multiple studies have reported that inflammation associated biomarkers circulate at higher levels in PAD patients with more severe disease ,109,124 I values . High leI values ,111,117 patients . hsCRP hpatients . Elevatepatients . Similarpatients . A recenpatients .in vitro thrombin generation potential was reported to correlate inversely with protease-activated receptors (PAR)-1-mediated platelet activation and was linked to the occurrence of athero-thrombotic events in patients with PAD [p < 0.05) suggesting its potential use as a prognostic marker [Myeloperoxidase (MPO) is a peroxidase enzyme stored in neutrophils and a key mediator of inflammatory and redox-dependent processes in atherosclerosis. MPO has been reported to promote atherosclerosis via inducing oxidative stress in animal models ,128. A pwith PAD . The prowith PAD . A five-c marker .Arterial occlusion results in inadequate oxygen supply to the lower extremities and concurrent defective clearance of toxic metabolites. The net result is the accumulation of ROS, leading to tissue necrosis and microcirculatory damage that eventually result in irreversible deterioration and injury to the endothelial lining ,132. A pN-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels are associated with functional capacity in patients with PAD and may be a marker of hemodynamic stress in these patients [A recent report suggests that serum patients . Natriurpatients . Higher patients , and alspatients ,136. Serpatients . PCA occpatients . Even thpatients . A recenpatients . Non-athOne of the most studied markers of angiogenesis in PAD is VEGF and its receptors R1 and R2. VEGF-R1 is characteristically up-regulated by hypoxia and its soluble form has been proposed as a marker for CLI. Patients with advanced PAD have been reported to have elevated serum and tissue levels of VEGF compared to age matched healthy volunteers ,85. FurtAnother, member of the VEGF family is VEGF-A, which exists as several isoforms produced as a result of alternative splicing. Reduced levels of circulating levels of total VEGF-A have been observed in IC patients compared to healthy controls . Lower lin vitro and in vivo studies suggest a crucial role of proteolytic enzymes and matrix proteins in creating a permissive microenvironment to promote blood vessel sprouting [The ECM plays a major role in regulating angiogenesis and prouting ,143,144.prouting ,82,145. prouting . A previprouting . This teprouting . AdditioIn this review, we have presented an overview of markers associated with PAD presence and outcome. A number of limitations exist for circulating markers currently identified. There is little consensus on which markers are consistently associated with PAD and there are definite challenges in identifying markers that are PAD-specific. The circulating markers should ideally reflect the changes occurring in the ischemic lower-limb muscles. In order to have clinical utility, the circulating biomarkers should predict risk independently of other established PAD risk factors. Furthermore, the circulating marker should be specific and sensitive and easily assayed.Biomarkers that could effectively predict PAD development, progression and outcome could be extremely useful in the clinical setting ,150,151.In summary: (1) PAD is multifactorial; therefore single biomarker may not be powerful enough for reliable diagnosis and/or prognosis. Rather a combination of risk factor and circulating marker data may be needed; (2) Identifying a marker specific to PAD rather than general athero-thrombosis may be technically challenging; (3) Despite considerable effort, no biomarkers have been currently shown as sufficiently robust to be incorporated into clinical practice. Even though a number of currently identified circulating markers show promise, further larger studies focused on the clinical value of such markers over existing risk predictors are needed.


International Classification of Diseases, 10th Revision code for varicella as the underlying cause. Because varicella deaths are nationally reportable, the Ohio Department of Health conducted an investigation to validate that the coding was accurate. Investigators learned that, on March 12, 2009, the adolescent girl was admitted to a hospital with a 3-day history of a rash consistent with varicella and a 1-day history of fever and shortness of breath. The patient was started on intravenous acyclovir (on day 4 of illness) and broad-spectrum antibiotics and antifungals, but she died 3 weeks later. The case underscores the importance of varicella vaccination, including catch-up vaccination of older children and adolescents, to prevent varicella and its serious complications.Varicella usually is a self-limited disease but sometimes can result in severe complications and death. Although infants, adults, and immunocompromised persons are at increased risk for severe disease, before varicella vaccine was introduced in 1995, the majority of hospitalizations and deaths from varicella occurred among healthy persons aged <20 years , dyspnea, facial edema, generalized petechial rash, and hypotension; she received a diagnosis of septic shock. She was awake and alert, and noninvasive mechanical ventilation was implemented during the first 6 hours of admission. However, her respiratory function continued to deteriorate with increasingly labored breathing, requiring invasive mechanical ventilation.μL; normal: 140,000–400,000/μL) and leukopenia ; blood cultures were negative. Vesicular fluid from a skin specimen collected on March 14 was positive for varicella-zoster virus (VZV) by direct fluorescent antibody test. Over the course of hospitalization, the patient developed pneumonia complicated by acute respiratory distress syndrome, pancytopenia, multi-organ dysfunction, health-care–acquired bacterial colonization and infection (including respiratory tract colonization with Enterobacter cloacae and urinary tract infection with Pseudomonas aeruginosa), and sepsis . Other blood cultures were negative, but they had been collected while she was on antibiotics.The patient’s laboratory results at admission indicated thrombocytopenia  in preventing severe varicella and deaths . VZV infThe Advisory Committee on Immunization Practices recommends routine administration of the first dose of varicella vaccine at age 12–15 months and the second dose at age 4–6 years. Catch-up vaccination also is recommended. Unvaccinated persons who do not have evidence of immunity to varicellaBefore varicella vaccination was included in routine childhood immunization, approximately 11,000 varicella-related hospitalizations and 100–150 deaths were reported annually in the United States . ImplemeThe case described in this report can serve as a reminder of the importance of catch-up vaccination of older children and adolescents  to preveExposure to VZV can occur when persons are exposed to patients with varicella (chickenpox) or herpes zoster (shingles). Unvaccinated children, adolescents, and adults are at risk for acquiring varicella; severe varicella can develop among healthy persons, and which patients might develop an especially severe course often is unpredictable at disease onset. Health-care providers should remind parents about vaccination during routine visits for children and adolescents, and parents should be informed of the risks, including potentially severe complications, from vaccine-preventable diseases. Resources for discussions with parents regarding vaccination are available.What is already known on this topic?Although varicella usually is a self-limited disease, it can lead to severe complications and death, even among persons without underlying conditions that put them at increased risk for severe disease. The varicella vaccine is highly effective in preventing severe varicella and death.What is added by this report?This report describes a varicella-related death that occurred in an unvaccinated, previously healthy adolescent aged 15 years. The case described in this report can serve as a reminder of the importance of catch-up vaccination of older children and adolescents to prevent varicella and its serious complications later in life when disease can be more severe. The case underscores the fact that severe complications of varicella and death can occur among persons without high-risk conditions for severe varicella.What are the implications for public health practice?Severe varicella can develop among unvaccinated healthy persons, and which patients might develop an especially severe course often is unpredictable. Persons without evidence of immunity to varicella should receive 2 doses of varicella vaccine, or a second dose if they have received only 1 dose, to prevent varicella and its severe complications.


Cardiovascular diseases (CVD) are the leading causes of morbidity and mortality worldwide. Although treatment for risk factors for CVD such as hypertension, hyperlipidaemia, obesity, and diabetes has steadily decreased mortality due to cardiovascular events in the last three decades, the underling mechanisms for several CVD remain elusive. It is well known that oxidative stress and inflammation have been implicated in the etiology of several CVD. Further, oxidative stress and inflammation triggered signals can either directly cause injury to the cardiac tissues or increase the atherosclerotic process. However, most of the data for these studies are derived from experimental animals. Long term prospective clinical trials are required to validate the contribution of oxidative stress and inflammation in CVD. Moreover, better understanding of the signaling mechanisms that interplay between oxidative stress and inflammatory signaling would be beneficial in designing more selective and targeted therapy to combat these deleterious mediators of CVD. The purpose of this special issue is to assemble information from preclinical as well as clinical studies in order to provide an additional opportunity to identify the potential molecules/mechanisms that disrupt equilibrium between immune, inflammatory, and oxidative responses involved in the pathogenesis of CVD.To better understand the pathogenesis of CVD in chronic kidney disease (CKD) P. Bartnicki et al. investigated the role of continuous erythropoietin receptor activator (CERA) on selective biomarkers of CVD. In this study, blood samples from 25 CKD patients with CERA treatment and 20 healthy subjects were evaluated for various inflammatory markers, biochemical parameters, and other endothelial specific biomarkers. Their results indicate that biomarkers of inflammation as well as endothelial dysfunction are significantly elevated in the nondialyzed CKD patients. Specifically, they found that biomarkers such as TNFr1, sICAM-1, and MMP9 could be the risk factors of CVD in CKD patients. Further, this study indicates that CERA treatment by using MPG-EPO diminished endothelial dysfunction and improves left ventricular function in CKD patients.Another research article by B. Al-Shammari et al. investigated the pulmonary toxicity associated with the amiodarone, a drug used for treating ventricular and supraventricular dysrhythmia. In this study, treatment of rats with amiodarone leads to a time-dependent toxicity in the lungs. Specifically, amiodarone decreased antioxidant enzymes such as catalase, SOD, GPx, and GR and increased oxidative stress. Further, long term treatment of amiodarone for 3 to 4 weeks leads to significant toxicity as determined by granulomatous inflammation and interstitial pneumonitis. These studies indicate that imbalance of oxidative stress and antioxidant status and resulting inflammatory response could lead to pulmonary toxicity with amiodarone treatment.Studies by Y. Cheng et al. reported the cardioprotective potential of formononetin, a natural plant derived isoflavone from Radix Astragali, using human cardiomyocyte H9c2 cells. Their results suggest that formononetin could protect cardiomyocytes from ischemia reperfusion injury by reducing the oxidative stress and inhibiting the mitochondrial permeability transition pore (mPTP) opening. Specifically, they have shown that formononetin induces AKT and GSK-3b phosphorylation leading to mPTP opening. These results also suggest that PI3K and PKC inhibitors could restore effects of formononetin-induced mPTP opening. Thus, these studies report that formononetin could be developed as a cardioprotective agent against acute myocardial infarction.Another study by G. Zhang et al. examined the antioxidant effect of simvastatin on high-cholesterol diet-induced oxidative stress injury in aorta and hippocampus of rabbits. Their results suggest lipid peroxidation products as biomarkers of oxidative stress in high-cholesterol induced brain injury in rabbits. They have shown that simvastatin enhances antioxidant status (GSH-Px) in atherosclerotic aorta and decreases oxidative stress . This study again addresses the significance of oxidative and antioxidant imbalance in high-cholesterol induced tissue injury.As an endnote, it is obvious from the recently published studies and current special issue papers that oxidative, immune, and inflammatory responses play a major role in the pathophysiology of cardiovascular complications. Therefore, the molecules that interrupt or neutralize the effects of oxidative, immune, and inflammatory responses could be the next important targets for the future drug discovery studies in CVD.


Injuries to the knee, including intra-articular fractures, ligamentous ruptures, andmeniscal and articular cartilage lesions, are commonplace within sports. Despiteadvancements in surgical techniques and enhanced rehabilitation, athletes returningto cutting, pivoting, and jumping sports after a knee injury are at greater risk ofsustaining a second injury. The clinical utility of objective criteria presents adecision-making challenge to ensure athletes are fully rehabilitated and safe toreturn to sport. A system centered on specific indicators that can be used to developa comprehensive profile to monitor rehabilitation progression and to establish returnto activity criteria is recommended to clear athletes to begin a progressive andsystematic approach to activities and sports. Integration of a sports knee injuryperformance profile with return to activity criteria can guide clinicians infacilitating an athlete's safe return to sport, prevention of subsequent injury, andlife-long knee joint health. The burden of musculoskeletal (MSK) injuries on the health of our population issubstantial as more than 110 million adults reported musculoskeletal injuries in2008-The knee is one of the most frequently injured joints in physically activeindividualsTraumatic knee injuries increase risk for the development of post-traumaticosteoarthritis (PTOA). Individuals with a previous knee injury have a 56.8% lifetime risk of development ofknee osteoarthritis (OA)Safe return to sports after a traumatic injury is the responsibility of all healthcareprofessionals involved. Despite best efforts, athletes returning to high-risk activityand demanding sports after a knee injury are at greater risk of sustaining a secondinjury. Many post-surgical rehabilitation guidelines are based solely on time fromsurgery and permit individuals to return to sports-specific activities between 4-9months; however, very few guidelines provide any objective criteria for assessing anathlete's readinessCurrently, there is no system centered on specific indicators that can be used todevelop a comprehensive profile to monitor rehabilitation progression and to compile allindividualized data to standardize education about the risks of re-injury to the kneeand the likelihood of returning to sports. The utilization of these profiles may providea more accurate and complete representation of an athlete's current status. The purposeof this paper is to build on the conceptual framework for the restoration oflimb-to-limb symmetry in its role of secondary and tertiary knee injury prevention by 1)reviewing the epidemiology related to traumatic knee injuries, 2) identifying the riskfactors that are associated with re-injury and poor knee function, 3) providingrecommendations for objective measures utilizing limb-to-limb symmetry as aperformance-based criteria for readiness to return to activity.--While it is difficult to quantify the number of anterior cruciate ligament (ACL)injuries, recent estimates in the US have reported 81 per 100,000 individuals betweenthe ages of 10 and 64 or about 250,000 per yearMeniscal injuries are the fourth most common knee injury in high school athletes,,-,,,,Almost one million individuals are affected annually by articular cartilageinjuries,Overall, the risk of ACL injury in an athlete with a history of ACLR is 15 timesgreater than that of a healthy athlete,-,Women with a history of ACL injury are at greater risk of a second ACL injury with16-fold greater risk of injury compared to healthy controls and four times greaterrisk than men with a history of ACLRYounger athletes have greater rates of re-injury within 2 years of ACLR , with 17% ofthose under the age of 18 having a second ACL injury compared to 7% of those between18 and 25, and only 4% of those over 25-,Failure for all meniscal surgeries ranges from 20.2-24.3%, depending on the type ofmeniscal surgery and status of the ACLAfter microfracture, those with a single defect have a lesser failure rate thanindividuals with multiple defectsIn a recent systematic review of outcomes after ACLR, 88% of athletes returned tosport, 65% returning to their pre-injury level, and 55% returning to competitiveplayReturn to sport rates have been reported as high as 98% after meniscal surgery,,In recreational and amateur athletes, 66% return to sports in eight months aftermicrofracture, with 67% of those eventually returning to a competition level. After2-5 years however, 49% of athletes have reduced their level of play and 42% havepoorer function,A history of knee injury, regardless of type, places an individual at a greater riskof subsequent injury. In a study of National Collegiate Athletic Association (NCAA)athletes, those with a history of knee surgery missed more days of sport, had agreater number of knee injuries, and received more magnetic resonance imaging (MRI)tests and surgeries than those athletes with no prior knee injuryTotal knee arthroplasty and other reconstructive surgeries have advancedsignificantly in the last decade, allowing former athletes to remain active. However,at a rate of nearly 600,000 per year, with an expected increase to 3.5 million peryear by 2030In order to develop a system using rehabilitation indicators for profiling recoveryafter knee injury or surgery, an understanding of the non-modifiable and modifiablefactors that can influence recovery or risk of re-injury is needed. A centralized portalthat can track the longitudinal record of rehabilitation indicators can then be used asa means to define an athlete's recovery performance profile. Additionally, profiles canbe utilized in establishing criteria to identify thresholds for safe return to sport.Furthermore, the profile can be used as a reference for any rehabilitation specialistinterested in developing a similar recovery monitoring system.,-While patient demographics (e.g. age and sex) are non-modifiable factors,understanding their relationship to re-injury and function can guide clinicians inmonitoring and counseling athletes appropriately. Younger athletes with knee injuriestypically return more frequently and earlier to sports than older athletesnd knee injury may be sex-specific.While the incidence of injury to the ACL is greater in men due to the greaterexposure to sports, women have a relative risk of injury two to eight times greaterthan men,,Primary knee injury and subsequent 2o is associated with poor post-surgical,patient-reported outcomes and task-specific activities-,Range of motion (ROM) symmetry is unique to the individual; however, a knee extensionloss of as little as 3--,-,,,--,Muscle strength deficits are pervasive after knee injury and surgery,,--Quadriceps strength deficits can persist for months or years after any knee jointsurgery, in spite of rehabilitationQuadriceps strength asymmetry can also be reflected in other impairment measures.Quadriceps index (QI) is expressed as a percentage of the peak value of thequadriceps muscles on the involved side divided by the peak value of the quadricepsmuscles on the uninvolved side. After ACLR, those with QI less than 85% have worsehop scores than those with a QI greater than 90% or controls. QI is a betterpredictor of hop test distance than graft type, presence of meniscal injury, kneepain, or knee symptoms,Balance and postural deficits have been reported after knee injury, and inparticular, after ACL injury and reconstruction. Various assessments have been usedto evaluate risk of injury, current status, and the magnitude of improvement after anintervention,--Performance-based measures can be used to assess a combination of muscle strength,neuromuscular control, confidence in the injured limb, and ability to completesport-specific activities,,-Side-to-side limb symmetry appears to have a critical role in the prevention ofinjury and return to sports after knee injuries. Varying performance standards (i.e.muscle strength or hop performance), ranging from 70% to 90% limb symmetry index(LSI), have been suggested as benchmarks for determining normal symmetry,,,,,,,,,,,,Early after injury or surgery, individuals have poor single-legged hop LSI andsubstantial limb-to-limb differencesWhen comparing individuals after ACI and after microfracture, those after ACI havegreater single hop asymmetry than those after microfracture six and twelve monthsafter surgery. However, there is no difference between the groups in cross-over or6-meter timed hop tests at six and twelve months. At 24 months, the microfracturegroups had minimal asymmetry in hop performance (4-8% asymmetry), while the ACI grouphad larger asymmetries (10-17% asymmetry) on all three hop testsPersistent symptoms, such as knee pain, joint swelling, stiffness, instability, orweakness, are common reasons many athletes cite for not returning to preinjuryactivity levels,Joint effusion is an over-accumulation of fluid within the joint capsule, indicatinginflammation or irritation-Symptomatic knee joint instability (giving way) is a hallmark of knee joint injury.Giving way episodes are usually described as buckling at the knee similar to theinitial injury. While the magnitude of passive ligament instability is poorlyassociated with functional ability in ACL-deficient athletes-nd ACL injuryWhile the measurement of movement using motion capture is not considered a typicalrehabilitation indicator, it does provide additional insight on the ubiquity ofasymmetries seen after knee injury and surgery. Side-to-side asymmetrical movementpatterns after knee injury are common and can persist for months or years afterinjury or surgeryEven two years after ACLR, Roewer et al.In higher-risk tasks such as jumping, women two years after ACLR demonstratelimb-to-limb asymmetries. Higher vertical ground reaction force and loading rate isseen on the uninvolved limb during landing compared to both the involved limb andcontrolsGait asymmetries have been noted following meniscal surgery. Smaller peak kneeflexion angles and lower peak external moments in the sagittal plane and larger kneeadduction moments have been observed in the involved limb compared to the uninvolvedlimb after partial meniscectomy and compared to controls,-,,After ACI surgery, aberrant movement patterns are present, specifically reduced kneemotion during weight acceptance and decreased external sagittal plane moments. Theseaberrant patterns can persist for months,,,,Patient-reported outcome (PRO) measures are self-report questionnaires that measurean individual's perception of daily life and physical activity,Knee performance and self-reported function generally improve over the first yearafter ACLR,The various surgical techniques for articular cartilage defects vary in theirself-reported outcomes. Pooled data indicates that 67% of individuals report normalIKDC2000 one year after microfracture, and 80% of individuals have significantincreases from pre-surgery in Lysholm, Tegner, and KOOS sports subscale scoresDetermining when a patient is performing well enough to safely and effectively return toplay or activity is a complex decision that must take into account the risk factors forre-injury or poor function. Meeuwisse et al.Creighton et al.Limb-to-limb symmetry or limb symmetry indexes are used after injury or surgery asimportant indicators of physical impairments, activity limitations, and function. Theyare also used to monitor the progress of rehabilitation and to assess readiness forreturn to activity or sports, therefore they should be benchmarked against performancestandards. Unfortunately, no empirically based benchmarks or expert consensus benchmarksexist regarding performance standards at specific time points after knee injury.Development of standards can provide relevant information about patient performance andcan help to determine if additional interventions are needed to achieve this level.Injury to the meniscus, cartilage, or ligaments of the knee results in a fairlyconsistent clinical presentation and an increase in the risk for post-traumaticosteoarthritis. Creating a profile of these individuals is important to promote acomprehensive evaluation of the patient to eliminate basic impairments after surgery andto facilitate a safe and effective return to sport process that minimizes the risk forsecond injury. Additionally, using a consistent set of measures at consistent timeframes allows for assessment of trends in patient outcomes.,,,-One of the challenges in developing an injury risk profile for post-injury orpost-operative management has been to select appropriate clinical or field tests thatcan detect side-to-side asymmetries, assess global knee function, and determine apatient's readiness to return to sport. Batteries of tests have been developed topredict the risk for musculoskeletal injuries,While many different tests and measures are available for functional testingQuadriceps and hamstring strength can be tested using isokinetic peak torque ormaximal voluntary isometric contraction (MVIC). Peak force or torque values achievedduring strength testing bilaterally are recorded and used to calculate a quadricepsindex (QI) or hamstrings index (HI). QI is expressed as a percentage of the peakvalue of the quadriceps muscles on the involved side divided by the peak value of thequadriceps muscles on the uninvolved side. Hamstrings index is expressedsimilarly.Following quadriceps strength testing, participants perform single-legged hop tests.Four single-legged hop tests are used in our clinic: single hop for distance (singlehop); cross-over hop for distance (cross-over hop); triple hop for distance (triplehop); and 6-meter timed hop,,Following hop testing, participants complete self-report questionnaires: KOS-ADLS,GRS, IKDC2000, and the ACL-Return to Sports after Injury (ACL-RSI). The KOS-ADLS is a14-item patient-reported outcome of symptoms and functional limitations of the kneeduring ADLs,ACL-RSI is a 12-item patient-reported outcome of emotions, confidence in performance,and risk appraisal after ACLR. It can discriminate psychological differences betweenathletes who returned to sports and those who did not return to sports,,The rehabilitation indicators from the SKIPP can be used to determine readiness toreturn to activities or sports - an improvement over the current timebasedrehabilitation protocols. No functional test battery for return to sports has beenvalidated to identify cutoffs which reduce the risk of injury to this point. Despiteimpairments, activity restrictions, poor self-report scores, and limb-to-limbasymmetries, many post-surgical rehabilitation guidelines permit individuals toreturn to sports-specific activities between three to nine months after surgery,depending on the lesion and surgical technique. However, the use of a time-basedapproach does not adequately account for these deficits,Recently, two paradigms of return to activity criteria have been proposed by theEuropean Board of Sports Rehabilitation and the University of Delaware asrecommendations to clear athletes to begin a progressive and systematic approach toactivities and sports and one endurable hop test  be at least 90% of the uninvolved limb (90%LSI). For the non-pivoting/non-contact/recreational group, they recommend thatinvolved limb knee extensor and knee flexor muscle strength performance be at least90% of the uninvolved limb (90% LSI) and that involved limb hop performance on onemaximum or one endurable hop tests be at least 90% of the uninvolved limb (90% LSI).These recommendations take into account both knee extensor and knee flexor strengthand hop performance; however, one limitation of these recommendations is the omissionof the use of PROs as criteria for return to activity. As stated before, PROs do notcorrelate highly with performance-based measures, but capture different aspects ofknee function. It has been suggested that both performance-based measures and PROsare needed to fully characterize an athlete's knee function,The University of Delaware has instituted return to activity criteria and used themfor over 15 yearsWork from our laboratory has demonstrated that the University of Delaware Return toActivity Criteria (RTAC) can accurately discern between two differently functioningcohorts of athletes after ACL injury or reconstruction. The RTAC demonstrated thatparticipants who successfully returned to high-level activity after non-operativemanagement of an ACL injury had less than a 10% deficit on their baseline scores onaverage,,,,The validation of the RTAC to determine safe and optimal return to activities or topredict future injuries is ongoing. Several clinical variables have been identifiedwith returning to sportsKnee injuries are common in sports. Despite the advances made in surgical techniques andrehabilitation interventions, return to sport rates are poorer than previously thought,and the risk of re-injury or failure after knee surgery is greater than expected. Thedevelopment of the Sports Knee Injury Performance Profile allows the clinician toconsistently monitor knee function, track progress throughout rehabilitation, andincorporate targeted, personalized interventions to achieve optimal sports performanceand function while potentially reducing the risk of re-injury or failure. Theimplementation of established return to activity criteria provides a platform to ensurethat athletes are fully rehabilitated and can begin to introduce loads needed toparticipate in their sport or activities. Consistent implementation of this profile willallow clinicians to track individual patient progress and to assess trends in theirpatients over time.


To document the prevalence of depression and anxiety disorders, and their associations with mortality among hospitalized breast cancer patients.We examined the associations between breast cancer diagnosis and the diagnoses of anxiety or depression among 4,164 hospitalized breast cancer cases matched with 4,164 non-breast cancer controls using 2006-2009 inpatient data obtained from the Nationwide Inpatient Sample database. Conditional logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CI) for the associations between breast cancer diagnosis and diagnoses of anxiety or depression. We also used binary logistic regression models to examine the association between diagnoses of depression or anxiety, and in-hospital mortality among breast cancer patients.We observed that breast cancer cases were less likely to have a diagnosis of depression , and less likely to have a diagnosis of anxiety  compared with controls. This association remained after controlling for race/ethnicity, residential income, insurance and residential region. Breast cancer patients with a depression diagnosis also had lower mortality  compared with those without a depression diagnosis, but there was no significant difference in mortality among those with and without anxiety diagnoses.Diagnoses of depression and anxiety in breast cancer patients were less prevalent than expected based on our analysis of hospitalized breast cancer patients and matched non-breast cancer controls identified in the NIS dataset using ICD-9 diagnostic codes. Results suggest that under-diagnosis of mental health problems may be common among hospitalized women with a primary diagnosis of breast cancer. Future work may fruitfully explore reasons for, and consequences of, inappropriate identification of the mental health needs of breast cancer patients. Recent progress in cancer treatment has markedly improved the prognosis for many breast cancer patients. Although breast cancer remains the most common cancer among women in the United States, accounting for over 230,000 new cases and 39,000 deaths in 2013, death rates are now about one third of their levels in 1990 . PreviouThere are multiple barriers to identifying and diagnosing mental health disorders among cancer patients. These include patient-level barriers such as fear of the stigma of a psychiatric diagnosis, and concerns that a focus on a psychiatric disorder may distract from oncological treatment . At the When considering mental health disorders among cancer patients, the research literature has typically emphasized the potential for depression and anxiety. However despite many years of research, the prevalence of depression and anxiety disorders among cancer patients is still subject to much debate,22, partThe aim of the present study was to assess the prevalence of clinically diagnosed depression and/or anxiety among hospitalized patients with a primary breast cancer diagnosis using ICD-9 clinical diagnostic codes, and to examine associations between a diagnosis of depression or anxiety with mortality.http://www.hcup-us.ahrq.gov/nisoverview.jsp.A cross-sectional study of hospital inpatient admissions was conducted. We obtained data for this study from the Healthcare Cost and Utilization Project (HCUP) produced Nationwide Inpatient Sample (NIS) database . The NISWe restricted our sample to women between ages 40 and 85 years, who were admitted to one of the HCUP participating hospitals. For the case-control analysis, we randomly selected a 10% sample of NIS data from 2006–2009 without replacement , and created matched dataset with breast cancer cases and matched controls. For the mortality analysis, we identified all breast cancer cases diagnosed in the NIS between 2006 and 2009, and identified all in-hospital deaths among those cases. We used the International Classification of Disease, ninth edition  to identify hospital admissions for women with a primary diagnosis of breast cancer.For the analysis of the association between mental health diagnosis and breast cancer diagnosis, we selected women without a primary breast cancer diagnosis and 1:1 matched them to women with primary breast cancer diagnosis on age at admission, length of stay, number of comorbidities, and discharge disposition using the % gmatch macro- a greedy matching algorithm published by the Mayo Clinic  . This ala priori groupings of depression and anxiety diagnoses based on ICD-9-defined categories and ad hoc clinical considerations. For this analysis, a clinical diagnosis of depression included ICD-9 codes for major depression , depressive disorder NOS (code 311); a clinical diagnosis of anxiety included ICD-9 codes for anxiety disorder NOS (code 300.0), acute reaction to stress (code 308) and posttraumatic stress disorder (PTSD) .We examined the NIS data from 2006–2009 for both cases and controls in order to evaluate mental health diagnoses. To achieve power, we created In addition to age, race/ethnicity, residential income, insurance type, residential region, length of stay, stage at admission (for breast cancer cases), we also created a modified Deyo comorbidity score based on ICD-9 codes for major comorbid conditions. These included myocardial infarctions, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, rheumatic disease, peptic ulcer disease, mild liver disease, diabetes mellitus with or without chronic complications, hemiplegia or paraplegia, renal disease, moderate or severe liver disease, and HIV/AIDS. We summed the number of these conditions for each patient into a single comorbidity score to reflect the overall comorbidity of the patient (COM). The Charleston index as modified by Deyo was previously examined in the NIS database . Length Residential income was estimated based on the median household income at the zip-code level, and was classified into quartiles with values ranging from 1 for the poorest zip code to 4 for the wealthiest zip code. Residential region was categorized at the county level into large metropolitan areas (metropolitan areas with 1 million residents or more), small metropolitan areas (metropolitan areas with less than 1 million residents), micropolitan areas (Non-metropolitan areas adjacent to metropolitan areas) and non-metropolitan or micropolitan areas (noncore areas with or without own town). These designations were developed by HCUP based on the 2003 version of the Urban Influence Codes (UIC) .The NIS does not include directly coded data on stage of presentation, so we created a new variable using the clinical criteria of disease staging based on ICD-9 codes. Metastatic disease was assigned when the ICD-9 code indicated metastatic disease to other organs , non-metastatic disease was assigned when those specific codes were absent, and in-situ was assigned when ICD-9 code 2330 was present. Disease staging has been evaluated and validated in previous studies , and wasWe were interested in examining two separate outcomes: 1) Diagnoses of mental health disorders in breast cancer inpatients comparing cases with matched non-breast cancer controls; and 2) In-hospital mortality among breast cancer patients, defined as death during hospitalization using a sample of breast cancer cases. The NIS only contains inpatient data; therefore deaths occurring after discharge are not captured. The Columbia University Medical Center Institutional Review Board exempted this study from ethical review.In the matched analysis of breast cancer patients and non-breast cancer controls, we used paired t-tests and McNemar’s test for descriptive analyses, and Bowker’s test of symmetry for paired variables with multiple levels. We examined the distribution of non-clinical characteristics between groups and computed p-values, taking into account the matched design. We used conditional logistic regression analyses to generate odds ratios and p-values for the association between depression and anxiety and odds of breast cancer adjusting for other variables. This allowed us to account for the matching design. We presented two models for this analysis; the first model adjusted for race/ethnicity, and the second model adjusted for race/ethnicity, residential income, insurance type and residential region. In the analysis of in-hospital mortality among breast cancer patients, we used simple descriptive statistics to compute the number of deaths in each category. We used binary logistic regression to examine the association between depression and anxiety, and odds of in-hospital mortality (yes/no) among breast cancer patients, adjusting for a priori specified confounders. We present three models for this analysis; the first model adjusts for race/ethnicity, age at admission and stage at admission, the second model additionally adjusts for residential income, region and insurance, while the third model additionally adjusts for length of stay and number of comorbidities. Longer hospital length of stay and higher number of comorbidities are associated with being sicker, and higher mortality. We assessed for confounding by entering potential confounders individually into models including the main predictive variables. We used SAS software, version 9.3  for all statistical analyses, and included sampling weights to account for the stratified study design.Our sample identified 6,512 women aged 40–85 with a primary diagnosis of breast cancer between 2006 and 2009. Of these, the algorithm was able to match 4,164 with non-breast cancer cases as controls. Cases and controls were similar on all matched  characteristics , and theAmong breast cancer cases, 355 (8.5%) women had a clinical diagnosis of depression, while 172 (4.1%) had a clinical diagnosis of anxiety . Among cAdjusting for race/ethnicity did not attenuate the associations between depression and anxiety diagnoses and breast cancer. Furthermore, in the fully adjusted model, the associations between depression diagnoses  or anxiety diagnoses  and breast cancer remained; breast cancer cases were 37% less likely to have depression diagnoses, and 32% less likely to have anxiety diagnoses compared with matched non-breast cancer controls after additionally adjusting for residential income, insurance type and residential region.Among the 64,425 breast cancer cases diagnosed in the NIS between 2006 and 2009, there were 1,146 in-hospital deaths . Black , and anxiety diagnoses remained non-significant. After additionally adjusting for residential income, residential region and insurance, the association between depression diagnoses and mortality became non-significant . However, in the fully adjusted model, which includes length of stay and number of comorbidities, the association between depression and mortality became significant , while anxiety remained non-significant . In addition, in the fully adjusted model, the racial/ethnic differences in mortality became non-significant for blacks , and Hispanics .Our analysis of the 2006–2009 NIS data of hospitalized breast cancer patients and matched non-breast cancer controls indicated that clinical diagnoses of depression and anxiety were less prevalent among breast cancer patients compared with non-breast cancer controls. These differences persisted after adjusting for potential confounders such as age at admission, length of stay, number of comorbidities, and discharge disposition through the matched design, and on race/ethnicity, residential income, health insurance and region of residence in the analysis. Additionally, we observed that a diagnosis of depression was associated with significantly lower mortality among breast cancer patients compared with non-breast cancer matched controls, but we found no difference in mortality with a diagnosis of anxiety.Although few population-based studies have examined the prevalence of clinically diagnosed mental health disorders among cancer patients, those have mostly been in mixed inpatient and outpatients records ,32 or onThe lower rates of diagnosed depression and anxiety observed in our study among hospitalized breast cancer patients compared with matched non-cancer controls was unexpected and raises questions about research focused on mental health in cancer patients. Despite many years of research, prevalence of depression and anxiety in patients with cancer is still subject to much debate ,22. PrevAlternative explanations for the low prevalence of depression and anxiety observed in our study among hospitalized breast cancer patients need to be considered, including one or more diagnostic barriers at the individual, provider or institutional levels. A recent study by Walker et al  demonstrOur results also indicated that hospitalized breast cancer patients with a clinical diagnosis of depression had lower mortality rates compared with matched patients without a depression diagnosis. This finding stands in apparent contrast to previously reported associations between depression and higher mortality among cancer patients ,13. In cEvidence about the association between depression and survival in cancer populations, has been inconsistent ,45–49. RThis study was based on data from a large administrative database that has several strengths and limitations. The NIS is a large representative sample of hospitalizations across the US, providing a unique opportunity to examine two relatively rare diseases simultaneously. The matched case-control design also helps to minimize measured and potential unmeasured confounders that may distort the association between breast cancer diagnosis and mental health diagnoses. However, the dataset is limited to in-patient hospitalizations and in-hospital deaths and therefore does not capture patients that were discharged home or to a hospice before deaths. In addition, since the dataset includes only de-identified patient records, it is not possible to exclude duplicate records if the same patient was admitted multiple times in the same year. Zhang et al. tried to identify possible duplicate situations by using zip code, income, and location data, however they were unable to exclude duplicate records . AnotherIn conclusion, we observed that breast cancer inpatients were less likely to receive a clinical diagnosis of depression or anxiety compared with non-breast cancer inpatients. Patients who did receive a diagnosis of depression were less likely to die compared with those undiagnosed. If confirmed by future studies, our study results provide further indication that depending upon the definition and methods of assessment, depression and anxiety may be less common in breast cancer patients than previously thought, and suggest the need for additional research to better understand effects on survival.


Although 1H-MRS does not specifically differentiate between cell types, it quantifies certain metabolites that are highly enriched in astrocytes , or that are involved in metabolic shuttling between astrocytes and neurons . Here we focus on metabolites detectable by 1H-MRS that may serve as markers of astrocyte metabolic status. We review the physiological roles of these metabolites, discuss recent 1H-MRS findings in the injured and aging brain, and describe how an astrocyte metabolite profile approach might be useful in clinical medicine and clinical trials.Following a brain injury, the mobilization of reactive astrocytes is part of a complex neuroinflammatory response that may have both harmful and beneficial effects. There is also evidence that astrocytes progressively accumulate in the normal aging brain, increasing in both number and size. These astrocyte changes in normal brain aging may, in the event of an injury, contribute to the exacerbated injury response and poorer outcomes observed in older traumatic brain injury (TBI) survivors. Here we present our view that proton magnetic resonance spectroscopy ( Once thought to be merely part of the “glue” that holds together the neurons in the central nervous system (CNS), astrocytes are now known to serve a variety of complex and essential roles in CNS function. Astrocytes are intimately involved in regulating neurotransmission and local cerebral blood flow, and in maintaining the osmotic, pH, and neurotransmitter homeostasis of the extracellular environment in a manner that is essential for normal synaptic function. They influence neuronal structure and function by releasing growth factors and cytokines, and they play a critical role in brain energy metabolism, taking up glucose from the blood and furnishing energy metabolites to neurons  provides this capability. 1H-MRS is a non-invasive imaging technique that quantifies specific brain metabolites within a defined brain region of interest  scanners, and can quantify from 3 to 20 or more metabolites in vivo depending on the magnetic field strength and the selected pulse sequences. These metabolites reflect various physiological processes including bioenergetics, oxidative stress, neurotransmission, and neuroinflammation. The high reproducibility of 1H-MRS data acquired in vivo has been demonstrated in humans and rodents  is the most abundant isomer of inositol in animal tissues. mIns is a component of membrane phospholipids, plays a role in intracellular second messenger cascades, and is an important organic osmolyte. Because the concentration of mIns is higher in astrocytes than in neurons  and human subjects  and S100b  and ascorbate  are the two most prominent endogenous antioxidants in the CNS, protecting cells from damaging reactive oxygen species and preserving essential cellular functions. While Asc predominates in neurons, GSH concentrations are considerably higher in astrocytes  serves as the major excitatory neurotransmitter and is a precursor of γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the CNS. Glu is also closely associated with glutamine (Gln) via the Glu-Gln cycle between neurons and astrocytes. After its release from neuronal synapses, Glu is taken up by nearby astrocytes, converted to Gln, then transported back to neurons. Overall, brain Glu concentrations range from 6–13 μmol/g and Gln from 2–4 μmol/g , which is then released from the astrocytes to serve as a preferred fuel for neurons (Pellerin and Magistretti, 1H-MRS. Since Lac has been shown to strongly predict poor outcomes after TBI in humans (Ashwal et al., in vivo could have important clinical applications.After a brain injury, an acutely increased energy demand results in increased glycolysis, which along with impaired respiratory function of mitochondria results in rapid Lac accumulation. Elevated brain Lac after injury has been well documented with spectroscopic methods (Ross et al., In contrast, reports on Lac concentrations in normal brain aging are inconsistent, ranging from falls to increases (Urrila et al., 1H-MRS biomarkers will aid in prognostication and in selecting therapies to mitigate the cognitive impairment seen with TBI, or the cognitive decline seen with aging. Furthermore, these biomarkers will provide a non-invasive means to track therapeutic target engagement and efficacy. Although at present we can acquire signals from numerous 1H-MRS biomarkers in animals, there remains considerable opportunity for developing new acquisition approaches to expand the repertoire of metabolites routinely quantified in humans.We envision a future in which Using widely available spectroscopic acquisitions, Lac and mIns are easily quantified in animal models and in humans. However, GSH, Glu, and Gln are more challenging, largely due to overlapping signals. The issue of overlapping signals can be resolved at higher magnetic field strengths; indeed, there is already a proliferation of MRI scanners at 7 T and higher for research use and some are advocating the use of fields greater than 3 T for clinical investigation. An alternative approach is to develop more sophisticated acquisition sequences such as two-dimensional spectroscopy (Lin et al., 1H-MRS biomarkers can be used in clinical applications. The precise mechanisms underlying altered mIns, GSH, Gln/Glu, and Lac following brain injury or in aging are yet to be clarified. Thus, the use of these metabolites as biomarkers of astrocyte metabolic status needs to be further validated specifically in the context of brain injury and aging, by comparing their levels with other quantitative measures of astrocyte physiology. In addition, there is currently little information available about the possible contribution of other CNS cell types such as microglia to the 1H-MRS profiles. Non-invasive 1H-MRS approaches in animal models are well suited to addressing these questions, since they permit intra-subject validation of pathological mechanisms when in vivo scanning is followed by invasive histological and biochemical analyses of the same tissue. Once validated in animal models, 1H-MRS can form the basis for translational imaging studies in humans, where it can be combined with measures of cognitive function and other clinically relevant outcome measures.In addition to technical challenges of data acquisition, challenges of data validation remain to be addressed before 1H-MRS-detectable metabolites related to astrocyte metabolic status. Although taken individually, each metabolite might provide valuable information on individual molecular or cellular mechanisms as discussed above, they can also be considered in combination—as an astrocyte metabolite profile. On the whole, the profiles of astrocyte-relevant metabolite changes in brain aging and injury look remarkably similar (Table bioenergetic disruption. Impaired mitochondrial respiration is known to increase Lac accumulation and may be related to increased Gln/Glu ratio in the aging and injured brain since Glu is derived from α-ketoglutarate, a TCA cycle intermediate. Moreover, bioenergetic deficit can also result in reduced production of endogenous anti-oxidants, including GSH. Disrupted mitochondrial respiration can also cause increased reactive oxidative species, which would further consume GSH. A second pathological mechanism is inflammation, associated with astrocyte activation and recruitment, which has also been reported in both aging and injured brain. An increased astrocyte pool would result in elevated mIns and could also yield elevated Gln/Glu.We have identified five Several lines of evidence suggest that a well-characterized metabolite profile is likely to be useful as an overall biomarker of injury severity and for prognostication, for stratifying patients into trials, and for treatment selection and management.1H-MRS-detectable metabolites is greater in tissue located closer to the primary lesion site (Harris et al., et al. found that greater Lac and mIns changes were associated with poorer Glasgow coma scores and also with poorer outcome (Ashwal et al., Larger metabolite changes are associated with greater injury severity and worse functional outcomes. For example, we have shown in an animal model of TBI that the magnitude of change in The astrocyte metabolite profile might also be useful in understanding cognitive decline in aging. As shown in Table 1H-MRS biomarkers might be used for treatment selection. To the extent that 1H-MRS-detected metabolites are associated with cellular and molecular mechanisms, changes observed in prognostic studies might identify targets for therapeutic intervention. For example, an elderly patient with cognitive impairment and lower GSH might benefit from anti-oxidant therapy and a TBI patient with high mIns might benefit from anti-inflammatory treatment. Finally, these biomarkers could be used as pharmacodynamic indicators to verify target engagement in the brain, and to help confirm treatment efficacy.Finally, astrocyte-associated 1H-MRS is one of the few techniques that can non-invasively assess the chemical concentrations and metabolic pathways of the brain in living individuals. We propose that 1H-MRS-detectable metabolites can serve as translational biomarkers of certain aspects of brain health and pathology. Specifically, certain metabolites seen on 1H-MRS promise insight into the metabolic status of astrocytes in vivo.1H-MRS findings in normal brain aging or brain injury. Although it is clear that the risk of brain injury is elevated in older individuals and that outcomes in these patients are significantly worse (Thompson et al., and brain injury. Thus, there is a critical need for further studies aimed at better understanding the effects of aging on TBI pathophysiology.The studies we have discussed here have largely focused on 1H-MRS provides the ability to monitor specific aspects of brain metabolic status in animals and humans as well as across different biological conditions. Taken together, the evidence we have presented suggests that 1H-MRS provides a unique window onto astrocyte metabolic changes in vivo. Given the many essential roles of astrocytes in brain function, we believe that the ability to monitor astrocyte metabolism in vivo will provide important insights into pathological changes in the aged and injured brain—a critical step for developing and translating therapies to improve long-term outcomes in this vulnerable patient population.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.