Selenium is an essential trace and there is a high selenium concentration in the thyroid gland. Selenium deficiency may impair the thyroid function. The aim of this study was to investigate the association between three selenoprotein genes polymorphisms and autoimmune thyroid diseases.We genotyped six single-nucleotide polymorphisms (SNPs), rs6865453 in selenoprotein P gene (SELENOP), rs713041 rs2074451 rs3746165 in glutathione peroxidase 4 gene (GPX4) and rs28665122 and rs7178239 in selenoprotein S gene (SELENOS) by MassARRAY system using the chip-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry technology in 1060 patients with autoimmune thyroid diseases and 938 healthy controls.Major alleles in rs6865453 of SELENOP, rs713041, rs2074451, rs3746165 of GPX4 decreased while the major allele C in rs28665122 of SELENOS increased in AITD patients than in the control. The allele C and genotype CC in rs7178239 of SELENOS showed different trend in GD and HT patients when compared with the control. All the distribution difference showed nonsignificant. Analysis according to clinical features including ophthalmopathy, hypothyroidism and family history came out to be negative either.Our findings suggest non-association between three selenoprotein genes and AITD, conflicting to the positive result in another population. Different selenium nutrition status in different populations may contribute to conflicting results, the contribution of genetic variants in AITD mechanism may be another reason. Selenium is an essential trace element and its distribution in nature varies widely. The soil of central and southern European countries is generally poor in selenium content, resulting in mild regional selenopenia, whereas in most North American regions it is abundant. Severe selenopenia was observed in large areas of central Asia. Selenium is present in the active site of selenoproteins, which are crucial to immune function, inflammation, redox processes and important for thyroid hormone synthesis and metabolism. There is a high selenium concentration in the thyroid gland, and selenium deficiency may impair the thyroid function. Reactive oxygen species (ROS), formed from thyroid hormone metabolism, may cause damage to different cellular structures and trigger tissue inflammation. Selenoproteins, which are powerful antioxidant enzymes, mitigate the effects of oxidative stress by elimination of ROS. In addition, selenoproteins play a vital role in the regulation of human immune system and Se deficiency is accompanied by dysregulation of both cell-mediated immunity and B cell function.Autoimmune thyroid diseases (AITD), mainly including Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), are the most frequent autoimmune disorders. GD is characterized clinically by hyperthyroidism, diffuse goiter and the presence of thyrotropin receptor antibodies (TRAb), while HT is characterized by apoptosis of thyrocytes leading to hypothyroidism and the presence of thyroid peroxidase antibodies (TPOAb) or antibodies against thyroglobulin (TGAb). Autoimmune thyroid disease (AITD) is a multifactorial disease in which autoimmunity against thyroid antigens develops against a particular genetic background facilitated by exposure to environmental factors. Environmental factors include smoking, vitamin D, iodine, selenium and so on. GD and HT also share some but not all susceptible genes.The value of selenium supplementation in autoimmune thyroid disorders had been investigated and most studies confirmed the beneficial effect of selenium supplementation in Hashimoto’s and Graves’s diseases, though some studies showed conflicting results as well –11. ReceThe role for selenium supplementation in the treatment of autoimmune thyroid diseases is still unresolved. Clinic studies provide evidence for a preventive effect of selenium on autoimmune thyroid disease, which may be mediated by the antioxidative and anti-inflammatory properties of selenoproteins, we therefore investigated whether genetic variants in selenoproteins are associated with GD and HT. Among 25 selenoproteins known to date, various functions are characterized for each of them. These include Se transport (selenoprotein P), antioxidant/redox properties (glutathione peroxidases (GPxs), thioredoxin reductases and selenoprotein P) and anti-inflammatory properties (selenoprotein S and GPx4). We chosed to study SNPs rs6865453 in selenoprotein P gene (SELENOP), rs713041 rs2074451 rs3746165 in glutathione peroxidase 4 gene (GPX4), rs28665122 and rs7178239 in selenoprotein S gene (SELENOS) in a Han Chinese population.n = 1998) consisted of 1060 Chinese AITD patients including 701 GD patients, 359 HT patients and 938 healthy unrelated controls. All AITD patients in the present case–control study were recruited from the Department of Endocrinology, Jinshan Hospital Affiliated to Fudan University. The diagnostic criteria for GD were mainly determined by clinical manifestation, laboratory biochemical proof of hyperthyroidism, the presence of diffuse goiter and the positive circulating TSH receptor antibody (TRAb). HT was defined on the basis of enlarged thyroid and the high level of either TPOAb or TgAb, with or without clinical and biochemical hypothyroidism. All healthy controls were unrelated individuals with neither thyroid diseases nor other autoimmune diseases, recruited from the Medical Examination Center of the same hospital. All the subjects, including AITD patients and controls, were Han Chinese and signed the informed consent. Both patients and controls have similar diet habits and individuals with distinct diet style such as vegetarians were excluded. The research project was approved by the Ethics Committee of Jinshan Hospital Affiliated to Fudan University.Our study population , according to the manufacturers’ protocol. Genotyping of SNPs  was performed by MassARRAY system  using the chip-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry technology. This is a well-selected platform by many researchers during studies including SNP genotyping. It has high specificity and sensitivity. Primers were obtained from Sangon Biotech . Briefly, multiplex reaction was designed using Assay Designer software version 3.0 (Sequenom) and was processed following standard protocols for iPLEX chemistry. The reaction products were then cleaned and dispensed onto a Spectro-CHIP bioarray. The chip was scanned using MassARRAY workstation version 3.3, and the resulting spectra were analyzed using the Sequenom TYPER software.We evaluated the Hardy-Weinberg equilibrium of SNPs within our population using the HWE program . Allele As shown in Table The distribution of genotype frequencies for each SNP (rs6865453/rs713041/rs2074451/rs3746165/rs28665122/rs7178239) was in Hardy–Weinberg equilibrium in both the patients and the controls . SePP, encoded by SELENOP gene, is a liver-derived plasma protein and the major selenium containing protein in serum. Serum levels of SePP in humans are considered a biomarker of selenium status in the entire body. Its promoter activity has been shown to be inhibited by cytokines including interleukin 1β, tumor necrosis factor α, interferon γ and transforming growth factor β1 , 16, sugPhospholipid hydroperoxide glutathione peroxidase  is an intracellular selenoprotein, a major antioxidant enzyme, which plays unique roles in the protection of cells against oxidative stress by catalysing reduction of lipid hydroperoxides. GPX4 may also play a role in regulation of leukotriene biosynthesis and cytokine signaling pathways , 26. GPxSelenoprotein S  has been classified as a new endoplasmic reticulum (ER) membrane protein that moves misfolded proteins from the ER to the cytosol and prevents stress responses that activate the inflammatory cascade . It is aOur findings suggested non-association between six SNPs of three selenprotein genes and AITD, non-association between SNPs and clinical genotypes. Our results were conflicted to the result from the Portuguese population study. In that study, the higher allele A in SELENOS rs28665122 had been found to be associated with the HT risk . Differe


The past decade has seen an increasing number of extensive studies devoted to the exploitation of ordered mesoporous carbon (OMC) materials in electrochemistry, notably in the fields of energy and sensing. The present review summarizes the recent achievements made in field of electroanalysis using electrodes modified with such nanomaterials. On the basis of comprehensive tables, the interest in OMC for designing electrochemical sensors is illustrated through the various applications developed to date. They include voltammetric detection after preconcentration, electrocatalysis , electrochemical biosensors, as well as electrochemiluminescence and potentiometric sensors.  Carbon is a traditional electrode material that has been commonly used for over a century. Various kinds of carbon-based electrodes have been exploited for electrochemical purposes , these Ordered mesoporous carbons (OMCs) constitute a subclass of 3D nanostructured porous carbon materials. Since their discovery in 1999 , the earThe present review aims at describing the development of electrochemical sensors and biosensors utilizing OMC materials for their elaboration, with special emphasis to the progress made in the past five years, as the corresponding state-of-the-art up to 2012 has been described in two reviews ,31, and The conventional strategy applied to generate OMC materials involves the use of mesoporous silica  as hard templates ,33. The Later on, efforts have been made to develop cost-effective strategies for mesoporous carbons in order to circumvent the main disadvantage of the hard template route . A more direct method is based on a soft templating approach ,36, invoMore recent developments concern the preparation of OMC with graphitic pore walls , the control of pore size and OMC morphology , as well as functionalization and modification (via either post-synthesis surface treatment or heteroatom doping). More information can be found in selected reviews ,20,34,362 adsorption-desorption experiments . Some typical TEM 3−/4− system .  sensing . HRP was sensing . Various sensing ,244 or m sensing . Copper  sensing . Finallye enzyme . Such im−1) [2+ biosensor , giving well-defined signals recorded by differential pulse voltammetry for the oxidation of adenine and guanine residues, which were directly proportional to dsDNA concentration over a wide range (10–600 µg∙mL−1) . Then, b−1) ,258. An on range ). Its pr strands .1 [1 (AFB1) antigen competing with negatively charged Nafion film for the labelled anti-AFB1 on the mesoporous particles, thus resulting in the dissociation of pAb-MSC-Thi from the sensing interface ;electrocatalytic detections based on either molecular/organometallic/polymeric mediator species deposited onto the OMC surface or catalytic nanoparticles  supported on the OMC host;electrochemical biosensors involving bioelectrocatalytic detection mechanisms  and immunosensors or aptasensors.Some other sensors  are also reported.Ordered mesoporous carbon materials are attractive and increasingly used electrode modifiers to design electrochemical (bio)sensors. Like other mesoporous materials, OMCs are characterized by an extremely-open rigid structure and very high specific surface areas that are particularly suited to the adsorption/immobilization of large amounts of reagents while keeping fast mass transport rates in the functionalized materials. But the main interests of OMCs, notably with respect to the widely-used mesoporous silica materials, are their good conductivity  and their intrinsic electrocatalytic properties. The outstanding performance of OMCs as electrode material for electrochemical sensing and biosensing can be ascribed to the existence of significant edge-plane-like sites and oxygen-rich groups (inducing fast electron transfer kinetics as well as surface reactivity) and the unique regular nanostructure . The main detection schemes are:The main recent trends concern a diversification of the OMC materials used for electrochemical sensing, with significant efforts in using graphitized or partially graphitized OMCs (with enhanced conductivity), nitrogen-doped OMCs , or OMC materials characterized by hierarchical and/or multimodal mesostructures (combining optimized hosting features with accelerated mass transport issues). The type of target analytes and nature of reagents used to modify OMC have also expanded. Finally, most applications were based on particulate OMC films , except for a micro glucose sensor based on direct prototyping mesoporous carbon electrode , and no continuous mesoporous thin film-based electrochemical sensors have been developed to date, even if self-assembly synthesis procedures are established for this kind of materials.


The genomic information of microbes is a major determinant of their phenotypic properties, yet it is largely unknown to what extent ecological associations between different species can be explained by their genome composition. To bridge this gap, this study introduces two new genome-wide pairwise measures of microbe-microbe interaction. The first (genome content similarity index) quantifies similarity in genome composition between two microbes, while the second  summarizes the topology of a protein functional association network built for a given pair of microbes and quantifies the fraction of network edges crossing organismal boundaries. These new indices are then used to predict co-occurrence between reference genomes from two 16S-based ecological datasets, accounting for phylogenetic relatedness of the taxa. Phylogenetic relatedness was found to be a strong predictor of ecological associations between microbes which explains about 10% of variance in co-occurrence data, but genome composition was found to be a strong predictor as well, it explains up to 4% the variance in co-occurrence when all genomic-based indices are used in combination, even after accounting for evolutionary relationships between the species. On their own, the metrics proposed here explain a larger proportion of variance than previously reported more complex methods that rely on metabolic network comparisons. In summary, results of this study indicate that microbial genomes do indeed contain detectable signal of organismal ecology, and the methods described in the paper can be used to improve mechanistic understanding of microbe-microbe interactions. It is still unknown to what extent ecological associations between microbes, as measured by co-occurrence of different taxa in 16S rRNA surveys, can be explained, or predicted, using composition and structure of microbial genomes alone. Here I introduce two new genome-wide, pairwise indices for quantifying the propensity of microbial species to interact with each other. The first measure quantifies similarity in genome composition between two microbes. The second measure summarizes the topology of a protein functional association network built for a given pair of microbes and quantifies the fraction of network edges crossing organismal boundaries. I then study the ability of two newly proposed and two previously reported indices to explain variation in microbial co-occurrence. All four measures are significantly correlated with co-occurrence of microbes even when accounting for evolutionary relationships between the species. One of the newly developed indices outperforms previously proposed ones and explains up to 3.5% of the variance in co-occurrence. In summary, the indices described here are able to detect ecological associations between species using only their genomic information; however, additional methods are needed to provide more reliable genomic tools for microbial ecology. Due to the rise of polymicrobial infections , the potClassical approaches for characterizing microbe-microbe interactions include environmental surveys where the presence or abundance of different species in the community is estimated from the presence or abundances of lineage specific 16S rRNA or other phylogenetic markers ,8. TheseWhile 16S rRNA based approaches do not lead mechanistic understanding of inferred patterns of microbe-microbe interactions, it is known that such interactions are driven by microbial metabolism and physiology: bacteria compete for essential nutrients ,15, formThe most popular currently existing genomics-based approaches for predicting relationships between microbes were developed within “reverse ecology” framework ,20. ThisMetabolic competition and complementarity indices are constructed upon the Kyoto Encyclopedia of Genes and Genomes (KEGG) biochemical pathway annotations, which are available only for some proteins  in any given genome. Additionally, level of KEGG pathway annotation depends heavily on how extensively a given microorganism has been studied. These are two potential limitations to using KEGG microbial comparative genomics in general and for understanding microbial ecology with metabolic indices in particular.An alternative to using KEGG pathways is to assess protein functional associations with genome content-based methods. These methods infer functional associations between proteins using measures derived from a number of distantly related genomes, summarizing information on their composition and structure . Well-knWhile the gene neighbor method or other genome content-based methods do not pinpoint the exact molecular mechanisms of functional associations between the proteins, they have been successfully used to predict novel cellular systems ,29, biosIn this study I aim to address two following points: (1) to develop new genomic indices for quantifying propensity of the microbes to interact with each other using gene neighbor method for predicting functional associations between proteins; (2) to understand to what extent microbe-microbe interactions, represented by microbial co-occurrence, can be explained using genomic information alone. I also evaluated how well newly developed genomics-based methods can predict microbial co-occurrence in comparison to already existing ones.To better understand what fraction of ORFs (Open Reading Frames) across variety of microbial genomes is annotated with KEGG pathways information or using gene neighbor-based predictions I surveyed. 308 microbial genomes from ecological dataset 2 (described later). Results indicate that between 10% and 65% of the ORFs are included in the KEGG pathways data from IMG JGI . On the I designed the “genome content similarity index” to capture the overall similarity of genome content of any two given microbes. The central idea of using this metric is that microbes with more similar genomes might ether exclude each other through competition or co-occur with each other due to habitat filtering. This index was calculated for every relevant pair of genomes as illustrated in I design the “microbe-microbe functional association index” to capture potential for interaction between proteins encoded in genomes of two microbes if there was no boundary between them. This metric was calculated for every relevant pair of genomes as illustrated in The approach of ignoring organismal boundaries and treating a community of microbes as one organism is consistent with the idea of a metagenome of a supra-organism, which is commonly used in microbial ecology . The ideEscherichia coli str. K-12 substr. MG1655, Clostridium tetani E88, or Halobacterium sp. NRC-1, to the other 759 microbial genomes in STRING  and E. coli and C. tetani (bacteria).Uneven representation of bacteria and archaea in STRING is evident from the bimodal distribution of phylogenetic distances between each of the three focal genomes and the rest of the included species  is calculated from Operational Taxonomic Unit (OTU) and sample information in the Greengenes database, which includes 308 genomes.Co-occurrence between microbial species from the human intestinal microbiome as reported in Levy and Borenstein, 2013 , which iThe two ecological datasets described above should represent different conditions for the metrics to predict associations between microbes within different habitats (dataset 1) or to capture concerted patterns of presence or absence of microbes within the same environment (dataset 2).Next, I calculate partial correlations between the indices and co-occurrence accounting for phylogenetic relationships between the species for both ecological datasets . Co-occuCo-occurrence is also correlated positively with the microbe-microbe functional association index in both ecological datasets . The PeaEcological dataset 2 is also used to compare metrics developed here to previously reported metabolic competition and complementarity indices, which are constructed using KEGG pathways. To compare predictive power of different metrics, I perform Mantel regression analysis between co-occurrence as the response variable, and ether phylogenetic distance alone (regression model 1), or one of the four available genomics-based indices, two generated in this study and two existing ones, and phylogenetic distance between organisms (regression models 2 to 5), or all five predictors as the independent variables (regression model 6), in ecological datasets 2 .All of the tested regression models are statistically supported , p-valueRegression model 5, which combines all four genomics-based indices, does not seem to improve over the predictive ability of regression model 2, which includes phylogenetic distance and genome content similarity. Microbe-microbe functional association index is the only other significant predictor in model 6 . The regression model 6 explains 3.81% of variance (in addition to phylogeny) marking the current predictive power of genomics-based techniques in predicting ecological associations between microbes.Firmicutes, found in stool samples. The set of taxa under consideration includes: C. comes, E. rectale, R. intestinalis and E ventriosum  than other combinations of four taxa . Three of the gene sets have assigned metabolic functions . For instance, gene set 1290 includes genes linked to butyrate metabolism. Sporadic phylogenetic distribution of butyric acid producing enzymes, potentially driven by HGT, has been reported in spiracea . Here thC. comes and E. rectale, several genes catalyzing initial steps in the pathways [E. rectale. These findings potentially suggest exchange of intermediates of vitamin B12 biosynthesis between co-occurring E. rectale and C. comes. Overall, the gene sets discovered here constitute a list of promising potential candidates for further functional studies but at this point inspire speculation.Gene set 105 includes genes related to vitamin B12 biosynthesis and while the overall gene family profile in this gene set is similar in co-occurring pathways –63 are mE. ventriosum, related to C. comes, for two gene sets (105 two 589) and concerted gene gain and loss by two co-occurring taxa (gene set 694 and 1290 respectively).Evolutionary processes generating detected patterns are not evaluated here and would require more in-depth phylogenetic analysis. However, a parsimonious assessment of the observed gene presence and absence profiles in the examined four taxa  suggestsIn summary, this study finds phylogenetic relatedness to be strongest predictor of microbial co-occurrence . Genome content similarity index is also identified as a strong predictor (explains 3.5% of the variance), highlighting the importance of habitat filtering in microbial community assembly. Genome content similarity index provides an improvement over more sophisticated metabolic competition index which requires metabolic pathway annotation for each of the genomes and is highly limited for poorly studied microbes. Despite the fact that none-trivial fraction of variance in co-occurrence data is explained by genomic indices, detected explanatory power is rather modest. This highlights the need for the development of methods to improve current genomic techniques to help in understanding the inner workings of microbial communities.Main functionalities and key data required for the analysis carried out in this study have been included within genomics2ecology R package deposited to GitHub . ScriptsThe files species.v10.txt, species.mappings.v10.txt and COG.mappings.v10.txt, which provide information on species and genome annotation, relationships between genomes, genes and gene families, were downloaded from the STRING version 10.0 website . The filThe global network of all the gene families existing in the STRING database was defined as a collection of all nodes (orthologous groups from STRING) and all edges  connecting the nodes. The network is available within the genomics2ecology R package under the reference_network table.Gene neighbor score values were not derived within this study but obtained from COG.links.detailed.v10.txt file from STRING . A critiTo compute microbe-microbe functional association index values edges of reference gene network were treated as unweighted.The genome content similarity index was calculated based on sets of functionally linked genes (putative pathways and complexes). To identify such gene sets the global network of gene families, constructed as described above, was clustered with mcl-14-137 ,68. EdgeGiven that I further used putative protein pathways and complexes to derive the genome content similarity index, it was of interest to understand how the fraction of genes contributing to putative protein pathways and complexes varies between genomes. I calculated this percentage for 308 genomes using clusters from mcl and protein.aliases.v10.txt file from STRING. I also obtained information on the percent of ORFs in KEGG pathways for the same genomes from JGI.This index was calculated as illustrated in This index was calculated for every relevant pair of genomes as illustrated in Network edges, which connect proteins encoded exclusively in two different genomes  from thData from the Greengens database were handled as follows: one representative sequence which had “isolation source”, “authors” and “title” annotation in its arb record was selected for each of the 97% OTUs from Greengens (97_otu_map.txt file from gg_13_5_otus.tar.gz archive). Sequences shorter than 900 and 1,200 nucleotides in the case of Archaea and Bacteria, respectively, were removed. The rest of the sequences were searched with 16S rRNAs from STRING genomes using blastn. Weak blast hits with less than 95% identity or covering less than 85% of the query sequence length were ignored. 16S rRNAs from STRING genomes and corresponding Greengenes sequence which produces strong blast hits were collected. Collected sequences were aligned to each other using the bacterial 16S model and clustered using complete linkage clustering based on sequence identity with tools available on the RDP website, 97% identity cut-off was used for clustering. One Greengenes OTU and one STRING genome were selected to represent each cluster that contained both STRING genome and Greengenes OTU. In total 1119 STRING genomes were assigned to Greengens OTU this way. R code is in get_data_ds1.R.txt on GitHub .In order to establish correspondence between 154 genomes from   as well as co-occurrence measures using the Jaccard similarity coefficient  for human gut microbiome data are provided as part of supporting information for  and wereGenome content similarity and microbe-microbe functional association indices were calculated for every relevant pair of genomes  Percent of the ORFs included in a KEGG pathways or (B) putative pathways predicted with MCL in 308 genomes from STRING from ecological dataset 1 which is introduced later in the paper.(PDF)Click here for additional data file.S2 FigGraphical representation of statistical analysis workflow.(PDF)Click here for additional data file.


Vulpes lagopus) is a circumpolar species inhabiting all accessible Arctic tundra habitats. The species forms a panmictic population over areas connected by sea ice, but recently, kin clustering and population differentiation were detected even in regions where sea ice was present. The purpose of this study was to examine the genetic structure of a population in the High Arctic using a robust panel of highly polymorphic microsatellites.The arctic fox  revealed the presence of genetic subdivisions. Overall, the sPCA revealed two spatially distinct genetic clusters corresponding to the northern and southern parts of the study area, plus another subdivision within each of these two clusters. The north–south genetic differentiation partly matched the distribution of a snow goose colony, which could reflect a preference for settling into familiar ecological environments. Secondary clusters may result from higher-order social structures (neighbourhoods) that use landscape features to delimit their borders. The cryptic genetic subdivisions found in our population may highlight ecological processes deserving further investigations in arctic foxes at larger, regional spatial scales.The online version of this article (10.1186/s13104-017-3002-1) contains supplementary material, which is available to authorized users. Vulpes lagopus has a circumpolar distribution and inhabits all accessible Arctic tundra habitats . Fourteen of these were resighted as adults and only six bred in the study area. Although not all pups in the study area were tagged, this suggests a lack of natal philopatry .This study confirms the absence of an isolation-by-distance pattern but reveals cryptic genetic subdivisions in our population. As reported in other studies , 31, usiOne limitation of our study is that the study area may have been too small to detect a clear pattern of isolation-by-distance for a mobile species. Considering the relatively large distances between close relatives reported in Svalbard , foxes iAdditional file 1: Figure S1. Barplot of spatial principal component analysis (sPCA) eigenvalues and screeplot displaying each eigenvalue according to its variance and spatial autocorrelation (Moran’s I) components. Graphical results of the sPCA analysis of arctic foxes (n = 203) from Bylot Island, Nunavut, Canada.Additional file 2: Figure S2. Bayesian genetic structure analysis conducted with the software STRUCTURE. Graphical results of the Bayesian genetic structure analysis of arctic foxes (n = 203) from Bylot Island, Nunavut, Canada conducted with the software STRUCTURE.


Oncolytic virotherapy represents a novel therapeutic strategy in the treatment of gastrointestinal malignancies. Oncolytic viruses, including genetically engineered and naturally occurring viruses, can selectively replicate in and induce tumor cell apoptosis without harming normal tissues, thus offering a promising tool in the armamentarium for cancer therapy. While this approach has garnered much interest over the past several decades, there has not been significant headway across various tumor types. The recent approval of talimogene laherparepvec, a second-generation oncolytic herpes simplex virus type-1, for the treatment of metastatic melanoma, confirms the therapeutic potential of oncolytic viral therapy. Herein, we will highlight and review the role of oncolytic viral therapy in gastrointestinal malignancies while discussing its limitations and potential alternative mechanisms to improve its treatment efficacy. Viral therapies represent one of many potential immunotherapeutic strategies in the treatment of gastrointestinal cancers. Historical evidence has shown tumor regression or remission of several advanced malignancies after the inoculation of naturally occurring viruses, including chicken pox, measles or hepatitis viral infections . These eThe anti-cancer activities from oncolytic viruses are a result from the direct lysis of cancer cells by the virus, and by cytotoxicity to cancer and stromal cells by activated innate and tumor specific immune cells ,4. “ImmuThe ability of oncolytic viral therapy to induce tumor cell apoptosis and stimulate an anti-tumor immune response has resulted in its interest as a potential treatment across various tumor types, including in the treatment of gastrointestinal malignancies, and will be reviewed in detail below .RAS; thus activated RAS signaling contributes to its tumor-specific viral replication and oncolytic properties [Respiratory enteric orphan virus (Reovirus) is a double-stranded RNA virus that occurs naturally in humans and can infect the gastrointestinal system and respiratory tract. Its infection is considered minor in humans, typically causing symptoms in early childhood and adolescent adults, where Reovirus exhibits cytopathic effects and oncolytic potential in cancer cells. Reovirus is dependent upon the cellular activity of operties ,15,16,17RAS signaling pathway with a tolerable safety profile [Early preclinical studies with Reovirus demonstrated its ability to infect, replicate and induce cancer cell specific apoptosis with no activity in normal tissue across several gastrointestinal malignancies ,19,20. R profile ,22,23,24 profile ,26.RAS mutations in colorectal and pancreatic cancer [RAS mutated pancreatic cancer cell lines [Given the ubiquitous nature of c cancer ,28, Reolll lines ,30. In eKRAS mutant colorectal cancer that received the combination of Reolysin with FOLFIRI (5-Fluorouracil (5-FU) and Irinotecan) [A phase I dose escalation study was conducted in patients with treatment refractory notecan) . The comKRAS mutations. Interestingly, increased levels in immunomodulating biomarkers (including Interleukin (IL)-6, Vascular Endothelial Growth Factor (VEGF), and regulatory T cells) were seen in patients that received Reolysin. These results are consistent with preclinical studies that suggest Reolysin may promote and enhance immune suppression in a pre-existing immunosuppressive environment that is seen in pancreatic adenocarcinoma [In pancreatic adenocarcinoma, several clinical trials with Reolysin added to chemotherapy were conducted. Noonan et al. reported the results of a randomized phase II trial where 73 treatment-naïve patients with metastatic pancreatic adenocarcinoma were randomized to receive carboplatin/paclitaxel alone or in combination with Reolysin . While tarcinoma . A seconarcinoma ,34.Overall, the lack of demonstrable clinical activity with Reolysin across a spectrum of gastrointestinal malignancies was very disappointing, and this agent is a very unlikely candidate for further development in this space.p53 alterations, but not in adjacent normal cells. Its first indication as a therapeutic option came in 2005 after the approval of H101, an oncolytic adenovirus similar to ONYX-015 for the treatment of nasopharyngeal cancer or esophageal cancer in China [Adenoviruses (members of the family Adenoviridae) are non-enveloped, linear double-stranded DNA viruses that have shown oncolytic activity across a large spectrum of tumor types. It was also the first oncolytic virus to be evaluated in a clinical trial for the treatment of pancreatic adenocarcinoma. ONYX-015 is an E1B 55-kDA region deleted adenovirus that preferentially replicates in cancer cells with in China . Based oin China . The treIn attempts to further enhance anti-tumor activity with the clinical application of adenovirus, genetic modifications have been employed. One strategy includes designing viral therapies that target tissue-specific promoters to control viral gene selective expression in tumor specific cells. For example, GD55 was developed as a genetically modified oncolytic adenovirus designed for the treatment of hepatocellular carcinoma (HCC) that targets GOLPH2, a Golgi membrane glycoprotein GP73 that is specific for this disease . In precGM−CSF), for the treatment of advanced, unresectable melanoma.Oncolytic HSV vectors have been investigated widely in various malignancies, including gastrointestinal malignancies, despite a primary interest in their therapeutic role in neurological malignancies given their neurotropic nature. The therapeutic potential has been validated with the recent Food and Drug Adminstration approval of Talimogene laherparepvec . This study was the first to demonstrate that local intratumoral injection provides local tumor growth suppression and through a presumed abscopal systemic effect. A more recent phase I study with intratumoral Oncovex GM-CSF injection in unresectable pancreatic cancer  has been completed and will provide further insight regarding a clinical role for this agent. Additionally, an ongoing phase I trial is examining the abscopal effect of radiation therapy with T-Vec in other solid tumor malignancies  by examining the combination of T-Vec with or without radiotherapy . Several early phase studies have been completed in gastrointestinal malignancies evaluating the role of HSV-1 as a potential therapeutic option. In Japan, a phase I study was conducted where patients with unresectable pancreatic adenocarcinoma received intratumoral injections with HF-10, an unadulterated naturally occurring oncolytic HSV. No treatment related adverse effects were observed and four patients experienced a clinical benefit  [T-Vec is a genetically modified double mutated HSV-1 oncolytic virus with deletions in the γ34.5 and α47 genes and the insertion of human granulocyte-macrophage colony-stimulating factor (GM-CSF) gene into the deleted γ34.5 loci. The deletion in the γ34.5 genes allows for selective replication within cancer cells while leaving normal tissue unharmed ,40,41. Odisease) . To furtMxA and OAS and aberrant activation of the JAK/STAT signaling pathway were observed; these findings may potentially limit the ability for the virus to adequately infect cancer cells [VSV is a RNA virus that is non-cell cycle dependent, resulting in rapid uptake by cells. The Indiana strain of VSV and its recombinant derivatives have shown promising oncolytic activity in various malignancies ,45. It her cells ,47.VSV, however, is sensitive to the anti-viral effects of interferon (IFN)-α and β produced by infected cells, which limit its potential replication and propagation to neighboring cells. Thus, genetically modified oncolytic VSVs that express human interferon-β (VSV-hIFNβ) are in development in an attempt to induce high levels of IFN and protect the neighboring normal cells while retaining its cytotoxicity effect against tumor cells .In early preclinical studies conducted in hepatocellular carcinoma and colorectal tumor xenografts in mice models, IFN-inducing VSVs have shown significant oncolytic activity with extensive tumor necrosis and prolongation of survival ,50. BaseCurrent work to modulate IFN signaling through genetic modification or in combination with small molecule inhibitors of the cellular signaling pathway may enhance the oncolytic activity of VSV. A phase I study  is examining the safety and tolerability from intratumoral administration of genetically modified VSV that expresses IFN in treatment refractory solid tumors.Vaccinia virus (VV) is a replication competent virus and is a member of the poxvirus family that has demonstrated promising anti-tumor activity, including in a number of gastrointestinal malignancies. It is highly immunogenic and produces a strong cytotoxic T cell and innate immune response . In coloVaccinia (GLV-1h68) has also shown promising activity as a single agent or in combination with gemcitabine chemotherapy in pancreatic adenocarcinoma, where vaccinia has shown the ability to infect, replicate and induce oncolysis in pancreatic cancer cell lines . GLV-1h5Another oncolytic VV under clinical investigation is JX-594, a genetically modified VV strain with the deletion of the thymidine kinase gene that enhances preferential replication and lysis of proliferating cancer cells . Its abiThe rationale for oncolytic virotherapy as a viable therapeutic option for gastrointestinal malignancies remains exciting, however many limitations must be overcome. An increased understanding of the regulation of the anti-tumor response is needed to allow for the development of more rational clinical treatment strategies in order to improve on its efficacy.A significant barrier for clinical application is the immunologic tolerance towards cancer specific antigens. Most tumor associated antigens are self-antigens and thus are weakly immunogenic. Additionally, the immunosuppressive tumor microenvironment suppresses the activity of tumor infiltrating lymphocytes, thus blunting anti-tumor immunogenic activity . TherefoThe mode of administration of the specific oncolytic virus also influences the effectiveness of its anti-tumor activity. While intravenous administration may be more practical, it is limited by hepatic and splenic sequestration or pre-existing serum anti-viral antibodies, which may result in insufficient viral particle delivery. Studies evaluating strategies to improve oncolytic virus (OV) distribution include modification of the viral coat proteins to evade antibody recognition and the utilization of mesenchymal stem cell carriers to increase the target delivery of the OV. Physical barriers can also influence the effectiveness of virotherapy. The stroma creates a complex microenvironment that not only serves as a physical barrier to prevent effective penetration of oncolytic viruses, but also provides an immunosuppressive environment that blunts the innate anti-tumor immune response ,68,69,70Despite the many promising advances, including recent FDA approval of T-vec in metastatic melanoma, the field of oncolytic virotherapy remains largely investigational in gastrointestinal malignancies. Early preclinical activity has not translated to meaningful clinical activity in larger randomized studies. An increased understanding in mechanisms of immunologic tolerance and treatment resistance has provided a stronger rationale that has spurred further clinical investigation. Through applications of innovative genetic modifications and combinatory strategies with novel immunotherapeutic agents including checkpoint inhibitors  or biologic therapies  inhibitors), oncolytic virotherapy will hopefully find a future role in the treatment of gastrointestinal cancers.


Relative to HCs, patients with OCD had lower fractional anisotropy (FA) values in the corpus callosum (CC), left anterior corona radiata (ACR), left superior corona radiata (SCR) and left superior longitudinal fasciculus (SLF), and higher radial diffusivity in the genu and body of CC. Among the TBSS de-projected region of interest results, compared with HCs, patients with OCD showed lower of the mean FA values of fiber bundles passing though the SLF, and shorter lengths of ACR, SCR and CC. In conclusion, this study provides novel evidence of widespread microstructural alterations in OCD and suggests that OCD may involve abnormalities affecting a broader network of regions than commonly believed.Obsessive-compulsive disorder (OCD) is a complex and severe psychiatric disorder whose pathogenesis is not fully understood. Recent studies have shown white matter (WM) alterations in adults with OCD, but the results have been inconsistent. The present study investigated WM structure in OCD patients with the hypothesis that large-scale brain networks may be disrupted in OCD. A total of 24 patients with OCD and 23 healthy controls (HCs) were scanned with diffusion tensor imaging. A tract-based spatial statistics (TBSS) approach was used to detect differences across the whole brain in patients with OCD vs HCs;  Changes in RD appears to be associated with dys- or demyelination (cell membrane and cytoskeleton) in WM, whereas variations in AD may be more specific to axonal degeneration (volume and organization).17An increasing number of studies using diffusion tensor imaging (DTI) are suggesting that the OCD brain has WM alterations apart from previously described alterations in gray matter regions.18 Studies of OCD using whole-brain and selected region of interest (ROI) analyses have revealed variable FA values in the anterior cingulate, internal capsule, bilateral semioval center extending to medial frontal WM, subinsular WM and corpus callosum (CC), as well as in WM in parietal,20 left lingual gyrus and occipital lobe20 regions. However, these prior results are rather heterogeneous. For example, FA values in OCD brains have been reported to be both increased and decreased, in some cases in the same brain areas.26 The heterogeneous findings might be due to limitations of voxel-based morphometry methods, which do not yield accurate inter-subject image registration.14DTI based on voxel based morphometry (VBM) can be used to investigate WM abnormalities within as well as beyond the cortico-striatal circuits classically associated with OCD.27 This feature makes TBSS highly sensitive to changes in microstructure within the major WM fiber pathways. The only three studies to have used TBSS to analyze DTI in OCD adults28 all found significantly reduced FA values, relative to controls, in the body of the CC. However, comprehensive MD, AD, and RD data reporting from these studies was lacking.Tract-based spatial statistics (TBSS) is an analytic method developed specifically for DTI data wherein analysis is restricted to center areas of major white-brain volumes.post hoc tractography analysis based on TBSS results by probabilistic tracking; they showed CC connections to the bilateral dorsal medial frontal cortex,22 dorsolateral prefrontal cortex22 and parietal regions as well as connections extending down to superior temporal regions,14 but neither reported further analyses on these commissural fiber tracts, such as the FA values or lengths.Importantly, TBSS analysis minimizes the potential misalignment problems of other voxel-based whole-brain analysis methods by producing a WM ‘skeleton' restricted to the center of major WM tracts, and mapping diffusion values from each individual participant directly onto this standard skeleton for group comparisons. However, TBSS analysis fails to reveal commissural connections to lateral cerebral areas, probably because of massive projection and long association fibers being situated lateral to the CC, beyond the reach of reconstruction tracking. Previous DTI studies have focused exclusively on hypothesis-driven ROIs or broad exploratory TBSS analysis; both approaches are important and the two are complementary. Only two studies conducted post hoc ROI tractography, we also examined anatomical connectivity via association and commissural fibers, which have not been investigated specifically previously.In the present study, we examined WM microstructure in patients with OCD compared with age-, handedness- and education-matched healthy control (HC) participants. Utilizing TBSS, we examined four diffusivity measures  within major WM pathways to explore whether abnormalities of large-scale brain systems were detectable in the brains of patients with OCD. Using 29 and general intelligence of all the participants was assessed with the Wechlser Abbreviated Scale of Intelligence.30 Final diagnoses were determined by the consensus of psychiatrists. In the 4 weeks preceding DTI, 11 OCD patients had been free of any psychotropic medication and 13 were taking antidepressants .A group of 24 OCD outpatients  was recr30A group of 23 age-, sex-, intelligence quotient- and handedness-matched HCs  from theThe study protocol was designed in accordance with the guidelines outlined in the Declaration of Helsinki and was approved by the Ethics Committee of the Second Xiangya Hospital of Central South University. All the subjects were made aware of the purpose of the study and provided written informed consent.3). A single-shot echo-planar imaging sequence was applied for DTI assessment . Each scan produced 55 slices  and 76 contiguous axial slices ). Both the sequences were reviewed by an experienced radiologist to exclude clinical abnormalities. All the participants were asked to remain quiet during scanning. Ear plugs and foam pads were used to minimize noise exposure and head movements.All the participants were subjected to magnetic resonance imaging in a Siemens Magnetom Skyra 3.0-T scanner . A T1-weighted sagittal isotropic magnetization-prepared rapid acquisition gradient-echo sequence was obtained for each subject with a standard head coil . Eddy Current Correction was performed by affine registration to a b0 reference volume. A diffusion tensor model was fitted to each voxel, and then used to generate FA, MD, AD and RD values. The diffusion-weighted images were registration to the BET applied structural (T1-weighted) images. TBSS was used to carry out voxel-wise analysis for relevant diffusivity measures in WM skeleton voxels (FA >0.2).Analyses of diffusion-weighted images were done in FMRIB'S Software Library . Finally, the FA values were extracted from the significant clusters via the ‘fslmeants' command.The differences in FA, MD, AD and RD values between the OCD and HC groups, and between medicated and treatment-naive OCD subgroups, were detected by voxel-wise independent two-sample http://www.trackvis.org/), and ROI drawing and visualization of the results were performed in TrackVIS software (http://www.trackvis.org/). The FACT approach was used to reconstruct fiber paths. Fiber propagation was terminated when fiber orientation changed by an angle ⩾35°, and an image mask based on the B0 image was applied to restrict tracking to biologically plausible results.Reconstruction and fiber tracking analysis of the DTI data were performed in Diffusion Toolkit software  between the two groups in the TBSS analysis were de-projected in native space by the back-projection procedure (tbss_deproject script) in TBSS .Group differences on demographic and psychometric characteristics were compared with the chi-square test for categorical variables and independent-sample The characteristics of the OCD and HC groups are summarized in TBSS analysis revealed that the OCD group exhibited three clusters with significantly lower FA values than those of the HC group, mainly in the regions of the left superior longitudinal fasciculus (SLF), left anterior corona radiata (ACR), left superior corona radiata (SCR) and CC , but no significant group differences were found for the length of these fiber bundles . Notably, FA values of fiber bundles passing through the ACR, SCR and CC  did not differ between the two groups , but the lengths of these fiber bundles were significantly shorter in the OCD group (lengthOCD=48.67±5.15) than in the HC group . No significant group differences were found for tract numbers, voxel numbers or volumes of fiber bundles passing through the ROIs  at 0.737 when comparing differences between HCs (N=23) and OCD patients (N=24) with 80% power at a 5% significance level . The actual Cohen's d values obtained for between-group differences ranged from 0.853 to 1.169, all of which exceeded the predicted detectable effect size, indicating that the sample size was acceptable.Power analysis predicted a detectable effect size 37 support such speculation. Hence, our findings suggest possible demyelination in the commissural fibers of patients with OCD. Previous TBSS studies, whole brain or of the CC as an ROI, have often not revealed commissural connections to lateral cerebral areas.28 In the current study, we found shorter corticopetal CC fiber lengths in the OCD group, compared with those in HCs, but commissural fiber tract FA values did not differ significantly between the two groups. These shorter than typical fiber bundles might constrain or augment local information processing within these regions, with reduced transmission to other larger areas. In this context, compromised WM integrity and abnormally short fiber tracts may result in hypo-transmission of information, particularly from the neocortex to the paleocortex. This altered connectivity could facilitate neuronal integration between limbic and motor systems, while also providing additional opportunities for fine-tuning of striatal processing through feedback from areas in the cortex and mesencephalon.38 Such changes might underlie, at least in part, the cognitive dysfunction and abnormal behavior characteristic of OCD. If so, the brain abnormalities underlying OCD symptoms may be reflected throughout a broad network .Combining TBSS and fiber tractography methods, we found FA alterations and changes of lengths in the CC, ACR and SCR of OCD brains, relative to HC brains, without volume or voxels differences. Previously, FA reductions have been attributed to changes in membrane permeability or the presence of non-axonal components, such as other cells, vessels or interstitial fluid.39 Impaired attention and spatial working memory, which have been documented in OCD patients,4 may be consequent to disturbances in SLF connectivity. Gariboto et al.4 found evidence of involvement of occipital and parietal regions in the clinical phenomenology of OCD, including distressful, intrusive imagery. In their recent review, Piras et al.10 highlighted that OCD-related brain abnormalities are not limited to the affective orbitofronto–striatal circuitry, but rather extend to dorsolateral prefronto–striatal executive cirtcuitry as well as to regions in the parietal, temporal and occipital lobes.36 Our findings confirm the involvement of executive circuit regions in OCD and further suggest the presence of multiple WM tract abnormalities in the brains of adults with OCD. However, as voxel size of left SLF was relatively small, the significance of their representations still needs to be further confirmed, even the findings in SLF were statistically significant.The present results also showed reduced FA values in the SLF of OCD brains, relative to HC brains. The SLF encompasses a heterogeneous set of bi-directional fibers connecting parieto-temporal association areas with prefrontal cortex areas.28 inferior and superior longitudinal fasciculus,40 cingulum bundle41 and internal capsule.22 Meanwhile voxel-based morphometry/ROI-based studies of OCD have reported mostly changes in the striatum; thalamus; and frontal, parietal, temporal and cingulate cortices.10 In this study, we did not observe any evidence of WM deficits in the frontal, parietal, temporal or occipital lobes. These inconsistencies between studies might be due to the fact that TBSS analysis assesses only the most common fiber pathways across individuals, typically excluding fibers penetrating the cortical mantle. Thus, with the TBSS approach, sensitivity in regions near the gray matter/WM boundaries may be limited. Alternatively, structurally compromised WM may be reflected in low FA values, while hyper-connected regions—perhaps produced in compensation for network hypo-connectivity—may yield increased FA values in some ROI studies. If so, such compensatory changes may become undetectable with the strict FWE correction in TBSS analyses, leaving only significant deficits.Previous TBSS-based studies of OCD have yielded evidence of abnormalities in the CC,This study had several limitations. First, we did not collect behavioral data, preventing us from relating WM changes directly to clinical behavior. Task-related neuroimaging studies are needed to examine how WM connectivity relates to cognitive function in OCD patients. Second, our OCD group included both medicated and treatment-naive participants. There were no significant differences observed between these two subgroups. However, given the relatively small size of the sample and the variety of medication types and doses among the medicated patients, it remains unclear whether DTI results in OCD patients are affected by pharmacological treatment. Finally, we did not account for age of OCD onset in our recruitment or analysis. It is possible that WM alterations may evolve over time in relation to OCD onset.In conclusion, the present study showed widespread microstructural alterations in the brains of patients diagnosed with OCD, predominantly in the CC and SLF, areas which may have important roles in OCD pathogenesis. Our findings suggest that OCD may involve abnormalities affecting a broader network of regions than commonly believed, that is, beyond the frontal–striatal–thalamic circuitry. Longitudinal studies are needed to elucidate the underlying mechanisms of WM changes in patients with OCD.


Malignant mucinous neoplasms of the appendix is an infrequently encountered entity. Extra-appendiceal spread of these tumor is one of the commonest etiology of pseudomyxoma peritonei, which demands a hightened vigilance in their early diagnosis. Although low-grade appendiceal mucinous neoplasms (LAMNs) largely stay confined to the appendix, but they can spread to the peritoneum as pseudomyxoma peritonei leading to an unpredictable outcome. Due to the rare occurrence of low-grade appendiceal neoplasm only tenuous and limited information is present in the medical literature. We report a case of LAMN with pseudomyxoma peritonei in a 45-year-old male, who presented with the complaints of abdominal distension associated with abdominal pain and constipation. Clinical examinations and computed tomography (CT) scan were suggestive of pseudomyxoma peritonei. Peroperative findings and histopathological examination rendered a conclusive diagnosis of low-grade appendiceal neoplasm.How to cite this article: Qadri S, Alam K, Alam F, Maheshwari V. Low Grade Appendiceal Muci-nous Neoplasm with Pseudomyxoma Peritonei: An Enigma for Pathologist. Euroasian J Hepato-Gastroenterol 2014;4(2):113-116. We hereby report this uncommon case of LAMN as it bespeak the potential of this tumor to spread to the peritoneal cavity causing pseudomyxoma peritonei that would lead to a disastrous clinical outcome.A 45-year-old male patient not known to have any previous medical illnesses, reported to the surgery outpatient department with a clinical history of severe pain in right lower abdomen, with abdominal distension and constipation since 2 days. The patient was febrile and also had history of nausea and vomiting. On clinical examination, tenderness and guarding were observed at McBurney’s point.Routine blood tests showed leukocytosis and raised erythrocyte sedimentation rate (ESR), while other hematological parameters were within normal limits. Chest X-ray were unremarkable while on plain X-rays abdomen (erect and supine), dilated intestinal loops were seen. Computed tomography (CT) scan revealed scalloping of visceral surface and hyperdense mucinous ascites filling the peritoneal cavity, bowel loops showing external compression by peritoneal implants, appendix was not visualized .Emergency laparotomy was done through a midline incision. Peroperative examination revealed, ruptured cystic mass (appendix) with adherent mucus material, attached to the dilated, tensed and inflamed cecum in the right iliac fossa. The small bowel appeared normal except for the mild dilatation of distal 8 cm of the terminal ileum. Pools of mucin were seen within the peritoneal fat and on the serosal surface of the viscera. No gross abnormality was visualized in the retroperitoneal organs, surgical debulking including appendectomy with partial resection of the attached cecum and extensive removal of gelatinous material was taken up. Subsequently, the peritoneal washing with normal saline was done, but chemotherapy was not given.All the tissues removed along with the gelatinous material were submitted for histopathological examination. Gross examination revealed dilatation of the cecal area, measuring 10 × 9 × 9 cm with very scant amount of mucin in the lumen. The appendix was received as a small tubular structure of 2 × 1 cm attached to a ruptured distorted mass measuring 7 × 6 × 1 cm  with abuOn microscopic examination, normal histomor-phological characteristics of an appendix were disturbed with the loss of lymphoid follicles in the submucosa  and replThe patient was discharged after a week stay in hospital in a satisfactory condition.5 with an approximately 1% reported prevalence of LAMN.1 Classification of appendiceal mucinous neoplasms has been a difficult job because of several different reasons. Cyto-logically, LAMN usually behave as a benign neoplasm, however, as soon as the mucin or adenomatous epithelium escapes the appendiceal confines, a significant rise in morbidity and mortality is noticed even the cytology still remains of low-grade tumor. World Health Organization (WHO) classify appendiceal mucinous neoplasm6 in following groups:Tumors of the appendix are rare clinical entities comprising of less than 2% of all appendectomies Adenocarcinoma Low-grade appendiceal mucinous neoplasm Mucinous adenocarcinoma Signet ring cell carcinoma Undifferentiated carcinoma7 Subsequently, they categorized mucinous appendiceal neoplasm into following four groups:Pai et al (2009) evaluated 116 cases of appendiceal mucinous neoplasms and derived a succinct set of histologic features with important prognostic implication. Mucinous (cyst) adenoma: Low-grade mucinous neoplasm confined to the appendix. Low-grade mucinous neoplasms with low risk of recurrence (LG-LR): Features identical to mucinous adenoma, with the added component of acellular extra appendiceal mucin. Low-grade mucinous neoplasms with high risk of recurrence (LG-HR): It is similar to LG-LR, but the extra appendiceal mucin contained neoplastic epithelium. Mucinous adenocarcinoma: It shows presence of invasion; usually, but not always they exhibit high grade cytology and a complex architecture.8 Occasionally, these tumors may present with intestinal obstruction, intussusception, gastrointestinal bleeding and extrinsic ureteral compression. Rupture or perforation of the appendiceal wall, leads to dissemination of septic or neoplastic contents, resulting in localized or diffuse peritonitis or pseudomyxoma peritonei respectively. Pseudomyxoma peritonei is a pathologic entity having a variable clinical consequences; if this condition is caused by a high-grade appendiceal tumors, it is usually associated with a worse prognosis.9Approximately, 25% of appendiceal mucinous neoplasms are asymptomatic and found incidentally either on abdominal imaging or during surgery.2 It is speculated that the mucin may spread to the peritoneal cavity causing pseudomyxoma peritonei, either by mucus tracking throughout the dilated, thinned appendiceal wall or through the appendiceal diverticulum. However the actual mechanism by which mucin traverses the app-endiceal wall in benign or low-grade neoplasm is still not fully illustrated, especially in cases in which definite invasion of the appendiceal wall is not observed.10 In our case, it occurred through ruptured thin walled appendix.Pseudomyxoma peritonei is distinctly defined entity characterized by the presence of intraperitoneal mucin, with or without associated mucin-producing epithelium. Not infrequently this condition is accompanied by fibrosis and granulation tissue formation.Due to frequent association of ovarian neoplasm causing pseudomyxoma peritonei, it should be kept in mind that, in all the cases of female with appendiceal mucinous neoplasms, the ovaries should be meticulously examined, similarly in all cases of ovarian mucinous neoplasms, the appendix should be looked for. Various surgical procedures can be implemented in managing mucinous appendiceal neoplasm complicated with pseudomyxoma peritonei, such as simple appendectomy, appendectomy with partial resection of the cecum, ileocecal resection and right hemicolectomy, performed either by open or laparoscopic approach. The histologic grade of peritoneal disease is considered as extremely important criteria. Patients with low-grade tumors may benefit from aggressive treatment that combines chemotherapy along with cytoreductive surgery, whereas high-grade tumor probably has a better response with systemic chemotherapy that includes peritoneal space washing with heated mitomycin solution or postoperative infusion of fluorouracil. Pseudomyxoma peritonei with scant, low-grade epithelium on microscopy has a good prognosis, while pseudomyxoma peritonei with abundant, high-grade (carcinomatous) epithelium has been found to have a bad prognostic outcome. This case emphasizes the existence of a distinct subset of appendiceal mucinous tumor that lacks usual forms of destructive invasion, but has a propensity to spread to the peritoneal cavity, viscera and ovaries progressing to the clinical syndrome known as pseudo-myxoma peritonei. LAMN with pseudomyxoma peritonei can result in the demise of the patient, despite the bland histology of the mucinous epithelium. Grading of epithelium in pseudomyxoma/peritoneal mucinosis is important for management and prognosis. Clear communication between the pathologists and clinicians and their collaborative effort is therefore a prerequisite in order to reach to a confirmatory diagnosis.


Basal airway epithelial cells (AEC) constitute stem/progenitor cells within the central airways and respond to mucosal injury in an ordered sequence of spreading, migration, proliferation, and differentiation to needed cell types. However, dynamic gene transcription in the early events after mucosal injury has not been studied in AEC. We examined gene expression using microarrays following mechanical injury (MI) in primary human AEC grown in submersion culture to generate basal cells and in the air-liquid interface to generate differentiated AEC (dAEC) that include goblet and ciliated cells. A select group of ~150 genes was in differential expression (DE) within 2–24 hr after MI, and enrichment analysis of these genes showed over-representation of functional categories related to inflammatory cytokines and chemokines. Network-based gene prioritization and network reconstruction using the PINTA heat kernel diffusion algorithm demonstrated highly connected networks that were richer in differentiated AEC compared to basal cells. Similar experiments done in basal AEC collected from asthmatic donor lungs demonstrated substantial changes in DE genes and functional categories related to inflammation compared to basal AEC from normal donors. In dAEC, similar but more modest differences were observed. We demonstrate that the AEC transcription signature after MI identifies genes and pathways that are important to the initiation and perpetuation of airway mucosal inflammation. Gene expression occurs quickly after injury and is more profound in differentiated AEC, and is altered in AEC from asthmatic airways. Our data suggest that the early response to injury is substantially different in asthmatic airways, particularly in basal airway epithelial cells. The epithelium lining human lung airways serves as a primary defense interface against particulates, inhaled pollutants, pathogens, and xenobiotics. Basal airway epithelial cells (AEC) comprise approximately 30 percent of the epithelium in the major airways. These cells operate as the progenitors for ciliated and goblet columnar cells within the airway –3, especAirways diseases, including asthma, substantially alter the epithelial response to injury , 10. Ordin vivo by repeated sampling of the same location in an airway via bronchoscopy, and demonstrated a distinctive ‘repair transcriptome’ at seven days that was dominated by cell cycle, signal transduction, metabolism, and transport genes. The transcriptome reverted more closely to a resting expression profile by the fourteenth day after the injury. However, these time points do not characterize the immediate (within hours) changes in the transcriptome after injury.Despite the importance of understanding how an asthmatic epithelium releases inflammatory mediators in response to environmental perturbation, little is known about the activation of gene networks in the first hours after injury. These networks of the early-responder genes are essential for shaping the immediate epithelial cell response. Heguy et al.  examinedTo address the questions related to the early events that occur after injury, we examined epithelial cell expression in a well-established mechanical injury model in both normal and asthmatic AEC grown under two distinct conditions: (1) in submersion culture with uniformly basal AEC phenotype, and (2) in air-liquid interface (ALI) culture that generates a more differentiated AEC (dAEC) phenotype seen in a homeostatic airway.Our data demonstrated the expression of pro-inflammatory cytokines and chemokines genes within hours of injury in normal but not asthmatic cells. Clear differences were also seen between the two cell phenotypes with greater expression of inflammatory cytokines after injury noted in differentiated AEC. Furthermore, the response to MI of asthmatic AEC in either culture environment responded differently compared to normal AEC and expressed genes that were related to cell cycle and proliferation, programmed cell death, and antimicrobial activity as opposed to cytokines and chemokines. These data suggest that epithelial cells can within hours express genes that encode inflammatory mediators and that these may differ qualitatively in asthmatic versus normal epithelial cells.Primary human tracheobronchial epithelial cells were collected from lungs provided by the Gift of Hope Organ & Tissue Donor Network, Itasca, IL, through the generous gift of donor families. Donors had previously provided consent for the use of discarded tissue in research to the Gift of Hope. These lungs had been collected for use in lung transplantation but rejected for use, and were considered to be exempt from IRB regulation by the University of Chicago IRB . In consLungs were collected from two groups of donors: those without known lung disease, and those with a history of chronic asthma. For the latter group, no specific information generally was available concerning disease severity, duration, or treatment. No other clinical or identifying information provided by the Gift of Hope was used or is disclosed in this study.5 cells onto collagen IV-coated, 12.5 mm diameter Millicell CM culture inserts (pore size 0.4 μm) . Cells were grown to 80% confluence, the apical medium was removed and cells were fed via the basolateral side every other day to day 21. Passage 1 cells used in submersion culture were seeded similarly onto collagen IV-coated plastic wells, 12.5 mm diameter, and grown to 100% confluence. Cell morphology was confirmed in cultures from each donor using immunostaining antibodies directed against cytokeratin 5 (CK5) to mark basal cells  [ImageJ software .To obtain either basal cell or differentiated cell phenotypes, AEC were grown in submersion or ALI culture (21 days) respectively , 22, 23.ta Cruz) , 25, alpta Cruz) , 27 or Mta Cruz) , 29. CelCells grown to confluence in either culture system were injured using a mechanical rake to ensure a large number of wound edges , then inTotal RNA was extracted from cells using QIAzol lysis reagent followed by RNeasy mini kits . Gene expression profiling was assessed using HumanHT-12 v4 expression BeadChips  that included probes for more than 47,000 genome-wide transcripts.We first grouped the expression data into 12 groups, each group with only one variant of injury versus no-injury. The 12 groups contain each time point , two culture conditions (submersion and ALI) and two disease states . Two major methods of analysis, weighted gene correlation network analysis (WGCNA) and differential expression based analysis, were applied to these groups. For microarrays passing initial quality control, expression levels were extracted using Limma after background subtraction and quantile normalization using the method of Xie et al. . Signifihttp://www.ncbi.nlm.nih.gov/geo) (accession numbers GSE 59128 and GSE109170).Gene expression pattern analysis was performed to identify the sets of genes differentially expressed under each culture condition over time . Heat-maGenes differentially-expressed under each condition were submitted to the Lynx/PINTA server. The PINTA  heat kerSystems level analysis of cellular responses was done by WGCNA , 39. ThiBasal AEC grown in submersion culture expressed cytokeratin 5 (KRT5) and did not express significant quantities of either gel-forming mucin 5AC (MUC5AC), characteristic of goblet epithelial cells, or of alpha-acetylated tubulin, characteristic of ciliated epithelial cells, as reported by the previous studies , 22. As The enrichment analysis of the genes differentially expressed  between the normal uninjured basal AEC and differentiated dAEC was performed using both the Lynx , 40 and Mechanical injury to normal AEC and dAEC was done using a rake that generated a substantial number of cells at wound edges . The anaTables D—G in Enrichment analysis was performed for identification of the functional categories overrepresented in the sets of the genes differentially expressed in normal vs injured AEC or dAEC cells. Systems level analysis of these responses was characterized using weighted gene co-expression network analysis (WGCNA) , 39. TheReconstruction of the molecular networks using DE genes (P < 0.05 and FC > 1.5) as seed genes for dAEC and AEC at each time point are presented in As with cells collected from normal donor lungs, transcriptomes of dAEC and basal AEC collected from asthmatic donor lungs demonstrated appreciable numbers of ciliated and goblet cells when grown in air-liquid interface and a significant number of up-regulated and down-regulated genes illustrated by volcano plot   using the STRING10 server is presented in WGCNA analysis for each condition only detected 1 or 2 significant modules  at each time point has revealed the significant activation of functional categories related to transcription (GO:0008134), cytokine and chemokine activity (GO:0034097), inflammation, programmed cell death (GO:0012501), and to defense responses against bacteria both in basal and differentiated AEC . AsthmatExamination of functional pathways based on the number of DE genes, confirmed the initial analysis of gene DE enrichment analysis. At each time point in many of the functional pathways, AEC from normal donors had a greater number of DE genes and higher Bayes factors compared to AEC from asthmatic donors, and differentiated cells had a greater number of DE genes compared to basal AEC .An important issue in tissue repair after airway mucosal injury is to define the mechanisms by which inflammatory factors, growth factors, and other effectors influence the renewal and differentiation of resident cells. Especially important are early events after injury that initiate or perpetuate inflammatory responses in the immediate and neighboring regions. Because multiple factors are produced in the first hours after injury, it is critical to understand the initial responses of cells so as to determine whether these signals, alone and in combination, serve as pro- or anti-reparative signals or as autocrine or paracrine signals for repair and inflammation in neighboring cells and tissue. While many studies to date have evaluated the role of an individual protein or a handful of factors in elegant ‘reductionist’ models to illustrate their key roles in these processes, few have examined the orchestrated response of epithelial cells, particularly in airways, after discrete injury. These orchestrated responses, from transcriptional to post-translational, serve to coordinate reparative and inflammatory signals that are appropriate in normal responses to injury, and that may become aberrant in disease states depending on context.We have examined the AEC transcriptome in the first hours after injury with an emphasis on the expression of cytokines and chemokines that can influence inflammation in the airway mucosa and submucosa, particularly that with identified importance in asthma. We identified a distinct gene expression profile of such mediators in both differentiated and basal normal AEC that left unchecked would contribute to inflammatory cell influx into the mucosa. Differentiated AEC demonstrated a richer gene expression pathways of pro-inflammatory chemokines than basal AEC, suggesting that a normal, homeostatic airway epithelium is more capable of responding to injury with pro-inflammatory mediator expression. Basal AEC have a central role in repair after injury in airways, from the initial steps of spreading and migration to later proliferation and phenotype shifting into needed new cell subtypes , 42, 43.Several classic inflammatory cytokines such as IL-6, IL-8, and TNF-α, and signaling intermediate genes common to these receptors in the NF-κB and TNF-α pathways, were increased in each cell set, particularly 2 and 8 hr after injury. The recently described IL1F9 (IL-36γ), a ligand for a heterodimeric receptor consisting of IL-1R2 and IL-1RAP subunits that can activate NF-κB, extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK) signaling pathways , also waOf interest is the observation that more differentiated cells have a richer DE early (2 and 8 hr) after the injury reflected by the variety of functional categories in enrichment analysis, than basal cells. Dissecting this difference is hampered due to the fact that the differentiated ciliated and goblet columnar cells require a mixed culture in which basal cells provide for anchoring and survival and cannot be isolated and grown in pure culture. The relative contribution of each cell type then is not clear from our findings, but may become important in models of chronic airway inflammation in which goblet cell metaplasia is prominent –63.sine qua non of asthma, intrinsic dysfunction of the asthmatic airway epithelium as demonstrated by decreased expression of inflammatory pathways after injury suggests that paracrine factors are required to augment epithelial-derived inflammatory responses after injury.Asthmatic airway inflammation frequently is initiated by injury to the epithelial cells lining central airways. Gene expression is essential for orchestrating the early response to epithelial cell injury. We report that basal and differentiated airway epithelial cells collected from asthmatic lungs have diminished immediate cytokine and chemokine response to injury in comparison to non-asthmatic, normal AEC and dAEC. Gene expression in asthmatic cells instead is centered on reparative processes including proliferation, cell cycle, and differentiation. While airway inflammation is the S1 Letter(PDF)Click here for additional data file.S1 FileSingle file that contains supporting information Tables A–M.(XLSX)Click here for additional data file.


The classic view of sensorineural hearing loss has been that the primary damage targets are hair cells and that auditory nerve loss is typically secondary to hair cell degeneration. Recent work has challenged that view. In noise-induced hearing loss, exposures causing only reversible threshold shifts (and no hair cell loss) nevertheless cause permanent loss of >50% of the synaptic connections between hair cells and the auditory nerve. Similarly, in age-related hearing loss, degeneration of cochlear synapses precedes both hair cell loss and threshold elevation. This primary neural degeneration has remained a “hidden hearing loss” for two reasons: 1) the neuronal cell bodies survive for years despite loss of synaptic connection with hair cells, and 2) the degeneration is selective for auditory nerve fibers with high thresholds. Although not required for threshold detection when quiet, these high-threshold fibers are critical for hearing in noisy environments. Research suggests that primary neural degeneration is an important contributor to the perceptual handicap in sensorineural hearing loss, and it may be key to the generation of tinnitus and other associated perceptual anomalies. In cases where the hair cells survive, neurotrophin therapies can elicit neurite outgrowth from surviving auditory neurons and re-establishment of their peripheral synapses; thus, treatments may be on the horizon. Our ears were not designed to withstand long and repeated exposure to the high sound pressures produced by the machinery that surrounds us in modern industrialized society, be it work-, leisure- or combat-related. Correspondingly, with increasing life expectancy, the prevalence of age-related hearing loss (AHL) is also on the rise. The National Institute on Deafness estimates that 33% of people over the age of 65 have significant hearing impairment. The two types of hearing loss are likely interrelated, as people in minimally industrialized areas (e.g. the Sudanese desert) do not show the inexorable age-related deterioration of hearing seen in the developed world4, as defined by the audiogram, which measures the minimal sound pressure required for pure-tone detection in a quiet test booth. For decades, it was assumed that cochlear neural loss occurred only after hair cell death5 and thus was rarely of functional significance in NIHL or AHL.Both NIHL and AHL are known as sensorineural hearing loss because the dysfunction arises in the inner ear, or cochlea, where sound-induced vibrations are transduced by sensory hair cells into electrical signals in cochlear neurons that relay the encoded information to the brain . For dec6. This synaptic loss silences large numbers of cochlear neurons but is invisible in routine histological material and does not affect tests of threshold detection, so long as the loss is not complete. This cochlear synaptopathy, also known as "hidden hearing loss", compromises performance on difficult listening tasks such as understanding speech in a noisy environment, which is the classic complaint of those with NIHL and AHL. In animal models, post-exposure treatment with neurotrophins, delivered locally to the inner ear, can repair or replace the damaged synapses7, suggesting possible future therapies for some of the most disabling sensory impairments in sensorineural hearing loss.Recently, my lab showed, in both NIHL and AHL, that synaptic connections between hair cells and cochlear neurons can be destroyed well before the hair cells are damagedThe mammalian cochlea is a spiraling, fluid-filled tube within a particularly dense bone . In cros8. The two hair cell types have different functions. The OHCs have been called the "cochlear amplifier" because they possess electromotility, which is driven by molecular motors containing a membrane protein called prestin9. Prestin undergoes a voltage-sensitive conformational change that turns sound-driven hair-cell receptor potentials back into mechanical motion that is powerful enough to vibrate the entire sensory epithelium, including the IHC stereocilia. The IHCs are more conventional sensory receptors, generating the pre-synaptic drive for all the myelinated sensory fibers of the auditory nerve. Each ANF has a bipolar "type I" cell body in the spiral ganglion that sends a myelinated peripheral axon towards the sensory epithelium, where its unmyelinated terminal contacts a single IHC, and a myelinated central axon to the cochlear nucleus  of thin, unmyelinated fibers13. These "type II" ANFs also project to the cochlear nucleus14. Their function is unclear, but they may be nociceptors17.In humans, the cochlear spiral is ~32 mm long and contains roughly 3,200 IHCs and 10,000 OHCsnucleus , the fir–5 newtons/m2, which is defined as 0 dB SPL (decibels sound pressure level). The dB scale is logarithmic, and each 20 dB increment corresponds to a 10-fold increase in the amplitude of the sound wave. The ear has an enormous dynamic range: loudness grows monotonically over at least a 100 dB range (105 × threshold pressure) and the threshold of pain is cited as 140 dB SPL (107 × threshold pressure)18.As for most types of hearing dysfunction, characterizing NIHL and AHL in humans begins with the threshold audiogram, which measures the lowest audible sound pressure for pure tones at octave-frequency intervals, typically 0.25, 0.5, 1, 2, 4, and 8 kHz . Human hearing is normally most sensitive near 1 kHz, where average sound pressure at threshold in young adults is 2 × 1019, where, prior to federal regulation of workplace noise, SPLs were in excess of 100 dB SPL (current regulations limit an 8-hour workday exposure to 85 dB SPL A-weighted). In its early stages, NIHL is often seen as a "notch" (i.e. threshold elevation) in the audiogram at 4 kHz. As exposure-time accumulates, the hearing loss extends to 8 kHz, and ultimately the audiogram can reveal no hearing sensation above 1 or 2 kHz, even at the highest sound pressures tested. AHL, as documented in cross-sectional studies, also affects the high frequencies first and can often lead to high-frequency deafness similar to that in advanced NIHL20.Cross-sectional studies in the 1960s documented the rise in audiometric thresholds with increasing years of exposure in noisy factories21. However, for continuous-noise exposures at sound pressures like those in even the noisiest pre-regulation factories, damage is restricted to the inner ear, and OHCs are particularly vulnerable2. Complete loss of OHCs will elevate thresholds by 40–60 dB22. Loss of IHCs will silence all sound-evoked activity from affected cochlear regions2. Many surviving IHCs and OHCs suffer stereocilia damage that compromises function and can produce larger threshold shifts than predicted by the number of lost hair cells alone23. In animal studies, a single 2-hour exposure at 115 dB SPL can destroy all IHCs and OHCs throughout the basal (high-frequency) half of the cochlear spiral24. Fortunately, humans may be somewhat less vulnerable to noise than are smaller mammals, requiring higher SPLs or longer exposures to produce comparable damage25. Nevertheless, human ears with advanced NIHL or AHL also show extensive hair cell loss throughout the high-frequency cochlear regions26.At extremely high sound pressures, such as in blast injury (>180 dB SPL peak), there can be eardrum rupture and disarticulation of the ossicles27. This observation led to the dogma that hair cells are the primary target of noise damage and that neurons die only secondarily to loss of their peripheral synapses5. It has been known since the early 1980s that noise can lead to severe swelling of ANF terminals at their IHC synapses when examined within 24 hours post exposure29. This swelling, often accompanied by membrane rupture and loss of cytoplasmic contents, appears to be a kind of glutamate excitotoxicity, as it can be mimicked by cochlear perfusion of glutamate agonists and partially blocked by perfusion of glutamate antagonists31. However, ANF terminal swelling can be observed in ears with temporary threshold shifts (TTSs), and it disappears within a few days as thresholds recover. This threshold recovery led to the idea that neural connections recover or regenerate after noise damage, so long as the hair cells survive32.Although hair cell damage and death can be seen in minutes to hours after acoustic overexposure, death of spiral ganglion cells (the cell bodies of ANFs) is delayed by months to years33. Furthermore, threshold recovery,per se, is not proof of synaptic recovery. Cochlear function in these animal experiments is measured by recording ensemble ANF activity in response to brief tone bursts via metal electrodes on the cochlear capsule  or in the skin of the external ear (auditory brainstem responses [ABRs]). Thresholds for these "gross" neural potentials are very sensitive to OHC damage, which can severely attenuate sound-evoked cochlear vibrations, but extremely insensitive to subtotal neural degeneration. This is because loss of ANFs and their contributions to the ensemble response can be readily compensated for, especially near threshold, by small increases in stimulus level, which recruit more responding fibers by spreading sound-evoked vibrations farther along the mechanically tuned cochlear spiral.However, for years, no one counted ANF terminals in recovered ears because these unmyelinated endings and their synaptic connections are invisible in routine light-microscopic material , and the34. Thinking back to the work on acute noise-induced ANF terminal swelling, we speculated that the exposure in our mice might be causing immediate and irreversible synaptic damage, which was revealed only by the extremely slow death of the disconnected spiral ganglion cells.Thus, for many years, the question of whether or not noise destroys ANF synapses on surviving IHCs was not pursued. Then, my colleague Sharon Kujawa asked me to collaborate on a study of the interaction between NIHL and AHL. She exposed mice as young adults to a noise designed to produce a modest (40 dB) permanent threshold shift (PTS) and then let them age for 2 years to see if the cochlea deteriorated more rapidly in exposed versus unexposed animals. No prior work, to our knowledge, had followed animals for so long post exposure. Two years later, the noise-exposed mice showed ~50% loss of spiral ganglion cells in the basal half of the cochlea versus <5% in age-matched controls despite no significant loss of IHCs or OHCs in either group35. Each ANF contacts a single IHC via a single terminal bouton  and a glutamate receptor subtype  show pairs of closely apposed red and green, pre- and post-synaptic puncta 41, and surviving IHCs at the end of the mouse lifespan have lost ~50% of ANF synapses41. Normal-aging humans, i.e. those without explicit otologic disease, can also show dramatic cochlear neuropathy in regions of minimal hair cell loss42: e.g. one 89-year-old ear retained only ~20% of the normal complement of ANF contacts despite minimal loss of either IHCs or OHCs12.We now know that even exposures producing only a TTS, and leaving all hair cells intact, can destroy up to 50% of IHC synapses across large cochlear regions . The dam31. Recent work showing that synaptopathy also occurs after a single high-intensity shockwave43 suggests that prolonged overexposure of the post-synaptic membrane to glutamate may not be required. Furthermore, it is unclear whether noise-induced, age-related, and drug-induced synaptopathy all share the same mechanism.The mechanisms underlying noise-induced synaptic damage have not been clarified beyond the cochlear perfusion studies of glutamate excitotoxicity in the 1980s44 because the damage is not visible in routine cochlear histopathology and because primary neural degeneration does not significantly affect the threshold audiogram until it exceeds ~80%46. Although not needed for pure-tone detection in quiet environments, a full complement of ANFs is likely required for more difficult listening tasks.Regardless of underlying mechanisms, emerging evidence suggests that surviving IHCs are partly or largely disconnected from their primary sensory fibers in many types of acquired sensorineural hearing loss. This synaptopathy has been called "hidden hearing loss"49. Although both high- and low-SR fibers can contact the same IHC  and high-threshold fibers with low SRs , constitame IHC , their same IHC  and thei61, but their loss should not affect threshold detection of stimuli in an otherwise quiet environment. In the presence of continuous masking noise, however, their contributions become more critical, and their loss becomes more handicapping. By virtue of their higher thresholds, low-SR fibers are more resistant to "masking" by continuous noise62. As the noise level rises, low-threshold, high-SR fibers are driven to "saturated" discharge rate, leaving only the high-threshold, low-SR fibers to carry information about stimuli embedded in the noise.As shown in63. However, the inner ear cannot be biopsied, so enhanced diagnostic tests are needed to screen living subjects.Difficulty hearing in noise is a major complaint of people with sensorineural hearing loss, and it has long been known that two people with the same audiogram, whether normal or abnormal, can perform differently on speech-in-noise tests. Prior to the discovery of hidden hearing loss, these differences were ascribed largely to differences in central auditory processing. A few human histopathological studies suggest that cochlear synaptopathy is an important component of human sensorineural hearing loss, and one even suggests that it is correlated with word-recognition scores41. Once thresholds are elevated, it is difficult to separate changes due to synaptopathy from those due to hair-cell damage. Auditory evoked potentials such as ABRs are easily measured in human subjects from scalp and/or ear-canal electrodes. In a recent study of young adults with normal audiograms, we found a correlation between performance on a difficult speech-in-noise test and alterations in auditory evoked potentials that were consistent with cochlear synaptopathy64. Having purposely sought out subjects who abused their ears (aspiring musicians who never wore ear protection) and those who routinely protected their ears, we also noted a correlation between ear abuse and poorer performance on speech-in-noise tests. Other studies have shown correlations among normal-threshold young subjects between the ability to perform complex listening tasks and alterations in ABRs that suggest a peripheral rather than a central origin65. A recent study of military veterans with normal audiograms has also found a correlation between ABR wave 1 amplitudes and noise-exposure history66, while another recent study of "normal-hearing" subjects in the UK failed to find such a correlation67. However, different metrics of noise history were used, and neither study correlated the electrophysiological results with performance on speech-in-noise tasks.In mouse studies, we showed that suprathreshold amplitudes of ABR wave 1, the summed onset responses of ANFs, were well correlated with the degree of cochlear synaptopathy, so long as cochlear sensitivity was not compromised due to OHC dysfunction68, a careful re-evaluation of these guidelines is warranted if hidden hearing loss is to be prevented as well.Clearly, more work is needed in this area. However, existing data from humans and animals make it clear that significant cochlear neural damage can occur without hair cell damage and thus can hide behind a normal audiogram. This neural damage is likely to be a handicap in difficult listening situations, especially as overt hearing loss (i.e. threshold elevation and hair cell damage) is added to the mix. Since existing federal guidelines on workplace noise exposure were derived based on the assumption that exposures producing no PTSs are benign69. In mammalian cochleae, including those in humans, hair cells and cochlear neurons are post-mitotic, and damaged or lost elements are never replaced70. Although limited hair cell regeneration via transdifferentiation of remaining support cells has been demonstrated in animal models71, the repair of cochlear synaptopathy is arguably simpler because there is an extended therapeutic window in which the hair cell targets as well as the spiral ganglions and their central axons survive6. Multiple animal studies have shown that local delivery of neurotrophins, endogenous players in the signaling pathways involved in neuronal development and maintenance, can elicit neurite extension from spiral ganglion cells even in the adult mammalian ear72. Several recent studies in the mouse and guinea pig have shown that at least within 24 hours post exposure, neurotrophin delivery can repair the noise-induced synaptic damage as it restores ABR amplitudes74. Regeneration is likely more difficult at longer post-exposure times, but even in humans the distance from cell body to hair cell is <0.5 mm, and spiral ganglion cell death must be extremely slow because cochlear implants inserted years after deafness onset still provide useful hearing75. Thus, it does not seem too far-fetched to imagine that there could be therapies for hidden hearing loss on the horizon.An exciting aspect of this work is the notion that some of the hearing handicap in sensorineural hearing loss might be treatable or preventable