It is now generally agreed that there are inherent sex differences in healthy individuals across a number of neurobiological domains . Moreover, there is a burgeoning body of evidence highlighting sex differences within neuropsychiatric populations . Here, we consider the extent to which attention and impulsivity are sexually dimorphic in healthy populations and the extent to which sex might modulate the expression of disorders characterised by abnormalities in attention and/or impulsivity such as attention deficit hyperactivity disorder (ADHD), autism and addiction. We then discuss general genetic mechanisms that might underlie sex differences in attention and impulsivity before focussing on specific positional and functional candidate sex-linked genes that are likely to influence these cognitive processes. Identifying novel sex-modulated molecular targets should ultimately enable us to develop more effective therapies in disorders associated with attentional/impulsive dysfunction. Sex difThere is perhaps even more compelling evidence for sexual dimorphic features in many neuropsychiatric disorders, notably in terms of their incidence, their clinical features and progression, and in their underlying pathology . A large2All animals live in a world of competing, multiple and simultaneous stimuli that must be resolved in order so that they behave adaptively. Attention represents the ability to select from a plethora of stimuli, responses, memories and thoughts, and in doing so, disregard any that are behaviourally irrelevant ; ‘attentAs with attention, a single definition that encapsulates all aspects of impulsivity has so far proved elusive  and thisNumerous studies investigating the neuroanatomical circuitry of impulsivity have demonstrated the key role that the frontal cortex plays in humans . This isd-amphetamine) can be used to treat disorders of impulsivity such as ADHD  differ considerably between the sexes in terms of their development and ongoing function  than ADHD males, but greater intellectual impairments and more internalising problems  . In contConsistent evidence for sex differences in brain structure/function within ADHD cohorts has been limited , in agre4.2per se, it is estimated that 30–80% of ASD children meet symptom criteria for ADHD (Autism spectrum disorders (ASDs) are characterised by abnormalities in social function and communication, excessive anxiety and high levels of repetitiveness . As withfor ADHD . ASDs difor ADHD  and it hfor ADHD . Whilst for ADHD  and poorfor ADHD  than thefor ADHD .Addictive behaviours, such as gambling and drug abuse, can be conceptualised as impulsive choices, whereby smaller, immediate rewards are favoured over larger, delayed rewards . Patholo5Ultimately, sex differences in behaviour and cognition must stem from the fact that the two sexes inherit different chromosomal complements: males inherit one cognition-gene rich X chromosome (invariably from their mother) , and a YMultiple lines of evidence have suggested a strong genetic component to attention and impulsivity phenotypes, including data from family, twin and adoption studies for disorders of attention/impulsivity such as ADHD , and theEvidence for the involvement of sex-linked genes specifically in mediating altered attention/impulsivity phenotypes has come from a combination of comparing males and females on measures of attention/impulsivity (described above), studying cohorts with unusual sex chromosome constitutions, from studying individuals with discrete mutations on the X or Y chromosomes, from linkage/association studies and from work in animal models. For example, using an elegant animal model, the so-called ‘four-core genotypes’ cross in which the direct effects of sex-linked genes on neurobiology may be dissociated from their downstream effects on gonadal hormone-mediated effects on neurobiology , it has There are three general mechanisms through which genes on the sex chromosomes may influence sex-specific neurobiology . First, de novo mutation of the Y chromosome  and ADHD suggests the possibility that over-dosage of Y-linked genes on the short arm and/or absence of Y-linked genes on the long arm could be important in mediating ADHD vulnerability  may result in abnormal attentional and/or impulsivity phenotypes. Subjects with such chromosomal abnormalities are relatively rare and their phenotype varies considerably, and as such, data from such studies should be treated with a degree of caution. Males with multiple Y chromosomes, and therefore over-dosage of Y-linked genes , have been reported to exhibit relatively high rates of attentional deficits (distractibility) and ADHD . These frability .Evidence for X-linked gene dosage being important in mediating attentional/impulsive function has come from studying subjects with Turner syndrome  and Klinefelter syndrome . Both of these disorders present with endocrinological abnormalities , so any 6SRY, STS and MAOA represent clear positional and/or functional candidates for effects on attentional and impulsive behaviours. For instance, SRY, either directly via neural expression or indirectly through downstream effects on gonadal hormone levels, may mediate dopaminergic effects linked with attention and impulsivity  (SRY gene is a Y-linked gene (Yp11.3)  which encodes a protein with a DNA-binding motif. This protein acts as a transcription factor in the bipotential gonad of the developing fetus to induce gene expression changes which facilitate differentiation into testicular tissues  (MAOA (the X-linked gene encoding the enzyme monoamine oxidase involved in monoamine breakdown)  . SRY gen tissues . Once fo tissues . Besides tissues ; these a tissues . In man,thalamus ; it is loxylase)  and for eakdown) ; the fac in vivo .SRY could potentially also act as an indirect mediator of attention/impulsivity via its downstream effects on testosterone secretion. Testosterone levels may influence attention/impulsivity in individuals with attentional/impulsive dysfunction  suggested that one of the genes on this chromosome could influence attention. The most promising candidate gene on the basis of its function, and the fact that it was already known to escape X-inactivation, was STS, encoding the enzyme steroid sulfatase (STS gene is X-linked (Xp22.3), escapes X-inactivation  show visuospatial attentional deficits, reduced levels of impulsive action (as indexed by performance on mouse variants of the 5-CSRT and SSRT tasks), elevated levels of aggression and increased locomotor activity  encodes the mitochondrial enzyme monoamine oxidase A (MAOA)  it may partially escape X-inactivation in some tissues in humans; however, the data for this from studies using fibroblasts and hybrid cell work are inconclusive (The X-linked A (MAOA) ; this enA (MAOA) . The abinclusive , and no MAOA gene in mice results in enhanced aggression (MAOA polymorphisms (including the 30 base pair variable number tandem repeat sequence near the promoter) and vulnerability to ADHD (MAOB (Xp11.23) encoding the enzyme monoamine oxidase B , may also influence attention/impulsivity phenotypes and vulnerability to ADHD  inactivating mutations within the gene may lead to extreme impulsiveness and aggression in males , whilst gression , (ii) cegression , (iii) a to ADHD ; these a to ADHD  and (iv) to ADHD . There i to ADHD , althougsiveness .7SRY acting as a transcriptional activator for the autosomal TH gene), or by the downstream pathways influenced by sex-linked genes such as gonadal hormone systems. One interesting gene in this regard is COMT (22q11.21) which encodes the enzyme catechol-O-methyltransferase. COMT was implicated as a candidate gene for ADHD based on its high frontal cortex expression, its absence in ADHD-prone 22q11 deletion syndrome patients, and its role in catecholamine metabolism  allele conferred risk of ADHD in boys, whereas possessing the valine  allele conferred risk of developing ADHD in girls (O-methyltransferase activity is greater in male prefrontal cortex (COMT homozygous knockout male mice have a twofold increase in dopamine levels in the prefrontal cortex compared with male wildtypes, whereas no such discrepancy occurs between female knockout mice and their wildtype counterparts (This review has focussed on sex-linked genetic mechanisms that may underlie attentional and impulsive phenotypes in mammals. However, there are without doubt a large number of autosomal genes whose products are likely to affect the phenotypes of interest here. It is possible that the expression/function of such autosomal genes may be modulated by sex, either by the products of sex-linked genes directly (e.g. tabolism . Most stin girls . In furtin girls . The idel cortex  and thatterparts .8There is persuasive evidence that the sexes differ with respect to their relative vulnerability to disorders of attention and impulsivity. Moreover, there is putative evidence that healthy males and females show differences in their attentional and impulsive profiles, and in the brain structures underlying these cognitive processes. However, these latter findings are, at present, inconsistent and the field requires further exploration. These sex differences in neurobiology must be underpinned by genes on the X and Y chromosomes exerting their effects by either direct action in the brain or via intermediary mechanisms such as systemic hormone secretion; here, we have reviewed several plausible mechanisms via which genes on the sex chromosomes may influence attention and impulsivity.a priori rather than analysing data from males and females a posteriori. Additional useful work in humans might focus upon identifying potential regions of interest underlying attention/impulsivity phenotypes on the X chromosome using large scale linkage or association or copy number variant analyses, although the idiosyncratic nature of this chromosome makes it difficult to study using standard methods (Future work, utilising state-of-the-art imaging techniques, should try to specify more accurately the neuropsychological and neuroanatomical differences that distinguish healthy males and females, male/female controls from their counterparts presenting with disorders of attention or impulsivity, controls from subjects with sex chromosome anomalies, and controls from subjects with mutations within specific sex-linked genes. To achieve the first two objectives, sex difference studies should ideally be planned  methods . Finally methods  and to e


Neural mass models (NMM) describe neural activity on a macroscopic scale, which can be compared to the electroencephalogram (EEG). This allows a better understanding of the processes responsible for various EEG patterns, including pathological rhythms as diffuse slowing or burst-suppression .Using available models which contain explicit expressions for the synaptic response and number of synapses , patholoHere, we present a method for constructing a neural mass model by using the relation between synaptic input of a single cell model and its firing rate. This allows an easy implementation for pathological conditions.We describe the average firing rate of a single population of neurons receiving one type of synaptic input, but this can readily be extended to multiple populations. A set of differential equations describes, traditionally, the average synaptic conductance . AssuminAs initial verification, the constructed mean field model is numerically compared to a network of single cells. From the single cell model we determine the dependence of the firing rate on (constant) synaptic conductance numerically. Furthermore, we show that, for fluctuating inputs, the firing rate is well approximated by the instantaneous synaptic conductance. 120 Hodgkin-Huxley type cells were connected all-to-all with inhibitory synapses: a simple configuration which results in intrinsic oscillations. Each cell receives inhibitory external input as well, consisting of Poisson trains. We find a close agreement between the constructed neural mass model and the network simulation (Figure The proposed method can easily be extended to model heterogeneous populations, multiple types of synapses, spatial structures, propagation delays, and bursting dynamics . Any pat


The biliary treeconsists of intrahepatic and extrahepatic bileducts and is lined by biliary epithelial cells(or cholangiocytes). There are also peribiliaryglands around the intrahepatic large bile ductsand extrahepatic bile ducts. The biliary tree isa conduit of bile secreted by hepatocytes andbiliary epithelial cells and also of theperibiliary glands and has severalphysiological roles. A number of diseases affectmainly the intrahepatic and extrahepatic biliarytree, and, in this special issue, thesecholangiopathies are reviewed in detail with respectto genetics, pathogenesis, and pathology. In thispaper, the anatomy and physiology of the biliarytree, basic injuries to biliary epithelial cellsfrom stress and bile duct damage, andrepresentative cholangiopathies are brieflyreviewed. A number of diseases affect the biliary tree (cholangiopathies), though the pathological mechanisms involved and the anatomical level of the biliary tree affected vary . For exa In this special issue, cholangiopathy with respect to genetics, pathogenesis, and pathology will be discussed in detail. Herein, the anatomy and physiology of the biliary tree, basic injuries to biliary epithelial cells, basic forms of bile duct damage, and etiological classifications of cholangiopathy are reviewed. This tutorial review will be helpful for a better understanding of cholangiopathy. The biliary tree is composed of extrahepatic and intrahepatic bile ducts . The forμm in diameter) are lined by tall columnar cells with basal nuclei, the interlobular bile ducts are lined by cuboidal cells. The fibrous ductal wall is evident in the former like large intrahepatic ducts, but not in the latter. The interlobular bile ducts are connected to the bile canalicular network by ductules (<20 μm diameter) lined by no more than a few minimally differentiated cuboidal cells and the canals of Hering, which are lined partly by biliary epithelium and partly by hepatocytes. The intrahepatic stem cell niches are the canals of Hering in postnatal livers [ The intrahepatic bile ducts can be classified as large and small, though there is no sharp delineation of the various segments , 5. The l livers . Bile du Peribiliary glands, the third biliary component, are present within the fibromuscular walls of extrahepatic bile ducts and also along the large intrahepatic bile ducts , 5, 7. GThe individual anatomical components of the biliary tree each have a rather characteristic antigen, probably reflecting a site-specific function , 10. ForThe intrahepatic and extrahepatic biliary tract is supplied by a network of fine vessels called the peribiliary vascular plexus (PBP) which exclusively derives from hepatic arterial branches –13. The  The inner layer, a layer of capillaries, is found just beneath the basement membrane of the epithelial layer and is regularly distributed like a chain. Ultrastructurally, the inner capillary layers are composed of fenestrated endothelial cells, and the number of fenestrae with a thin diaphragm is rather high on the capillary side facing the bile duct epithelium . These o3− to induce an alkakine state [The biliary tree is lined by specialized epithelial cells called BECs or cholangiocytes  and is nne state . BECs alThe biliary tree is essentially sterile under normal conditions, but bile is potentially contaminated by bacterial components such as pathogen-associated molecular patterns (PAMPs) including lipopolysaccharide (LPS) and bacterial DNA originating from intestinal flora, which are actually detectable in bile of patients with chronic inflammatory biliary diseases . In thisβ-defensins (hBDs) and cathelicidin, another antimicrobial peptide contributing to innate immunity at mucosal surfaces, are expressed in the biliary tree. hBD-1 is constitutively expressed in the biliary epithelium, while hBD-2 is expressed in large intrahepatic bile ducts in extrahepatic biliary obstruction, hepatolithiasis, and, to a lesser degree, PBC and PSC, suggesting a response to local infection or bacterial components, cytokines such as IL-1β and TNF-α, and/or active inflammation. Cathelicidin is expressed by normal biliary epithelial cells in addition to hepatocytes. Trefoil factor family (TFF) 1, 2, and 3 peptides expressed at the apical surface of the epithelium play a major role in mucosal repair. Nonspecific bactericidal enzymes such as lactoferrin and lysozyme are also detected in the intrahepatic biliary tree, peribiliary glands, and bile . Human β IgA is known to be secreted into bile by binding with the secretory component (SC), and secretory IgA (SIgA) functions in a number of ways to protect the biliary tract. For example, it can directly bind and neutralize bacterial toxins. SIgA can bind to bacteria and prevent their adhesion to the mucosal membrane. Additionally, IgA has been demonstrated to neutralize intracellular microbes and their products. Biliary intraepithelial lymphocytes (bIELs), which are markedly increased in immune-mediated cholangitis, are occasionally encountered in normal intrahepatic bile ducts. Most of them are positive for CD8, some are positive for CD57, and these cells may participate in biliary innate immunity .Several pathologic agents and stress affect the intrahepatic and extrahepatic biliary tree including viral, bacterial, and even parasitic infections, oxidative stress, and immunological assaults, as well as biliary epithelial injuries from necrosis, apoptosis, and hyperplasia, and also bile duct damages.In some biliary diseases such as primary biliary cirrhosis (PBC) and chronic ductopenic allograft rejection, the ongoing apoptosis of BECs is important for progressive bile duct loss. In H&E stained sections, eosinophilic, shrunken slender cells with pyknotic nuclei in the biliary epithelial layer and fragmented and condensed nuclei in the bile duct lumen can be regarded as apoptotic bodies , 15. EleINK4 and p21WAF1/CIP  , and increased activity of senescence-associated β-galactosidase . Recent studies showed that cellular senescence has at least two pathological effects in the development of biliary diseases: impaired regeneration and senescence-associated secretory phenotypes (SASPs).Senescent BECs show characteristic features such as an eosinophilic cytoplasm, cellular and nuclear enlargement, multinucleation, and an irregular arrangement with uneven nuclear spacing . ActuallSenescent cells no longer have the ability to proliferate and they are irreversibly arrested at the G1 phase of the cell cycle . The expAccumulating evidence suggests that senescent cells remain metabolically active and play an important role in modulating the microenvironment around them by secreting cytokines, chemokines, growth factors, and profibrogenic factors . For exabcl-2 family of proteins or senescence-associated factors such as p16 and p21. The biliary epithelial cells of bile ductules or small bile ducts may be replenished by bile ductular cells or hepatic progenitor cells in the canal of Hering, though such processes may be unlikely in the intrahepatic large bile ducts. As mentioned, the peribiliary glands themselves or progenitor cells located in these glands may be involved in renewal of the biliary epithelium of intrahepatic large bile ducts and extrahepatic bile ducts and also proliferation of the epithelia lining these bile ducts [The homeostasis of physiological and pathological biliary epithelia operates through a balance between cell loss and cell renewal. Cell loss in the biliary epithelium is mainly due to apoptosis or senescence and mostly regulated by the le ducts , 8.Clonorchis sinensis infections or hepatolithiasis, the term adenomatous hyperplasia or chronic proliferative cholangitis has been used. As for the proliferation and hyperplasia of bile ductules and small interlobular bile ducts, they appear tourtous and increase in their number in the portal tracts. Some of these lesions are included in the so-called ductular reactions [Inhibition of the apoptotic or senescent process in the biliary epithelia may cause hyperplasia with an increased risk of neoplastic transformation . Hyperpleactions .Gastrointestinal metaplasia resembling pyloric glands and goblet cells is not infrequently seen in chronically inflamed large bile ducts and peribiliary glands. This change is associated with the aberrant expression of gastric type mucus core protein (MUC) 5AC and MUC6 and also intestinal type MUC2. Such gastric and intestinal mucin is involved in lithogenesis in hepatolithiasis [Goblet cells are occasionally encountered among bile duct-lining cells and also in peribiliary glands. Intestinal metaplasia with Paneth cells may also be encountered in the peribiliary glands. The expression of other molecules in intrahepatic large bile ducts, such as REG I and trefoil factors, appears to be related to intestinal or gastric metaplasia. While pancreatic acinar metaplasia is also reported infrequently in PSC, its differentiation from heterotopic pancreatic acini is controversial. Hepatocytic metaplasia occurs in interlobular bile ducts and bile ductules in various pathological situations but remains of unknown significance. Squamous metaplasia is rarely encountered in long-standing inflammation of large bile ducts such as PSC or in the lining of biliary cysts.Several kinds of metaplasia are reported in the biliary epithelium of the intra- and extrahepatic biliary tree, usually in cases of chronic biliary diseases such as hepatolithiasis, parasitic cholangitis, and primary sclerosing cholangitis (PSC). ithiasis . The so-Chronic biliary diseases such as hepatolithiasis and PSC are occasionally complicated by cholangiocarcinoma. In such cases, dysplastic or early neoplastic lesions are known to precede the invasive cholangiocarcinoma. Such biliary epithelial lesions are known as dysplasia or atypical hyperplasia of the biliary epithelium and characterized by atypical, enlarged, and hyperchromatic nuclei, an increased nucleocytoplasmic ratio, and a loss of polarity , 26. UsuIn the biliary tree, there are several types of bile duct damage such as cholangiopathies and cholangitis. Representative pathological features of the biliary tree are as follows.Cholangitis is characterized by biliary epithelial damage with inflammatory cell infiltration. Some cholangitis is also associated with ductal and periductal fibrosis. It occurs along the biliary tree, and the term cholangitis is used for inflammatory damage to bile ductules. Suppurative cholangitis implies the presence of numerous polymorphonuclear cells around and within the wall as well as within the lumen of the ducts. This may involve ducts of any size and is occasionally associated with abscess formation—cholangitic abscess. A microbial infection is often responsible, but the change also occurs in the presence of sterile bile, particularly after bile extravasation. The release of chemokines or cytokines is the likely cause in some cases.  Cholangitis can be histologically classified into suppurative and nonsuppurative forms. Nonsuppurative cholangitis” includes a spectrum of bile duct inflammation which may be granulomatous cholangitis, lymphoid cholangitis, fibrous cholangitis, and pleomorphic cholangitis according to the predominant type of inflammatory reaction present [Granulomatous cholangitis almost always seems to be destructive. This type involving the interlobular bile ducts constitutes the hallmark of PBC and is also found in drug-induced liver disease and sarcoidosis. The other types can be either destructive or nondestructive. Lymphoid cholangitis refers to a close association between duct branches, usually interlobular bile ducts, and lymphocytic aggregates, which may show a follicular arrangement. This is found in PBC and PSC with concomitant bile duct destruction or in nonbiliary disorders, in particular autoimmune and viral hepatitis C. Pleomorphic cholangitis is associated with inflammatory cell infiltration. All other types of cholangitis are found in CAH, PBC, PSC, and other liver diseases. Fibrous cholangitis  with evident ductal fibrosis develops as a consequence of long-standing bile duct inflammatory, obstruction, or ischemic injury; it can be obliterative or nonobliterative. BECs show variable damage. The former is characteristic of PSC, though, in our experience, it may be seen in acquired forms of sclerosing cholangitis too. BECs of obliterative type are actually lost in fibrous lesions, appearing as a fibrous core. Sclerosing cholangitis with bile duct obliteration suggests a diagnosis of PSC in adults. “ present . Granuloα). The biliary epithelium itself produces and secretes fibrogenic substances such as bFGF, transforming growth factor-beta (TGF-β), and platelet-derived growth factor (PDGF), as well as basement membrane proteins and extracellular matrix proteins. In biliary atresia, BECs of the affected bile ducts variably express mesenchymal markers such as vimentin and might have acquired phenotypes of mesenchymal cells, though distinct morphological epithelial mesenchymal transition (EMT) of biliary epithelium is hardly recognizable [In long-standing sclerosing cholangitis and also in other biliary diseases such as ischemic cholangitis, the bile duct wall shows a marked deposition of collagen fiber (bile duct sclerosis). The affected bile ducts in sclerosing cholangitis show a marked increase in the number of c-kit receptor-expressing mast cells which secrete fibrogenic factors such as histamine, basic fibroblast growth factor (bFGF), and/or tumour necrosis factor-alpha  or mucin-producing bile duct tumors , 30. Whe In cases of hemobilia, impacted erythrocytes are encountered in bile duct lumens. Recent endoscopic or surgical biliary manipulations in association with a primary or secondary malignancy may be underlining diseases for hemobilia.To date, many pathological terms such as oval cell proliferation, intermediate cells, and atypical bile ductular proliferation have been used to describe the “increased ductule-like cells or clusters of small epithelial cells different from mature hepatocytes” in the portal tract or the periportal area. This is a reaction of the ductular phenotype, possibly but not necessarily of ductular origin, commonly seen in many kinds of acute and chronic hepatobiliary diseases. Recently, an international working group proposed the term “ductular reaction” for this lesion . “Ductul A ductular reaction itself is heterogeneous in its development and has many meanings. There are several reports that bile ductules are very reactive anatomical elements in the liver, and proliferated bile ductules are involved in the progression of various chronic liver diseases. Our recent studies showed that bile ductular cells in PBC, PSC, and also NAFLD may undergo cellular senescence, and these cells could produce and secrete biologically active molecules and thereby be involved in hepatic fibrogenesis and other pathologic features of the liver. Ductal plate malformations (DPMs), which are different from reactive changes of bile ducts or ductules, develop as a result of a remodeling failure of the ductal plate followed by the development of intrahepatic bile ducts. DPMs are characterized by increased numbers of abnormal bile duct-like structures and show a bridge-like structure in the dilated lumen and bulbar protrusion of biliary epithelia . DPMs arDiseases that mainly target the biliary tree (cholangiopathies) can be divided into several categories according to the pathogenetic mechanism involved . HoweverEtiologic classification of cholangiopathy.α/β are predominant in PBC, supporting that Th1 immune response-predominant cytotoxicity and/or cytokine release are involved in the pathogenesis of the bile duct lesions of PBC. HLA-class II antigens are aberrantly expressed in the affected bile ducts of PBC, PSC, and chronic allograft rejection [The biliary tree could be affected by immunological assaults, and lymphoplasmacytic infiltration is evident around the damaged bile ducts. Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are representative immune-mediated cholangiopathies . Autoimmejection . Biliaryejection . BECs poejection . The anaClonorchis sinensis and Opisthorchis viverrini are endemic in East Asia, particularly northern Thailand and some parts of Korea, and cholangiocarcinoma is a serious complication of parasitic cholangitis [The biliary tree is affected by several types of infectious diseases, such as bacterial, fungal, protozoan, parasitic, and viral cholangitis. Stagnation of bile due to biliary stenosis or obliteration is followed by bacterial cholangitis, frequently with sepsis or abscess formation. Parasitic infections are also reported in the biliary tract including the liver, and liver flukes such as langitis . Hepatollangitis , 34. Muclangitis . PatholoGenetic alterations affecting the biliary tree manifest as biliary dilatation, bile duct paucity, obstruction, proliferation, stone formation, and so on. Caroli's disease with congenital hepatic fibrosis (CHF) is a representative genetic cholangiopathy. Some cases of biliary atresia (BA) also belong to this category. The former is characterized by multiple saccular dilatations of the intrahepatic bile ducts. Caroli's disease with CHF belongs to autosomal recessive polycystic kidney disease (ARPKD) with ductal plate malformation characterized by a disordered remodeling of the intrahepatic biliary tree . DisordeIschemic cholangiopathy is defined as focal or extensive damage to bile ducts due to an impaired blood supply . Most caα-naphthylisothiocyanate, 4,4′-diaminodiphenylmethane, and paraquat (toxin-induced cholangiopathy) [Bile ducts, particularly interlobular bile ducts, are occasionally affected by drug-induced hepatobiliary damage, various bile duct injuries, various types of cholangitis, and bile duct loss (drug-induced cholangiopathy) . This tyiopathy) . In conclusion, the anatomy and physiology of the biliary tree, basic injuries to biliary epithelial cells, basic forms of bile duct damage, and etiological classification of cholangiopathy were reviewed. This tutorial review will be helpful for better understanding cholangiopathies.


Although proteins and lipids have been assumed to be distributed homogeneously in the plasma membrane (PM), recent studies suggest that the PM is in fact non-uniform structure that includes a number of lateral domains enriched in specific components . These domains are called as microdomains and considered to be the platform of biochemical reaction center for various physiological processes. Microdomain is able to be extracted as detergent-resistant membrane (DRM) fractions, and DRM fractions isolated from some plant species have been used for proteome and other biochemical characterizations to understand microdomain functions. Profiling of sterol-dependent proteins using a putative microdomain-disrupting agent suggests specific lipid–protein interactions in the microdomain. Furthermore, DRM proteomes dynamically respond to biotic and abiotic stresses in some plant species. Taken together, these results suggest that DRM proteomic studies provide us important information to understand physiological functions of microdomains that are critical to prosecute plant’s life cycle successfully in the aspect of development and stress responses. The plasma membrane (PM) is a typical cellular membrane with selective permeability and surrounds all organelles and cellular substances. Therefore, the PM is thought to be the most important cellular membrane due to relationships to various important cellular processes including cell division, differentiation, and biotic/abiotic stress adaptation. The PM contains a variety of proteins associated with transport, signaling, cytoskeleton construction, metabolism, and stress protection in the form of transmembrane, peripheral, and lipid modified types.Lateral distribution of these membrane proteins has been described by diffusion of each lipid and protein molecule which is proposed as fluid mosaic model . In addiArabidopsis thaliana, leek, Medicago truncatula, Solanum tuberosum, rice, oat, and rye , which is known as a sterol chelator and, hence, a sterol-dependent microdomain disrupter, was used to characterize how protein was associated with the primary microdomain lipid, sterol . ComprehFigure 1). DRM fractions were isolated from a number of plant species and tissues as described above, and the preparation protocols of DRM fractions are in general quite similar regardless of plant species. First, a highly pure PM fraction is prepared using a two-phase partition system and then treated with 1% (w/v) Triton X-100 detergent at low temperature (on ice or 4°C) for 30 min. Next, treated membrane fraction is subjected to sucrose density gradient centrifugation. After centrifugation, white band appeared at the interface of sucrose layers recovered and collected by centrifugation. Precipitated membrane fraction is suspended in a proper buffer as DRM fraction. Because unknown artificial effects might be caused due to detergent treatment at low temperature, some researchers concerned that intact microdomains that function in vivo are not extracted by the widely adapted preparation protocols , and label-free quantification software . However+-ATPases, aquaporins, clathrins, actins, and tubulins. Further, microscopic observations and biochemical analyses of DRM fractions or intact plant cells implied that microdomains play some functional roles in the physiological aspects. Table 1 summarizes proteins that were found in common in some plant species on papers published so far. Localization or function of some of these proteins in distinct regions in the PM was further confirmed by additional approaches either morphologically or biochemically.Detergent-resistant membrane proteomes have been determined in some plant species . CompariCandida albicans was also observed  were changed by sterol depletion. Thus, these results strongly suggest that sterol is an important factor for segregation of specific proteins into DRM fraction and PM is “phase-separated” to form specific domains  recognizes barley mildew resistance locus o (Mlo) that seems to re-localize as microdomain-like structure at pathogen invasion site. In addition to pathogen infection, plant immune responses against biotic stress may be supported by functional microdomain. receptor-like kinases (RLK), disease resistance proteins and band7 family proteins, members of disease-related proteins, were detected in rice DRM fractions as well as some other plant species (Plant proteomic studies for elucidating microdomain function have been carried out intensively in the research area of plant–pathogen interactions. The possibility of lipid microdomain-pathogen interactions was first reported by  species . InteracPotato virus X (PVX) through plasmodesmata. Detailed analysis of DRM proteome against elicitor signaling in tobacco BY-2 cells revealed that the DRM enrichment of cell trafficking related proteins (dynamins) and a signaling protein (14-3-3 protein) altered after cryptogein treatment (reatment . These sArabidopsis leaves reported by Arabidopsis DRM proteomic analysis to find the possibilities of microdomain functions for adaptation to freezing temperature. Plants can increase survival at severe freezing temperatures by sensing non-freezing low temperature and subsequently reconstituting cellular processes (called as cold acclimation; Abiotic stress response and adaptation mechanism in association with microdomain is not well characterized. The only study showing changes of DRM compositions in response to abiotic stimuli was with How interactions between these proteins and microdomain properties affect cold acclimation processes, however, is still to be elucidated. We need to conduct additional physiological and microscopic experiments to understand responsiveness of microdomain and/or DRM proteins to cold acclimation. We have evidence from proteomic studies that there are several interesting abiotic stress-related proteins in DRM fractions such as RLKs, aquaporins, heat shock proteins, actins, and clathrins in various plants . To elucProteomic analyses of DRM fractions have been conducted and provided information for suggestive but important functions of PM microdomain in plants. Several physiological studies using both intact cells and isolated membrane fractions supported implications derived from proteomic analyses with DRM and added further interesting information on the roles of membrane microdomains. However, evidence of functional roles of microdomains in the PM is in a large part lacking. Now we are entering in next phase for elucidating microdomain characteristics and functions in plants. We need to consider morphology and dynamics of microdomains, physical and chemical state of PM proteins in microdomains from the perspective of post-translational modifications and molecular ultrastructure, and ultimately functional significance of microdomains in various events in plant’s life. Development of microscopic and biochemical techniques, such as single-molecule tracking and artificial membrane system, will help us to understand physiological roles of microdomain in plant cells.Plants are immobile and, thus, perception and response to environmental stimuli are quite important for plant’s life. The PM is thought to be the primary cellular compartment of these reactions because it surrounds intracellular organelles and the cytoplasm and transduces extracellular stimuli to the specific components in the cell. Microdomain is expected to play important roles in these processes. Thus, proteomic approaches will further provide useful information for understanding plant physiological responses and microdomain significance in the future.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Drosophila melanogaster. Studies in model organisms indicate that sarcopenia is driven by a combination of muscle tissue extrinsic and intrinsic factors, and that it fundamentally differs from the rapid atrophy of muscles observed following disuse and fasting. Extrinsic changes in innervation, stem cell function and endocrine regulation of muscle homeostasis contribute to muscle aging. In addition, organelle dysfunction and compromised protein homeostasis are among the primary intrinsic causes. Some of these age-related changes can in turn contribute to the induction of compensatory stress responses that have a protective role during muscle aging. In this Review, we outline how studies in Drosophila and mammalian model organisms can each provide distinct advantages to facilitate the understanding of this complex multifactorial condition and how they can be used to identify suitable therapies.A characteristic feature of aged humans and other mammals is the debilitating, progressive loss of skeletal muscle function and mass that is known as sarcopenia. Age-related muscle dysfunction occurs to an even greater extent during the relatively short lifespan of the fruit fly  After the age of 60 years, there are marked changes in multiple tissues and organs that together comprise the geriatric syndrome of frailty in humans. This condition is defined by decreased ability of the organism to withstand physical challenges and homeostatic perturbations . SkeletaMuscles are composed of different types of muscle cells (myofibers) that are classified as slow-twitch (type I) and fast-twitch (type IIb) fibers according to the mode of metabolism employed: slow-twitch fibers use aerobic (oxidative phosphorylation) respiration, whereas fast-twitch fibers utilize anaerobic metabolism (glycolysis) . In bothAlthough the maintenance of both muscle mass and strength is needed for optimal performance, decrements in maximal strength are three times greater than the decline in muscle mass during human aging , suggestin vivo, as routinely done in invertebrates, suggests that analyses in simple model organisms might provide important complementary insight into the etiology of sarcopenia.The analysis of sarcopenia in mammals has provided important insights into the mechanisms responsible for the progression of this condition in humans. Rhesus monkeys are the model organisms with the highest genetic similarity to humans  and, givDrosophila melanogaster, the organization and metabolism of skeletal muscle fibers is similar to that in mammals ; neither an age-related decrease in total muscle mass (muscle ‘quantity’) nor disuse atrophy or other types of wasting have been reported in adult flies . Studies in Drosophila are favored by the availability of an extensive genetic toolkit that enables genome-wide, muscle-specific interrogation of gene function during normal aging and in response to pharmacological, dietary and environmental interventions. Large cohorts of flies of a given age and genotype can be easily analyzed using several experimental approaches. Moreover, whereas aged rodents are housed in small laboratory cages that limit their physical activity, fruit flies can be housed in proportionally larger cages that allow the maintenance of activities and behaviors closer to those of populations in the wild. Because of these characteristics, Drosophila is emerging as a useful model organism to study muscle aging in concert with mammalian models. Here, we provide a comprehensive overview of the multifactorial origin of sarcopenia as gleaned through studies in mammals and, more recently, Drosophila, with particular emphasis on the role of protein homeostasis and stress responses.The decline in muscle function in lt flies . The lacDrosophila.In humans, sarcopenia develops via multiple mechanisms. Age-related changes intrinsic to skeletal muscle seem to contribute to the decrease in muscle mass and strength; however, many extrinsic factors are also important. For example, aged organisms typically have lower nutrient intake, physical activity and anabolic hormone levels  than younger organisms, in addition to showing neuronal loss (i.e. fiber denervation) and decreased regenerative capacity (i.e. satellite stem cell dysfunction). Sarcopenia also enhances susceptibility to various highly catabolic diseases  that are also more prevalent in the aged population. In turn, pharmacological treatments for cancer and other age-related diseases often induce muscle weakness as a side effect , thus agMuscle atrophy in juvenile mammals seems to be largely reversible. For example, muscle loss upon fasting is rapidly and completely reversed upon re-feeding. Similarly, interventions such as exercise allow recovery from disuse atrophy in the young. However, such interventions are less effective in older individuals . ChangesAged muscles are also less responsive to anabolic and catabolic stimuli than are young muscles. Exercise and ingestion of amino acids normally stimulate protein synthesis in human muscles but are less effective at doing this in the elderly, a phenomenon termed ‘anabolic resistance’, which likely contributes to sarcopenia . Among tSatellite cells are progenitor cells involved in muscle repair after injury and perhaps in the maintenance of muscle mass . AlthougAlong with endocrine and paracrine stimuli, intrinsic defects in satellite cells might play a role in skeletal muscle aging. For example, the decreased maintenance of telomere length in Ku80 heterozygous mutant mice, which are defective in DNA double-strand-break repair, diminishes stem cell renewal and accelerates muscle aging . HoweverDrosophila muscle compared with mammals, and is presumably related to Drosophila’s short lifespan.Muscle stem cells have not been identified in adult insects. This suggests that their skeletal muscles lack the capacity for regeneration during aging. This fundamental difference could account for the more obvious morphological and functional changes in aging In addition to changes in endocrine signals and reduced regenerative capacity, age-related defects in neuromuscular junctions (NMJs) and death of motor neurons  can leadDrosophila  in skeletal muscles. Muscle contraction results from the ATP-dependent sliding of sarcomeric myosin-based thick filaments over actin-based thin filaments. In mice and humans, age-related structural and functional alterations in sarcomeric proteins might explain the decline in force generation that is typical of old age . Studiesactivity . One stuactivity . Oxidatiactivity . Decreasactivity .Drosophila, sarcomere-related defects have also been reported, including changes in myofibrillar protein composition and function ] and the autophagy adaptor proteins p62 (SQSTM1) and NBR1 localize to sarcomeres , presuma2+ storage and release from the SR  membranes . This phm the SR . Additiogumin-29  and muscgumin-29 , as wellchannels . These cresidues , which rweakness . Andersscapacity . The theDrosophila might provide insight into the mechanisms of age-related deterioration of this cellular compartment. However, insect indirect flight muscles have a less extensive SR than mammalian muscle  is present in flies, unlike rodents.Muscle membranes are susceptible to damage caused by the mechanical stress of contraction. In mammals, the membrane-associated network of surface proteins known as dystrophin glycoprotein complex (DGC) helps maintain plasma membrane integrity by stabilizing the muscle membrane and limiting any physical damage caused by contraction. If membrane tears are generated, components of the ferlin family of proteins, including dysferlin and myoferlin, and their interacting partners  accumulate at the site of membrane disruption, and function as Caesealing . Null muesealing . Furtheresealing . DrosophDrosophila homologs of the DGC components result in muscle degeneration, mobility defects and shortening of lifespan   , which presumably contributes, together with decreased IGF1 levels, to the overall decline in muscle protein synthesis during aging in both mammals (Drosophila (In  (UPRmt) , a trans (UPRmt) , providi (UPRER) . Moreove in mice . The UPR mammals  and Drososophila . AlthougER is also activated in muscles during exercise via PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1α) and the transcription factor ATF6α  and the UPRER (Atg5 (another autophagy gene) also leads to loss of muscle mass and accumulation of protein aggregates in mice , whole-genome linkage studies, and gene expression and quantitative trait loci (QTL) mapping in both human populations and mammalian models are expanding our understanding of the genetic propensity to develop sarcopenia  gene, which is present in ∼18% of the world’s population  gene, a key component of the renin-angiotensin pathway and a stress hormone that promotes muscle proteolysis  could streamline the experimental selection, over several generations, of Drosophila strains that have increased or decreased lifespan and motor activity (Drosophila homologs of ACTN3 (Actn3) and ACE (Ance and related genes) might illuminate differences in the severity of muscle aging in distinct populations and individuals.Although mammalian models are useful in these studies, the short generation time of activity , which cactivity . For exaAlthough there are no approved pharmacological therapies for the treatment of sarcopenia in humans, inhibition of the myostatinactivin pathway has been proposed as a possible intervention to prevent muscle mass loss in the aged. For example, administration of anti-myostatin antibody improves exercise resistance in aged mice . MoreoveDrosophila (Resistance and aerobic exercise is a well-known intervention that improves muscle function and metabolism and delays the loss of muscle mass . Howeverosophila , making de novo mitochondrial biogenesis (In addition to physical activity, DR might also slow sarcopenia in humans: it reduces myofiber atrophy and functional decline in rats, mice and rhesus monkeys . In miceogenesis .Drosophila. In addition, protein supplementation has also been shown to improve physical performance in old age in humans (Drosophila are needed to better understand the mechanisms of action of exercise and DR, and to identify pharmacological interventions against sarcopenia.Similarly, DR reduces the prevalence of flight defects in aged flies by increasing mitochondrial function and fatty-acid oxidation in the predominantly aerobic flight muscles . Howevern humans , somewhaDrosophila and the sarcopenia and loss of muscle function seen with aging in mammals (Drosophila is a postmitotic organism with no known regenerative or growth capacity of skeletal muscles in the adult. Studies in Drosophila have already pinpointed key cellular age-related changes in muscle and the role of stress resistance pathways in preserving muscle function during aging. These studies demonstrate the utility of Drosophila as a system for probing the role of signaling pathways in regulating age-related intrinsic changes in pre-existing myofibers, without any confounding effects deriving from regeneration and satellite cell function. Studies in Drosophila and mammals thus offer distinct advantages for investigating the mechanisms of muscle aging, and integrating insights from both experimental systems will benefit future research efforts, which could provide pharmacological targets for the development of effective therapies for sarcopenia in humans.In this Review, we have highlighted several important similarities and differences between the age-related decay of muscle function in  mammals . In mamm


However, as white matter pathology long received predominant attention in this disease, and histological staining techniques for detecting myelin in the gray matter were suboptimal, it was not until the beginning of the 21st century that the true extent and importance of gray matter pathology in MS was finally recognized. Gray matter damage was shown to be frequent and extensive, and more pronounced in the progressive disease phases. Several studies subsequently demonstrated that the histopathology of gray matter lesions differs from that of white matter lesions. Unfortunately, imaging of pathology in gray matter structures proved to be difficult, especially when using conventional magnetic resonance imaging (MRI) techniques. However, with the recent introduction of several more advanced MRI techniques, the detection of cortical and subcortical damage in MS has considerably improved. This has important consequences for studying the clinical correlates of gray matter damage. In this review, we provide an overview of what has been learned about imaging of gray matter damage in MS, and offer a brief perspective with regards to future developments in this field.At the early onset of the 20 For many years, focal inflammatory demyelination in the white matter (WM) was considered the most important pathological 'hallmark' of multiple sclerosis (MS). However, demyelination in the cerebral cortex was already observed in early pathology studies by Sander 1898), Dinkler 1904), Schob (1907) and Dawson (1916) [898, Dink, Schob  techniques, became central issues in MS research  located in or around the cortical and subcortical GM . ExtensiAt that point in time, the detection of GM demyelination in tissue sections was difficult, as standard histochemical myelin stains like luxol fast blue (LFB) were not sufficiently adequate for visualization of changes in GM myelin density. Detection of GM pathology with conventional T2-weighted MRI also proved to be difficult because of the intrinsically low myelin density in the cortex, which generates little contrast between normal GM and demyelinated GM lesions, and because of the fact that cortical lesions may be small and partial volume effects with cerebrospinal fluid in the sulci can interfere with reliable lesion detection ,8. To imst century. Using immunohistochemistry for myelin basic protein (MBP) and proteolipid protein (PLP), Bö and colleagues shed more definitive light on the extent and distribution of cortical demyelination in MS [Histopathological detection of intracortical MS lesions improved with the use of myelin protein immunohistochemistry in the beginning of the 21on in MS ,16. In con in MS . The invThe pathology of GM lesions generally differs considerably from that of WM lesions. Lymphocyte infiltration, complement deposition, and blood-brain-barrier disruption have not been detected in GM lesions, whereas WM lesions are known to harvest substantial inflammation -18. AnotPathological studies demonstrated that cortical demyelination is most frequent and extensive in patients with a longer disease duration  and with a more progressive form of MS , whereas it was found to be rare in relapsing remitting MS patients (RRMS) ,21. HoweAlthough histopathological studies had improved as a result of the new staining methods, GM lesions remained extremely difficult to detect on conventional MRI. For example, it was shown that T2-weighted and FLAIR imaging detected only 3 to 5% of a total of 63 histopathologically defined cortical lesions . NeverthIn parallel, MRI studies focused on imaging the normal appearing GM of MS patients  using more advanced, quantitative MRI techniques. These techniques are generally more sensitive to (subtle) pathology in the GM than conventional MRI sequences . ClinicaTo sum up, around the turn of the century, GM pathology in MS became increasingly recognized as an important pathological hallmark in this 'typical' WM disease. The introduction of new histopathological staining methods improved the visualization of GM damage and revealed that GM demyelination was frequent, widespread, and more extensive in patients with longer disease duration. The pathological substrate of GM lesions was found to be different from WM lesions, as GM lesions are largely non-inflammatory. On conventional MRI, only a minority of GM lesions could initially be visualized. However, these lesions were associated with clinical deterioration. Besides cortical lesions, quantitative MRI also demonstrated clinically relevant abnormalities in the NAGM of MS patients.Whereas the detection of focal GM lesions was difficult using conventional MRI measures, GM atrophy measurements proved to be robust and reliable using standard MRI sequences . AutomatIn 1994, a new MRI sequence, the double inversion recovery (DIR), was introduced. This technique provided excellent distinction between the cerebral cortex and the WM in the healthy human subjects by suppression of the signal from WM and the cerebrospinal fluid (CSF) . DIR proA series of important scientific contributions by Calabrese and colleagues subsequently confirmed histopathology studies by reporting that intracortical lesions detected on DIR are already present early in the disease -74 and aThese results notwithstanding, the use of different DIR sequences and different lesion scoring criteria in different research centres made the comparison of available cortical lesion data in the literature challenging. Therefore, in an attempt to improve consistency of cortical lesion scoring between raters and centres using DIR, international cortical lesion scoring guidelines were proposed ,82. ThesSo far, no specific pathological properties were found that determine whether cortical lesions become MRI-visible or MRI-invisible. Instead, it was shown that the visibility of cortical lesions on MRI is predominantly determined by their size. Furthermore, MRI-visible cortical lesions were strongly associated with a higher total cortical lesion load in brain tissue specimens, which suggests that when cortical lesions become visible on MRI, they merely reflect 'the tip of the pathological iceberg' .Other studies aiming to improve visualization of cortical GM lesions used phase-sensitive inversion recovery (PSIR) and 3D T1 weighted sequences ,85. FutuWith the introduction of (ultra) high-field MRI, signal-to-noise ratio, spatial resolution, and image contrast improved, which all benefited the detection of GM lesions -88. In vMRI and histopathology studies showed that atrophy and demyelinated lesions do not only exist in the cortical GM but also in other GM structures such as the thalamus, hippocampus, caudaute, putamen, pallidum, claustrum, hypothalamus, amygdala and substantia nigra ,93-105, Of all the GM structures, the thalamus has been studied most extensively with MRI ,99-110. The hippocampus was found to be a predilection site for GM demyelination in MS ,95,115. Besides structural differences in the MS brain, functional changes can be studied as well by using e.g. functional MRI (fMRI). Different cognitive paradigms for task-fMRI have been used so far, as well as resting-state fMRI. Several differences between healthy controls and MS patients were found in terms of brain activation and brain connectivity -125. SomTo summarize, during the past few years, the number of studies investigating GM damage in MS has tremendously increased. GM atrophy and cortical thinning were shown to be robust and reliable measures. GM atrophy correlated more strongly than WM atrophy with disability and cognitive impairment. New imaging techniques, such as DIR, improved the detection of cortical lesions in vivo. With the introduction of (ultra) high-field MRI, the visualization of cortical lesions improved even further. Recently published international consensus guidelines for scoring cortical lesions on DIR will likely increase the consistency between different research groups, and will improve the comparability of different DIR studies. Post mortem work demonstrated that DIR is pathologically specific, but lacks sensitivity. This means that many cortical lesions are still missed and MRI detects only 'the tip of the pathological iceberg'. Despite their under representation on MRI, cortical lesions were shown to be clinically relevant. Both imaging and histopathology studies showed that GM damage in MS is not limited to the neocortex; the cerebellum, spinal cord, and non-neocortical GM structures are affected as well.From a pathological point of view, it is clear that GM damage is common, widespread, and different from WM damage. A challenging next step is to investigate the cause(s) of GM pathology. For example, whether damage to the GM develops purely as a result of inflammatory demyelination in the WM or whether pathological processes in these two compartments of the brain are less connected than formerly thought, still remains to be elucidated -130.As discussed in this review, from the neuroimaging perspective, MRI techniques have substantially improved over the past years and several new imaging modalities to better detect GM abnormalities are now available. It is possible to visualize cortical lesions with DIR, T1-based or phase-sensitive sequences, as well as with (ultra) high-field MRI. Moreover, GM tissue loss can be reliably measured with the help of conventional MR sequences, and more subtle tissue changes can be observed with quantitative MRI. Finally, the function of specific GM structures or functional systems, as well as functional and structural connectivity changes within the brain can be imaged with MRI. With all these different imaging techniques to visualize GM pathology in vivo, it now remains to be determined which image modality, or combination of imaging modalities, best explains or predicts clinical symptomatology, and whether these techniques can be reliably used to monitor future treatment effects. Furthermore, the spatiotemporal relation between structural and functional changes, as well as changes in network dynamics in the brain as a consequence of disease will be difficult but exciting topics for future research in this field. The past few years of GM imaging research have seen tremendous progress; with the knowledge and technology now available, it is likely that ongoing joint efforts between different fields of research will create an even greater understanding of the role of GM pathology in MS in the near future.▪ GM damage in MS is common and widespread, especially in chronic MS;▪ The underlying pathological correlates of GM damage in MS are different from WM damage;▪ GM pathology is present in all stages of the disease, but is more prominent in SPMS and PPMS compared to RRMS;▪ Although a relatively non-specific measure of overall pathology, GM atrophy measurements are reliable and robust and correlate strongly with disability and cognitive impairment (more so than WM atrophy);▪ Cortical lesions are of clinical relevance and are associated with a worse physical and cognitive performance;▪ Cortical lesions have been difficult to visualize with conventional MRI, but due to newer imaging techniques (like DIR) lesion detection improved;▪ Post mortem DIR verification showed high specificity of DIR lesions and increased sensitivity compared to conventional MR sequences; however, a substantial number of cortical lesions is still missed with in vivo MRI;▪ International consensus guidelines on DIR cortical lesion scoring will likely improve the comparability of different DIR studies;▪ (Ultra) high-field MRI holds promise for more precise detection of cortical lesions, with maybe even the possibility to categorize GM lesions in vivo according to the pathological classification system used post mortem; especially the detection of subpial lesions (type III lesions) is likely to benefit from the use of (ultra) high-field MR imaging;▪ Non-neocortical GM damage is frequently detected in histopathological studies as well as on MRI. Thalamic and hippocampal abnormalities have been studied most extensively and were shown to correlate with clinical parameters;structural changes in the GM of MS patients, functional changes can be detected as well by using fMRI; this should shed more light on the relationship between functional and structural changes in the MS brain in future studies.▪ Besides The authors declare that they have no competing interests.HEH and JJGG participated in the preparation of the manuscript. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2377/11/153/prepub


Over the decades, research into placebo responses has shed light onto several endogenous (i.e. produced from within) mechanisms underlying modulation of pain perception initiated after the administration of inert substances (i.e. placebos). Chiropractors and manual therapists should embrace analgesic-placebo-research in an attempt to maximize clinical benefit. Historical views that placebo responses are fake, passive, undesirable, and require deception and therefore should be minimized and avoided in clinical practice are outdated. Further, statements that contend the placebo response represents a single mechanism are overly simplistic. This commentary will discuss research that shows that there are several active biological processes underlying modulation of pain perception involved in placebo analgesia and its counterpart nocebo hyperalgesia. We contend that it is highly likely that, to some extent, all of these biological processes are engaged, in varying degrees, following all interventions and represent endogenous pain modulating processes. Failure, of chiropractors and manual therapists, to embrace a more contemporary view of analgesic-placebo-research serves as a barrier to transferring knowledge into clinical practice and represents a missed opportunity to improve the delivery of current treatments. Evidence-based medicine deals with the use of current best evidence in clinical decision-making and other aspects of patient care. The assumption that simply having the evidence available or providing authoritative clinical practice guidelines will result in practice change and improved patient outcomes is incorrect,2. A numMisconceptions about placebo responses continue in the general public and among healthcare professionals,5. ThereChanges in the perceived intensity of pain are often attributed to a variety of factors lumped into three board categories: (1) condition related factors, (2) the specific effects of treatment, and/or (3) treatment contextual effects. ConditiFor example, findings from one study significantly challenge the convention that an active biological agent produces a consistent therapeutic effect within an individual. By convention, researchers acknowledge that the active biological agent in a drug will vary across people, depending on a multitude of personal factors. However, what is not acknowledged so frequently is that within one individual, the therapeutic effect can significantly vary. By experimentally manipulating an individual’s expectation through instructional sets, it was shown that the therapeutic effect of the active ingredient of remifentanil, a potent synthetic μ-opioid agonist, can be significantly modulated. The stuEmbedded in every pain-relieving treatment are contextual effects. Physician interactions, signs and symbols convey information to the individual with the potential for producing therapeutic and counter-therapeutic responses (ie placebo and nocebo responses respectively). The estPlacebo-analgesia-research has also shown that deception is not integral to inducing a placebo response. One study administered open labeled placebos with patient education that described an active biological pathway for symptom improvement. In thisFinally, placebo-analgesia-research has shed light onto neural mechanisms underlying endogenous pain modulation. Cortical networks involved in processing and modulating the pain experience have been identified and continue to be reinvestigated, redefined and undergo reconceptualization. Activity in these cortical networks influence the perception of pain and modulation can be inhibitory or facilitatory. Research has identified various neurotransmitters including opioids, cannabinoids, dopamines and cholecystokinins, that are used within these cortical networks-31. AttrOver the decades, research into placebo responses has shed light onto several endogenous (i.e. produced from within) mechanisms underlying modulation of pain perception initiated by the administration of inert substances (i.e. placebos/nocebos). In addition, this growing body of work emphasizes the need for chiropractors’ and manual therapists’ to be more alert to, and embrace, 'psychologically informed practice’; that is, practice in which recognition of neural mechanisms is equally as important as identification of structural pathology. Chiropractors and manual therapists should embrace analgesic-placebo-research in an attempt to maximize endogenous pain relieving mechanisms to produce maximum clinical benefit. Historical views that placebo responses are fake, passive, undesirable, and require deception and therefore should be minimized and avoided in clinical practice are outdated. Further, statements that contend the placebo response represents a single mechanism are too simplistic. Instead, in this commentary the authors discussed how several active biological processes underlie analgesic-placebo responses. We contend that it is highly likely that to some extent all of these biological processes, which represent endogenous pain relieving processes, are engaged to various degrees following all interventions that produce a positive clinical outcome.Failure to embrace a more contemporary view of analgesic-placebo-research may negatively bias chiropractors’ and manual therapists’ opinions about the potential clinical value of results emerging from this field. These biases serve as a barrier to successfully translating potential benefits for patients into clinical practice in an ethical manner. Analgesic-placebo-research provides insight on how to improve the delivery of current treatments by optimizing clinical benefit and matching the right treatment to the right spinal pain patient at the right time.The authors of this manuscript attest there are no conflicts of interest to report.


The two main types of PSCs, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), share common features such as colony morphology, high expression of Oct4 and Nanog, and strong alkaline phosphatase activity. In recent years, increasing evidences suggest that telomere length represents another important internal factor in maintaining stem cell pluripotency. Telomere length homeostasis and its structural integrity help to protect chromosome ends from recombination, end fusion, and DNA damage responses, ensuring the divisional ability of mammalian cells. PSCs generally exhibit high telomerase activity to maintain their extremely long and stable telomeres, and emerging data indicate the alternative lengthening of telomeres (ALT) pathway may play an important role in telomere functions too. Such characteristics are likely key to their abilities to differentiate into diverse cell types in vivo. In this review, we will focus on the function and regulation of telomeres in ESCs and iPSCs, thereby shedding light on the importance of telomere length to pluripotency and the mechanisms that regulate telomeres in PSCs.Pluripotent stem cells (PSCs) have the potential to produce any types of cells from all three basic germ layers and the capacity to self-renew and proliferate indefinitely  During the process of DNA synthesis and cell division, telomeres are shortened as a result of the incomplete replication of linear chromosomes, which is called “end-replication problem”. Telomere attrition, which can cause chromosome recombination, end-to-end fusion, DNA damage, and genome instability, represents one of the nine hallmarks of aging de novo telomere extension, to prevent telomere exhaustion after multiple rounds of cell division  . ALT has been found to occur in about 10%–15% cancers and is often characterized by co-localization of telomeres with the promyelocytic leukemia (PML) bodies (known as ALT-associated PML bodies (APBs)), exceedingly heterogeneous telomere length, extra-chromosomal DNA circles, and high frequencies of telomere sister chromatid exchange (T-SCE)  of blastocysts in 1981  disease models need further investigation.On the other hand, telomere dysfunction can also impact cell metabolism through affecting mitochondrial function. Progressive telomere shortening limits the replication capacity of dividing cells such as stem cells  and form ALT-associated PML-NBs (APBs), one of the hallmarks of ALT cells  is a gene cluster that contains six members, and expressed specifically in late 2-cell embryos and ESCs (Falco et al., In addition, novel factors have been found to take part in telomere regulation in PSCs as well. For example, zinc finger and SCAN domain containing 4 (Multiple links between telomere biology and stem cell pluripotency have been established. Interestingly, the longest telomeres appear to exist in adult stem cells where they become shortened as stem cell function declines. Additionally, higher expression of the shelterin/telosome complex component TRF1 correlates with higher pluripotency of stem cells. Consequently, long telomeres and high TRF1 level have been proposed as stem cell markers (Flores et al.,


The trauma-disrupted network forms a subnetwork of regions within a larger, widely recognized network organized into ventral and dorsal streams for processing emotional and cognitive information that converge in the medial PFC and cingulate cortex. Models of fear learning, while not a cognitive process in the conventional sense, provide important insights into the maintenance of the core symptom clusters of PTSD such as re-experiencing and hypervigilance. Fear processing takes place within the limbic corticostriatal loop composed of threat-alerting and threat-assessing components. Understanding the disruptions in these two networks, and their effect on individuals with PTSD, will lead to an improved knowledge of the etiopathogenesis of PTSD and potential targets for both psychotherapeutic and pharmacotherapeutic interventions.Individuals with posttraumatic stress disorder (PTSD) show altered cognition when trauma-related material is present. PTSD may lead to enhanced processing of trauma-related material, or it may cause impaired processing of trauma-unrelated information. However, other forms of emotional information may also alter cognition in PTSD. In this review, we discuss the behavioral and neural effects of emotion processing on cognition in PTSD, with a focus on neuroimaging results. We propose a model of emotion-cognition interaction based on evidence of two network models of altered brain activation in PTSD. The first is a  On the other hand, impairment of cognitive processes may result from emotional interference. In PTSD, an emotional facilitation effect would permit trauma-related information to be processed faster and/or more accurately than trauma-unrelated information. Conversely, emotional interference would impair cognition when processing trauma-related information. However, emotional interference or facilitation of cognition in PTSD may extend beyond trauma-related material to trauma-unrelated emotional material. The effects of emotion on cognition will be examined to explain how attending to emotional information influences cognitive processes in individuals with PTSD. We will explore whether trauma information influences cognitive processes in the same way as emotional non-trauma information or whether trauma information is a special case of emotional information that holds privileged status vis-à-vis cognitive processes.Posttraumatic stress disorder (PTSD) is triggered by trauma and characterized by intrusive memories, hypervigilance, and difficulties with concentration and memory. The dysfunctions in PTSD suggest an inability of cognitive control areas in the brain to regulate affective areas, particularly in the context of trauma-related information. In this review, we examine the effects of PTSD on neural substrates of cognitive processes, with a specific focus on the interaction of cognition and emotion. We will extend an established neural model describing cognitive-emotional interactions to understand how specific regions of this network are involved in emotion processing are dissociated in response to trauma-related information. Meanwhile, understanding the neural processes underlying major symptom clusters of PTSD that also involve emotion-cognition interactions, require disease-specific models. Emotion can have opposing effects on cognition. On one hand, High intensity acute stress, as experienced during a traumatic event, sets off a cascade of neurobiological changes which initially help the body respond to acute threat. In PTSD, however, the stress response is maintained and becomes maladaptive. Changes in hypothalamic-pituitary-adrenal (HPA) axis and catecholamine function reflect the long-term effects of this stress response Yehuda, . InitialEarlier neurobiological models of PTSD based on neuroimaging findings, hypothesized a hypoactive hippocampus and prefrontal cortex (PFC) that are unable to fully regulate a hyperactive amygdalar response to trauma Brewin, . Howevertrauma-disrupted regions include the ventral PFC, dorsal PFC, dorsal ACC, and hippocampus, whereas other emotion-processing regions such as the amygdala, insula, and ventral ACC appear not to be uniquely affected by trauma-related information. The trauma-disrupted regions show differential responses to trauma-related information, reflecting attentional biases to trauma-related information in PTSD. The remaining emotion-processing regions show activation differences based on the emotional content of information rather than its relevance to trauma. This organization reflects two related dysfunctions of cognition in PTSD: difficulties processing trauma-related information and problems with processing emotional information more generally. Understanding how these two networks are altered, and how the alterations affect individuals with PTSD, will lead to an improved knowledge of the etiopathogenesis of PTSD and potential targets for therapeutic interventions.During cognitive processes, the dorsal anterior cingulate and ventral prefrontal areas, including orbital frontal cortex, inferior frontal gyrus, and ventromedial PFC, show greater activation in trauma-related contexts , or it may reflect amygdala engagement in oddball tasks, unlike other emotionally neutral paradigms  has either demonstrated lack of differences in patients with PTSD  have failed to demonstrate amygdala response in PTSD, suggesting that amygdala dysfunction is specific to emotional information, despite evidence from normative groups implicating the amygdala in decision making  information. Moreover, this comparatively narrow treatment of cognitive-emotional processing does not encompass major symptom clusters of PTSD such as re-experiencing , hyperarousal , and avoidance of persons and places that trigger reminders of the trauma . For instance studies of Stroop tasks . Although this approach addresses many methodological issues in fMRI analysis, concordant behavioral findings were not reached in many of the studies we reviewed. Indeed, most studies lacked evidence that behavioral performance showed interaction of stimulus type by diagnosis, yet they reported an interaction for the corresponding neuroimaging findings. Another issue with this analysis setup is the necessity of relative, rather than absolute, baselines in fMRI. The conventional approach of contrasting emotional with neutral stimuli, first within and then between subjects, may not capture the nature of the neural differences. As an example, an emotionally neutral attention task may find less activation in ventral ACC in PTSD when contrasting attentional tasks with a non-attentional baseline. When examining emotion processing, the same neutral attentional task may be contrasted with an emotional attentional task, and a greater difference in ventral ACC activation is found in PTSD. However, it is unclear if this larger activation difference is due to lower activation during the neutral attention task or to greater activation during the emotional task. A focus on correlating behavioral effects with differences in neural activations, more sensitive task paradigms such as parametric modulation studies, and the use of neuroimaging techniques that go beyond cognitive subtraction to study network-based connectivity, will improve the relevance of neuroimaging findings to behavioral dysfunction in PTSD.Despite finding significant neural differences in PTSD while processing information with emotional or trauma-related content, few studies found corresponding behavioral differences. The behavioral components of these generally found a main effect of stimulus type or a main effect of PTSD diagnosis, but failed to find an interaction effect. However, a significant interaction of stimulus type by PTSD diagnosis has generally been reported by purely behavioral studies (lacking a neuroimaging component). Several reasons for this discrepancy are possible. First, the addition of neuroimaging may impose restrictions on the complexity and sensitivity of task design and/or analysis methods; the lack of behavioral findings may reflect the difficulties of teasing apart small behavioral effects in paradigms ill suited for the fMRI, PET, or EEG environment. Second, the lack of behavioral differences in the setting of corresponding neural findings indicates that the task is insufficiently sensitive to detect differences between groups that become evident only when probing the underlying neural processes. Third, the neural effects may reflect successful compensatory efforts by participants with PTSD who are able overcome behavioral deficits.In conclusion, behavioral evidence of emotional facilitation or interference of cognition is sparse in PTSD. However, individuals with PTSD have difficulty withdrawing attention or shifting attention away from emotional information, particularly when the information is trauma-related. During emotion-related cognitive processes, individuals with PTSD show altered neural responses in a number of brain regions, which can be grouped into a trauma-disrupted and an emotion-disrupted network. These networks show that although trauma-related material has unique effects on brain activation in PTSD, the effects of emotion processing on cognition are not limited to trauma-related information. Elucidating how these areas differ through direct comparison and how the neural differences in PTSD can be addressed by psychotherapy and pharmacotherapy will improve our understanding and treatment of PTSD.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


There are several pieces of evidence showing occurrence of pulmonary edema (PE) in healthy subjects in extreme conditions consisting of extreme psychophysical demand in normal environment and psychophysical performances in extreme environment. A combination of different mechanisms, such as mechanical, hemodynamic, biochemical, and hypoxemic ones, may underlie PE leading to an increase in lung vascular hydrostatic pressure and lung vascular permeability and/or a downregulation of the alveolar fluid reabsorption pathways. PE can be functionally detected by closing volume measurement and lung diffusing capacity test to different gases or directly visualized by multiple imaging techniques. Among them chest ultrasonography can detect and quantify the extravascular lung water, creating “comet-tail” ultrasound artefacts (ULCs) from water-thickened pulmonary interlobular septa. In this paper the physiopathological mechanisms of PE, the functional and imaging techniques applied to detect and quantify the phenomenon, and three models of extreme conditions, that is, ironman athletes, climbers and breath-hold divers, are described. Pulmonary edema (PE) is a life-threatening condition that may lead to acute respiratory failure. There are several pieces of evidence showing the occurrence of PE in healthy subjects in extreme environment and/or under extreme psychophysical stress –3. HumanPE can be functionally detected by an increase in closing lung volume , reflecting an early small airways compression due to pulmonary interstitial fluid accumulation . AnotherIn this paper the physiopathological mechanisms of PE, the functional and imaging techniques applied to detect and quantify the phenomenon, and three models of extreme conditions, that is, ironman athletes, climbers and breath-hold divers, are described.The pulmonary blood-gas barrier is continuously subject to mechanical stress. Precisely its integrity depends on balance between circumferential tension , longitudinal tension in the alveolar wall elements (related to the inflation of the lung), and surface tension of the alveolar lining layer , 9. TherBesides the local pulmonary mechanisms of PE, systemic factors may also predispose to PE. Exercise-associated hyponatremia, due to altered body fluid homeostasis, represents emerging potential cause of both PE and cerebral edema . Severalβ and IL-6 has been reported in clinical cases of primary pulmonary hypertension but it is not fully clear up to now the role of pulmonary inflammation in the pathogenesis of acute PE in healthy subjects under extreme psychophysical conditions. Exhaustive endurance exercise leads to systemic inflammatory response secondary to metabolic, hormonal, thermal stress, and muscle damage thus potentially affecting microvascular endothelial function and lung tissue integrity. Moreover, in endurance athletes the activation of the inflammatory cascade within six hours from the end of strenuous exercise has been associated with a reduction in ventilatory performance [Perivascular inflammatory cell infiltration as well as increased serum levels of proinflammatory IL-1formance .It is well known that prolonged heavy exercise increases lung ventilo-perfusive heterogeneity and affects the efficiency of gas exchange , 39. TheRadiographic, CT, or MRI imaging resulted equally effective in detecting PE induced by exhaustive endurance sports . Since iImmersion PE has been seen in the dependent lung on CT scans  whereas recurrent HAPE has showed patchy distribution of pulmonary infiltrates bilaterally on chest radiographs and on CT scans. These last findings strongly support the heterogeneous distribution of elevated capillary pressures, that in summary is likely to rely on an unevenly distributed hypoxic vasoconstriction in either pulmonary arteries or veins, or both.r = .78; P < .01) was found [The technical developments and the use of high-field-strength MR have improved the image quality, with a better signal-to-noise ratio, and the speed of acquisition of MR imaging, overwhelming the motion artefact due to heart and lung movements and susceptibility due to the presence of air in the lung. MR can give in the same exam information regarding both tissue characterization (in this context the presence of pulmonary fluid accumulation) and perfusion. In the clinical practice lung MR has comparable sensitivity to CT for the detection of lung diseases with MR having lower spatial but greater contrast resolution than CT , 47. MR as found . Furtheras found –53. The Ironman race is also called ultratriathlon and consists of the following three different endurance sports: swim , bike ride , and marathon . This multidisciplinary sport demands an extraordinary psicophysical performance in terms of both endurance and exercise intensity. Reversible changes in the cardiovascular system, consisting of biohumoral and functional signs of cardiac damage have been documented after an ironman race. In particular there is an increase in cardiac troponins and B-type natriuretic peptide in presence of impairment of regional and global cardiac performance . Indeed The likelihood of developing clinical PE is at least 65% in presence of maximum or near-maximum effort, whereas it is low or absent in presence of submaximal exercise. In this context interstitial PE has been detected by various imaging techniques, such as TC scan, MR, chest ultrasonography, as well as by a decline in lung function  and impairment of the pulmonary blood gas-barrier gas exchange, that is reduction in DL , 60, 61.Combination of mechanical, hemodynamic, biochemical, and hypoxemic mechanisms seems to be behind the PE in both hypoxic hypo- and hyperbaric conditions , leading to an increase in both lung vascular hydrostatic pressure (either heterogeneous or not) and permeability.Breath-hold diving causes hyperbaric and hypoxic stress on the cardiopulmonary system , 66. PerAn additional potential mechanism responsible for such stress is the pulmonary vasoconstriction secondary to breath-holding hypoxia, with similarity to HAPE. Behind HAPE, physical exertion associated with hypoxic vasoconstriction may lead to an uneven redistribution of pulmonary capillary blood and ventilation, further leading to ventilo-perfusive mismatch that ultimately affects pulmonary gas exchange , 72. WesBesides perplexities about mechanisms underlying PE in extreme environment and hypoxic conditions another problem is how early interstitial PE can be detected and measured. For example, there is the evidence that 92% of recreational climbers presenting chest rales or interstitial edema on the chest radiograph after ascent had increased closing volume. Furthermore 74% of climbers with no clinical or radiological evidence had probable subclinical edema, having an increase in closing volume at altitude  [Chest ultrasonography revealed an increased number of ULCs within 10 minutes after immersion (depth range 31 to 112 meters) in 45% of 14 top-level breath-hold deep divers, which resolved completely after 24 hours . Of thesLung fluid accumulation in healthy subjects during the above-mentioned extreme conditions is a complex and multifactor phenomenon, still with unanswered questions. In particular whether the acute, reversible increase in lung fluid content is an innocent and benign part of the adaptation to extreme physiological condition or rather the clinically relevant marker of an individual vulnerability to life-threatening PE remains to be established in future studies. Thus the question if encouraging more conservative habits is right or not remains open. Chest ultrasonography is a low-cost highly feasible and versatile, nonionizing and noninvasive technique, with the undiscussed advantage to be used on the field early after exercise and repeated in the followup on a large sample of subjects. Further, chest ultrasonography has the potential to detect even subclinical episodes of lung fluid accumulation, thus it can provide new features on physiological mechanisms, incidence, and progression of this phenomenon with the final goal to identify vulnerable subjects.


Recently, bisphosphonates (BPs) have been widely used in medical practice as anti-resorptive agents owing to their anti-osteoclatic action. In addition, these compounds are also used for their analgesic action and their potential anti-tumour effect. Patients treated with BPs may subsequently develop osteonecrosis of the jaw or maxillary bone after minor local trauma including dental work, recently labelled as bisphosphonate osteonecrosis of jaw (BRONJ). However, the etiopathogenic mechanisms of this pathological condition are poorly understood. Although, several pathways have been proposed for BRONJ occurrence, no single model can explain all morphological changes observed at the macro- and microscopic level. Recent research suggests that BPs may promote an anti-angiogenic effect which contributes directly to the clinical features associated with BRONJ. Remarkably, the anti-angiogenic effect promoting BRONJ might be in keeping with the anti-neoplastic action of BPs. The current review, presents clinical diagnostic criteria. In addition, based on our own experience we describe the histopathological criteria for diagnosis of BRONJ and the possible pathways which may lead to this frustrating pathological condition. Bisphosphonates (BPs) are a group of pharmacological agents used as anti-osteoclastic, anti- resorptive agents in calcium metabolism disorders such as osteoporosis, multiple myeloma, Paget’s disease and hypercalcemia of malignancy . The pri1 and R2 on the carbon atom of BPs molecule attached to basic P-C-P structure. This allows variations in molecular structure and a range of potency corresponding to the changes in the structure [1 position, usually hydroxyl, enhances the molecule’s affinity to bone  and the variable group at R2 position decides its anti-resorptive action, specifically its potency and efficacy [Chemically, BPs represent pyrophosphate analogs possessing two variable regions, Rtructure . The groefficacy .2 group. However, Russell et al. [Classically, BPs have been classified into: non-nitrogen containing BPs (NNBP) and nitrogen containing BPs (NBP) depending on the presence or absence of nitrogen in their Rl et al.  further Clinically, both the NNBPs and NBPs are used as antiresorptive agents Table  but the Orally administered BPs may induce recurrent ulcers with burning sensation and blisters in the oral cavity, erosive oesophagitis, oesophagal stenosis, uveitis, gastric ulcerations and abdominal pain -13. HoweThe first clinical description of BRONJ by Marx et al. 2003) ushered several reports from all across the world where BPs are used . In gene03 ushereIn 2007, the American Association of Oral and Maxillofacial Surgeons and the American Society for Bone and Mineral Research described BRONJ as an area of exposed bone in the maxillofacial region in a patient on BPs or who has taken in the past these pharmacological agents, without any history of radiotherapy. Furthermore, the lesions must not be healed within 8 weeks after identification by a healthcare practitioner to qualify as a BRONJ case ,22. ReceA careful application of these criteria is of paramount importance as other intraoral conditions such as gingivitis and periodontal disease, mucositis, periapical lesions due to pulpal infection and resulting osteomyelitis, sinusitis, bone tumours (primary and metastasic) and osteoradionecrosis need to be ruled out.As other types of osteonecrosis determined by different etiologies, BRONJ is characterized by the presence of osteocyte-depleted bone lacunae. Our diagnostic experience suggests that this avascular necrosis is characterized by lacunae osteocyte depletion which is more obvious in the deeper layers of the bone while the lacunae located towards the surface of the bone lamellae will lose the osteocytes at a later stage Figure .The associated morphological features of this specific type of avascular necrosis are quite heterogeneous. Some areas of the affected bone with show extensive haemorrhage associated with massive chronic inflammatory cells infiltrate represented by lymphocytes and plasma cells which is best observed towards the surface of the bone Figures , 3. In aIt is known that angiogenesis or formation of new immature blood capillaries is an essential factor in healing of wounds as well as invasion of normal tissues by malignant cells . Also, nVascular endothelial growth factor (VEGF), in circulation as well as local VEGF mRNA expression, is considered a classic parameter of angiogenesis. Remarkably, in non-small cell lung cancer cell lines, zoledronic acid promotes a significant reduction in mRNA and protein expression of VEGF . MoreoveAlthough, there are no studies evaluating the duration of anti-VEGF effect after BPs treatment, it might be possible to be time limited. In vitro and in vivo experiments have revealed that clodronate is an efficient anti-angiogenic agent. The clodronate-related anti-angiogenesis seems to be related to its direct inhibitory action on endothelial cell proliferative activity coupled with inhibition of powerful pro-angiogenic factors such as fibroblast-growth factor 2 (FGF2) .Other authors have reported that NBPs have a significant anti-angiogenic effect inhibiting human umbilical vein endothelial cells (HUVEC) proliferation, adhesion, survival, migration and actin stress fiber formation by interfering with protein prenylation ,33. MoreOur own histological evaluation of patients treated with BPs has confirmed that BRONJ represents an avascular process of necrosis of the jaw bone due to the lack of blood vessels in the necrotic areas paradoxically associated with an on-going bone resorptive action induced by osteoclasts. However, numerous studies have revealed that bisphosphonates inhibit the osteoclasts by preventing their differentiation from their marrow precursors or inhibiting the mevalonate pathway which is crucial for their functionality ,37. TherClosely related to their anti-angiogenic effect, the BPs may affect the soft tissue structures seen in the immediate vicinity of the jaw or maxillary bone, potentially creating a vicious circle whereby the anti-angiogenesis is enhanced and complicated by soft tissue cells damage.In studies with oral keratinocyte/model, BPs were shown to induce senescence, apoptosis and inhibition of cell growth by blocking FPPS enzyme of cholesterol biosynthetic pathway -43 whichA histological evaluation of BRONJ has revealed a reduced p53 gene expression of tissue samples via mevalonate pathway which results in a reduced numbers of basal epithelial progenitor cells which could result in an impaired healing capacity of oral mucosa . An immuHowever, recent studies have revealed that the reduced migration ability of various cell types of hard and soft tissues such as bisphosphonate-treated human umbilical cord vein endothelial cells (HUVEC), fibroblasts  and osteogenic cells may be potentially prevented by administration of factors with anti-BPs action. Some authors have claimed that the mevalonate pathway metabolite, geranylgeraniol (GGOH) or naturally occurring farnesol could an anti-BPs effect healing the lesions seen in BRONJ ,47. TherClearly bisphosphonates have a demonstrated multimodal ability to interfere with normal angiogenesis. Given the critical role of vasculature development in tissues and in particular bone, where the turnover rate is markedly higher than in other tissues, this represents a potential process that may therefore be intimately associated with the development of necrotic bone conditions such as that seen in the oral maxillofacial area of patients on high potency bisphosphonates following routine dental procedures.This research is in compliance with the Helsinki Declaration. Approval has been obtained from Griffith University Human Research Ethics Committee. Written informed consent was obtained from the patient for publication of this report and any accompanying images.The authors declare that they have no competing interests.DS: drafted part of the manuscript including the digital graphics, performed the literature search, assisted the histopathological selection, SI: designed the project, drafted part of the manuscript including the digital graphics, provided clinical feed-back, analysis and interpretation and supervised DS, MS: provided histopathological research information and evaluation, helped drafting the manuscript, SH: provided histopathological analysis, experimental research information and evaluation, helped drafting the manuscript, TSP: helped drafting the manuscript, provided research and clinical interpretation , performed digital imaging processing, KB: helped drafting the manuscript, provided basic research information and histopathological evaluation, EBP: drafted part of the manuscript, performed histopathological selection, processing and evaluation, experiential data interpretation, designed the project and supervised DS, RIM: designed the project, drafted the manuscript, provided clinical background and analysis, performed the literature search, evaluated experimental data and digital imaging processing. All authors read and approved the final manuscript.