The perineuronal net (PNN) represents a lattice-like structure that is prominently expressed along the soma and proximal dendrites of parvalbumin- (PV-) positive interneurons in varied brain regions including the cortex and hippocampus. It is thus apposed to sites at which PV neurons receive synaptic input. Emerging evidence suggests that changes in PNN integrity may affect glutamatergic input to PV interneurons, a population that is critical for the expression of synchronous neuronal population discharges that occur with gamma oscillations and sharp-wave ripples. The present review is focused on the composition of PNNs, posttranslation modulation of PNN components by sulfation and proteolysis, PNN alterations in disease, and potential effects of PNN remodeling on neuronal plasticity at the single-cell and population level. Within the central nervous system (CNS), there are three main types of extracellular matrix (ECM). A homogenous, hyaluronic acid- (HA-) based, relatively loose form of ECM enwraps cell bodies, dendrites, and synapses of most neurons within the brain and may serve as a reservoir for proteins including thrombospondins and guidance molecules , 2. The In terms of the overall structure, the PNN is composed of a linear nonsulfated hyaluronic acid polymer that forms the backbone of the lattice. Chondroitin sulfate proteoglycans (CSPGs), including the lecticans aggrecan, versican, neurocan, and brevican, are joined to the hyaluronic acid polymer through “link” proteins including cartilage link protein (Crtl1). Tenascins bind to the C-terminal domains of CSPGs to complete the complex structure of the lattice , with tePNNs are expressed in varied brain regions including the cortex, hippocampus, amygdala, hypothalamus, basal ganglia, and cerebellum. In the prefrontal cortex, the PNN is highly colocalized with PV GABAergic interneurons . ExpressSpecies differences have also been described with respect to PNN deposition . For exaDeposition of PNN typically increases with neuronal activity and brain maturation . A shiftIn vitro work has shown that neurons express the CSPG aggrecan and that expression is substantially upregulated with depolarization [Both neurons and glial cells express specific components of the structure. rization . Aggrecarization –31. Exprrization . This prrization  and takerization , 35.Neurons can also express HA when cultured in the absence of glia. Nonetheless, glia are an important source of HA and are important for the expression of PNN components including brevican and hyaluronan, as well as proteoglycan link protein 1 (HAPLN1) . In nonnIntriguingly, maturation of the PNN has been associated with the closure of critical periods of CNS plasticity . ThPNN integrity also controls plasticity in the amygdala and hippocampus. In the amygdala, PNN deposition is followed by fear memory persistence and chondroitinase treatment can render fear memories susceptible to erasure . In the Overall, PNN deposition appears to be important to structural stability of the neuronal circuitry that underlies long-term memory. Reductions in PNN integrity may instead be associated with improved cognitive flexibility . TogetheIn terms of flexibility, PNN abundance is modulated by proteolytic processing. While experimental studies often utilize hyaluronidase or chondroitinase to affect PNN degradation , 47, 48,−/− and Adamts-5−/− mice following spinal cord injury [Numerous studies have investigated the role for specific proteases as effectors of PNN component processing. Both ADAMTSs and MMPs are able to degrade aggrecan –53; howed injury . In contd injury .Though ADAMTS proteases and MMPs may differ in terms of overall substrate specificity, in the case of shared lectican substrates, they can cleave at distinct sites. This has allowed for the investigation of enzyme-specific cleavage based on the different neoepitopes that are formed (reviewed in ).Lectican-degrading enzymes have been shown to be expressed and/or activated in a temporally dependent manner which often parallels neuronal development . For insCSPG sulfation can also influence plasticity –67 and pProteolytic processing of PNN has broad implications in terms of neurological disease and therapeutics. Indeed, PNN degradation has been observed in association with seizure activity, CNS infection, cerebral ischemia, and traumatic brain injury –73. A leThough HIV infects CD4-expressing lymphocytes and monocyte-derived cells, associated CNS dysfunction is thought to be driven in large part by the latter . NeuronsWisteria floribunda (WFA), such as N-acetylgalactosamine, are decreased [Analyses of PNN integrity in AD have yielded contradictory findings, which may be due to complex interactions between degrading enzymes and their inhibitors, differences in ECM detection methods, or differences in mouse models that have been studied. ECM proteins such as the heparan sulfate proteoglycan (HSPG) agrin have been associated with senile plaques (SPs) and neurofibrillary tangles (NFTs) , 87. Speecreased . To furtecreased . Interesecreased . This fiecreased –95.Literature regarding PNNs in AD mouse models has also provided conflicting results. PNNs have been found to be largely unaffected in the Tg2576 mouse model of AD when using both aggrecan immunoreactivity and WFA staining; however, in the APP/PS1 tg mouse, total protein levels of neurocan, brevican, and tenascin-R are increased as is the number of WFA-labeled PNNs . InteresExtensive PNN alterations have been observed in epilepsy models . AggrecaReported reductions in ECM are largely thought to be due to increased MMP activity given that MMP-9 levels increase within hours of kainate application , 105. InReductions in PNN staining have been observed with focal cortical photothrombotic stroke injury in rats . Moreoveβ may regulate extracellular matrix remodeling and the PNN in a rat model of TBI, as well in brains of human epileptic patients [β signaling again playing an important role [A loss of PNN and parvalbumin immunoreactivity is also observed in models of traumatic brain injury (TBI). In rodent models, PNN immunoreactivity is reduced in the perilesional cortex following fluid-percussion injury  or contrpatients . Albuminant role .Alterations in PNN staining have been observed in patients with depression , 116. FoAdditionally, monoamine antidepressants have been linked to alterations in PNN. For example, chronic treatment with fluoxetine decreases PNN staining in the murine medial PFC and hippocampus . FluoxetLithium, an effective treatment for bipolar illness, has also been associated with alterations in the PNN and more specifically with CSPG digestion , 125. InIn terms of the significance of PNN remodeling in the setting of antidepressant treatment, since reduced PNN integrity may reduce PV interneuron excitability to increase overall excitatory/inhibitory balance , 126, wh+ and K+ [PNNs likely serve varied nonmutually exclusive functions. Constituent components impart nets with an overall negative charge , which m+ and K+ , 131, as+ and K+ , 133. Th+ and K+ .An intact PNN can also serve to anchor bioactive molecules including growth factors and cytokines. This could be adaptive or nonadaptive depending on the extent of remodeling and physiological or pathological background on which it is occurring. With respect to the former, PNN digestion can facilitate enhanced axonal sprouting –136. If Several studies suggest that the PNN contributes to the stability of preformed synapses. Elegant work has shown that PNN disruption allows for increased lateral diffusion of glutamate receptor subunits . The difOverall, it appears that an important function of the PNN is to restrict plasticity and instead support synaptic stability (this concept is reviewed in ). ConsisThough we have thus far concentrated our discussion of PNN-enwrapped PV cells, which represent the predominantly ensheathed neuronal population in the sensory cortex as well as in the CA1 and CA3 hippocampus, it should be noted that in regions including hippocampal CA2, the PNN also envelops pyramidal cells , 24. IntGiven that PV-expressing interneurons represent the predominant neuronal subtype that is enveloped by PNNs, changes in PNN integrity likely have a substantial effect on PV-stimulated neuronal activity. Along with cholecystokinin- (CCK-) expressing cells, the PV subpopulation represents one of the two major GABAergic basket cell subtypes. As compared to CCK-positive cells, PV-positive cells receive strong excitatory input, are fast firing, and can release GABA in a relatively reliable fashion. For these reasons, PV neurons represent pacemakers for synchronous network events –146.Emerging evidence supports the role for PNN alterations in synchronous network activities such as cortical gamma oscillatory activity. For example, a recent study demonstrated that PNN removal could decrease activity in inhibitory units as inferred from their waveforms . In assoThough PNN staining in the hippocampus is less robust than that in the visual cortex , reducedThe potential for modulation of the PNN to affect gamma rhythms has physiological implications. Gamma activity is thought to provide a temporal structure for information processing . It may Similarly, effects of PNN modulation on SWR frequency are of potential interest. SWRs represent a population event in which sequential replay of previously activated neuronal assemblies occurs in a time-compressed manner , 153. ThIt should be noted that while limited remodeling of the PNN might have beneficial effects on CNS function, excess remodeling might instead enhance seizure susceptibility. Consistent with this, published work suggests that PNN disruption can induce hyperexcitability and epileptiform-like activity in cultured hippocampal networks , 158. MoDespite their cage-like appearance and lengthy backbones, perineuronal nets are relatively plastic structures that can be modulated by sulfation and proteolysis. At the single-cell level, PNNs may limit diffusion of released transmitters and transmembrane receptors to influence the efficacy of synaptic transmission. Importantly, however, factors that are known to influence PNN integrity including infectious agents, ischemia, and select therapeutics tend to affect PNN integrity in a widespread manner which may in turn have important effects on neuronal population dynamics , 71. Giv


Brain imaging technology has allowed researchers to conduct rigorous studies of the dynamic course of alcoholism through periods of drinking, sobriety, and relapse and to gain insights into the effects of chronic alcoholism on the human brain. Magnetic resonance imaging (MRI) studies have distinguished alcohol-related brain effects that are permanent from those that are reversible with abstinence. In support of postmortem neuropathological studies showing degeneration of white matter, MRI studies have shown a specific vulnerability of white matter to chronic alcohol exposure. Such studies have demonstrated white-matter volume deficits as well as damage to selective gray-matter structures. Diffusion tensor imaging (DTI), by permitting microstructural characterization of white matter, has extended MRI findings in alcoholics. MR spectroscopy (MRS) allows quantification of several metabolites that shed light on brain biochemical alterations caused by alcoholism. This article focuses on MRI, DTI, and MRS findings in neurological disorders that commonly co-occur with alcoholism, including Wernicke’s encephalopathy, Korsakoff’s syndrome, and hepatic encephalopathy. Also reviewed are neuroimaging findings in animal models of alcoholism and related neurological disorders. This report also suggests that the dynamic course of alcoholism presents a unique opportunity to examine brain structural and functional repair and recovery. Apart from direct effects on the brain, excessive alcohol consumption is associated with increased risk for trauma  , seizureTo evaluate alcohol’s central nervous system effects, researchers distinguish “uncomplicated alcoholism”  from the various clinically diagnosable consequences of chronic alcohol consumption, including Wernicke’s encephalopathy (WE), Korsakoff’s syndrome (KS), hepatic encephalopathy (HE), central pontine myelinolysis (CPM), alcoholic cerebellar degeneration (ACD), alcohol-related dementia (ARD), and Marchiafava-Bignami disease (MBD).Approximately 7 percent of adults age 18 and older have an AUD . PrevaleEstimates of HE are derived from estimates of alcoholic cirrhosis, which can range from 8 percent to 20 percent . Mild HEHuman studies offer a full depiction of the consequences of chronic alcohol exposure but are limited by ethical considerations. That is, rigorous experimentation requires the ability to control for relevant variables such as the premorbid condition of the brain. The wide variation (or heterogeneity) of alcoholic populations examined with respect to genetic predisposition, age of onset, pattern of drinking, frequency of withdrawals, length of sobriety, nutritional, and hepatic status has hampered researcher attempts to isolate specific brain regions and mechanisms affected by alcohol, per se. This heterogeneity, and the complexity that it introduces, makes it difficult to thoroughly characterize the disorder. Animal models, in contrast to the indefinite natural course of alcohol use in humans, allow researchers to determine alcohol toxicity in a way that allows them to control for multiple genetic, environmental, and alcohol consumption factors. Animal models permit the study of underlying mechanisms, enabling researchers to better interpret findings from human studies.On the other hand, animal models also have limitations. Species differences in brain structure and function—among myriad other differences between humans and other animals—can give inadequate information when animal data are applied to human disease. For example, mice models fail to mimic human inflammatory disease with respect to genomic responses , and corThis article reports key findings in humans, from macrostructural findings using magnetic resonance imaging (MRI), microstructural findings using diffusion tensor imaging (DTI), and metabolic findings from MR spectroscopy (MRS). Studies of alcohol-related central nervous system disorders are used as a framework for findings in uncomplicated alcoholism. The article also examines studies of abstinence and relapse and current imaging studies of animal models of alcoholism and co-occurring brain disorders. The evidence suggests that human studies are necessary to identify and classify the brain systems modified by concomitants of alcoholism versus alcoholism, per se, and that animal models of alcoholism and its co-occurring brain disorders are essential for a mechanistic understanding of vulnerable brain systems.Since the early 1980s, conventional structural MRI has allowed researchers to visualize the living human brain. Detailed images of the brain are possible in part because the different brain tissue types  contain different proportions of water . With MRWE occurs with chronic alcoholism and thiamine deficiency. If untreated, WE patients can develop KS, a severe neurological disorder characterized by anterograde amnesia . MalnutrHE, occurring in acute or chronic liver disease, including acute liver failure and cirrhosis, is believed to arise, at least partially, from high levels of ammonia circulating in the blood. HE patients may appear confused and disoriented and have poor coordination . T1-weigA significant proportion of CPM cases  include ACD patients most frequently display ataxia, although other symptoms can include uncontrollable and repetitive eye movement  and speech problems resulting from impaired muscle control  . NeuroimAlcoholic dementia, or ARD, a currently preferred term, remains a controversial diagnosis because of confounding syndromes such as WE and HE. Nevertheless, certain clinically distinguishing features of ARD exist. It often occurs in socially isolated men at younger ages of onset  than other types of dementia ; deficitMBD, a disease marked by mildly impaired mental status  and sometimes by dysarthria  or ataxiGiven the aforementioned findings in clinically differential and diagnosable alcohol-related syndromes, the following section examines whether similar brain disorders also appear in alcoholics who do not manifest the full spectrum of symptoms present in these conditions. That is, how do the brains of uncomplicated alcoholics compare? Quantitative MRI has shown that relatively mild yet significant structural deficits characteristic of alcoholic syndromes can occur in uncomplicated alcoholics.Relative to findings in WKS, research demonstrates mild volume deficits in the mammillary bodies , hippocaOther regions selectively affected in WE and KS include the orbitofrontal cortices (KS), periaqueductal gray matter, and tissue surrounding the third ventricle (WE). Reports suggest that propensity to relapse following sobriety is related to pronounced atrophy in bilateral orbitofrontal cortices . The thiKey regions affected in HE include the globus pallidus and substantia nigra. Volume effects on these two structures have not been reported in uncomplicated alcoholics; however, in children with fetal alcohol syndrome, globus pallidus volume is reduced in size compared with unaffected children . In contCPM targets the pons and ACD affects the cerebellum. Total infratentorial volume  is significantly smaller in uncomplicated alcoholics than control subjects. The volume of the pons  and cereThe frontal cortex is notably damaged in ARD. With respect to cortical regions in uncomplicated alcoholism, various methods have shown significant, widespread shrinkage of both cortical gray and white matter with corresponding increases in CSF-filled spaces . In partThinning of the corpus callosum occurs in uncomplicated alcoholics and is more prominent in the anterior than posterior regions . As withLongitudinal MRI investigations show that the ventricles become smaller following weeks  or monthSober alcoholics reveal several associations between brain-volume gain, as determined by MRI, and improvement in neuropsychological test performance: Reduced lateral-ventricle volume is related to improved memory performance , reducedThe brain’s capacity to return to “normal” following long-term sobriety is unknown. Short-term (6 weeks) abstinence seems sufficient to observe some brain-volume recovery but does not result in equivalent brain volumes between recovering chronic alcoholics and healthy controls . It is dDespite evidence for recovery of brain volume with abstinence, the mechanisms accounting for recovery remain unclear. One hypothesis, brain rehydration, was not supported by early human research studies . An alteTurning from studies with humans to animals, the following section examines imaging studies in models of alcoholism and related disorders.There are two experimental approaches to model WE in rodents. The slower approach uses a thiamine-deficient diet , which can take 3–4 weeks to produce symptoms. Behavioral symptoms can be achieved in ~2 weeks using a combination of a thiamine-deficient chow and intraperitoneal (i.p.) administration of a thiamine pyrophosphokinase inhibitor such as pyrithiamine . Both moResearch with animals demonstrates that thiamine deficiency impairs several biochemical pathways requiring the thiamine derivative thiamine pyrophosphate  , therebyEvidence also shows that thiamine deficiency alters norepinephrine, dopamine , serotonCurrent rodent models to study HE include models of acute and chronic liver failure . AccordiUsing a rat model of CPM to study white-matter degeneration, it was found that blood–brain barrier breakdown, detected with MRI, was associated with a higher risk of developing demyelination, as detected using postmortem histopathology . This stAlthough there are no known studies using structural MRI in animal models of ACD, ARD, or MBD, the following section examines animal studies in uncomplicated alcoholism.An important initial report in the rodent MRI literature was the demonstration that brain growth continues beyond what would be considered adulthood in rats bred to prefer alcohol . Indeed, whole-brain volume in such rats continued to grow until approximately postnatal day 450 a, well pOne of the most consistent findings in alcohol-exposed rodents, ventricular enlargement, varies with timing and method of alcohol exposure. It is far more pronounced in rats achieving average blood alcohol levels (BALs) of 250 mg/dL in just 4 days of involuntary binge-type administration of EtOH , 2014b tIn monkeys trained to voluntarily consume alcohol, those that drank at least 3 g/kg EtOH per day for 15 months showed significant brain-volume shrinkage in the cerebral cortices . BecauseA number of sources provide extensive descriptions of the principles of DTI . BrieflyDTI findings are described in terms of diffusion. The magnitude of diffusion, referred to as mean diffusivity (MD) or the apparent diffusion coefficient (ADC), is calculated mathematically. Increased MD corresponds to white-matter damage. Fractional anisotropy (FA), ranging between 0 and 1, reflects axonal integrity, with lower integrity reflected by FA values closer to 0. Thus, disruption of white-matter microstructure detectable with DTI can reflect compromised myelin, cytoskeletal structure, or axonal density .Several approaches have been used to quantify DTI metrics. One of the more desirable approaches is the use of quantitative fiber tracking, which is able to evaluate fibers along their entire length and can thus detect compromised white matter. This technique can be used to depict selective commissures , projection fibers, and association fibers.n = 7) and without (n = 20) WKS showed FA deficits in the fornix and cingulum bundle of the Papez or medial limbic circuit, measured using tract-based spatial statistics (TBSS). These FA effects were greater in alcoholics with WKS relative to those without it , symptomatic stage (days 12 and 14), and after recovery on days 31 and 87. A decrease in FA in the inferior colliculi was first noted on day 10 but showed recovery on day 87. On the other hand, the FA decrease in the thalamus first noted on day 12 persisted through day 87 . This moAdolescent animals exposed to intermittent EtOH and evaluated postmortem showed no effects on FA but reduced axial diffusivity , reduced radial diffusivity (hippocampus and cortex), and reduced MD  in several brain regions . Adult rWhereas chronic exposure to vaporized EtOH did not result in detectable effects on FA or MD, binge EtOH exposure resulted in transient decreases in FA and transient increases in MD . TogetheAlthough MRI primarily depicts the distribution of water protons, similar technology can also be used to obtain information about chemical constituents other than water, primarily due to a small frequency shift, or “chemical shift,” relative to the water signal. The acquisition of MR-detectable signals other than those of water and fat is referred to as MRS and is an in vivo application of traditional laboratory-based NMR spectroscopy.N-acetylaspartate (NAA), creatine and phosphocreatine , and choline-containing compounds (Cho). Signals from the combined resonances of glutamate (Glu) and glutamine (Gln)  are also sometimes reported, as are myo-inositiol (mI) and lactate (lac). Signals from Glu and GABA can also be detected under certain conditions.MRS reveals information about several biochemicals, or metabolites, in the brain. The largest signals arise from N-acetyl compounds, especially N-acetyl aspartyl glutamate. NAA is found almost exclusively in neurons   and is aMyo-inositiol is present in glial but not neuronal cell cultures  and playAs with the other imaging modalities, MRS reports of WE are primarily case studies. For example, a Japanese man who had consumed alcohol for 50 years and had eaten poorly for several days as a result of a cold presented with gait disturbances and incoherent speech. MRS before and after thiamine treatment found an initial low level of NAA/tCr in the thalamus, which appeared to increase with thiamine replacement. NAA/tCr levels in the cerebellum did not increase, although a lactate peak initially present in the cerebellum resolved . MRS conIn a variety of brain regions, MRS findings in alcohol-related cirrhosis and HE are remarkably consistent and comparable with findings in nonalcoholic HE e.g., , showingMild swelling of astrocytes is proposed as the key event in the pathogenesis of HE e.g., . In cirrIn the only report of MRS conducted in a case of alcoholism-associated CPM, elevated Cho/tCr was found and interpreted as reflecting edema or demyelination in a 53-year-old man with gait disturbances and hearing loss . In 12 pResearch also has found compromised NAA/tCr levels in patients with cerebellar degeneration . Two MRSMost MRS studies show lower levels of NAA in recently sober alcoholics relative to healthy controls in several brain regions, including frontal areas  and cereMRS studies suggest that NAA e.g., , particuIn rat models of WE induced using pyrithiamine, the dominant MRS pattern is a reduction in both NAA and Cho in several brain regions , includiMRS has been used to evaluate models of HE achieved using various methods  and mostAlthough in vivo MRS studies in both humans and animals have persisted in interpreting elevations in brain Gln as reflecting elevations in peripheral ammonia and brain edema , ex vivoMRS can be used in animals to detect and quantify in vivo and real-time brain EtOH kinetics (e.g., rats: Imaging investigations of alcohol-related brain disorders show unique neuropathology (as outlined in In vivo imaging studies in humans and animal models will continue to provide an evolving picture of the course of alcoholic brain disease through remissions and exacerbations as long-term studies follow human alcoholics as they age and as new initiatives evaluate adolescents before they are exposed to alcohol.


The recent development of analogs of brefeldin A (BFA), a fungal metabolite, for the improvement of BFA apoptosis-inducing activity is described. BFA has been isolated from various soil or, more recently, marine fungi and has shown versatile beneficial activities. More importantly, the apoptosis-inducing activity of BFA in cancer cells highlights the possibility of further developing this natural product as an anticancer agent. Besides its biological importance, its structural features have also gathered tremendous interest from both medicinal and synthetic chemists. By a medicinal chemistry and total synthesis approach, numerous analogs from BFA have been developed to improve its inferior bioavailability and its antiproliferative ability. In this review, the recent medicinal chemistry efforts in relation to the production of BFA analogs are extensively presented. Penicillium decumbens in 1958 -cycloaddition route was reported to enable a versatile synthesis of BFA strategy . In ScheThe apoptotic activity of BFA has been deeply researched and studied from a medicinal chemistry point of view. Based on an early report that a simple esterification of BFA still maintains its biological activity, a lot of prodrugs or esterified analogs, such as Nitric oxide-releasing BFA and long linker-containing BFA have been synthesized. Although some analogs showed better activity than BFA, the problem related to its physical properties is not solved yet, despite numerous advances in this sense. Hopefully, more soluble sulfide-conjugated BFA analogs have been developed for the purpose of producing BFA prodrugs. In addition, advanced synthetic technologies have been developed to more efficiently obtain the BFA skeleton. Studies on the mechanism of action of BFA were also carried out using these BFA analogs. By employing molecular studies it was shown that esterified BFA analogs were tolerated when inserting between ADP ribosylation factor (ARF) and ARF nucleotide binding site opener (ARNO) proteins, although this molecular interaction did not correspond to the disruption of the Golgi complex . Co-crys


Root-associated bacterial communities play a vital role in maintaining health of the plant host. These communities exist in complex relationships, where composition and abundance of community members is dependent on a number of factors such as local soil chemistry, plant genotype and phenotype, and perturbations in the surrounding abiotic environment. One common perturbation, drought, has been shown to have drastic effects on bacterial communities, yet little is understood about the underlying causes behind observed shifts in microbial abundance. As drought may affect root bacterial communities both directly by modulating moisture availability, as well as indirectly by altering soil chemistry and plant phenotypes, we provide a synthesis of observed trends in recent studies and discuss possible directions for future research that we hope will provide for more knowledgeable predictions about community responses to future drought events. Plants are intimately intertwined with the bacterial communities found in and around their roots, which include both rhizosphere (soils in close enough proximity to the root to be influenced by root exudate release) and root endosphere (the root interior) communities . Plant hUnfortunately, elucidating just how drought impacts root-associated bacterial communities is challenging due to the complexity and interconnectedness of the factors that govern the establishment of root microbiome. Plants recruit bacteria from soil communities and enrich for a host-specific root endophytic community typically of decreased diversity . HoweverFigure 1). While we attempt to synthesize the available literature by grouping results into commonly observed trends in several major topical areas, we acknowledge that there are many factors with potential influence on soil and root microbiomes which we do not cover in great detail, including climatic variables, host genotype and host developmental stage. However, we propose that a first step is establishing an understanding of the effects of drought on soils and on plant physiology. The first section focuses on drought-induced compositional and functional responses of soil bacterial communities, with an emphasis on non-plant associated soils, and discusses possible reasons for the observed responses. In the second section we consider how root-associated communities shift under drought, we address the plant’s physiological responses to drought and how these exert an impact on root-associated communities, and we discuss the role of specific plant growth-promoting traits in the selection of drought-enriched taxa. We conclude with a discussion of technical challenges and limitations in current research approaches used to study the plant root microbiome under drought, and offer suggestions on directions for future research.In this review, we address the complex interplay between soil, plant and microbe that together determine the dynamics in the root microbiome during drought  are known for being slow-growers, but can sustain growth under poor conditions. They also tend to be specialists in terms of substrate utilization , rather A second putative and more direct cause of the altered soil community composition under drought is related to differences in tolerance to loss of soil moisture. The various physiological mechanisms that allow bacteria to tolerate drought, including sporulation and thick cell walls, are not evenly distributed between bacterial groups. Many genera within primarily Gram-positive phyla are known sporulators, while Gram-negative phyla largely lost the capacity to sporulate during the course of evolution . Sporula2 efflux is observed after rewetting of dry soils , the latter being more common . For theAgave species, season was the greatest contributing factor to variance in the root endosphere microbiome, whereas the rhizosphere and leaf phyllosphere were primarily influenced by host species  properties in the enriched taxa within Proteobacteria, such as nutrient solubilization or presence of ACC deaminase, which plants select for under drought. Indeed, as broad trends of enrichment are not necessarily universally true for all members of a phylum, it is feasible that specific outlying lineages may be actively recruited by the root based on the presence of specific PGP traits despite harboring a degree of drought sensitivity.Interestingly, identification of a ‘core microbiome’ of drought-enriched taxa in root endospheres in several different studies  found thAgave roots under drought  had more unique droughted root core microbiome, sharing much fewer of their core OTUs with other species’ cores. Perhaps most interestingly, C4 grasses had more pronounced average drought enrichment (3.4-fold) for class Actinobacteria than C3 grasses (2.4-fold). Given that Actinobacteria are implicated in promoting plant growth under stress . Furthermore, the proportion of carbon allocated to roots vs. shoots increases , but of these forms, root exudates are most directly implicated in recruitment of the root microbiome. Root exudates are carbon-containing compounds  releaseArabidopsis accessions have distinct exudate profiles, and both root and rhizosphere bacterial communities were in turn found to be distinct between these accessions   species . PGPB ma species , and in  species . Creatin species . A conso species . These rA variety of PGP abilities are implicated in conferring drought tolerance, of which perhaps the most studied is the enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACCd). Through ACCd activity, the plant hormone ethylene remains below inhibitory levels, maintaining normal root growth and delaying senescence under drought . PGPB arPaenibacillus polymyxa lacking an Sfp-type 4′-phosphopantetheinyl transferase had heightened biofilm production, which upon inoculation on drought-stressed wheat plants was shown to enhance plant survival and biomass production two and threefold, respectively. In the presence of droughted Arabidopsis roots, Bacillus megaterium BOFC15 secretes the polyamine spermidine, which scavenges ROS, upregulates ABA biosynthesis and response genes, and by extension augments photosynthesis and root system architecture (Pseudomonas chloroaphis O6 will synthesize 2R-3R-butanediol, which is involved in the SA signaling pathway and elicits stomatal closure in Arabidopsis (While it is difficult to elucidate the explicit mechanism by which PGPB act to enhance drought tolerance, in certain cases it has been demonstrated. For example, PGPB in itecture . Similarbidopsis .DREB1B-like or ERD15 (Altering plant gene expression is a common mechanism PGPB can use to confer drought tolerance in the plants. Often this has been demonstrated in a non-specific manner, such as upregulation of marker drought-response genes such as or ERD15 , which hor ERD15 , and calIn this review, we have addressed the interdependent factors that determine drought response in root-associated bacterial communities. While there are promising findings that have come out of the extensive research conducted thus far, numerous limitations in experimental methodologies preclude drawing more concrete conclusions about the observed trends. Here, we present a brief overview of three of these issues and present suggestions for future research to address them.Firstly, conclusions drawn about responses in the root microbiome to an external drought stress may be spurious when conducted in a traditional experimental framework – that is, when plants under control and drought conditions differ only by a single factor, the amount of water supplied. However, multiple environmental variables may accompany drought, including increases in temperature and soil salinity , all of 2] and soil temperature . For thPlant response to drought involves a number of dynamic phenotypic modifications that will differ depending on how long they have been under water limitation. Thus, it might be expected that the length of exposure to drought will affect the root microbiome, such that community composition at drought onset could be drastically different from that seen weeks or months later. It has already been demonstrated that root and rhizosphere assemblages are affected by plant age and developmental stage , indicatWith respect to the bacterial community under drought, a question that warrants future investigation is: what exactly are the criteria that lead to proliferation of certain bacterial taxa in water-limited systems? In our review, we have extensively discussed divisions that might influence drought enrichment, including Gram-positive vs. Gram-negative, monoderm vs. diderm, oligotrophy vs. copiotrophy, and presence vs. absence of known PGP traits. However, none of these traits are universally linked with drought enrichment: for example, Proteobacteria are almost universally Gram-negative, yet members of Proteobacteria have been found in core droughted root microbiomes . Thus, bIn this review, we have attempted to summarize existing knowledge regarding the complex interplay between soils, plants, microbes and drought, which ultimately act to determine root-associated bacterial community composition. Plants are non-autonomous systems in their ecosystems, and much of their functioning, including nutrient uptake and stress response, is linked to soil bacterial communities. However, despite the importance of the root microbiome on plant health, as well as the increasing frequency of drought events due to climate change, very little research is available on the root microbiome under drought. This gap exists in part due to our incomplete understanding of relative contributions of and interactions between the various factors that produce the resultant bacterial communities. Future refinement and consolidation of methods by which the drought-root microbiome is studied will lead to a much richer understanding of these processes. Insight into plant enrichment of bacterial taxa under drought will identify taxa implicated in plant growth promotion, and in turn enhance development of microbial-based soil amendment strategies to alleviate drought stress for crops in arid regions, thus boosting food security against the increasing threat of climate change.DN organized and wrote the manuscript. DC-D edited the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The sudden death of a friend or relative, particularly by suicide, is a risk factor for suicide. People who experience sudden bereavement report feeling highly stigmatised by the loss, potentially influencing access to support. We assessed whether perceived stigma following sudden bereavement is associated with suicidal thoughts and suicide attempt. We analysed cross-sectional survey data on 3387 young adults bereaved by the sudden death of a close contact. We tested the association of high versus low perceived stigma  with post-bereavement suicidal ideation and suicide attempt, using random effects logistic regression, adjusting for socio-demographic factors, pre-bereavement psychopathology, and mode of sudden bereavement . Subjects with high perceived stigma scores were significantly more likely to report post-bereavement suicidal thoughts (adjusted odds ratio (AOR) = 2.74; 95% confidence interval (CI) = 1.93–3.89) and suicide attempt  than those with low stigma scores. People who feel highly stigmatised by a sudden bereavement are at increased risk of suicidal thoughts and suicide attempt, even taking into account prior suicidal behaviour. General practitioners, bereavement counsellors, and others who support people bereaved suddenly, should consider inquiring about perceived stigma, mental wellbeing, and suicidal thoughts, and directing them to appropriate sources of support. The search for modifiable risk factors for suicide underpins the suicide prevention research agenda. Sudden bereavement, particularly by suicide , is now The means by which stigma creates barriers to help-seeking have been well-described in relation to mental illness , but lesn = 3387). We analysed data from the UCL Bereavement Study ,9. This The study was approved by the UCL Research Ethics Committee in 2010 (ref: 1975/002). All participants provided online informed consent. Our exposure measure was high perceived stigma of the bereavement, defined using the 10-item stigma subscale of the Grief Experience Questionnaire (GEQ) . The GEQBox 1Stem: Since the death how often did you….feel like a social outcast?feel like no-one cared to listen to you?feel that neighbours and friends did not offer enough concern?feel avoided by friends?think people were gossiping about you or the person?think that others didn’t want you to talk about the death?feel somehow stigmatised by the death?feel like people were probably wondering about what kind of personal problems you and the person had experienced?think that people were uncomfortable offering their condolences to you?feel like the death somehow reflected negatively on you or your family?Our primary outcomes were self-reported suicidal ideation   and selfOur three secondary mental health outcomes were post-bereavement non-suicidal self-harm  using the standardised, validated APMS measure  ; receipWe selected nine confounding variables on the basis of existing literature and clinical judgement: age; gender; socio-economic status ; mode oMissing data for model covariates and outcomes were less than 7%.We investigated simple associations between the outcome variables and exposure using χ2 tests or one-way analysis of variance, as appropriate.p = 0.006 for multiple testing.We investigated the relationship between outcomes and high stigma scores using multilevel regression models with HEI as random effect, to take into account the clustering effect at the HEI level. We used ordinal logistic regression to investigate the relationship between social support and high levels of perceived stigma scores. All multivariable models included the nine pre-specified confounding variables described above. Models were fitted using complete case analysis. We used the Bonferroni correction to set a significance threshold of p-value threshold (p = 0.1) to reflect the limited statistical power of interaction tests.To test whether the effect of high stigma scores on primary outcomes varied by gender and by mode of bereavement, we added interaction terms to these models, using a less stringent n = 1510). To test an additional research question about whether high perceived stigma helps differentiate those who attempt suicide after bereavement from those with suicidal ideation after bereavement, we ran our multivariable model for suicide attempt in the sub-sample of those who reported suicidal thoughts or attempts post-bereavement  or as negative  respectively . In the All analyses were conducted using Stata version 12 .The majority of the sample were female (81%), of white ethnicity (90%), bereaved by sudden natural causes (61%), and reported the death of a relative (71%). The mean time elapsed since bereavement was 5 years (standard deviation (SD) = 5.3 years; range = 1 day to 30 years), with no group differences . The ageAmongst subjects who had made a suicide attempt since the bereavement, those who reported high stigma scores were significantly less likely to have sought help for it than those reporting low stigma scores.Overall, 32% of the sample had received no informal support after the bereavement .In an adjusted analysis , high stHigh stigma scores were positively associated with poor social support , and use of formal bereavement support , but negatively associated with use of informal bereavement support .n = 1510 individuals who reported suicidal thoughts or attempts post-bereavement, we found a significant association between high stigma scores and post-bereavement suicide attempt .In the sub-sample of Gender did not modify the associations between stigma and primary outcomes, but there was an interaction with mode of bereavement, such that the magnitude of the association between high stigma and suicidal ideation was higher for those bereaved by sudden natural death  or sudden unnatural death  than for those bereaved by suicide .p ≤ 0.001) and suicide attempt . On all other measures, it also showed directions of associations consistent with those in our main analysis .The magnitude and direction of adjusted odds ratios for primary outcomes were unchanged in four sensitivity analyses simulating potential biases introduced by missing data and by our sampling strategy. Conducting the analysis using linear regression showed that stigma scores were significantly associated with suicidal ideation (adjusted coefficient = 0.033; 95% CI = 0.029–0.037; The findings of this analysis of British cross-sectional data support our hypothesis that people who feel highly stigmatised by the sudden death of a friend or relative are at increased risk of suicidal thoughts, suicide attempt, non-suicidal self-harm, and depression. The cross-sectional nature of the data limits interpretation of the chronology of the pathways between high stigma scores and outcomes. However, associations with support measures suggested a buffering effect of social support on the negative effects of perceived stigma: those with low perceived stigma scores were more likely to report use of informal support, whereas those with high stigma scores perceived poor social support. Contrary to our hypothesis, use of formal support was more likely in people who felt highly stigmatised, perhaps because they could not rely on friends and family. It is possible that informal support plays an important role in preventing and/or redressing perceived stigma and in mitigating the effects of stigma on suicidality and depression. The results of our interaction tests are interpretable in the context of previous findings from this dataset, namely the increased risk of suicide attempt in people bereaved by suicide . AmongstPrevious studies measuring the stigma of sudden bereavement have compared groups defined by cause of death ,9, but nWe analysed data from a large, UK-wide sample of 3387 bereaved adults using a validated stigma measure. We tested specific hypotheses formulated on the basis of theory and clinical experience, and our models were adjusted for pre-selected potential confounders. Results were robust to sensitivity analysis simulating potential biases. We acknowledge the potential for male non-response bias, and selection bias of highly educated adults from HEIs. This, and the restricted 18–40 age range, suggest that this study’s findings may only be generalizable to highly-educated young women in the UK. All measures were potentially subject to recall bias. Although validated, our measure of lifetime depression was derived from a brief screening tool , and mayThis study has identified perceived stigma after sudden bereavement as a potentially useful marker for suicidality, depression, and for poor social support. Indeed, among those who had felt suicidal following sudden bereavement, perceptions of high stigma helped differentiate attempters from ideators. Identification of people who feel highly stigmatised after bereavement creates an opportunity to intervene and prevent suicide attempt. General practitioners and bereavement counsellors who encounter bereaved people might consider inquiring about perceived stigma as a way of building a rapport before probing, where appropriate, for low mood and thoughts of self-harm and suicide. Anyone in contact with someone bereaved traumatically has a role in providing information on sources of voluntary sector bereavement support ,46,47. GThe role of stigma as a putative mediator in the association between sudden bereavement and suicide-related outcomes, and the role of informal support as a moderator of this effect, would need formal testing using longitudinal approaches. If stigma is confirmed as mediating risk of suicidality, the next step would be to develop and trial individual-level or community-level anti-stigma interventions. These might address the barriers to seeking or receiving support, and potentially reduce suicide rates. Cultural dimensions of grief  suggest The results of this study suggest that people who feel the most stigmatised by a sudden bereavement are at greater risk of suicidal behaviour and depression, and are more likely to feel inadequately socially supported by friends and family. High perceived stigma helps differentiate those who attempt suicide after sudden bereavement from those who consider it. Clinicians who inquire about perceived stigma are in a position to identify suicidal distress and address support needs. All those who have contact with people bereaved traumatically should direct them to appropriate sources of support, to overcome any barriers to help-seeking and the effects of perceived stigma.


A significant correlation was found between the decrease performance of ANT and the increase in CBF changes in some brain regions of the patients with breast cancer. The results demonstrated that neoadjuvant chemotherapy influences hemodynamic activity in different brain areas through increasing cerebral perfusion, which reduces the attention abilities in breast cancer patients.To investigate the neural mechanisms underlying attention deficits that are related to neoadjuvant chemotherapy in combination with cerebral perfusion. Thirty one patients with breast cancer who were scheduled to receive neoadjuvant chemotherapy and 34 healthy control subjects were included. The patients completed two assessments of the attention network tasks (ANT), neuropsychological background tests, and the arterial spin labeling scan, which were performed before neoadjuvant chemotherapy and after completing chemotherapy. After neoadjuvant chemotherapy, the patients exhibited reduced performance in the alerting and executive control attention networks but not the orienting network ( An increasing body of evidence demonstrates that breast cancer patients suffer from many cognitive impairments related to adjuvant chemotherapy, including problems with verbal and/or visuospatial memory, attention deficits, difficulty in learning, confused thought processes1As a major component of the cognitive system, the attention work is involved in the centralization of brain or mental activities and the allocation of psychological resources7810In recent years, arterial spin labeling (ASL) has become an important noninvasive functional magnetic resonance imaging technique that uses magnetically labeled arterial blood water as an endogenous contrast agent to measure resting CBF images. This method has been widely applied to assess the cerebral perfusion in various clinical conditions, including neurodegenerative diseases1619Due to the cross-sectional design used in our previous study, attention was not measured in the patients before their chemotherapy treatment. In the current study, patients with breast cancer were used to assess the potential changes in attention function before and after exposure to neoadjuvant chemotherapy in which the term “neoadjuvant” refers to the chemotherapy given before surgery, radiation, and anti-estrogen treatment, which offers advantages in terms of adding prognostic information and improving surgical options. Moreover, we used ASL to measure longitudinal differences in cerebral perfusion in these patients. Based on findings from the literature and our previous study, we hypothesize that after neoadjuvant chemotherapy, breast cancer patients have impaired performance in attention and changes in cerebral perfusion compared to themselves before neoadjuvant chemotherapy and healthy control participants. We also examined the relationships between the cerebral perfusion alterations and attention function changes that were observed in these patients.A total of 68 participants meeting the criteria were initially enrolled in the study. One patient did not complete the follow-up assessment. Two additional participants  were excluded from the analysis because of excessive head motion artifact during data acquisition. Therefore, the final analytical sample size was 31 patients and 34 healthy controls.Participant demographic and clinical information is shown in t-tests showed that post-treatment patients performed significantly worse in attention and concentration tests (WAIS Digit Span backward), memory , and executive function  when compared with pre-treatment patients  and a higher mean executive control network RT after treatment. Paired As shown in To identify the significance of the perfusion increase and the mechanism of attention deficits, we performed a correlation analysis between the perfusion change and attention performance. We calculated the change in CBF values (CBF at post-treatment minus CBF at pre-treatment) in the aforementioned significantly increased regions. Likewise, the post-treatment scores minus the pre-treatment scores of the attention networks were calculated to indicate changes in the attention networks. Significant correlations were observed between the changes in the alerting network score and the changed CBF values in the left posterior cingulate gyrus , bilateral inferior parietal gyrus , bilateral middle temporal gyrus , bilateral precuneus , and bilateral cuneus . Additionally, significant correlations were also found between the changes in the executive control network score and the changed CBF values in the left posterior cingulate gyrus , left superior frontal gyrus , left inferior frontal gyrus , bilateral inferior parietal gyrus , bilateral superior temporal gyrus , bilateral middle temporal gyrus , bilateral inferior temporal gyrus , bilateral precuneus , and bilateral cuneus .To the best of our knowledge, our study is the first to investigate potential neoadjuvant chemotherapy-induced changes in the attention network in combination with cerebral perfusion changes, as indicated using ASL measures. Our results demonstrate impairment of the alerting and executive control attention networks and an increase in perfusion in brain regions after chemotherapy in patients with breast cancer. We found that after chemotherapy, the patients exhibited reduced performance in the alerting and executive control attention networks, and showed a significant increase in CBF of brain regions as shown above, when compared with patients before chemotherapy and healthy controls. In contrast, these differences were not present in either the patients before chemotherapy or the healthy controls. In addition, the patients performed worse on neuropsychological background tests from baseline to post-treatment. Furthermore, we found that such a decrease in the performance of the ANT task was significantly correlated with an increase in the CBF changes in different brain regions in the patients with breast cancer. Taken together, these results demonstrate that the neoadjuvant chemotherapy-induced cerebral perfusion changes may account for the attention deficits of the patients with breast cancer.Pre-operative systemic therapy with AC (doxorubicin/cyclophosphamide) followed by pre-operative T (docetaxel) is a commonly used regimen for the neoadjuvant chemotherapy treatment of breast cancer. The individual agents of this regimen could induce cognitive changes via several processes that influence brain structure and function, such as oxidative stress, DNA damage, altered hormone levels, and immune response deregulation2325According to Posner’s dominant theory of attention network, which emphasizes the involvement of neural attention networks in alerting, orienting, and executive control networks. Clinical studies and neuroimaging evidence indicate that the alerting system is associated with the frontal and parietal cortices and thalamus and that prefrontal cortex has a central role in supporting the executive control network2830et al. revealed that patients with chemotherapy showed an altered functional connectivity in the right frontoparietal and left superior frontal gyri networks34The frontal and parietal lobes play a more direct role in regulating the focus of attention function, as previously shown. Furthermore, the posterior cingulate gyrus, precuneus and temporal cortex play an important role in attentional processing through organizing corresponding brain networks, such as the attention network, frontoparietal network, and default mode network (DMN), to help guide attention taskset al. showed that the healthy controls showed no change in cerebral perfusion using the ASL when the inter-scan interval was approximately 160 days39Several limitations of the present study should be considered. First, the design of this study lacks the matched interval time for healthy controls to eliminate time factors that could affect brain structure and function. Previous studies show that changes in cognitive function, including those related to the ANT task, do not exist in short period intervals for healthy persons37In conclusion, our study represents a significant step toward understanding potential neoadjuvant chemotherapy-induced changes in the attention network and cerebral perfusion. Our findings demonstrated that the neoadjuvant chemotherapy-induced breast cancer patients exhibited impairment of attention networks, which includes the reduced performance in the alerting and executive control attention networks and an increase in the perfusion of specific brain regions. We also reveal the reduced performance in the attention networks, which was correlated with an increase in CBF in related brain regions.The present study was approval from the Research Ethics Committee of the First Affiliated Hospital of Anhui Medical University. We recruited a total of 33 young women with middle-to-late-stage breast cancer who were scheduled to receive neoadjuvant chemotherapy. The patients received preoperative systemic therapy with AC (doxorubicin/cyclophosphamide) followed by preoperative docetaxel for 4 cycles after breast cancer diagnosis. The dosing schedules for AC were followed by docetaxel chemotherapy. Specifically, doxorubicin at 60 mg/m intravenously (IV) was given on day 1, and cyclophosphamide at 600 mg/m IV was given on day 1, which were cycled every 21 days for 4 cycles. Subsequently, docetaxel treatment at 100 mg/m IV was given on day 1 and cycled every 21 days for 4 cycles. Pre-treatment assessment was conducted after diagnosis but before neoadjuvant chemotherapy. Follow-up post-treatment assessment was performed within 1 month after completing eight cycles of neoadjuvant chemotherapy. Thirty-five matched healthy controls participated in the present study. There was only a single assessment for these healthy controls. The detailed information recorded from each participant is described in As in our previous studies, neuropsychological background tests and the ANT task were assessed for all patients and healthy controls. General cognitive functions were assessed using the Beijing version of the Montreal Cognitive Assessment (MoCA) test. The digit span test was used to measure attention. The Hamilton Depression Rating Scale (HAMD) and HAMA were used to assess participants’ possible depressive and anxiety symptoms. The Stroop test, Trail Making test and Verbal fluency test were used to measure executive function. The Chinese version of the Auditory Verbal Learning Test (AVLT) was used to assess memory. The ANT taskAll imaging data were acquired on a 3.0-T MR system  at the First Affiliated Hospital of Anhui Medical University. Multiple modalities included 3D T1-weighted, T2-weighted turbo spin echo (TSE), fluid attenuated inversion recovery (FLAIR) images, and whole brain 3D pseudo-continuous ASL (pcASL) . A voxelwise two-sample t-test was performed using AFNI  between every two of the three groups except for the comparison between after treatment and before treatment, where a paired t-test was used instead. The multiple comparison issue was addressed at the cluster level using false discovery rate (FDR) correction, with q < 0.01. A minimum voxel size of 100 was set to exclude small clusters  was used to analyze the clinical and demographic data. Paired How to cite this article: Chen, X. et al. The attention network changes in breast cancer patients receiving neoadjuvant chemotherapy: Evidence from an arterial spin labeling perfusion study. Sci. Rep.7, 42684; doi: 10.1038/srep42684 (2017).Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


Ischemic stroke is a major cause of death and disability globally, and its incidence is increasing. The only treatment approved by the US Food and Drug Administration for acute ischemic stroke is thrombolytic treatment with recombinant tissue plasminogen activator. As an alternative, therapeutic hypothermia has shown excellent potential in preclinical and small clinical studies, but it has largely failed in large clinical studies. This has led clinicians to explore the combination of therapeutic hypothermia with other neuroprotective strategies. This review examines preclinical and clinical progress towards developing highly effective combination therapy involving hypothermia for stroke patients. Hypothermia is a remarkable neuroprotectant and can mitigate brain injury induced by stroke, trauma, cardiac arrest or hypoxic-ischemic encephalopathy in newborns -3. Yet hTo overcome these limitations, preclinical and clinical studies over the last few decades have been exploring the combination of hypothermia with a second neuroprotective strategy . Such coIn this approach, hypothermia is combined with the administration of NMDA receptor antagonists in order to reduce excitotoxicity. To date, this approach has been tested in preclinical studies. The approach is based on the fact that the abrupt deprivation of oxygen and energy depolarizes neurons and glial cells, which release large amounts of excitatory amino acids into the synaptic cleft. These amino acids bind to several receptors, one of which is the NMDA receptor, which in response triggers calcium influx that leads to programmed cell death. Not surprisingly, efforts to develop neuroprotective therapies have been focusing on NMDA receptors for decades, and various antagonists have been studied on their own or combined with hypothermia.The first studies were conducted using the non-competitive antagonists dextromethorphan and MK-801. In one study, animals were exposed to MK-801, hypothermia (33°C) or both and then subjected to permanent middle cerebral artery occlusion . Either It is difficult to understand the mechanism of combination therapies involving hypothermia and non-competitive antagonists such as MK-801, since this compound by itself induces hypothermia , 14. As Therefore, research has also focused on competitive NMDA receptor antagonists such as selfotel CGS-19755). Despite being a potent antagonist, this compound did not provide significant neuroprotection in gerbils when administered alone or with hypothermia 30 min after 5-min forebrain ischemic insult . In cont755. Desp2+). Mg2+ exerts anti-excitotoxic effects by antagonizing calcium entry via the NMDA receptor [2+ does not confer neuroprotection in transient or permanent stroke, but when combined with hypothermia, it has shown promising benefits in both injury contexts [2+ and hypothermia after ischemic stroke [An alternative to exogenous antagonists is to use endogenous antagonists such as magnesium ion , which can lead to further excitotoxicity and hemorrhagic transformation. Hypothermia induced shortly after reperfusion can reduce NO efflux in the brain and BBB leakiness, minimizing reperfusion injury , 26.One study reported that combining hypothermia and plasminogen activator reduced infarct size as well as the hemorrhagic transformation ratio that plasminogen activator therapy usually increases . HypotheNevertheless, the benefits of this combination therapy are not without controversy. Studies of embolic stroke reported no therapeutic enhancement when the two treatments were combined , 30. OthThese results suggest a somewhat inconsistent picture of therapeutic benefits of combination therapy, highlighting the need for more detailed mechanistic insights.On the basis of the strong benefits reported for thrombolysis or hypothermia on their own, clinical trials have explored the safety and efficacy of combining the two for treating acute ischemic stroke patients. The ICTuS-L trial recruited acute ischemic stroke patients within 6h of symptom onset and administered intravenous thrombolysis with or without 24-h endovascular cooling (33°C) . Based oTherapeutic benefit of combination therapy may depend on the relative timing of the procedures: performing hypothermia after thrombolysis has been shown to reduce edema and hemorrhagic transformation  as well Endovascular mechanical thrombectomy  is an alternative to plasminogen activator therapy that has significantly improved the success rate of stroke treatment in recent years , 36. OneThese clinical studies show the feasibility and safety of combining hypothermia with plasminogen activator therapy or intra-arterial recanalization in acute stroke patients. They also highlight the feasibility of intra-arterial hypothermia as a potentially safer alternative to systemic cooling. Further work is needed to determine whether such combination therapies are superior to thrombolysis or recanalization on their own.This approach has been tested so far only in preclinical studies. It is well known that neuroinflammation is a key element in the ischemic cascade after cerebral ischemia, and that it leads to the damage and death of neurons in the subacute phase. This death and especially the release of necrotic cell debris triggers inflammation, strongly activating phagocytic cells . InductiThe anti-inflammatory effects of minocycline, a second-generation, semi-synthetic tetracycline, are thought to contribute to its ability to protect neurons from ischemic injury in preclinical models . VariousThis approach aims to increase brain perfusion in order to protect neurons from ischemic injury, and so far, it has been evaluated only in preclinical studies. Statins up-regulate endothelial nitric oxide (NO) synthase (eNOS) and are recommended for treating patients with atherosclerotic ischemia . NO is aThis approach, which has been tested so far only in preclinical studies, aims to scavenge excess free radicals produced when cerebral ischemia and reperfusion injury perturb the balance between free radical production and degradation . Since 2Mannitol is a free-radical scavenger also used clinically as a dehydrating agent because it can reduce intracranial pressure by creating an osmotic pressure gradient . Combini+/K+ ATPase, and it inhibits the activation of phospholipase A2, the formation of free radicals and the release of free fatty acids [This approach, which has been evaluated so far only in preclinical studies, takes advantage of the ability of citicoline to mimic cytidine-5’-diphosphocholine, which is an intermediate in the generation of phosphatidylcholine and is essential for the biosynthesis of membrane phospholipids . Citicolty acids , 63. Citty acids . Combinity acids .The combination of low-dose caffeine and ethanol, termed caffeinol, can effectively reduce brain damage in rodent models of focal cerebral ischemia , perhapsIn addition to preclinical studies, the combination of caffeinol and hypothermia has been explored in patients. In one study in which caffeinol, tissue plasminogen activator and hypothermia (33-35°C) induced from 5 to 24 h after stroke onset were given to patients with acute ischemic stroke, caffeinol did not enhance the effects of plasminogen activator .Phenothiazines are among the oldest synthetic anti-psychotic drugs. They block dopaminergic receptors to induce neuroleptic effects, but they also reduce energy consumption by inhibiting calmodulin, protein kinase C, and P-glycoprotein transport, suppressing cell proliferation , 71. ComNumerous preclinical studies have explored the combination of hypothermia with barbiturates and volatile anesthetics, which on their own have been shown to protect against cerebral damage in animal models of focal ischemia , 74. TheMethohexital administered 30 min before stroke reduced infarct volume and neurological score in a preclinical study, and these benefits were not enhanced by adding hypothermia . In a st2+ stores from endoplasmic reticulum, protecting neurons from oxygen-glucose deprivation toxicity [The anesthetic dantrolene, an inhibitor of ryanodine receptors, shows good preclinical promise for enhancing the therapeutic benefits of hypothermia after stroke. It blocks the release of Catoxicity  and apoptoxicity . Dantroltoxicity  and redutoxicity , both cotoxicity .One of the initiators of ischemic pathophysiology is shortage of oxygen to the brain. Normobaric hyperoxia (NBO), induced by breathing air containing 21-100% oxygen at a pressure of 1 absolute atmosphere, effectively reduced infarct volume and neurological deficits in rodents following acute ischemic stroke , 95. NBOHyperbaric oxygen (HBO) may provide superior neuroprotection than NBO during transient and permanent cerebral ischemia , 102. AtHematopoietic cytokines, by binding receptors on the membranes of neurons and glial cells in the central nervous system, stimulate intracellular signaling pathways that can help protect against injury and/or support neurogenesis , 107. ThInsulin-like growth factors (IGFs) are peptide hormones with significant structural homology to insulin. IGF-1 is a potent cardiomyocyte growth and survival factor , which cBrain-derived neurotrophic factor (BDNF) plays an important role in proliferation, differentiation, maintenance, plasticity, survival and neurite extension in the central and peripheral nervous systems . BDNF ad2+ is a non-competitive endogenous NMDA antagonist [2+ and tirilazad given pre-ischemia resulted in better neurologic function and smaller infarct volume [2+, tirilazad and hypothermia gave better results than the combination of nimodipine, mannitol, dexamethasone, and methohexital [2+, tirilazad and hypothermia showed potent neuroprotection when administered before ischemia onset or up to 3 h afterwards [Mgtagonist , and tirtagonist . Administagonist , 131. Tht volume . Combinit volume . The samohexital . At leasterwards .This approach, which has been evaluated only in preclinical studies, is based on the ability of albumin to inhibit endothelial apoptosis and to act as an antioxidant . It alsoDecompressive craniectomy, in which part of the skull is removed and the dura is opened, can reduce intracranial pressure; edema is a lethal complication of malignant supratentorial stroke, and it leads to high mortality . This suThe combination of hypothermia and decompressive craniectomy has also been evaluated in clinical trials. The combination of surgery and hypothermia (35°C) induced immediately afterward led to better clinical outcomes than surgery alone in patients with malignant supratentorial stroke .in vivo and in vitro [This approach, which has been evaluated only in preclinical studies, takes advantage of the fact that Bax promotes apoptosis, whereas Bcl-2 and Bcl-xL inhibit apoptosis by blocking the translocation of cytochrome C. Substituting three amino acids in Bcl-xL enhances the anti-apoptotic activity, and the resulting variant, called FNK, can be fused to the protein transduction domain of HIV/Tat protein and efficiently introduced into cells . In cellin vitro . Combiniin vitro .The rationale of gene therapy is to insert genes encoding neuroprotective proteins into neurons to promote their survival against cerebral insults . Such thThe combination of diverse neuroprotective strategies with hypothermia has been extensively investigated for the alleviation of ischemic injury arising from cardiac arrest, hypoxic-ischemic encephalopathy or spinal cord impairment. The literature applying such combination therapy to focal stroke is more limited. In addition, studies of such combination therapy often report inconsistent results about the efficacy for treating stroke . SeveralAn important consideration when assessing evidence about efficacy of combination therapy is whether the study was conducted in preclinical models or in patients. Hypothermia has shown clear neuroprotective effects in animal studies, but not sure in clinical trials. Hypothermia is induced differently in preclinical animal models and in patients and hypothermia complications such as shivering and infections are generally ignored in the laboratory but can pose substantial problems in the clinic. At the very least, the studies reviewed here make clear that hypothermia induction is feasible in stroke patients, though the optimal conditions still need to be explored.This review also illustrates the broad range of neuroprotective treatments that have shown promise in preclinical studies, but have not yet been evaluated in the clinic or have failed to show success in patients. So far, only tissue plasminogen activator, intra-arterial recanalization, caffeinol and decompressive hemicraniectomy have been combined with hypothermia in stroke patients. Much more work remains to be done, which should take into account the heterogeneity of human stroke.


The hypothalamus is involved in the regulation of homeostatic mechanisms and migraine-related trigeminal nociception and as such has been hypothesized to play a central role in the migraine syndrome from the earliest stages of the attack. The hypothalamus hosts many key neuropeptide systems that have been postulated to play a role in this pathophysiology. Such neuropeptides include but are not exclusive too orexins, oxytocin, neuropeptide Y, and pituitary adenylate cyclase activating protein, which will be the focus of this review. Each of these peptides has its own unique physiological role and as such many preclinical studies have been conducted targeting these peptide systems with evidence supporting their role in migraine pathophysiology. Preclinical studies have also begun to explore potential therapeutic compounds targeting these systems with some success in all cases. Clinical efficacy of dual orexin receptor antagonists and intranasal oxytocin have been tested; however, both have yet to demonstrate clinical effect. Despite this, there were limitations in these cases and strong arguments can be made for the further development of intranasal oxytocin for migraine prophylaxis. Regarding neuropeptide Y, work has yet to begun in a clinical setting, and clinical trials for pituitary adenylate cyclase activating protein are just beginning to be established with much optimism. Regardless, it is becoming increasingly clear the prominent role that the hypothalamus and its peptide systems have in migraine pathophysiology. Much work is required to better understand this system and the early stages of the attack to develop more targeted and effective therapies aimed at reducing attack susceptibility with the potential to prevent the attack all together.The online version of this article (10.1007/s13311-017-0602-3) contains supplementary material, which is available to authorized users. The hypothalamus is involved in the modulation of a number of fundamental physiological processes, including sleep, circadian rhythms, appetite, thirst, urination, and the regulation of the autonomic, cardiovascular, endocrine, and trigeminal pain systems . ModulatThe opportunity to identify and target the early stages of the attack is an exciting step forward in migraine management and treatment. Currently, the majority of therapies are ineffective or poorly tolerated and largely focus on treating the head pain component of the disorder . By shifAs alluded to in the introduction, the hypothalamic involvement in migraine is complex with dysfunction evident from the earliest stages and throughout the different phases of the migraine attack. The first section of this review will thus highlight the general hypothalamic involvement throughout each phase before exploring the unique roles of its peptide systems and the current targeted pharmacotherapies..Premonitory symptoms occur up to 72 h before the onset of migraine pain . Such syAs the attack progresses, autonomic symptoms, including nausea, nasal congestion, and lacrimation, may develop in addition to head pain. Aberrant hypothalamic activity, particularly a hypersensitivity to dopamine, may largely account for symptoms of nausea, vomiting, and excessive yawning. This has been supported experimentally, where administration of dopamine agonists increase these symptoms in migraine patients . FurtherMigraine pain is centered around aberrant activation of the trigeminovascular system leading to an overall dysregulation of sensory processing. Pseudo-unipolar trigeminal afferents innervate pain-sensing extracranial structures while sending central projections to the trigeminal cervical complex (TCC) of the brainstem , 13. SecThe hypothalamus is known to be involved in nociceptive processing and is linked with key areas of the pain neuro-axis, including the cortex, thalamus, amygdala, PAG, and the spinal cord dorsal horn . As suchIn specific regard to migraine-related pain, imaging studies have shown hypothalamic activation during the pain phase of the migraine attack . The hypHypothalamic-related perturbations, such as sleep disturbances, changes in arousal, and appetite dysregulation, can increase the probability of an attack in addition to being an indication of early symptoms. Sleep and feeding behaviors are regulated by both circadian periodicity and individual mechanisms of which dysfunction could contribute to migraine pathophysiology.Increasing evidence from clinical and basic scientific research suggests that circadian rhythm dysregulation plays a significant role in migraine susceptibility. The hypothalamus, specifically the suprachiasmatic nucleus, controls the circadian periodicity of biological processes such as sleep–wake, appetite, metabolism, and thermoregulation . AlteratIn clinical practice, patients with migraine commonly report sleep disturbances and circadian disruption as reliable triggers. This can include too much or too little sleep, jetlag, and shift work , 33. PatFeeding and appetite also exhibit circadian rhythmicity controlled by the hypothalamus and have been implicated in increased migraine susceptibility and attack symptomology. For example, skipping meals is a common migraine trigger, and attack frequency and severity have been seen to increase with body mass index , 41–43. As we have seen in the previous section, the hypothalamus is deeply involved in the migraine attack, including increasing susceptibility, attack triggering, and symptomology. What we have not explored yet is how the hypothalamus is able to control and regulate such a wide variety of physiological functions. The hypothalamus is an extremely heterogeneous nucleus that synthesizes many neuropeptides. Each uniquely contribute to the regulation of physiological functions such as sleep–wake regulation, appetite, and nociceptive processing, and thus individual peptide systems have been proposed to play a key role in the pathogenesis of migraine. This section will explore the role of orexins, pituitary adenylate cyclase activating protein (PACAP), oxytocin, and neuropeptide Y (NPY), and highlight preclinical and clinical therapies specifically targeting these systems.The orexins  are a pair of hypothalamic neuropeptides synthesized in cell bodies exclusively in the lateral hypothalamus , 49. TheSuch widespread projections implicate the orexins and thus the hypothalamus in the modulation of homeostatic functions, including appetite, sleep–wake, hormone secretion, and autonomic regulation –55. WithOrexin levels experience a circadian periodicity where they tend to be highest during awake periods , 55. FurThe central role that orexins play in the regulation of homeostatic mechanisms points to a potential role for orexin disruption in migraine pathophysiology. Such a role has been supported by increasing clinical and anatomical evidence. Migraineurs, both chronic and episodic, have shown altered levels of orexin as measured in the cerebrospinal fluid (CSF). Episodic migraineurs have been shown to have lower levels, whereas patients with chronic and medication overuse headache exhibit higher levels , both ofvs 30% and 8% in the general population) [Perhaps the most convincing clinical association is in the increased prevalence of migraine in narcoleptic patients  , indicatAnatomically, the orexin system is closely integrated with other brain systems involved in migraine pathophysiology. Hypothalamic orexinergic afferents widely project to many brain areas involved in trigeminal nociception, including the cerebral cortex, cingulate cortex, paraventricular thalamic nuclei, LC, PAG, nucleus raphe magnum, and spinal and trigeminal dorsal horns , 68, 69.Taken together, disrupted orexinergic systems can contribute to altered homeostatic mechanisms that can influence attack susceptibility, premonitory and associated symptoms, and migraine nociception; as such, this system has been identified as a potential therapeutic target for migraine.Dual orexin receptor antagonists (DORAs) have already been developed for the treatment for insomnia  and giveAs the name suggests, DORAs have equal affinity for both orexin receptors. DORA-12, commonly known as suvorexant, antagonizes an orexin-induced calcium increase in cells expressing OXR1 or OXR2 . PreclinHowever, there has been some concern over the clinical efficacy of dual orexin receptor antagonism in migraine therapy. The selective targeting of individual receptors may prove to be more efficacious as OXA and OXB have consistently shown to have differential experimental effects on trigeminal nociception. Bartsch et al.  demonstrAlthough several preclinical studies have demonstrated the possible beneficial therapeutic effect of orexin-related chemicals, only 1 randomized, double-blind, placebo-controlled clinical study has been conducted. Chabi et al.  investigOxytocin is a hypothalamic neuropeptide and peptide hormone that plays a diverse role in physiological functions, including social bonding, sexual reproduction, childbirth, and modulation of pain processing. Oxytocin is a small polypeptide of only 9 amino acids and is synthesized in magnocellular neurosensory cells in the supraoptic and paraventricular nuclei of the hypothalamus , 82. As Many brain areas involved in pain modulation have been shown to express oxytocin receptors such as the dorsal root and trigeminal ganglia, thus suggesting a role in migraine-specific pain modulation . In clinin vitro has been shown to block CGRP release, indicating that oxytocin agonists may be a novel therapeutic target for migraine [In support of this postulated role for oxytocin migraine nociception, trigeminal afferents have been shown to co-express oxytocin receptors and calcitonin gene-related peptide (CGRP) , a neuromigraine .in vitro and produce analgesia in vivo in pre-existing states of inflammation or injury [Preclinical studies have subsequently demonstrated analgesic effects of oxytocin in pain processing with some indication of efficacy on trigeminovascular nociception. In agreement with animal models of pain having previously demonstrated oxytocin to be a strong analgesic , 96, 97,r injury . Furtherr injury . TherefoRecent work has begun to investigate intranasal oxytocin as a viable treatment for migraine. Intranasal administration has been chosen as the treatment route of choice as oxytocin is a small polypeptide with a short half-life of 3 to 4 min , making versus models without inflammation [A preclinical study conducted by Tzabazis et al.  has showammation , indicatClinical studies, both case studies and clinical trials, provide good evidence for the further investigation of the therapeutic effect of oxytocin in migraine treatment. In 2006, Phillips et al.  reportedA clinical trial investigating the effectiveness of oxytocin in migraine was reported in 2017. Tzabazis et al.  conducteThe same group also conducted the study in patients with chronic migraine. Forty patients with chronic migraine were randomized to receive either 32 IU of intranasal oxytocin  or a matched placebo intranasal spray (18 subjects). They found that although there was not a significant difference in the proportion of subjects experiencing substantial pain relief (reduction from moderate or severe pain to mild or none) at 2 h), there was a significant difference by 4 h after treatment. Interestingly, the effectiveness of oxytocin was compromised by prior taking of nonsteroidal anti-inflammatory drugs. These series of studies also tested the effect of intranasal oxytocin on migraine frequency. Two hundred and eighteen migraine sufferers  were included in a multinational double-blind, placebo-controlled study. One hundred and forty-three subjects were in the oxytocin treatment group and 75 in the placebo treatment group. The intervention consisted of a 28-day baseline phase followed by 56 days of “as needed” dosing with either 30 IU of intranasal oxytocin or matching placebo. The primary endpoint was the reduction in migraine headache days from the baseline period to the final 28 days. The results showed a clear reduction in headache frequency as well as responder rate in the oxytocin treatment group. Unfortunately, the study did not meet the primary endpoint owing to an extremely high placebo rate at one study site. The authors concluded that their studies provide a strong argument for further development of intranasal oxytocin for migraine prophylaxis.PACAP is a neuropeptide that was first identified from the hypothalamus of sheep . PACAP bin vitro study showed that PACAP-responsive receptors in rat trigeminal neurons and glia were pharmacologically distinct. PACAP-38, but not PACAP-27, activated ERK in glia, whereas both forms stimulated cellular cyclic adenosine monophosphate production [PACAP binds with 3 different receptors, namely pituitary adenylate cyclase activating polypeptide 1 (PAC1), vasoactive intestinal polypeptide receptor 1 (VPAC1), and vasoactive intestinal polypeptide receptor 2 (VPAC2) , 114. Sioduction . All typoduction .Owing to its vasodilating property and its presence in parasympathetic and specifically trigeminal ganglia , PACAP iMEF2D gene variant (the mutation that increases risk of migraine without aura) with preictal changes in plasma levels of neuropeptides, tumor necrosis factor-α, and pituitary hormones [Several studies have shown that administration of PACAP can induce migraine-like headache , 125. Alhormones , 129.Considering that PACAP-38 is a trigger of migraine attacks, antagonizing PACAP receptors, especially PAC1 receptor, can be a potential mechanism for antimigraine drugs , 131.Preclinical studies confirm the role of PACAP in controlling cranial vascular tone. Electrical stimulation of nerves in the superior sagittal sinus increased levels of PACAP and CGRP in the cranial circulation in the cat . PACAP-36–38, a PAC1 receptor antagonist, significantly inhibited neurogenic dural vasodilation. Given that the PAC1 receptor is not responsible for direct vasodilatory actions on the vessels, this inhibition is likely to be mediated via PAC1 receptors located on presynaptic nerve terminals of the trigeminal innervation of the dural vasculature [Both VIP and PACAP-38 cause short-lived meningeal vasodilation mediated by VPAC2 receptors, which did not coincide with activation of central trigeminovascular neurons. Administration of PACAPculature . The PACculature .6–38 receptor antagonist [On the neuronal side, PACAP-38 causes delayed activation and sensitization of central trigeminovascular neurons. After a 90-min delay, PACAP-38 increased ongoing spontaneous firing and hypersensitivity to intra- and extracranial somatosensory stimulation without a late response of meningeal artery vasodilation. The dural nociceptive-evoked action potentials in central trigeminovascular neurons was inhibited only by intracerebroventricular administration of the PAC1 receptor antagonist . Microintagonist .ClinicalTrials.gov Identifier: NCT03238781).Evidence confirming clinical efficacy of drug affecting PACAP in migraine treatment is not present at this moment. A phase IIa randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of AMG 301, a PAC1 receptor monoclonal antibody, in migraine prevention has been registered but has not yet recruited . Y1 receptors contribute to the antihyperalgesic effects of NPY by inhibiting SP release, and Y1 receptor signaling in the dorsal horn is increased during inflammatory nociception . In ratsY1 receptors are enhanced after intraplantar injection of complete Freund’s adjuvant in rat. NPY administered intrathecally in rats inhibits hyperalgesia associated with nerve injury and inflammation, and the expression of Fos, a protein marker of neuronal activity –166. BotNPY acts on Y1 receptors in the spinal dorsal horn to decrease nociception by inhibiting SP release, and that this effect is increased by inflammation , 167. NPUnfortunately, no clinical trial investigating effectiveness of NPY-related compounds in migraine has been conducted.The prominent role that the hypothalamus and its peptide systems have in migraine pathophysiology is becoming increasingly clear. The above evidence, mainly preclinical, suggests that modification of hypothalamic peptides may be potential targets in migraine pharmacotherapy Fig. , Table 1In addition to the above, other related peptides such as melatonin and melanin-concentrating hormone (MCH) may also play a role in controlling the excitability of trigeminal nociceptive neurons and thereby may be involve in the migraine pathogenesis. Melatonin is synthesized in the pineal gland rather than hypothalamus, but is involved in the circadian regulation of sleep  and has In conclusion, it is clear that perturbed hypothalamic peptide networks play a role in migraine pathogenesis from the earliest stage of the attack. Evidence that these peptides are able to modulate trigeminovascular nociception and thus the potential remains to develop new therapies to alleviate head pain. However, where the true potential lies is in the ability to identify and target the hypothalamic-driven premonitory phase, by focusing our attention on better understanding these early mechanisms there is great opportunity to stop migraine in its tracks.ESM 1(PDF 1224 kb)


We assessed the efficacy of surgical treatment for the patients with eso-respiratory fistulas. The following cases revealed the anesthesic and surgical difficulties, and also intraoperative and postoperative complications that can occur when the esophageal contents get into the respiratory system. In these situations, therapy must be adapted according to fistula’s topography and etiology, and also to patients’ biological conditions. There are 3 types of eso-respiratory fistulas: canalicular type, diverticular type and direct contact type. No matter the type of fistulas, the management of this disease has 2 importants steps: diagnosis and treatment [2]. Good timing of these two steps can provide excellent outcomes for the patients. Clinical exams are not sufficient for establishing the correct diagnosis and gravity of this disease. These patients request complementary exams; chest X-ray exams with or without barium solutions, esophagoscopy, bronchoscopy, thoracic CT scans and complete evaluation of biological status of patients. Surgical treatment is, by far, the main therapeutical solution for non-malignant eso-respiratory fistulas. Eso-respiratory fistulas have a low frequency but they are life-threating because esophageal content is passing into the respiratory system .- Congenital eso-respiratory fistulas are usually tubular, longues, and facilitate surgery .- Traumatic eso-bronchial fistulas are the most difficult to dissect and to suture [6].The presence of eso-respiratory fistula caused the aspiration of esophageal content into the bronchial tree, leading progressively to congestion, bronchial and lung infections with bronchial occlusion, athelectasy, respiratory distress and exitus. Usually, eso-respiratory fistulas are followed by piosclerosis and lung abscess  and should not be delayed. Spontaneus healing of fistula is seldom  and fistulas’ occlusion with acrylic polymer or electrocauterisation are controversial. Paleativ procedures such as endotracheal or esophageal stents could be experimented on inoperable patients [7]. However, these procedures depend on ethiology and they take place with or without esophageal by-pass.With regard to fistulas’ etiology, therapy is neccessarily surgical [As far as eso-respiratory fistulas’ etiology is concerned, surgery represents the first choice in therapy of non-malignant cases.


To the Editor,1 recently published inArquivos Brasileiros de Cardiologia 2016; 106: 510-8. The reseearchers reported thatonly the intensity of smoking consumption had influences over cardiac autonomicmodulation of the evaluated smokers. Smokers with severe smoking consumption intensitypresented worse autonomic modulation than moderate ones.1I have read, with great interest, the article entitled "Influence of Smoking Consumptionand Nicotine Dependence Degree in Cardiac Autonomic Modulation" by Santos etal.,4Antidepressant medications are a first-line treatment option for moderate to severe moodand anxiety disorders; however, some studies suggest that long-term use may beassociated with an increased risk for cardiovascular disease.5 reported that all users ofselective serotonin reuptake inhibitor - except fluoxetine - display alterations inheart rate or heart rate variability (HRV) in comparison to non users. Similarly, usersof paroxetine also display small to moderate reductions in HRV relative to users ofcitalopram, fluoxetine, and sertraline, but not escitalopram.Kemp et al.In this context, it might be beneficial to give more details about medications due totheir effect on cardiac autonomic activity. Firstly, I would like to thank you for your interest in our manuscript entitled"Influence of Smoking Consumption and Nicotine Dependence Degree in CardiacAutonomic Modulation" by Santos APS et al., recently published in this magazine.As described in the Methods section of the study, individuals on medications thatinfluence cardiac autonomic modulation were not included. Antidepressants, which areamong said medications, are commonly used by smokers, sometimes as a part of a drugtherapy to aid in the cessation of the smoking habit.Even though participants of the study were part of an Antismoking Awareness andOrientation Program, which consists of the association of cognitive behavioral anddrug therapy, they had not yet started the offered treatment, and the cardiacautonomic modulation evaluation was done with smokers who were not abstinent or onspecific cessation medication.Given the above, we can state that, in our study, there was no influence ofmedications that could alter cardiac autonomic modulation.Ana Paula Soares dos Santos


Chronic kidney disease affects more than 10% of the population. Programming studies have examined the interrelationship between environmental factors in early life and differences in morbidity and mortality between individuals. A number of important principles has been identified, namely permanent structural modifications of organs and cells, long-lasting adjustments of endocrine regulatory circuits, as well as altered gene transcription. Risk factors include intrauterine deficiencies by disturbed placental function or maternal malnutrition, prematurity, intrauterine and postnatal stress, intrauterine and postnatal overnutrition, as well as dietary dysbalances in postnatal life. This mini-review discusses critical developmental periods and long-term sequelae of renal programming in humans and presents studies examining the underlying mechanisms as well as interventional approaches to “re-program” renal susceptibility toward disease. Clinical manifestations of programmed kidney disease include arterial hypertension, proteinuria, aggravation of inflammatory glomerular disease, and loss of kidney function. Nephron number, regulation of the renin–angiotensin–aldosterone system, renal sodium transport, vasomotor and endothelial function, myogenic response, and tubuloglomerular feedback have been identified as being vulnerable to environmental factors. Oxidative stress levels, metabolic pathways, including insulin, leptin, steroids, and arachidonic acid, DNA methylation, and histone configuration may be significantly altered by adverse environmental conditions. Studies on re-programming interventions focused on dietary or anti-oxidative approaches so far. Further studies that broaden our understanding of renal programming mechanisms are needed to ultimately develop preventive strategies. Targeted re-programming interventions in animal models focusing on known mechanisms will contribute to new concepts which finally will have to be translated to human application. Early nutritional concepts with specific modifications in macro- or micronutrients are among the most promising approaches to improve future renal health. AlthougIn humans the pronephros begins to form around day 22, urine production starts after 10 weeks , and maxVice versa, decreased renal function is associated with increased blood pressure and cardiovascular morbidity  in infant milk formula (IF) during the first 4 months of life lowered blood pressure at 6 years of age compared to IF without LCPUFAs. Blood pressure of children fed LCPUFA-IF was similar compared to breast fed children . A diet Re-programming interventions with anti-oxidative substances have only been performed in animals. Supplementation of maternal LP diet with anti-oxidative (ACH09)-derived polyphenols extracted from grape skins reduced signs of renal oxidative stress in the offspring on the first postnatal day and attenuated the adverse effects of maternal LP diet on glomerular number and maturity . AdminisThe concept of “developmental origins of health and disease” highlights the interrelationship between environmental factors throughout life and differences in morbidity and mortality between individuals. Chronic kidney disease affects more than 10% of the population . PrematuEN performed the majority of literature research, and designed and wrote the review. K-DN contributed to literature research, and designed and wrote the review. JD and LW contributed to literature research and writing. All authors revised and approved the review.The authors declare that the article was written in absence of any commercial or financial relationships that could be a potential conflict of interest to the topic.