Nevertheless, in vivo treatment of several animal species with the combination of LF and PA  leads to morbidity and mortality, suggesting that LT-dependent toxicity is mediated by cellular interactions between host cells. Decades of research have revealed that a central hallmark of this toxicity is the disruption of key cellular barriers required to maintain homeostasis. This review will focus on the current understanding of the effects of LT on barrier function, highlighting recent progress in establishing the molecular mechanisms underlying these effects.The pathological actions of anthrax toxin require the activities of its edema factor (EF) and lethal factor (LF) enzyme components, which gain intracellular access via its receptor-binding component, protective antigen (PA). LF is a metalloproteinase with specificity for selected mitogen-activated protein kinase kinases (MKKs), but its activity is not directly lethal to many types of primary and transformed cells  Bacillus anthracis, the causative pathogen underlying anthrax infection, whose proximal mechanisms of action have been recently reviewed . In. In12]. ecycling . In addiecycling . In cultecycling , providiIn addition, LT has both inhibitory and stimulatory effects on immune responses of endothelial cells, likely through a mechanism related to the cumulative effect of LT-mediated enhancement of IκB kinase (IKK)-NF-κB activation and suppression of the activity of activator protein-1 (AP-1) . LT alsoBacillus anthracis usurps host immune protective mechanisms. Bacillus anthracis spores are phagocytosed by pulmonary macrophages, which translocate the spores into the mediastinal lymph nodes where they germinate. It appears that symptoms of inhalation anthrax are manifested initially in response to the production of anthrax toxin. During the inhalation infections that occurred during the 2001 bioterrorism attacks in the United States, clinicians observed the classic appearance of a widened mediastinum in chest X-rays (CXR). In addition, pulmonary infiltrates and pleural effusions were detected via CXR and/or computed tomography (CT), while bronchoscopic examinations performed on some of these patients showed edematous and erythematous pulmonary mucosa . Th. ThBacilechanism . However the BBB .vs. susceptible allele of the Nalp1b gene [Nalp1b, indicating that LT-induced disruption of endothelial barriers occurs through mechanisms independent of cytokine production as well [Bacillus anthracis S-layer protein A (BslA). This newly identified pXO1-encoded protein is likely to play a critical role in breakdown of the BBB by Bacillus anthracis, as mice challenged with BslA-deficient Bacillus anthracis exhibit a significant decrease in the frequency of brain infections compared to mice injected with the parental Sterne strain [It is also important to note that anthrax LT also has strain- and species-specific effects on the production of cytokines, depending on whether the animal encodes a resistant p1b gene . For exap1b gene ,4,5. Cytp1b gene . Howevere strain ,79. Bacillus anthracis to establish infection, but also they are leading contributors to morbidity and mortality. A central theme of recent studies is that LT causes dysregulation of junctional complexes by altering the localization of key junction associated proteins, including the cadherins and ZO1 [It has been well documented that LT disrupts the anatomic and functional integrity of critical host barriers. These effects not only allow  and ZO1 ,52. Intr and ZO1 . Bacillus anthracis-derived factors may also contribute to the pathology in barrier tissues . Investigation of the interactions of these bacterial factors with LT should be undertaken to assess the overall effect of LT in vivo. It will also be important to delineate the MKK pathways targeted by LT that underlie toxic effects on host barriers. In this regard, the MKK1/2 pathways appear to be promising candidates.Nevertheless, important questions remain to be addressed, including whether other pathogen- and host-associated factors work in concert with LT. For example, administration of lethal doses of edema toxin (ET) into mice leads to extensive pathological lesions in a broad range of organ/tissues including barrier tissues . In addiBacillus anthracis is just one of several enteric pathogens that disrupt MAPK signaling as a virulence mechanism. Virulence factors of Shigella, Yersinia and Salmonella also target and inactivate MAPK signaling pathways [Although important strides have been made toward understanding the mechanisms underlying LT-induced barrier dysfunction, we have much to learn regarding the exact molecular and cellular interactions between LT and toxin-targeted host barrier tissues. It will be critical to determine whether the effects of anthrax LT on junctional complexes represent critical and universal mechanisms that would amenable to therapeutic targeting. With regard to the potential to develop anthrax therapies, treatment strategies for anthrax infection have focused thus far on antibiotics and, more recently, upstream anti-toxin therapeutics  ,82. A copathways ,84,85,86


Retinitis pigmentosa (RP) is a genetically heterogeneous retinal disease. Typically beginning with night blindness, RP is characterized by rod cell degeneration followed by cone cell death, which may ultimately lead to complete blindness. Despite extensive knowledge about genes involved in RP pathogenesis, in several cases the genetic cause remains elusive.We aimed to identify novel genes that are involved in the etiology of RP.MVK, encoding mevalonate kinase (MK), patients with mutations in this gene underwent extensive clinical re-examination. MK enzyme activity was analyzed in cultured lymphoblastoid cells and mevalonic acid levels were measured in urine samples.After detailed clinical characterization including funduscopy and optic coherence tomography, exome sequencing analysis was performed in a proband of Dutch origin with non-syndromic autosomal recessive RP. Identified mutations were tested for segregation within the family and in a large cohort of genetically unsolved RP patients. Upon identification of mutations in MVK (p.I268T and p.A334T) in the proband and her affected brother. Screening of 269 non-syndromic RP patients revealed an additional individual who was homozygous for the p.A334T alteration. Clinical re-evaluation of all three patients revealed a relatively classic form of RP with variable extra-ocular symptoms, such as history of recurrent childhood febrile crises in two, and mild ataxia in one patient. All three affected individuals showed a significantly decreased mevalonate kinase activity and strongly elevated levels of urinary mevalonic acid.Exome variant filtering and prioritization led to the identification of compound heterozygous mutations in MVK.Although the MK activity in cells and mevalonic acid concentrations in urine are strongly aberrant as in patients with systemic mevalonate kinase deficiencies (MKD), only mild clinical symptoms related to these phenotypes are observed in our patients, who were initially classified to have non-syndromic RP. Herewith, we add another phenotype to the spectrum of diverging disorders associated with mutations in None declared.


Magnaporthe oryzae is one of the most destructive fungal diseases of rice and a model for studying fungal-plant interactions. The fungus penetrates plant cells with appressoria and develops the narrow primary invasive hyphae (IH) and, subsequently, the bulbous secondary IH. As a hemibiotrophic pathogen, biotrophic IH are enclosed in the extra-invasive-hyphal membrane (EIHM) produced by the plant cells M. oryzae secretes effector proteins to manipulate plant immunity and physiology to promote infection.Rice blast caused by AVR) genes, could be recognized by corresponding R proteins and lead to the race-specific recognition M. oryzae interaction, over 40 AVR genes have been identified. Among the AVR genes that have been cloned, all but ACE1 encode secreted proteins expressed in IH. ACE1 is specifically expressed in appressoria, and it encodes an intracellular hybrid PKS-NRPS protein AVR-Pita encodes a putative neutral zinc metalloprotease Avr proteins, a special class of effectors encoded by the avirulence  and resistance in cultivars carrying the Pi-CO39 R gene M. oryzae is Slp1, a secreted LysM protein that is accumulated at the interface between IH and EIHM in planta. It competes with the chitin elicitor binding protein CEBiP for binding to chitin oligosaccharides. Thus, Slp1 functions to suppress chitin-induced plant immune responses, including generation of reactive oxygen species and expression of defense-related genes The best characterized non-Avr effector in BAS1–BAS4, were confirmed to be fungal biotrophy-associated secreted (BAS) proteins in planta expressed secreted protein genes MoCDIP1–5 were found to induce plant cell death in a transient expression assay with rice protoplasts. Four of them also induced cell death in Nicotiana benthamianaUsing an expression profiling approach, a number of low molecular weight secreted proteins specifically expressed or highly induced in biotrophic invasive hyphae were identified, including 58 candidate effectors that were up-regulated over 10-fold during plant infection. Four of them, M. oryzae effectors can be divided into two distinct types based on their localization in plant cells  for IH to move through the subsequently invaded cells than in the first colonized cells (12 h) In the rice leaf sheath cells penetrated by Magnaporthe effectors may be moved symplastically through plasmodesmata M. oryzae preferentially contacted and crossed the plant cell wall at the pit fields Interestingly, movement of cytoplasmic effectors from vein-associated cells into neighboring cells was rare and of low efficiency in comparison with effector movement among regular epidermal cells in planta is relatively limited in comparison with that of bacterial effectors. Studies in M. oryzae showed that some effectors may be secreted via an unconventional protein secretion system to the BIC M. oryzae and other fungal pathogens may have conserved mechanisms to recognize plasmodesmata for the movement of effector proteins and spreading of IH.Although more and more fungal effectors are being discovered, our understanding of effector delivery and cell-to-cell movement


Even if Chronic lymphocytic leukemia (CLL) often has an indolent behavior with good responsiveness to cytoreductive treatment, about 20% of the patients, so called “poor-risk” patients, show an aggressive course and die within a few years despite early intensive therapies. Criteria for poor-risk disease according to the European Bone Marrow Transplantation (EBMT) CLL Transplant Consensus are: purine analogue refractoriness, early relapse after purine analogue combination therapy, CLL with p53 lesion requiring treatment.Allogeneic transplant has potential curative role in CLL, however burden with very high transplant related mortality (TRM) rates of 38–50%. A major advance in reducing the short-term morbidity and mortality of allogeneic stem cell transplantation (SCT) has been the introduction of non-myeloablative or reduced intensity conditioning (RIC) regimens to allow engraftment of allogeneic stem cells. There is no doubt that the crucial therapeutic principle of allo-SCT in CLL is graft versus leukemia (GVL) activity.The major complications of allogeneic SCT in CLL are: chronic graft-versus-host-disease (GVHD) affecting quality of life, high graft rejection and infection rates correlated with preexisting immunosuppression. Disease relapse remains the major cause of failure after RIC allo-HCT in CLL patients.Sensitive minimal residual disease (MRD) quantification has strong prognostic impact after transplant. Chronic lymphocytic leukemia (CLL) is the most common adult leukaemia in the Western WorldIn parallel with improvements in treatment outcome, recent advances in the understanding of CLL biology have allowed us to identify selected subgroups of patients with adverse characteristics such as chromosomal abnormalities,Even if CLL often has an indolent behavior with good responsiveness to cytoreductive treatment, about 20% of the patients who need treatment show an aggressive course and die within a few years of diagnosis despite early institution of intensive therapies. These so called “poor-risk” patients are characterized by preexisting or rapidly developing resistance to conventional chemotherapy, including modern purine analogue-antibody combination regimens9Although alemtuzumab, lenalidomide, and flavopiridol, show promising activity in some patients with poor-risk CLL, none of these compounds seem to be able to change the natural course of poor-risk CLL.14Myeloablative allogeneic SCT has several theoretical advantages over autologous SCT. Firstly, any potential tumor contamination of the stem cell product is eliminated even if new data are emerging about the potential possibility of CLL transmission by unrecognized CLL/MBL  donor.The enthusiasm for myeloablative allogeneic SCT in CLL, using either related or unrelated donors, is however tempered by registry reports showing very high TRM rates of 38–50%: these published data showed that approximately two-thirds of allotransplanted CLL patients will succumb either to TRM or to recurrent disease, and approximately one-third will be cured of their disease.A major advance in reducing the short-term morbidity and mortality of allogeneic SCT has been the introduction of non-myeloablative or reduced intensity conditioning (RIC) regimens to allow engraftment of allogeneic stem cells. So the RIC regimens were developed in the 1990s to allow allo-SCT in older patients or younger patients with comorbidities and the total number of allogeneic transplantations for CLL patients in Europe, has almost treble in the last 7 years. In the last decade, many reports, which enrolled primarily patients with chemorefractory end-stage disease, have stressed the potential curative role of RIC allo-SCT in CLL.There is no doubt that the crucial therapeutic principle of allo-SCT in CLL is GVL activity. This evidence derives from some interesting observations such as: decreasing relapse incidence over time even in RIC alloSCT, in contrast to autologous SCT or other intensive therapies,27Table 1).Multiple single-center phase 2 studies have evaluated several different RIC regimens with different myeloablative and immunoablative potential  negativity was clearly linked to immune intervention, such as tapering of immunosuppression or donor lymphocyte infusions that lead to develop chronic GVHD, also he suggests that a “GVL escape” mechanism might be acquired during the post-transplantation course probably caused by survival of clonogenic cells at “GVL sanctuary” sites.Ex-vivo and in-vivo T-cell depletion are effective means of preventing acute and chronic GVHD after alloSCT. In CLL, however, T-cell depletion has been associated with increased relapse and rejection rates.Table 1). In the absence of prospective randomized trials, the Consensus recommendations were based on evidence of grade II or less.European Bone Marrow Transplant (EBMT) guidelines have now been established outlining indications for SCT in CLLCriteria for poor-risk disease according to the EBMT CLL Transplant Consensus are: purine analogue refractoriness, early relapse after purine analogue combination therapy, and CLL with p53 lesion requiring treatment.However considering the recent improvements in CLL treatment outcome, now-a-day one should test other innovative and very promising therapeutically approach before giving the indication to alloSCT, such as: antibody-purine analogue combination regimens as first-line or salvage treatment,32The EBMT guidelines conclude that there is evidence-based efficacy of allogeneic SCT in CLL and that this procedure is indicated in high-risk CLL patients. It should be stressed that none of the EBMT categories requires assessment of biologic risk factors except for cytogenetics for detection of p53 deletions, who deserves allogeneic SCT in first response. Ongoing prospective clinical studies will determine the impact of biomarkers including IgVh mutational status and other cytogenetic abnormalities in identification of patients at sufficiently high risk to deserve use of allogeneic SCT in first CR.Another crucial point in the allogeneic transplant is a better selection of patient, as recently suggested by Sorror.Table 2). However in addition to the disease risk, patient-related risk factors, such as age and comorbidity, have to be considered when the decision about allo-SCT is made.33In conclusion, allo-SCT is the only therapy with curative potential in CLL and, in contrast to conventional treatment, with potential of providing long-term disease control even in patients with a very unfavorable biological and clinical risk profile  after purine analogue combination therapy (second EBMT criterion) needs to be defined by systematic studies.On the other hand, RIC allo-HCT is able to mitigate the adverse prognosis conferred by purine analog resistance and unfavorable genetics. The EBMT guidelines identify a group of patients in whom available therapies are unlikely to achieve a prolonged disease-free survival.Several prospective RIC studies with a combined number of more than 300 patients included on the basis of modern CLL-specific risk stratification give relatively concordant results. In contrast, the experience with myeloablative conditioning in CLL largely relies on registry analyses and a few small single-center studies.The choice of RIC alloSCT as the standard procedure rather than myeloablative conditioning emerged by the fact that the crucial therapeutic principle of allotransplantation in CLL is GVL activity. That evidence for superior direct cytotoxic activity of myeloablative conditioning over RIC is lacking, and also one should consider that CLL is an elderly disease.29A matched sibling donor should be preferred for alloSCT in CLL whenever possible, but a matched unrelated donor (MUD) is a reasonable alternative if an HLA-identical sibling is not available. In fact from published RIC studies in CLL, unfavorable effect of MUD respect to sibling donor did not significantly emerge.38Due to the median age of patients, experience with haploidentical transplant and cord blood transplant is very scanty in CLL, and it is unlikely that disease-specific evidence for benefit of these procedures can ever be obtained.RIC allo-SCT was associated with a NRM of 11%–34%, a PFS of 34%–67%, and OS of 48%–72% depending on the conditioning regimen and follow-up. Long-term disease control was obtained in a substantial proportion of patients, particularly in those with chemosensitive and non-bulky disease at the time of transplantation.In the CLL3X trial of the German CLL Study Group (GCLLSG) and also in Schetelig data, poor risk CLL as defined by purine-analogue refractoriness or presence of deletion 17p- had a similar outcome to patients without poor-risk characteristics in terms of PFS, with a median follow up of 2 years.19The outcome of 82 patients treated at the FHCRC consortium using a non-ablative conditioning regimen  was recently updated.At 5 years after RIC allo transplant, the NRM and relapse rate were 23% and 38% respectively, which translated into a OS of 50% and PFS of 39%. Patients with bulky lymphadenopathy (>5 cm) at the time of transplantation had a particularly poor outcome, with a 5-year relapse rate and PFS of 71% and 8% respectively. Extensive chronic GVHD was diagnosed in 50% of patients, but it resolved in most of them.21A retrospective analysis of the EBMT on alloSCT in 44 patients with del 17p- CLL showed a 3-year PFS of 37% with no event occurring later than 3.5 years after transplant.26We recently reported in a single centre experience the efficacy and feasibility of RIC allo-SCT in heavily pre-treated CLL patients, even if in a small number of patients and with a relatively short follow-up. In our series, 45% of patients were considered “high-risk” for fludarabine-refractory disease or 17p deletion. At median follow-up of 20 months (range 12-44) 80% of them are alive, confirming literature data.39In conclusion, RIC alloSCT seems to be effective in poor-risk CLL, thereby overcoming the adverse prognostic impact of purine analogue refractoriness and del 17p-. However, active, unresponsive and bulky disease at the time of alloSCT still remains a predictor of an unfavorable outcome.37The major determinant of long-term morbidity affecting quality of life after alloSCT is chronic GVHD. Active chronic GVHD documented a significantly reduced long-term health status in patients allografted for various hematological malignancies.The high graft rejection rates remain a complication either of myeloablative or non-myeloablative transplant in CLL: it ranges between 18%– 20% in conventional conditioning,43Another complication is represented by the high infection rates correlated with preexisting immunosuppression. Infections are the cause of about 50% of all CLL-related deaths,49Disease relapse remains the major cause of failure after RIC allo-HCT in CLL patients. Early relapses are correlated with chemorefractory disease at the time of transplantation, perhaps due to the ineffectiveness of RIC regimens in controlling the disease before the graft vesus CLL (GVCLL) effect can take place.Late relapse an be explaned with different mechanism including: CLL clonal evolution, the development of tolerance52Sensitive MRD quantification can be studied in CLL by polymerase chain reaction (PCR) or flow cytometry-based assays and has strong prognostic impact after transplant. The generally delayed decline of the MRD level and its close correlation with immune-relevant events strongly supports the assumption that GVL activity is the crucial contribution to tumor control in the allo-SCT. GVL-induced MRD negativity after allogeneic transplant is highly predictive of freedom from relapse.24Moreover in CLL quantitative MRD monitoring seems to be a valid instrument for sensitive guidance of immune interventions aimed at disease eradication after allo-SCT. In contrast to donor’s lymphocyte infusion (DLI) upon clinical relapse which often shows only limited benefit in CLL,53The best approach to post transplant immunotherapy, including monoclonal antibody


During cortical development, proliferating neural progenitors exhibit polarized apical and basolateral membranes that are maintained by tightly controlled and membrane-specific vesicular trafficking pathways. Disruption of polarity through impaired delivery of proteins can alter cell fate decisions and consequent expansion of the progenitor pool, as well as impact the integrity of the neuroependymal lining. Loss of neuroependymal integrity disrupts radial glial scaffolding and alters initial neuronal migration from the ventricular zone. Vesicle trafficking is also required for maintenance of lipid and protein cycling within the leading and trailing edge of migratory neurons, as well as dendrites and synapses of mature neurons. Defects in this transport machinery disrupt neuronal identity, migration, and connectivity and give rise to a malformation of cortical development termed as periventricular heterotopia (PH). PH is characterized by a reduction in brain size, ectopic clusters of neurons localized along the lateral ventricle, and epilepsy and dyslexia. These anatomical anomalies correlate with developmental impairments in neural progenitor proliferation and specification, migration from loss of neuroependymal integrity and neuronal motility, and aberrant neuronal process extension. Genes causal for PH regulate vesicle-mediated endocytosis along an actin cytoskeletal network. This paper explores the role of these dynamic processes in cortical development and disease. The development of the mature six-layered cerebral cortex involves a highly ordered and complex sequence of events that requires tight control of neural progenitor cell proliferation, cell fate specification, and initial migration from their site of origin. Neuroblasts must then migrate to their final destination and undergo region-specific differentiation. Many excitatory neurons within the cerebral cortex originate from the pseudostratified ventricular epithelium that lines the embryonic cerebral ventricle wall . The venNeuronal migration in humans occurs between gestational age of 10–20 weeks and immediately follows neurogenesis . During Disruptions in one or more aspects of corticogenesis  can give rise to a group of abnormal brain developmental syndromes called cortical malformation disorders. These disorders have recently been reclassified into subgroups based upon their anatomical abnormalities and the shared pathways and mechanisms of action for the specific classifications: malformations secondary to abnormal neuronal and glial proliferation or apoptosis, malformations due to abnormal neuronal migration, and malformations secondary to abnormal postmigrational development . In a simplistic view, initial cortical development requires expansion and generation of sufficient neural progenitors. Many genes causal for proliferative disorders such as the primary microcephalies  are expectedly involved in various pathways implicated in cell cycle and cell division including transcriptional regulation, cell cycle progression and checkpoint regulation, centrosome duplication and replication, mitotic spindle formation, and DNA repair . More foFollowing expansion of the progenitor pool, cells must migrate into the cortical plate. Abnormalities in neuronal migration have been thought to give rise to periventricular heterotopia , subcortical heterotopias , and lissencephalies . Taken in the context of the anatomical abnormality, periventricular heterotopia has been viewed as a disruption in initial neuronal migration due to disruption of the ventricular neuroepithelium . Loss ofFollowing migration, neurons which reach the cortical plate but develop abnormally can give rise to some poorly understood cortical malformations. Polymicrogyria  and schizencephaly  are heterogeneous disorders. The underlying pathophysiology is poorly understood.Periventricular heterotopia (PH) refers to a malformation of cortical development characterized by bilateral near-contiguous ectopic neuronal nodules found along the lateral ventricles (so-termed periventricular heterotopia) . The nodThe anatomical localization of this disorder raises interesting implications for genes that are causal for this disorder. During normal cortical development, neural progenitors reside along the VZ, undergo progressive expansion through proliferation, and then undergo cell fate specification either to remain as a progenitor, transform into an intermediate progenitor or assume a postmitotic neuronal fate. Intermediate progenitors and postmitotic neurons must undergo initial migration from the VZ toward the cortical plate, whereas progenitors reenter the cell cycle. Interactions between progenitors and the extracellular environment and regulation of cell cycle proteins are going to influence the developmental fate of neural progenitors. Given that PH reflects a developmental defect specifically within this population of cells during a fairly confined temporal framework, genes involved in this disorder will in all likelihood play a significant role in regulating neural progenitor proliferation and migration.FLNA gene [ARFGEF2 gene. ARFGEF2 encodes Brefeldin-A inhibited Guanine Exchange Factor-2 (BIG2) [ARFGEF2 mutations is an autosomal recessive disorder, all migratory neurons harbor the gene mutation. Thus, it is unlikely that a cell motility problem alone causes this malformation because only some and not all the neurons fail to migrate from the VZ into the cortical plate. Neurogenetic analyses have identified two human genes are known to cause PH formation. The most common form of PH is inherited in an X-linked dominant fashion from mutations in the LNA gene . FilaminLNA gene . Given FLNA gene . A rare 2 (BIG2) . BIG2 isHIP1 and YWHAG genes [FMR1 gene can lead to PH in Fragile X [PQBP1 [Other genetic abnormalities have been associated with this disorder. Anterior PH has been reported with duplication of human chromosome 5p15 . DiffuseAG genes , 39. DelAG genes . GenomicAG genes , 42. Finragile X , as can X [PQBP1 . TripletX [PQBP1 .Several mouse genes have been associated with PH formation. Stem-cell-factor- (SCF-) c-kit regulates proliferation and migration of neural progenitor cells. Direct administration into the ventricles during cortical development led to neuronal and glial heterotopia as well as disruption of the neighboring cytoarchitecture .Napa gene, which encodes for soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein alpha  and is involved in SNAP receptor- (SNARE-) mediated vesicle fusion [Deletion of the rho GTPases Cdc42 also disrupts local adherens junctions and proliferation of basal progenitors leading to heterotopia formation through both impaired intranuclear migration and disruption of the neuroependymal lining . Spred1,e fusion , 50.FLNA are the most common cause of inherited PH in the central nervous system (CNS) [While mutations in em (CNS) , it has In the CNS, familial PH is associated with an X-linked dominant inheritance pattern such that males are hemizygous lethal and females present with the classical PH phenotype. In females, X-inactivation leads to a proportion of cells which normally expresses FLNA whereas others have no protein expression. In addition to the bilateral heterotopic nodules, the disorder is associated with thinning of the corpus callosum and an enlarged cistern magna. Females can develop varying degrees of epilepsy and dyslexia, as well as worse adaptive skills and conduct problems , 53. TheMutations in FLNA have been increasingly recognized to affect extra-CNS organ systems in giving rise to phenotypic heterogeneity , 57. RobSeveral observations can be drawn from the various phenotypes reportedly due to FLNA mutations. First, heterotopiae are not the only anatomical malformation seen in the CNS with this disorder. The reduced cortical layer width and mental retardation seen in males with this disorder implicates FLNA in neural progenitor proliferation. The thinning of corpus callosum, dyslexia, and epilepsy also argues that FLNA is likely involved in neuronal process extension and formation. Second, FLNA is broadly expressed throughout the body and its phenotypes do not always appear to be fully penetrant, suggesting that there are extrinsic factors which modify the clinical presentation. Third, some shared features are seen in the abnormalities within the different organ systems. As with the brain where there appears to be disruption of the cell connectivity and adhesion along the neuroependyma , weakeniFLNA represents one of three members  of the filamin family of actin-binding proteins. The filamin proteins share a high degree of homology between the conserved exon/intron structure with significant differences in exon 32 of all paralogs encoding the hinge I region, as well as the insertion of a novel exon 40A in FLNC only . MoreoveFLNA is a 280 kD actin-binding phosphoprotein represented by an N-terminal actin-binding domain, followed by Immunoglobulin- (IG-) like repeat domains, that contains the receptor binding region at the C-terminus. FLNA associates with itself to form a homodimer that can regulate the actin cytoskeleton through interactions derived from its multiple receptor binding regions, thereby directing cell stability, protrusion, and motility , 73. Filβ-integrin, dopamine, and G-protein-coupled calcium sensing receptors, (2) signaling through diverse intracellular cell signaling kinases, phosphatases, and adaptor molecules such as SHIP-2 or SEK1, and (3) regulation of cortical actin networks through molecules including the Rho family of small GTPases [FLNA has been shown to interact with numerous other proteins, suggesting many potential mechanistic roles that could influence cortical development. These interactors demonstrate great diversity but can be clustered into several general functional groups including (1) interactions with transmembrane receptors and signaling molecules such as  GTPases , 77–80.FLNA has been reported to interact with a vast array of cell surface receptors. For example, FlnA interactions with integrins provide a link between the extracellular matrix and regulation of the actin cytoskeleton . FlnA alFollowing receptor activation, FLNA may alter the cortical actin cytoskeleton. In general, FLNA is thought to bind and activate RhoGTPases, thereby regulating their consequent effectors involved in actin dynamics. CD4 and its coreceptors interact with FLNA to direct both the clustering of these HIV receptors on the cell surface but also mediate actin assembly and disassembly through a RhoA-ROCK-dependent mechanism . FilaminFLNA serves as a scaffold in intracellular cell signaling. For example, the actin-binding protein binds CMIP/TCMIP which are adaptor proteins involved in the T-cell signaling pathway . It simiOverall, FLNA integrates activation and signaling from various cell receptors, thereby mediating changes in actin dynamics through RhoGTPases and directing intracellular signaling of varied pathways. In this respect, the actin-binding proteins serve primarily as scaffolds that may bring together certain molecules within a given signaling pathway through actin assembly and disassembly. Classically, such a pathway involves extracellular matrix-dependent activation of integrin receptors, transduction of this signal through filamin onto PKC or FILGAP which directly promotes RhoA and RAC activation and subsequent changes in the actin cytoskeleton , 96. Prior studies have described vascular and skeletal abnormalities in null FlnA mice and in the Dilp2 mouse , 98. TheFLNA is involved in neural progenitor proliferation. Loss of FLNA function in mice results in a thinned cerebral cortex. Moreover, loss of ventricular surface adherens junction proteins  along the basolateral surface suggests some disruption in neuroepithelial cell polarity and potentially, cytokinesis . More reArfgef2  physically binds and interacts with FlnA. Loss of Big2 leads to upregulation of both FlnA and phospho-FlnA. Phosphorylation of FlnA alters FlnA binding affinity to actin and changes the size and distribution of paxillin focal adhesions, thereby altering cell autonomous migration into the cortex [FLNA is involved in initial neural progenitor migration. In early embryonic lethal (E13.5) null FLNA mice, migration into the cortical plate was ultimately preserved in neurons that had incorporated BrdU early in development , 98. Othe cortex . These fARFGEF2 on chromosome 6 cause a rare autosomal recessive form of PH in humans. Affected individuals uniformly present with bilateral periventricular nodular heterotopia and microcephaly with generalized atrophy. Imaging studies tend to show hyperintensities in the basal ganglia. In one limited report, mutations in this gene are also associated with severe choreadystonic movement disorder [Mutations in disorder , 29.ARFGEF2 gene has been previously described in three pedigrees [ The autosomal recessive PH due to mutations in the edigrees , 29. TheBrefeldin A guanine exchange factor 2 (BIG2) is a 180 kDa protein which belongs to a family of three highly conserved large molecular weight mammalian Sec7-GEFs  . They arin vivo through GTP activation[The ARFs are members of the Ras family GTPases involved in lipid vesicle budding from the membrane. They are generally myristoylated at the N-terminal domain to allow for membrane association and undergo cycling between the GTP and GDP-bound states. The active GTP form leads to a conformational change that exposes the myristate and hydrophobic N-terminal, thereby allowing for association with the membrane. The activated ARF binds to vesicle coat proteins and adaptors, including coat protein I (COPI) and various phospholipids. Guanine exchange factors (GEFs) such as BIG2 mediate ARF activation (GDP to GTP), whereas ARF GTPase activating proteins (GAPs) hydrolyze ARF-GTP back to ARF-GDP at the membrane. In the GDP-conformational state, the ARF becomes less hydrophobic and dissociates from the membrane. There are in total six ARF isoforms in mammals, which are grouped into three classes  . BIG2 hactivation. ARF1/3 ctivation, 119. Arfgef2 gene-trap mouse model, with insertion after exon 7. Fertilized eggs fail to develop after the four stage embryo [The functional role of Big2 in the CNS is not well understood. BIG2 expression is developmentally regulated during cortical development and is most strongly localized to the neural progenitor cells along the neuroependymal lining of the ventricular zone during embryonic development. Expression of BIG2 is later downregulated during postnatal development and adulthood . Recent e embryo . This moe embryo . The losThe endoplasmic reticulum (ER) is the primary site of lipid and protein synthesis in a cell, and vesicle budding from the ER provides a means with which to distribute proteins to their designated cellular location. These transport vesicles are defined by their lipid composition and protein coats, with coat proteins I/II (COPI/II) mediating protein/lipid export from the ER and Golgi. Rab GTPases are peripheral membrane proteins that are anchored into the membrane and regulate many steps of membrane traffic, including vesicle formation, vesicle movement along actin and tubulin networks, and membrane fusion. The composition of these various proteins mediates the transport to other endosome compartments or the plasma membrane , 123. Endocytosis is a process characterized by four general mechanisms: clathrin-mediated endocytosis, caveolae, macropinocytosis, and phagocytosis . ClathriProteins synthesized in the ER traffic to the Golgi and then through specific endosomal compartment. When endocytosed, these compartment-specific proteins enter early endosomes and are sorted either to late endosomes, lysosomes, or degradation/recycling endosomes prior to return to the parent membrane. Alternatively, the proteins may undergo transcytosis; this process refers to the transfer of endocytosed proteins residing in one membrane  that are sorted and modified in common endosomes and then transported to the opposite membrane . The movement of vesicles is facilitated by the actin cytoskeletal network and associated motor proteins to maintain the apical and basolateral domains . With deβ-catenin, E-cadherin). Overexpression of dominant negative mutant FLNA (actin-binding deficient) within neural progenitor cells along the ventricular surface leads to the mislocalization of β-catenin from the basolateral cell membrane [Flna gene display the loss of vascular endothelial cadherin along the neuroependymal surface [β-catenin and E-cadherin in polarized Madin Darby Canine Kidney cells (MDCK) [β-catenin, N-cadherin) along the neuroependymal surface and the denudation of the ventricular surface followed by PH formation [An overriding defect in the vesicle trafficking machinery contributes to PH formation . The chamembrane . In addi surface . Similars (MDCK) . Intraveormation . OverallMouse genes causal for PH collectively suggest a defect in vesicle trafficking in this disorder and appear to be involved in filamin-dependent pathways. Alpha SNAP is a SNARE-related protein, involved in vesicle fusion. Prior reports have shown that alpha SNAP mediates VE-cadherin localization through a b1-integrin-associated process . FlnA biAlthough disruption in the neuroependymal lining may be the primary cause of heterotopia formation, altered vesicle trafficking would be expected to contribute to other CNS and extra-CNSanatomicaldefects. Several studies have demonstrated impaired neuronal migration and motility following inhibition or overexpression of FlnA or Big2 function , 101–103The ventricular neuroepithelium of the cerebral cortex is a dynamic structure, whose maintenance depends on the continuous turnover of polarized vesicle trafficking. During cortical development, neuroepithelial cells  give rise to all the neurons and astrocytes of the cerebral cortex. The cell fate decision of progenitors from self-renewal to differentiation is a crucial factor in determining the morphology and size of the brain. Cell fate specification is regulated by symmetric and asymmetric divisions, which are further governed by mitotic spindle orientation. Vesicle trafficking maintains the apical-basal polarity of neuroepithelium through directional vesicle transport and vesicle sorting, thereby dictating cell polarity and symmetric/asymmetric division. These mechanisms will also dictate the integrity of the neuroepithelium, the direction and rate of neuronal migration, as well as connectivity between neurons. While FLNA and BIG2, as well as various mouse genes, have been implicated in endosomal vesicle trafficking and defects in this pathway can give rise to the various neural defects, the downstream effectors of these processes are not know. It will be important to determine which actin effectors (besides the RhoGTPases) are responsible for changes in actin dynamics through FLNA and which endocytic vesicles  and the stage of endocytosis  through BIG2 are responsible for the various phenotypes. Lastly, the direct interplay between actin and vesicle trafficking is poorly understood and studies going forward will be aimed at addressing this biological process.Vesicle trafficking plays a central role through the various stages of cortical development, and disruption of these mechanisms contributes to different aspects of cortical malformations. Cyclin-associated proteins regulate the rate of progression through the cell cycle and thereby dictate neural progenitor proliferation. The turnover of cyclin-associated proteins is dependent on vesicles and impaired degradation leads to prolongation of the cell cycle and a reduction in brain size. During neural progenitor expansion cells translocate from the neuroependymal lining toward the cortical surface and back again. Neuroependymal integrity is maintained by cell-cell junctions, which are dependent on vesicle transport. Disruption of the neuroependymal lining causes displacement of progenitors near the ventricular lining and PH formation. Next, migrating neurons must travel from the ventricular zone to the cortical plate. The leading and trailing processes of migrating neurons require active turnover of lipid membranes and focal adhesion-associated proteins for proper motility; disruption of these vesicle-dependent processes results in impairments in neuronal migration. Although unproven, it seems likely that the dyslexia and seizures associated with genes cause for PH will also reflect vesicle trafficking-related problems in synaptic connectivity. Thus, while disorders of vesicle trafficking may be linked to PH formation also, these fundamental processes give rise to a much broader cortical phenotype than previously realized.


F-18 FDG PET-CT scanning plays an important role in the management of fever of unknown origin (FUO). Some elderly patients with FUO can be in their terminal stage of life. An elderly woman was referred for a PET-CT scan to find the etiology of FUO. The scan was inconclusive but showed significantly reduced FDG uptake in the brain and heart, despite normal physiological uptake in the liver and bowel. The patient deceased within the hour post scan. Contrary to common belief, we have shown that cerebral glucose metabolism via cerebral perfusion may be compromised before hepatic and bowel perfusion in a dying patient. Conflict of interest:None declared. Although F-18 FDG PET-CT scanning has now become widely available as a new radiological and nuclear medicine investigation, it is by large considered as a tool of non-acute clinical management such as oncology staging , detectiA 70 year-old female, with a reduced level of consciousness but who was stable and capable to talk slowly and communicate at the time of investigation, was referred for a F-18 FDG-PET-CT scan to investigate FUO ,7,8. TheReduced cardiac FDG uptake  was considered as a result of ‘fasting’ (9), with no feeding for 6 hours prior to the scan . The serThe patient had no relevant past medical history and was not on any medication. In particular, the patient did not suffer from any forms of dementia nor pathology involving cerebrum such as Creutzfeldt-Jakobs disease. Physical examinations and routine blood tests were all normal and previous imaging investigations including CT, MRI and abdominal ultrasound did not find significant abnormalities.Diffusely decreased cerebral and cerebellar FDG uptake  was an unexpected finding , especiaThe patient deteriorated unexpectedly and was deceased 45 minutes after the scan despite attempts of resuscitation. Autopsy did not reveal significant pathology including normal appearances of the cerebrum.It is widely believed cerebral perfusion and glucose metabolism may be sustained until all peripheral perfusion is compromised in a dying patient. However, this case unexpectedly demonstrated that cerebral perfusion and glucose metabolism appeared compromised before hepatic and intestinal perfusion and glucose metabolism.There exist many physiological mechanisms, such as peripheral vascular shutdown in the event of large blood volume loss, to protect central blood circulation  . But in Diffuse decrease in intracranial glucose metabolism may occur in various conditions . OrganicA potential learning point of this case report is when significantly reduced cerebral FDG uptake was observed in a PET-CT scan, then staff immediately need to ascertain if the study was conducted appropriately e.g. injection extravasation or wrong dose injection. After exclusion of such operational errors, these abnormal findings should be discussed with duty doctors immediately and appropriate clinical management/resuscitation should be initiated .


Dynamic adjustments to neuronal energy supply in response to synaptic activity are critical for neuronal function. Glial cells known as astrocytes have processes that ensheath most central synapses and express G-protein-coupled neurotransmitter receptors and transporters that respond to neuronal activity. Astrocytes also release substrates for neuronal oxidative phosphorylation and have processes that terminate on the surface of brain arterioles and can influence vascular smooth muscle tone and local blood flow. Membrane receptor or transporter-mediated effects of glutamate represent a convergence point of astrocyte influence on neuronal bioenergetics. Astrocytic glutamate uptake drives glycolysis and subsequent shuttling of lactate from astrocytes to neurons for oxidative metabolism. Astrocytes also convert synaptically reclaimed glutamate to glutamine, which is returned to neurons for glutamate salvage or oxidation. Finally, astrocytes store brain energy currency in the form of glycogen, which can be mobilized to produce lactate for neuronal oxidative phosphorylation in response to glutamatergic neurotransmission. These mechanisms couple synaptically driven astrocytic responses to glutamate with release of energy substrates back to neurons to match demand with supply. In addition, astrocytes directly influence the tone of penetrating brain arterioles in response to glutamatergic neurotransmission, coordinating dynamic regulation of local blood flow. We will describe the role of astrocytes in neurometabolic and neurovascular coupling in detail and discuss, in turn, how astrocyte dysfunction may contribute to neuronal bioenergetic deficit and neurodegeneration. Understanding the role of astrocytes as a hub for neurometabolic and neurovascular coupling mechanisms is a critical underpinning for therapeutic development in a broad range of neurodegenerative disorders characterized by chronic generalized brain ischemia and brain microvascular dysfunction. The brain receives 10% of cardiac output but consumes 20% of total blood glucose and oxygen during cerebral activity to restore ion gradients after action potential conduction and neurotransmission  in human tissue   activity and uptake rates in astrocytes  which transfer reducing equivalents to the mitochondrial electron transport complexes. While the level of involvement of the glycerol-3-phoshpate shuttle in neuronal NAD+ homeostasis is not clear , oxygen, and NADH concentrations within the neuronal and astrocyte energy compartments, while also considering the subcellular compartments (cytosol and mitochondria)  to determine metabolite concentrations in different cell populations in various brain regions during activation    channels , which hydrolyzes phospholipids to produce arachidonic acid (AA)  or COX-1 inhibitor blocked arteriolar vasodilation after astrocyte Ca2+ stimulations, suggesting AA is metabolized by astrocyte COX-1 to prostaglandin E2 (PGE2)  channels, triggering hyperpolarization and decreased voltage-gated calcium channel (VGCC) activity . In brain slices and retinal preparations equilibrated with 95–100% oxygen, elevated astrocyte Cain vitro  16-fold, administering 100% oxygen to anesthetized rats only modestly elevates retinal pO2  of 60–70 mmHg  on vascular endfeet  concentration of 20 mM. Lower than this threshold, conductance of smooth muscle inward rectifying Kir2.1 K+ channels  is produced by heme oxygenase (HO) and can have vasoactive effects. On a cellular level, CO can relax vascular smooth muscle by increasing coupling between smooth muscle BKy Figure . CO-mediy Figure , 1995 any Figure , but cery Figure . Brain ay Figure , while ay Figure , 2011 ory Figure . In pigly Figure  and pial+, and CO, in response to synaptic transmission. We are only just beginning to understand how these pathways work in concert to fine-tune regulation of cerebral blood flow.In summary, astrocytes are not only important for regulating synaptic environments and the supply of energy metabolites to neurons, but they are also central to the regulation of neurovascular coupling by releasing several molecules, including AA metabolites, KMultiple brain diseases and injuries are associated with aberrant energy metabolism, dysfunctional glutamate cycling by astrocytes, and altered neurovascular coupling. Here, we discuss the major bioenergetic changes and astrocyte dysfunction in Alzheimer's disease (AD), cerebral ischemia, and epilepsy.AD is the most common form of dementia, characterized by declining cognitive performance and memory  during ischemia exacerbates neuronal death and astrocytes display increased conversion of glycogen to lactate (via glucose-6-phosphate) during this time  glutamate uptake and recycling via the glutamate-glutamine cycle, (b) increased glycolysis and shuttling of metabolites to neurons for oxidative phosphorylation, and (c) elevated CaThe 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.


Many developing countries face the decision of whether to approve the testing and commercial use of insecticidal transgenic cotton and the task of developing adequate regulations for its use. In this review, we outline concepts and provide information to assist farmers, regulators and scientists in making decisions concerning this technology. We address seven critical topics: 1) molecular and breeding techniques used for the development of transgenic cotton cultivars, 2) properties of transgenic cotton cultivars and their efficacy against major insect pests, 3) agronomic performance of transgenic cotton in developing countries, 4) factors affecting transgene expression, 5) impact of gene flow between transgenic and non-transgenic cotton, 6) non-target effects of transgenic cotton, and 7) management of pest resistance to transgenic cotton. More than two-thirds of the world's cotton is produced by countries with developing economies. Cotton is an important cash crop in such countries as it supports the livelihoods of millions of households, may represent a significant part of a country's total export, or play a key role in sustaining textile industries that create employment opportunities . WorldwiBacillus thuringiensis (Bt) were cultivated in nine countries on five continents; more than 10 million resource-poor farmers used this technology in the six developing countries  where it is authorized  that could not be developed through conventional plant breeding. Insertion of this gene alone would not reliably produce the desired characteristic without the promoter. A promoter is a regulatory sequence of DNA that determines where, when, and how much of a gene is expressed. Promoters can be constitutive, tissue-specific, or inducible. The final part of transgenic DNA is a marker gene, which produces a selectable characteristic . Expression of the marker gene signifies that the gene of interest has been successfully transferred to the plant's genome.The process that makes transgenic cotton different from conventional cotton is the insertion of DNA from a different organism into the plant's genome. The inserted DNA, or transgenic DNA, generally consists of three main parts: a gene of interest, a promoter, and a marker gene. The gene of interest produces a novel characteristic  that is absorbed by the bacterium. Plant tissue or cell cultures are inoculated with the Agrobacterium, which transfers the transgenic DNA to the plant's genome. Inoculated plant tissue in which the marker gene is expressed is selected and allowed to regenerate into a whole cotton plant.Many techniques for transforming plants are available, but the development of most commercial transgenic cotton cultivars has been conducted using one of three techniques:  pathway . AgrobacAgrobacterium-mediated transformation, particle bombardment requires plant cell or tissue cultures. However, instead of using a bacterium to transfer DNA, this technique uses ballistics. DNA-coated micro-projectiles are inserted into plant cells at high velocities using an instrument called a “gene gun”. Once the transgenic DNA enters the cell, it is absorbed into the recipient plant's genome. Plant tissues expressing the marker gene are selected and grown into whole plants.The second transformation technique is called particle bombardment. Like The final technique, the pollen-tube pathway, is distinct from the previous methods because it does not require cell or tissue cultures. Flowering cotton plants are allowed to self-pollinate. The plant produces a pollen tube from the tip of the pistil to the ovule . Sperm pAgrobacterium-mediated transformation and particle bombardment are both established and accepted techniques that have been used successfully to create many transgenic cotton cultivars. These techniques have consistently produced transgenic plants in which the transgene is expressed in subsequent generations. The largest drawback to these techniques is the required use of cell or tissue cultures for transformation. Most cotton cultivars cannot regenerate from these cultures. Thus, most scientists choose the American “Coker” cultivar as the recipient plant because it readily regenerates  or grown from seed (pollen-tube pathway), a rigorous selection process is undertaken to identify plants with good agronomic characteristics and with the highest and most consistent levels of transgene expression. The selection process begins by eliminating transformed plants with obvious abnormalities. Abnormalities can occur from disruptive mutations that may arise during the tissue culture and regeneration process  and a non-transgenic cultivar with desirable agronomic characteristics. This cross produces hybrid seeds that contain characteristics of both varieties , which can then be sold commercially. Hybridization between cotton cultivars has, until recently, been somewhat difficult to perform. Because cotton plants typically self-fertilize, breeders must hand-pollinate cotton plants to produce hybrids, a labor-intensive and potentially uneconomical process. Recent advances in breeding  have greatly improved the efficiency of this process . AlthougHybridization can result in plants that are more vigorous than either of their parental cultivars, a phenomenon called heterosis. However, not all transgenic hybrids perform better than their parental cultivars. For example, if one parent cultivar requires regular irrigation and the other parent is drought-tolerant, the hybrid progeny may be more sensitive to drought than the drought-tolerant parent. For this reason, cotton breeders must choose the most appropriate cultivars when developing hybrids and field test these hybrids to avoid any negative effects of parental genetic background.Bacillus thunrigiensis (Bt) toxin Cry1Ac or Cry1A  are commercially available or nearly commercialized in cotton  δ-endotoxins from the soil bacterium e midgut . Such bie midgut . Five crn cotton . While cAb genes .Bacillus thuringiensis. Vip toxins affect insects in a manner similar to that of Cry proteins. However, Vips bind to different receptors on midgut cells , is also derived from ut cells . None ofut cells .The third group of toxins used in cotton transgenics includes protease inhibitors, which are typically derived from plant proteins. Protease inhibitors inactivate the enzymes in an insect's gut that digest proteins. This leads to amino acid deficiencies that cause delayed development and death . The cowlecGNA 2) in cotton is being investigated in India but has not been commercially released  provides moderate to high levels of protection against bollworms and budworms, while the recently developed LecGNA 2 cotton cultivar, which targets pests other than bollworms and budworms (see below), only offers low protection against Helicoverpa spp. Several bollworm species in the genera Earias and Diparopsis, which are important pests in parts of Asia and Africa, have not been tested for their susceptibility to most transgenic cultivars.Most transgenic cultivars target lepidopteran pests, which include bollworms, sis spp.  and 3. Isis spp. . Most ofsis spp.  and 3. HSpodoptera spp.) are close relatives of bollworms and can be important pests of cotton in certain parts of the world  during the 1990s  that kill aphids (The introduction of transgenic cotton in China has had mixed effects on non-bollworm cotton pests. Cotton pests not affected by transgenic toxins  and 3 stl aphids . Becausel aphids .Helicoverpa armigera and Earias spp.), can cause yield losses of 50–60%  and cry1A  have also become available to growers , the Center for Plant Molecular Biology (CPMB), and the Indian Institute of Technology Kharagpur (IIT Kharagpur) succeeded in developing four different transgenic cotton cultivars. Two cultivars contain lecGNA 2 . The NBRThe biggest benefit of Bt hybrids for smallholder cotton growers in India is larger yields . Field tAlthough higher yields are the most important benefit of Bt cotton to Indian smallholder farmers, Bt adopters also used significantly less insecticide than farmers growing their non-Bt counterparts or other conventional varieties . StudiesWe note that not all reports of Bt cotton performance in India are positive. A survey of growers in the regions of Maharashtra and Andhra Pradesh found that Bt hybrids yielded 15–17% less than two conventional (non-counterpart) hybrids, causing economic losses for farmers . The autThe simplest explanation for the reported failures of Bt hybrids in some regions in India may be that researchers compared hybrids with very different genetic backgrounds, which may have confounded the results. As noted above see . Sahai aLow performance of Bt hybrids in regions such as Andhra Pradesh and Maharashtra could also result from regional differences in environmental conditions or insecticide use . As mentIn addition, levels of bollworm infestation vary annually and can affect the performance of Bt cotton . Higher cry1Ac transgene. Thus, saved seed from hybrid plants will not provide the same level of protection against insects as the previous year's plants. Although saved seeds and unofficial Bt hybrids yielded less than official hybrids, fields planted from saved seeds and unofficial Bt hybrids still out-yielded non-Bt plants, which illustrates the high efficacy of Cry1Ac against cotton pests  was saved from previous years . Some seon pests .Cotton agriculture in South Africa is split between large commercial farms and resource-poor smallholders . The majH. armigera, Diparopsis castanea, and Earias spp.) are the most economically important group of cotton pests in South Africa  was commercially released in South Africa in 1998 , which may vary among cultivars because of their genetic background.The genetic background of a Bt cultivar affects the amount of toxin produced . HoweverHelicoverpa spp. . However, the expression of cry1A with a non-CaMV 35S promoter in the Chinese cultivar GK19 also declined over the growing season, and Cry1A toxin levels were generally lower during the reproductive stages than Cry1Ac levels in Bollgard cotton  had significantly higher (19–36%) leaf nitrogen contents than conventional isogenic cultivars, suggesting a higher uptake of nitrogen in Bt than conventional cotton . Furthercry1A or cry1Ac genes into the cotton genome may cause higher nitrogen contents and metabolisms. Chen et al. . A buffer zone is the area bordering a field on all sides and defined by a fixed distance from the edge. Seeds from plants occurring in the buffer zone, which are expected to receive the majority of gene flow from surrounding fields, are not harvested at the end of the season. In California, growers of cotton seed receiving the “registered” designation for seed purity must separate their cotton fields from other cotton varieties by a minimum of 200m and must set aside 6m of unharvested buffers around the fields , over a billion farmers plant their fields with farm-saved seed , Bt cotton does not release Bt proteins from root exudates . Thus, BDegradation of Bt plants  in the soil was generally slower than the degradation of non-Bt plants . Reasons for slower degradation of Bt plants were unclear but unlikely due to the presence of Bt toxins. Higher lignin contents of Bt plants presumably arising from indirect effects of genetic transformation were implicated, although other differences in plant composition could be involved . Slower Most studies of non-target effects on soil organisms have been conducted with crops releasing Bt toxins through root exudates rather than with Bt cotton. Organisms such as earthworms, isopods, collembolans, nematodes, fungi, protozoa and bacteria were assessed. Overall, little or no adverse effects of Bt crops on soil organisms were apparent . Howeverin vitro digestion, acute toxicity, and allergenicity , and equivocal evidence indicates that a second key pest (H. armigera) may be in the process of doing so. We do not explicitly discuss resistance monitoring and remediation methods here. These critical aspects of resistance management have been addressed in several recent publications , but are only moderately effective against others . For highly susceptible pests, even if there are many alleles that may slightly increase resistance to Bt toxins within insect populations, these alleles may very rarely combine to allow survival on transgenic cotton . Similarly, it is assumed that two genes each with two alleles  confer resistance to Bt crops producing two toxins that act independently.Transgenic cotton cultivars produce concentrations of Bt toxins that are extremely effective against some pests . Internal refuges have been used to manage resistance in pests with sedentary larvae  is expected to be extremely rare. Accordingly, when refuges provide many susceptible insects, most offspring from rare resistant individuals will bear at least one s allele and will be killed on two-toxin plants, which substantially delays resistance evolution. Because the heterozygous genotypes (r1s1 s2s2 and s1s1 r2s2) carry the majority of resistance alleles after commercialization of a new transgenic crop, a low survival of these genotypes is critical to delay resistance. The pyramid strategy is expected to be efficient when two-toxin plants kill most susceptible insects , the survival of r1s1 s2s2 or s1s1 r2s2 on plants with 2 toxins would be low , which increases the success of the pyramid strategy (Fitness costs (see below) keep resistance alleles rare before populations are exposed extensively to transgenic toxins . Thus, tstrategy .H. virescens  indicate that cotton producing Cry1Ac and Cry2Ab can kill all susceptible larvae .Many small farmers could save seed from their current crop to plant the next year's crop see , the impBt toxin production in cotton is expected to be inherited as a dominant trait see . MoreoveRedundant killing would be diminished in seed mixtures arising from gene flow between two-toxin cotton and non-transgenic cotton. Thus, in the presence of external refuges, seed mixtures arising from gene flow between two-toxin cotton and non-transgenic cotton would likely accelerate resistance evolution compared to a situation where uncontaminated fields of Bt cotton are planted. The evolution of resistance could also be faster when seed mixtures involving one-toxin cotton are used instead of uncontaminated Bt seed. Larval movement between transgenic and non-transgenic plants could be a critical factor affecting the efficacy of such seed mixtures . In the rs and ss larvae in seed mixtures compared to fields of uncontaminated Bt cotton could hasten the evolution of resistance if larval mortality is density-dependent. In such a situation, a lower density of larvae on non-transgenic plants in seed mixtures than in external refuges could decrease the extent of density-dependent mortality in seed mixtures compared to external refuges. This could increase the relative survival of rs larvae in seed mixtures compared to external refuges, which would raise the probability of mating between rr and rs individuals in seed mixtures and accelerate resistance . However, changes in survival of rs and ss larvae in seed mixtures would likely have little effect on resistance evolution when density-dependent mortality of larvae is absent or weak, or when the density of larvae is similar on non-transgenic plants in seed mixtures and in external refuges.Increased dominance of resistance is not the only condition that could accelerate the evolution of resistance in seed mixtures. Even a slight increase in survival of both Plutella xylostella, and broccoli. However, neither provided direct evidence that the rate of resistance evolution was more rapid in seed mixtures than in transgenic broccoli with external refuges  seem to lack the ability to avoid Bt toxins  clearly have the capability to move between Bt and non-Bt plants in seed mixtures , physiology, and phenology. Environmental factors such as soil nitrogen levels and temperature can result in changes in the concentration or toxicity of Bt toxins. Bt cotton has higher nitrogen content than non-Bt cotton, suggesting that Bt cotton may have greater nitrogen uptake and metabolism than conventional cultivars. Performance studies conducted in China, India and South Africa indicate that such differences in nitrogen requirements may have little effect on yield. However, more research is needed to assess whether the relative performance of Bt cotton will be maintained across the range of soil nitrogen content typically encountered in developing countries. High temperatures may also reduce toxin production by stressing the plants and altering their nitrogen metabolism, although there is currently no evidence that high temperatures negatively affect yield.Unwanted gene flow between transgenic and conventional cotton could be problematic for insect resistance management strategies, organic cotton production, and maintenance of the intellectual property rights of biotechnology firms. Moreover, gene flow from transgenic cotton to wild cotton species could endanger the genetic integrity of native species. Buffers of 60m or less of non-transgenic cotton can be used to limit gene flow from transgenic cotton fields. Cotton growers relying on buffers should make sure that buffers are only planted with certified non-transgenic seed. Fields with abundant pollinating insects may require larger buffers than fields with limited insect activity. Growers should exercise caution when planting transgenic cotton in areas with genetically compatible wild cotton species and are advised to use large buffers or avoid using transgenic cotton in those regions. In regions where farm-saved seed is used, precautions should be taken to protect conventional cotton cultivars, as farm-saved seed is particularly vulnerable to gene flow from transgenic varieties. Similarly, providing affordable, certified seed of transgenic cotton to farmers could help preserving integrity of transgenic cultivars. This would contribute to preserving insecticidal properties of the transgenic cultivars and to the sustainable management of pest resistance.Insecticide use can be much lower in Bt cotton than in non-Bt cotton. Thus, assessments of non-target effects of Bt cotton should consider patterns of insecticide use in Bt and non-Bt cotton. The abundance of non-target insects often declined moderately but significantly in unsprayed Bt cotton compared to unsprayed non-Bt cotton, presumably due to a reduction in the abundance of lepidopteran insects that are important resources for non-target arthropods. The reductions in predator abundance in unsprayed Bt cotton compared to unsprayed non-Bt cotton did not affect predation rates, suggesting that predation rates in cotton can be sustained despite declines in abundance of certain predators. Lower insecticide use in Bt cotton than in non-Bt cotton often benefited non-target organisms in Bt cotton and improved biocontrol in some cases. However, decreased abundance of parasitoids specializing on lepidopteran pests occurred in Bt cotton in parallel with decreased abundance of lepidopteran hosts. Overall, few adverse effects on non-target arthropods have been observed for cotton producing the Bt toxin Cry1Ac. More data are needed to thoroughly assess impacts of Cry1Ac cotton on soil organisms, as well as impacts of transgenic cultivars producing toxins other than Cry1Ac.H. armigera and other key cotton pests in developing countries. After more than a decade of use of transgenic crops, one key pest of cotton, H. zea, has evolved resistance in the field to Bt cotton producing Cry1Ac. Furthermore, a second key pest, H. amigera, may be in the process of doing so. Two key pests of corn, B. fusca and S. frugiperda, have evolved resistance in the field to Bt corn producing Cry1Ab and Cry1F, respectively. Because factors influencing resistance evolution often change across regions, region-specific evaluation of resistance risks and implementation of resistance management is required to sustain the effectiveness of transgenic cotton for pest control. While the refuge strategy has so far been implemented in countries where seed purity is high, many small farmers in developing countries where transgenic cotton will be introduced could plant their cotton fields with farm-saved seed. In such cases, small farmers may end up unknowingly planting seed mixtures of transgenic and non-transgenic cotton. The possibility that seed mixtures of non-transgenic and transgenic cotton may accelerate the evolution of resistance needs critical investigation. Experiments assessing fitness of larvae with and without resistance alleles in seed mixtures are needed to rigorously evaluate this possibility. In some cases, the deployment of Bt cotton associated with lower use of insecticidal sprays has reversed pest resistance to synthetic insecticides, thereby increasing options for controlling key cotton pests.The refuge strategy is widely used to delay pest resistance to transgenic cotton. This strategy is most effective when resistance is recessive and sufficient refuges of non-transgenic host plants are available. Transgenic cotton that kills < 99% of susceptible insects may need large refuges to significantly delay resistance. Fitness costs and incomplete resistance can be exploited to delay resistance evolution. Research is needed to identify plants or natural enemies that increase fitness costs in


In patients with acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS), recent randomised controlled trials (RCTs) showed a consistent trend of mortality reduction with prone ventilation. We updated a meta-analysis on this topic.RCTs that compared ventilation of adult patients with ALI/ARDS in prone versus supine position were included in this study-level meta-analysis. Analysis was made by a random-effects model. The effect size on intensive care unit (ICU) mortality was computed in the overall included studies and in two subgroups of studies: those that included all ALI or hypoxemic patients, and those that restricted inclusion to only ARDS patients. A relationship between studies' effect size and daily prone duration was sought with meta-regression. We also computed the effects of prone positioning on major adverse airway complications.P = 0.39), but it significantly reduced the ICU mortality in the four recent studies that enrolled only patients with ARDS . Meta-regression on all studies disclosed only a trend to explain effect variation by prone duration (P = 0.06). Prone positioning was not associated with a statistical increase in major airway complications.Seven RCTs  were included. The four most recent trials included only ARDS patients, and also applied the longest proning durations and used lung-protective ventilation. The effects of prone positioning differed according to the type of study. Overall, prone ventilation did not reduce ICU mortality (odds ratio = 0.91, 95% confidence interval = 0.75 to 1.2; Long duration of ventilation in prone position significantly reduces ICU mortality when only ARDS patients are considered. Despite significant and sustained increase of oxygenation, prone positioning had no impact on mortality -4. Most  II ≥50) ,8. Thesetilation ,12.Meta-analysis of individual patient data helps to avoid ecological bias, allows sufficiently powered subgroup analysis, and even allows powerful and reliable evaluation of treatment effects across individuals . This tyIn a previous aggregate meta-analysis we emphasised the substantial clinical  heterogeneity of primary studies, making it difficult to conduct a study-level meta-analysis evaluating prone ventilation . This heGiven the large sample sizes of the initial studies, the heterogeneity in terms of severity as well as patient management heavily impacted the study-level meta-analyses -9. Of noIn the present article, we update our recent meta-analysis of the effects of prone positioning on intensive care unit (ICU) mortality. Along with a global meta-analysis, a subgroup meta-analysis is performed on the group of studies that restricted inclusion to only adult ARDS patients. We also explore the effects of proning duration.The search strategy and selection of studies are similar to those described in our previous meta-analysis . Pertine2/FiO2 ratio), prone position duration on a 24-hour basis, and ICU mortality reported on an intention-to-treat basis. The methodological quality of each trial was evaluated using the five-point scale (0 = worst and 5 = best) as described by Jadad and colleagues [Three investigators  independently evaluated studies for inclusion and abstracted data on methods and outcomes; disagreements were resolved by consensus between investigators. We extracted the study design, type of population and disease severity  to compute individual odds ratios (ORs) with 95% confidence intervals (CIs), and a pooled summary effect estimate was calculated. Since a clear change of primary study design has progressively occurred along with incorporation in everyday practice of new evidence generated by research, we evaluated the impact of publication date on the overall effect of prone ventilation by a cumulative meta-analysis. Indeed, this type of presentation roughly evaluates the trend over time for the overall effect of an intervention as new studies are published. We also compared the effect size of prone ventilation in two subgroups of studies: those that included all ALI patients, and those that included the most severe patients (ARDS patients). Noteworthy, this separation allows also comparison of earlier (before 2006) versus recent studies (after 2005), and studies that applied longer prone duration (≥17 hours/day) versus studies applying shorter prone duration.z test. Publication bias was assessed by visual inspection of the funnel plot and the Begg and Mazmudar rank correlation test. A relationship between study results (the effect size) and daily prone duration was sought with meta-regression. The incidence of complications related to prone positioning was also compared by means of a random-effects model. We analysed the incidence of major airways events corresponding to accidental extubation, and tracheal tube displacement with or without selective intubation. Statistical significance was set at the two-tailed 0.05 level for hypothesis testing and 0.10 for heterogeneity testing. Between-study heterogeneity was assessed using the I2 measure. The meta-analysis was conducted using Comprehensive Meta Analysis v2 . The present study was performed in compliance with the PRISMA guidelines  was sought by comparing the mean effect size for the two subgroups using the We identified 48 studies for detailed evaluation Figure . Seven Rn = 1,135) with a large spectrum of disease severity (ALI and ARDS), used a short duration of prone positioning (<17 hours), and did not use a protective lung ventilation, the four most recent trials were quite similar regarding patient severity , applied the longest proning duration (17 to 24 hours/day), and ventilated patients with protective lung ventilation.The study characteristics and methodological quality are presented in Table P = 0.39; I2 = 0%). Cumulative meta-analysis, which sorts studies chronologically, shows a progressive shift of the pooled summary effect of prone ventilation from a negative to a positive effect starting with the publication by Mancebo and colleagues, which was the first RCT to include ARDS patients only  that included patients with variable disease severity - that is, all ALI or hypoxemic patients  - while it significantly reduced the ICU mortality rate in the four most recent studies (n = 540 patients) that included only patients with ARDS . The z test of interaction was not significant , indicating that a heterogeneity of treatment effects between both subgroups was not certain. Funnel plot inspection did not suggest publication bias, and Begg's rank correlation test was not statistically significant (P = 0.23).As anticipated, the effects of prone positioning were different in both subgroups considered according to disease severity Figure . Proningz = -1.88; P = 0.06).The result of a meta-regression that assessed the relationship between prone duration and effect size in included studies is presented in Figure P = 0.5) .All included RCTs reported data regarding airway complications related to prone positioning. The prone positioning was associated with a nonsignificant increase in the incidence of accidental extubation, selective intubation, or tracheal tube displacement , however, which does not allow one to ensure that the effects of proning were significantly different between subgroups. Another confounder may also be the daily duration of ventilation in the prone position (P = 0.06). Prone positioning was not associated with an increase in major airway complications. The current study-level meta-analysis confirms and reinforces recent findings of individual patient data meta-analyses made by Sud and colleagues and Gattinoni and colleagues [The current meta-analysis shows that global analysis of RCTs assessing ventilation in the prone position in ALI/ARDS patients does not show a significant benefit on ICU mortality. The subgroup analysis stratified on the type of included patients in primary studies, however, disclosed a statistically significant reduction in mortality in the studies that restricted inclusion to only patients with ARDS, and not in those also enrolling patients with less disease severity. The comparison of the mean effect size between subgroups was close to significance .A way to fully account for the ecological bias inherent to diversity of designs in primary studies is the performance of a meta-analysis using individual patient data . Indeed,100 mmHg ,12. ThisOur study used a different meta-analysis approach and stratified subgroups of studies according to the disease severity of included patients, rather than performing a subgroup analysis of included patients. This study reached the same conclusions as individual patient data meta-analyses, although our findings suggest that the benefits can go beyond the recommended threshold and concern all patients meeting ARDS criteria. A study-level meta-analysis like ours could therefore be an alternative for clinicians to detect true intervention effects  despite differences among studies regarding participants, interventions, and co-interventions (noise) . We shouIt is also difficult to control for important confounders such as the differences in prone duration, ventilation strategy, or associated treatments. Indeed, studies that included only ARDS patients also implemented lung-protective ventilation and longer prone duration, making it difficult to ascribe the observed reduction in ICU mortality to only one of these variables. Lung-protective ventilation has proved to lessen ventilation-induced lung injury and to reduce mortality, while longer prone duration helps to increase lung recruitment and enhances gas exchange ,24. FollThe fact that the test of interaction yielded only a trend to different mean effect size of prone ventilation in the subgroup of ARDS patients when compared with studies that included all ALI is not surprising given that studies including ALI patients also enrolled a substantial proportion of patients with ARDS. Without specific studies enrolling only ALI non-ARDS patients, this type of effect comparison may be difficult. Apart from a type II statistical error, the nonsignificant test of interaction might also reflect a true lack of heterogeneity of prone ventilation effects. The use of confidence intervals is helpful to solve this uncertainty . The 95%Our cumulative meta-analysis shows that beneficial effects of prone ventilation have progressively become apparent as new studies have been published. This finding suggests that the gradual incorporation of research advances  influenced the trend toward an apparent benefit from prone positioning. This cumulative meta-analysis also shows that the size effect of prone ventilation on mortality has become almost constant since 2006 following the study by Mancebo and colleagues . SubsequOur meta-analysis did not disclose a statistically significant increase in major airway complications of prone positioning. The most recent RCT (Prone-Supine II Study), however - which should be regarded as the most reliable reflection of real-life practice - recorded a higher incidence of adverse events associated with prone positioning . This coThe survival difference between ALI/ARDS studies and only ARDS studies might have additional possible contributors, other than the disease severity. The ALI/ARDS studies are the older studies, characterised by several methodological differences such as the absence of relevant co-treatments , other criteria of enrolment (time window between ARDS criteria and enrolment), and so forth. The main difference is that the length of the proning treatment - which may constitute an important determinant of the survival benefit - is profoundly different between older studies (shorter duration) and newer studies (longer duration). Indeed, alveolar recruitment in the prone position is a time-dependent phenomenon . Our stuThe present study-level meta-analysis based on an observation  and a working hypothesis (only ARDS patients would derive benefit from prone ventilation) tried to overcome primary trial heterogeneity by a subgroup meta-analysis of studies that restricted inclusion to only ARDS. This meta-analysis shows that prone ventilation significantly reduces ICU mortality in ARDS patients and suggests that long prone durations should be applied.• The use of prone positioning during ARDS ventilation has a robust scientific ground.• Available RCTs that were frequently underpowered failed to document an impact on mortality mainly because they included patients with a wide spectrum of disease (ALI and ARDS) and applied variable length of prone positioning.• Study-level meta-analyses published so far only suggested beneficial effects on mortality.2/FiO2 ratio <100 mmHg).• Meta-analyses of individual patient data have recently shown that prone positioning could reduce ICU mortality in the subgroup of the most severe patients (PaO• Using a subgroup analysis focusing on trials that restricted inclusion to only ARDS patients, our study-level meta-analysis shows that prone positioning reduces ICU mortality in patients with ARDS.2: inspiratory fraction of oxygen; ICU: intensive care unit; PaO2: arterial partial pressure of oxygen; OR: odds ratio; RCT: randomised controlled trial.ALI: acute lung injury; ARDS: acute respiratory distress syndrome; CI: confidence interval; FiOThe authors declare that they have no competing interests.FA conducted the literature searches, selected studies, extracted data, assessed study quality, prepared initial and subsequent drafts of the manuscript, and integrated comments from other authors into revised versions of the manuscript. LO-B, FD, and IO screened abstracts, selected studies meeting inclusion criteria, extracted data, and assessed study quality. FA and LO-B carried out the statistical analyses with input from IO, FD and LB. LB provided methodological guidance on drafting the manuscript. All authors read and approved the final manuscript.PRISMA checklist. Checklist according to the PRISMA guidelines.Click here for file


Non-small-cell lung cancer (NSCLC) represents 85% of lung cancer. The most frequent sites of distant metastasis are the liver, adrenal glands, bones and brain. Gastrointestinal metastases are uncommon and rectal metastases are extremely rare. Here we report a case of squamous cell carcinoma of the lung with rectal metastases. Non-small-cell lung cancer is a common neoplasm and frequently metastasizes to lung, liver, adrenal, and brain. However, gastrointestinal metastasis development is relatively rare, except esophagus localization by local invasion. Colon metastases have been previously reported but rectal metastases from NSCLC are an extremely rare localization.A 81-year-old former smoker man (45 pack-years) with history of colonic diverticulosis with annual colonoscopy surveillance was presented with haemoptysis and fatigue of several-month duration. As part of the evaluation of these symptoms, a chest X-Ray was performed, which revealed hilar fullness. As result of this finding a computed tomography (CT) was performed and showed a right lower lobe mass with contralateral metastases . The lunTreatment was commenced with chemotherapy (gemcitabine × 4 cycles) achieving stable disease. Three months later the patient presented abdominal pain and the CT scan showed progression of the disease with an increase in size and number of lung nodules and the presence of a thickening of the rectum wall with enlarged regional lymph nodes . Rectum Metastatic involvement of the gastrointestinal tract (GI) secondary to NSCLC is relatively frequent in necropsies series 4,3%–18,5%) but rarely recognized clinically [8,5% but Esophagus is the more frequent GI metastatic localization by contiguity invasion and small bowel and stomach are frequent localization as part of haematogenous dissemination. Colonic metastatic from NSCLC has been rarely described and rectal localization is an extremely rare finding , 3.At our knowledge, only two possible cases of rectal metastases from lung cancer have been reported in the literature. In a review of 18 patients with lung cancer initially manifesting as gastrointestinal tract metastases in one centre, there is mention of a possible patient with rectal metastasis . A 73-ye GI metastases from NSCLC are used to be occasional findings in radiological tests and clinically significant symptoms are rare except for the complications. However, clinical manifestations depend on the site of the metastases with digestive bleeding in case of gastric metastasis, abdominal pain, anemia, and bowel perforation in lower gastrointestinal tract , 6.GI metastasis has been described as synchronous at the initial diagnoses but more frequently metachronous in the context of progression at various sites . The hisThe lung cancer with intestinal metastasis has been reported to have a poor prognosis with median OS of only 4–8 weeks –5. The t GI metastases from NSCLC are more frequent than we observe in clinical daily practice. However, rectal localization is a very uncommon event and, when it happened, worsened the prognosis.


Traumatic brain injury (TBI) is defined as an impact, penetration or rapid movement of the brain within the skull that results in altered mental state. TBI occurs more than any other disease, including breast cancer, AIDS, Parkinson’s disease and multiple sclerosis, and affects all age groups and both genders. In the US and Europe, the magnitude of this epidemic has drawn national attention owing to the publicity received by injured athletes and military personnel. This increased public awareness has uncovered a number of unanswered questions concerning TBI, and we are increasingly aware of the lack of treatment options for a crisis that affects millions. Although each case of TBI is unique and affected individuals display different degrees of injury, different regional patterns of injury and different recovery profiles, this review and accompanying poster aim to illustrate some of the common underlying neurochemical and metabolic responses to TBI. Recognition of these recurrent features could allow elucidation of potential therapeutic targets for early intervention. Traumatic brain injury (TBI) occurs when a traumatic event causes the brain to move rapidly within the skull, leading to damage. As illustrated in the poster (panel A), the event can be classified as either impact or non-impact, depending on whether the head makes direct contact with an object (impact) or encounters a non-impact force such as blast waves or rapid acceleration and deceleration (non-impact). A TBI occurs every 15 seconds in the US, generating 1.7 million new head injury victims per year. These events are responsible for 50,000 deaths, leave 80,000 individuals with permanent disabilities and cost more than US$77 billion on average per year . The freCurrently, the severity of TBI is categorized based on the Glasgow Coma Scale (GCS), in which patients are scored on the basis of clinical symptoms, and the resulting overall score classifies their injury as mild (score: 13–15), moderate (score: 9–12) or severe (score: <9). Symptoms of mild to moderate TBI can include headaches, dizziness, nausea and amnesia; these injuries usually resolve within days to weeks of the insult. However, occasionally these injuries can result in long-term cognitive and behavioral deficits. Furthermore, there is evidence to suggest that moderate to severe TBI, and even repeat mild TBI, might be associated with increased risk of neurodegenerative diseases such as Alzheimer’s disease , chronicTo study TBI pre-clinically, researchers have developed several experimental animal models to replicate human pathophysiology. TBI models are used to study aspects of primary and secondary brain injury. Primary injury refers to the initial impact that causes the brain to be displaced within the skull. Secondary injuries gradually occur as a consequence of ongoing cellular events that cause further damage. Fluid percussion (FP), controlled cortical impact (CCI) and weight-drop injury are the most commonly used TBI models that can be modulated to generate injuries with characteristics of mild or severe TBI  levels that was blocked by tetrodotoxin (a neurotoxin that prevents brain cell firing), suggesting that this rise in [K+] is related to neuronal firing. More severe injuries produced greater increases (4.3- to 5.9-fold) in [K+] that were tetrodotoxin-resistant. Administration of kynurenic acid, an antagonist of excitatory amino acids, attenuated the [K+] increase in a dose-dependent manner, suggesting that the K+ surge is dependent on excitatory neurotransmitters. In order for brain cells to fire again, ionic equilibrium must be re-established, which requires ATP (cellular energy).Normal transmission of signals involves neurotransmitter-mediated activation of receptors and subsequent controlled ionic changes in the postsynaptic membranes of neurotransmitter-releasing cells. Ionic changes across the bilipid membrane are meticulously regulated by energy-dependent sodium-potassium  accumulation is also commonly observed after TBI  was measured in adult rats after FP injury. Increases in 45Ca2+ were seen as early as 6 hours after the initial injury, and a return to control levels has been observed between 4 days  are frequently used to measure glucose uptake (transport) into the brain. Glucose analogs are metabolized by the enzyme hexokinase, which is the first enzyme in the glycolytic pathway . Once these isotopes are cleaved by hexokinase they become trapped in the cells, which allows the accumulation of glucose to be measured. Autoradiographic images are generated to look at regional changes in isotope-glucose uptake, which can be quantified according to the density of the gray scale. Darker regions reflect greater glucose uptake and whiter regions reflect lower glucose uptake . These isotopes have been used to show a rapid increase in glucose uptake followed by a prolonged period of glucose metabolic depression, as observed in both experimental and clinical head injury (Glucose is the primary fuel source of the adult brain and its processing through the glycolytic pathway provides carbons for the tricarboxylic acid (TCA) cycle for energy production in the form of ATP. Changes in cerebral glucose metabolism (CMRglc) have been established as a hallmark response after TBI. Two chemical isotopes . Specifically, the duration of glucose metabolic depression increases with age. FP-injured postnatal day (PND) 17 juvenile rats show glucose metabolic recovery to the level of age-matched control animal (sham) levels within 3 days , whereasAlthough decreased glucose uptake after injury seems to be a universal response, the underlying mechanism remains unknown. There are three possibilities: decreased blood availability [which depends on cerebral blood flow (CBF)], defects in glucose transporter function or decreased metabolic demand for glucose. The rapid increase in CMRglc immediately after injury reflects an acute period of increased glucose consumption (as outlined above) and this occurs during a time when CBF has been shown to decline . In an e18F-DG kinetic changes following moderate to severe TBI in humans and determined that hexokinase activity was globally decreased, with glucose transport impairments occurring specifically within the contusion sites  immunoreactivity 2–4 hours after FP injury ; howeveron sites . Collect13C]-labeled glucose infusion (+) concentrations have been shown to decrease after injury , so reductions in NAD+ levels can cause glycolytic inhibition , which can generate hydroxyl radicals (•OH) via the Fenton reaction. The •OH is one of the most reactive chemical species. Reaction of O2− with nitric oxide (NO•) produces peroxynitrite (ONOO−). Normal metabolic activities produce levels of ROS that are well managed by cellular antioxidant defense systems. It is only after cerebral injury that the levels of ROS production overwhelm scavenging systems and result in oxidative damage , which increase O2− and NO• production . There are two main families of free radicals: reactive oxygen species (ROS) and reactive nitrogen species (RNS). Production of Oe damage . Mitochooduction .•OH) production increases 60% within the first minute, peaks at 30 minutes after injury and subsequently decreases  is a nuclear DNA repair enzyme that consumes NADoduction . Evidencoduction . This acoduction . Partialter maze .Although age-dependent effects on free radical production or consequent damage in TBI have not been studied in depth, age-related differences in antioxidant defense systems have been examined. After CCI injury, glutathione peroxidase (GPx) activity was examined in immature (21-day-old) and adult mice . GPx act2+ and ROS after injury, as discussed above, contributes to mitochondrial impairments. Excessive Ca2+ influx can overwhelm mitochondrial Ca2+-buffering capacity and the rate of efflux by the mitochondrial Na+-Ca2+ exchanger. The resulting Ca2+ accumulation has been shown to contribute to mitochondrial membrane-potential collapse . Growing evidence has documented the brain’s ability to increase its reliance on alternative substrates under conditions of energy stress [starvation , hyperkenile rat . The fasI injury .L-carnitine after injury improved behavioral outcomes and decreased lesion volume (Addition of ethanol pyruvate to cerebrocortical slices exposed to oxidative stress alleviated ATP decreases and improved cell survival . Pyruvatn volume . Despiten volume . UnfortuTBI is a complex dynamic process that initiates a multitude of cascades of pathological cellular pathways. Its symptomatic presentation varies with each individual, injury type, injury severity, age and gender, making it challenging to diagnose, understand and treat. Research efforts to understand the common underlying neurochemical and metabolic responses to TBI could provide further therapeutic options for early intervention of TBI in patients of all ages.