Despite wide-spread use of Nuclear Magnetic Resonance (NMR) in metabolomics for the analysis of biological samples there is a lack of graphically driven, publicly available software to process large one and two-dimensional NMR data sets for statistical analysis.1H,13C-HSQC spectra) is facilitated by the use of a spectral library derived from publicly available databases which can be extended readily. The software allows to display specific metabolites in small regions of interest where signals can be picked. To facilitate the analysis of series of two-dimensional spectra, different spectra can be overlaid and assignments can be transferred between spectra. The software includes mechanisms to account for overlapping signals by highlighting neighboring and ambiguous assignments.Here we present MetaboLab, a MATLAB based software package that facilitates NMR data processing by providing automated algorithms for processing series of spectra in a reproducible fashion. A graphical user interface provides easy access to all steps of data processing via a script builder to generate MATLAB scripts, providing an option to alter code manually. The analysis of two-dimensional spectra (The MetaboLab software is an integrated software package for NMR data processing and analysis, closely linked to the previously developed NMRLab software. It includes tools for batch processing and gives access to a wealth of algorithms available in the MATLAB framework. Algorithms within MetaboLab help to optimize the flow of metabolomics data preparation for statistical analysis. The combination of an intuitive graphical user interface along with advanced data processing algorithms facilitates the use of MetaboLab in a broader metabolomics context. Metabolomics has become an important technique in the context of systems biology to characterize changes in metabolite composition and concentration in biological systems such as cells, tissues or in bio-fluids. One-dimensional 1D) NMR spectra used in the context of metabolomics contain hundreds of signals arising from 50-100 metabolites. To utilize this wealth of information in the context of statistical analysis, consistent and accurate processing of the data is paramount. This includes phase correction of complex NMR signals to pure absorption line shapes and consistent baseline correction across series of spectra, along with various linear and non-linear scaling algorithms and spectral alignment . Scaling includes linear scaling algorithms, specifically total spectral area scaling and probabilistic quotient normalization D NMR spe, used prTo become accessible to a broader range of users in a translational setting, metabolomics software needs to provide intuitive and transparent control over all processing steps, without limiting more sophisticated uses. This need has been addressed by a batch processing interface, suitable to handle larger series of spectra with standard processing parameters, with an option to create user editable scripts allowing more sophisticated changes and providing access to algorithms from other packages.J-resolved or HSQC spectra, are similar to those for 1D-NMR spectra. Owing to the reduced congestion in 2D spectra and the smaller number of data points, algorithms such as baseline correction are easier to implement. 2D spectra also present additional opportunities, especially for the assignment of metabolites depending on user driven decisions for ambiguous signals. This requires a spectral library, ideally one that has been recorded for the same field strength and sample conditions . MetaboLab implements an easy mechanism to add spectral data for metabolites taken from databases.The fundamental requirements for spectral processing of two-dimensional (2D) NMR spectra, such as Assignment decisions will often depend on the size of signal intensities in relation to other signals of the same metabolite, facilitated by the display of intensity values for picked peaks within regions of interests for the resonances of the metabolite of interest. MetaboLab also includes a simple mechanism to transfer peak lists between spectra and automatically adjusts small shifts of signals arising from pH variations.MetaboLab is based on the previously developed NMRLab software , which i1. to create a simple and transparent software interface providing access to state-of-the-art algorithms,2. to provide automated or graphically facilitated algorithms, e.g. for phase correction, spectral referencing, glog transform optimisation, baseline correction of series of spectra,3. to create a graphical batch processing interface,4. to enable data output for statistical packages such as PLS Toolbox (Eigenvector Research Inc.),5. to enable semi-automated assignment of 2D-HSQC spectra,6. to provide tools capable of generating peak lists and intensities for series of spectra.MetaboLab includes the processing of the original spectrometer data (implemented for Bruker and Varian/Agilent data and parameter files), followed by common processing steps. The free induction decay (FID) is Fourier transformed, phase corrected and referenced, a robust automated algorithm is included for phase correction, which has worked well for most spectra acquired with the Bruker 'baseopt' acquisition parameter. Automated referencing to chemical shift standards such as TMS, TMSP or DSS is available. If no chemical shift standard has been added referencing is performed on the assumption that the transmitter offset has been set to the water frequency .For batch processing of NMR series of NMR spectra a script builder generates scripts using standard processing steps including zero filling, several algorithms for post acquisition water suppression , apodizaJ-resolved and for HSQC spectra have been included. For a series of 2D J-resolved spectra a projection using either the skyline or summation algorithm along the frequency axis can be applied after optionally calculating a tilted 2D spectrum. Apodization functions default to either exponential multiplication for 1D spectra or square cosine for 2D spectra. A window function composed of a shifted sine multiplied by an exponential (SEM window function [J-resolved spectra.Processing scripts can similarly be composed for 2D spectra. Parameter sets for 2D function ) is alsoMetabolomics NMR data analysis requires additional post-processing applied to the data series in order to remove distortions causing artifacts in subsequent statistical data analysis or quantification. Post-processing includes spectral alignment , various algorithms for baseline correction, the scaling of spectra , bucketing and data export for subsequent multivariate statistical analysis. The graphical user interface Figure  allows fThe MetaboLab graphical user interface provides easy access to post-processing tasks. Even on modern spectrometers the spectral baseline is often not ideally flat or shows a small DC offset. Such distortions typically may arise from the use of digital filters in the context of oversampling or from imperfections in the water suppression. Moreover, small baseline distortions in high-resolution 1D spectra are enhanced by non-linear scaling algorithms such as the glog transform , Pareto MetaboLab includes a new algorithm to compute an optimized glog parameter that maximizes the variance in the spectral series of NMR spectra. For sufficiently large data sets this algorithm yields good glog parameters. MetaboLab also allows manual modification of glog parameters and facilitates its adjustment by updating the display of processed spectra in real time.The assignment tool presents itself as a graphical user interface to assign signals in 2D-HSQC spectra based on metabolite peak lists in a spectral library  with fields storing the information for the different data post-processing steps, e.g. metaboSpc.baseline contains further data structure fields for the different baseline correction algorithms. For example, metaboSpc.baseline.spline contains the field baseline_points as a vector, the field baseline_average_points as a number indicating how many baseline points are averaged around each baseline point (selected in baseline points), the field linear determining whether a linear interpolation of adjacent baseline points is to be used for regions where no spectral baseline is available within a range of linear_points. All post-processing steps can be reconstructed from the information stored in the metaboSpc data structure.The automatic phase correction algorithm uses the TMSP signal if present, employing baseline properties between the TMSP signal and its 1H NMR spectra shown in Figures 3 cell extracts of K562 CML cells fed with 13C-labeled Glucose, as described in [NMR spectra. HSQC spectra were recorded using echo/anti-echo coherence selection for quadrature detection in the indirect dimension. The first spectrum was manually processed using the NMRLab software, then all spectra were automatically processed with the script builder interface using referencing and phasing information from the first spectrum. Resonance assignment was performed inside the HSQC assignment tool.1D-ribed in  except f3: Chloroform; DSS: Dimethylsilapentanesulfonate; FID: free induction decay; glog: generalised logarithm transformation; HSQC: heteronuclear single quantum coherence; MeOH: Methanol; NMR: nuclear magnetic resonance; NOESY: Nuclear Overhauser spectroscopy; PCA: principal component analysis; PLS-DA: partial least squares discriminant analysis; presat: presaturation of the solvent resonance; SEM: Sine and exponential multiplication; TMS: Tetrasilylmethane; TMSP: Sodium Trimethylsilyl-propionate.1D: one dimensional; 2D: two dimensional; CHClCL conceived and implemented the graphical user interfaces and the script builder application. Algorithms were conceived and implemented by UG and CL, who also wrote the manuscript. Both authors read and approved the manuscript.contains additional screenshots of the MetaboLab graphical user interface to illustrate several steps of data post-processing, an illustration of the user interface for the script builder application, and shows the usage of the graphical HSQC assignment tool. Furthermore, step by step instructions are given to extend the HSQC library for the graphical HSQC assignment tool.Click here for file


The role of autophagy is known to be highly complex and context-dependent, leading to both cancer suppression and progression in several tumors including melanoma, breast and prostate cancer. In the present review, recent advances in an understanding of the involvement of autophagy in prostate cancer treatment are described. The regulatory effects of androgens on prostate cancer cell autophagy are particularly discussed in order to highlight the effects of autophagy modulation during androgen deprivation. A critical evaluation of the studies examined in the present review suggests the attractive possibility of autophagy inhibition combined with hormonal therapy as a promising approach for prostate cancer treatment. Prostate cancer is one of the leading causes of cancer-related death in human males worldwide, being the second most current form of cancer in men. Prostate cancer grows locally at a slow rate, often for many years; eventually, it extends outside the prostate into neighboring tissues or by travelling to distant tissues through the blood. Common classification of prostate cancer stages is based on the TNM  system thus indicating the size of the main area of prostate cancer, the involvement of lymph nodes and metastatic dissemination. The TNM system may be combined with the tumor grading of prostate cancer by the Gleason scoring system, usually ranging from 2 to 10 [Locally advanced prostate cancer is initially hormone-sensitive and is treated with hormone therapy, also called androgen-deprivation therapy (ADT) or androgen suppression therapy. Approximately 50% of patients in industrialized nations are treated with ADT . The maiWhen prostate cancer recurrence is observed, cancer cells are no longer responding to ADT even though they still express ARs . ARs areAutophagy is a genetically programmed, evolutionarily conserved process occurring in all eukaryotic cells. This dynamic process, schematically represented in Autophagy has a controversial and still not completely clarified role in cancer. Cancer cells tend to re-program their metabolism machinery to evade cell death. In this context, when the tumor microenviroment is hypoxic and poor in nutrients, autophagy may help cancer cells to adapt to changing conditions, preventing their apoptotic death . HoweverThe controversial role of autophagy in tumor cell survival is also reflected in the ability of several anti-cancer treatments to exert an undesired cytoprotective effect by inducing autophagy, whereas others induce cell death through autophagy stimulation . In partbeclin1 gene is allelically deleted in many prostate cancers, suggested that autophagy might act as a tumor suppressor mechanism in the prostate [The observation that prostate ,22. Furtprostate . Thus auprostate . The Srcprostate . Indeed prostate .In general the protective function of autophagy in cancer cells subjected to chemotherapy or radiation has led to generate intense interest in evaluating autophagy inhibition as a possible clinical strategy to counteract therapeutic resistance in prostate cancer –30. On tin vivo in a mouse model, involves ADT-induced hypoxia in the tumor microenvironment, likely due to local vasculature degeneration [in vitro and involves multiple metabolic genes enhancing nutrient availability; in fact, since androgens normally activate such genes, prostate cancer cells, after androgen removal, face an energetic stress which turns on their autophagic response [ex vivo study has showed that AMPK is expressed at high levels in about 40% human prostate cancers thus confirming the frequent activation of a metabolic stress pathway [At least two mechanisms underlie the autophagy stimulation by androgen- ablation: the first one, shown neration . Low oxyresponse . Autopharesponse . Furtherresponse  and autoresponse . Interes pathway . The act pathway .Autophagy stimulation by androgen-ablation in prostate cancer cells parallels autophagy induction observed in breast cancer during anti-hormone therapies. Remarkably, as observed in prostate cancer, breast cancer cells also trigger autophagy to achieve a survival response that is critical for the development of anti-estrogen resistance .Altogether the data presented in the scientific literature and reported above suggest metabolic stress-induced signalling pathways and autophagy as possible targets of intervention to inhibit androgen-independent prostate cancer development.in vitro on epithelial prostate cancer cell lines demonstrated that blocking autophagy by genetic and pharmacological means in the presence of androgen deprivation causes cell death. In particular chloroquine synergistically kills LNCaP cells during androgen deprivation in a dose- and time-dependent manner [in vivo studies on autophagy inhibition combined with androgen deprivation are still lacking, the results obtained in vitro sustain the potential therapeutic value of combining autophagy-modulation with conventional ADT in vivo for prostate cancer.Autophagy inhibition may be therapeutically beneficial in various other cancers, as it can sensitize cancer cells to different therapies, including DNA-damaging agents, anti-hormone therapies  and radiation therapy . On the t manner . Similart manner . Chloroqt manner , appear t manner . Severalt manner ,44. In at manner . Unfortut manner . Althougin vitro further indicate blocking autophagic process combined with targeted therapy as a promising therapeutic approach for prostate cancer.Autophagy inhibition during ADT might be useful to further sensitize prostate cancer cells to different apoptotic stimuli. In fact, prostate cancer cells evolve toward an androgen-resistant phenotype but they are still capable of undergoing apoptosis with appropriate stimuli . Tumor nFinally, findings regarding the cytosolic deacetylase HDAC6 role in autophagy progression strongly suggest that its inhibition may represent a promising novel basis for combinatorial treatments ,55 in prTherapies impairing tumor metabolism modulating autophagy must consider their effect on lymphocytes activated in the immune response to cancer. The role of autophagy on anti-tumor immune cells has only recently begun to be defined ,57. It iIn the tumor microenvironment, several factors modulate cancer progression and severity . Among dAutophagy has been recently described as one of the mechanisms activated by TGF-β, which leads to different effects on tumor progression in a cell-type-dependent and context-dependent fashion, but the relationship between TGF-β signaling and autophagy has not yet been clearly defined. It has been demonstrated that TGF-β activates autophagy in human hepatocellular carcinoma cell lines  and in sin vitro [Interestingly, besides its role in tumor progression, TGF-β has been recently involved in ADT. Cross-talk between TGF-β and AR exists since androgens negatively regulate the expression of both TGF-β and its receptors in vitro ,73. Remain vitro . In lighin vitro ). Since in vitro and in vivo has been also shown to cause cellular senescence, which is attenuated by androgen receptor antagonists [Continuous androgen receptor activation agonists . Cellulaagonists . Senescei.e., almost 60%) are based on pharmacological treatments and interventions known to exert a known moderate effect (++) or a strong effect (+++) on autophagy. An interesting further point comes from the observation that, analyzing the 80 NIH-funded clinical trials currently recruiting prostate cancer patients more than 66 years old, (see Altogether data discussed in the present review highlight autophagy as an important process activated in prostate cancer after androgen removal; autophagy plays a relevant role for both cell physiology and immune system homeostasis and its inhibition combined with ADT must be considered as a valuable potential therapeutic opportunity to counteract prostate cancer growth by increasing cell death sensitivity . All the


Although a large body of research has documented that severe consequences are associated with alcohol use among college students, this may not be the case for all students who consume alcohol. Identifying those variables associated with risk for negative consequences in this population has important public health implications. Mixed findings are available on the relationship between alcohol-related negative consequences and alcohol consumed, depressive symptoms, and use of illicit substances. We examined the relationship between alcohol-related consequences and amount consumed during a typical and a heavy drinking week, cannabis use in the previous 12 months, and depressive symptoms. Participants consisted of a convenience sample of 85  undergraduate college students (mean age = 19 years) taking part in an on-campus mental-health screening. Participants reported use of alcohol and of other drugs, mental heath symptoms, and negative consequences. Results showed a direct association between alcohol-related negative consequences and total drinks consumed during a typical week  and during a heavy drinking week . Students with any cannabis use in the previous 12 months reported a significant greater number of alcohol-related negative consequences . Alcohol-related negative consequences were not associated with depressive symptoms. In a hierarchical linear regression model including cannabis use, total drinks during a typical week, and total drinks during a heavy drinking week, the latter was the only predictor of alcohol-related negative consequences. The other two variables did not predict any variance over and above the one explained by total drinks during a heavy drinking week. In conclusion, programs aimed at reducing the negative outcomes of alcohol consumption should aim at screening for heavy rather than typical drinking.


Neural Development describes the use of a synapse-specific label in Caenorhabditis elegans to implicate local UNC-6/netrin signaling in this developmental process. Thus, as well as their well known roles in cell migration and axon guidance, UNC-6/netrin signals distinguish an appropriate synaptic partner from other potential targets.Forming synaptic connections of the appropriate strength between specific neurons is crucial for constructing neural circuits to control behavior. A recent paper in http://www.neuraldevelopment.com/content/6/1/28See Research article:  Constructing neural circuits to perform biological functions is an intricate multi-step process that includes generating neurons, moving them to the right location, ensuring that they send out axons and dendrites to certain destinations, delivering pre- and postsynaptic components to the right parts of these neuronal outgrowths, and finally making the appropriate synaptic connections of the correct strength.Specificity is crucial throughout this developmental process. In the final step of circuit formation, when axons or dendrites reach their target region, they are likely to be confronted with many potential synaptic partners within a relatively small space, from which they need choose the correct one. As circuit construction occurs in the context of the complex developing nervous system, multiple steps in the formation of multiple circuits might overlap in time and space, posing an additional requirement that distinct circuits do not cross-interfere. That neurons robustly form synapses with the correct partner, while avoiding unsuitable targets, is therefore especially important to ensure correct information transmission and eliminate inappropriate crosstalk between circuits.Neural Development , which efficiently identifies specific synaptic contacts in living animals [What are the signals that govern this level of synapse specificity? A paper from Miri VanHoven and colleagues in k et al. ) adroitl animals .et al. report the first application of the GRASP technique for identifying molecules that influence synaptic partner choice  and its postsynaptic interneuron (AVA)  Figure , bottom.Using GRASP-labeled PHB-AVA synapses to facilitate a screen of candidate mutants, the authors identified UNC-6/netrin and its receptor UNC-40/DCC as central players in the formation of this synaptic connection. They also find that a mutant in UNC-40/DCC shows the predicted increase in posterior movement consistent with reduced transmission between PHB and AVA, thus providing a behavioral correlate to structural synaptic changes in living animals to demonstrate biological relevance .et al. indicate that the graded strength of synaptic connections can be controlled by UNC-6/netrin levels. Bidirectional control of graded transmission across two neurons also occurs during neuronal plasticity, raising the question as to whether proteins such as UNC-6/netrin are also involved in synaptic plasticity after the circuit is constructed.The number of PHB-AVA synaptic contacts is reduced in UNC-6/netrin or UNC-40/DCC mutants, whereas overexpression of UNC-6/netrin increases their number . TogetheDrosophila neuromuscular junction [C. elegans . In theet al. [UNC-6/netrin first gained prominence as an axon guidance molecule ,6; additet al.  now showet al. reveals that several downstream effectors of UNC-40/DCC are not essential for synaptic partner recognition even though they play important roles in axon guidance [First, how does the same signal lead to different biological outcomes? The work of Park guidance . Perhapsguidance ), and doDrosophila neuromuscular junction [Second, how is neural development compartmentalized such that early signals do not influence late steps, and that the development of one circuit does not interfere with another nearby? Signaling specificity is likely to require a combination of several developmental and molecular mechanisms. UNC-6/netrin is deployed in different cells for guiding PHB axon outgrowth versus synapse formation ,8. Thus,junction , might aFinally, would the repeated use of the same molecule require developmental programs to minimize cross-interference and thus constrain the types of structures and anatomy that could develop? Or would it be an economical way of coordinating complex structures so that related structures are organized around a single cue? An integrated analysis of the multiple processes involved in neural circuit formation will be an important next step in addressing these big picture questions in development, and tools like GRASP  are very


Allergenic fining agents and processing aids from hen's egg and cow's milk used in wine production are hidden allergens and could demonstrate a health threat for allergic persons. Hence, the European parliament adopted Directive 2003/89/EC amending 2000/13/EC to declare ingredients, contaminations and processing aids which are known to trigger allergic reactions. The Amendment Directive 415/2009/EC excludes the labeling of wine which are processed with eggs or milk and products thereof until the 31st of December 2010.In 2006 Rolland et al. did a double-blind, placebo-controlled trial and basophil activation analysis about potential food allergens in wine including 5 egg-allergic and 1 milk-allergic patients. Among others they collected 24 egg white-fined or whole egg-added red wines, 34 milk-fined white wines and 25 casein-fined white wines. In this study no anaphylaxis was induced by wine consumption. But adverse reactions against treated wines could not be excluded. Due to the rarity of adult milk or egg-allergic patients reliable statistical analysis of allergic reactions against milk or egg-fined wines is inhibited.Casein, ovalbumin/hen's egg white and lysozyme products of different commercial producers were investigated by SDS-PAGE and immunoblot. These investigations show that every product contains beside casein, ovalbumin or lysozyme other milk or egg allergens respectively in different amounts. The investigations show the necessity to have analytical methods for determination of residues of fining agents or stabilizers in wine which are able to detect not only casein, ovalbumin and lysozyme but also take into account the other milk and egg allergens. This could be guaranteed by certain antibodies used in ELISA systems binding not only to casein, ovalbumin or lysozyme but also to the other allergens in processed casein, ovalbumin or lysozyme for wine production. Therefore polyclonal antibodies raised against fining agents casein and ovalbumin and stabilizer lysozyme of one fining agent producer were used in this study.


Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis and is a member of more than 500 bacterial species that live in the oral cavity. This anaerobic bacterium is a natural member of the oral microbiome, yet it can become highly destructive (termed pathobiont) and proliferate to high cell numbers in periodontal lesions: this is attributed to its arsenal of specialized virulence factors. The purpose of this review is to provide an overview of one of the main periodontal pathogens—Porphyromonas gingivalis. This bacterium, along with Treponema denticola and Tannerella forsythia, constitute the “red complex,” a prototype polybacterial pathogenic consortium in periodontitis. This review outlines Porphyromonas gingivalis structure, its metabolism, its ability to colonize the epithelial cells, and its influence upon the host immunity. Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis, an inflammatory disease that destroys the tissues supporting the tooth which eventually may lead to tooth loss. Among the over 500 bacterial species living in the oral cavity, a bacterial complex named “red complex” and composed of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia has been strongly associated with advanced periodontal lesions [ lesions . Porphyromonas gingivalis, a periodontopathogen, has provided a tremendous amount of information in terms of phylogenetic as well as proteomic criteria over the last 20 years, which may exceed other closely related members, including Bacteroides fragilis and Bacteroides thetaiotaomicron, as major anaerobic, opportunistic pathogens in the dental field. The microbiota of the human oral mucosa consists of a myriad of bacterial species that normally exist in commensal harmony with the host. Porphyromonas gingivalis, an etiological agent in severe forms of periodontitis (a chronic inflammatory disease), is a prominent component of the oral microbiome and a successful colonizer of the oral epithelium [Research on Porphyromonas gingivalis, such as pathogenicity and its possible relation to certain systemic diseases.The authors have used both latest as well as older reviews and studies to compile a comprehensive overview of this key periodontal pathogen. Special attention has been paid to clinically relevant properties ofThe perturbation of epithelial cells by bacteria is the first stage in the initiation of inflammatory and immune processes which eventually cause destruction of the tissues surrounding and supporting the teeth which ultimately result in tooth loss .Porphyromonas gingivalis can locally invade periodontal tissues and evade the host defense mechanisms. In doing so, it utilizes a panel of virulence factors that cause deregulation of the innate immune and inflammatory responses [esponses .Porphyromonas gingivalis rapidly adheres to the host cell surface followed by internalization via lipid rafts and incorporation of the bacterium into early phagosomes. Porphyromonas gingivalis activates cellular autophagy to provide a replicative niche while suppressing apoptosis. The replicating vacuole contains host proteins delivered by autophagy that are used by this asaccharolytic pathogen to survive and replicate within the host cell. When autophagy is suppressed by 3-methyladenine or wortmannin, internalized Porphyromonas gingivalis transits to the phagolysosome where it is destroyed and degraded. For that reason, the survival of Porphyromonas gingivalis depends upon the activation of autophagy and survival of the endothelial host cell, but the mechanism by which Porphyromonas gingivalis accomplishes this remains unclear [ unclear .The harsh inflammatory condition of the periodontal pocket suggests that this organism has properties that will facilitate its ability to respond and adapt to oxidative stress. Because the stress response in the pathogen is a major determinant of its virulence, a comprehensive understanding of its oxidative stress resistance strategy is vital . Porphyromonas gingivalis to cause adult periodontitis is determined by its arsenal of virulence factors. Biofilm formation and bacterial dipeptidyl peptidase IV (DPPIV) activity contribute to the pathogenic potential of Porphyromonas gingivalis. Furthermore, biofilm formation may enhance Porphyromonas gingivalis virulence through increased DPPIV activity. Because of their importance for bacterial colonization and growth, biofilm formation and DPPIV activity could present interesting therapeutic targets to tackle periodontitis [The ability ofdontitis .Porphyromonas gingivalis is strongly correlated with chronic periodontitis. Its chronic persistence in the periodontium depends on its ability to evade host immunity without inhibiting the overall inflammatory response, which is actually beneficial for this and other periodontal bacteria. Indeed, the inflammatory exudate  is a source of essential nutrients, such as peptides and hemin-derived iron [ved iron .Porphyromonas gingivalis contributes to the pathogenesis of aggressive periodontitis by inducing high levels of proinflammatory cytokines, such as IL-1β and IL-6 by peripheral CD4+ T helper cells [ Porphyromonas gingivalis serotypes K1 and K2 but not others are associated with an increased production of the osteoclastogenesis-related factor RANKL. This important information suggests that these serotypes could elicit a greater bone resorption in vivo and have a significant role in the periodontitis pathogenesis. Destructive periodontitis is associated with a Th1-Th17-immune response and activation of RANKL-induced osteoclasts. In addition, Porphyromonas gingivalis K1 and K2 serotypes induce a strong Th1-Th17-response. These Porphyromonas gingivalis serotypes induce higher osteoclasts activation, by increased Th17-associated RANKL production and an antigen-specific memory T lymphocyte response [ Porphyromonas gingivalis oral infection prior to arthritis induction increases the immune system activation favoring Th17 cell responses which ultimately accelerate arthritis development. These results suggest that chronic oral infection may influence rheumatoid arthritis development mainly through activation of Th17-related pathways [er cells . Porphyrresponse . Chronicpathways .β, and Porphyromonas gingivalis are associated with various clinical and radiographic measures of periodontitis. The CRS index, combining the three salivary biomarkers, is associated with periodontitis. High salivary concentrations of metalloproteinase MMP-8, interleukin IL-1β, and Porphyromonas gingivalis have been associated with deepened periodontal pockets and alveolar bone loss and MMP-8 and IL-1β with bleeding on probing [Salivary concentrations of metalloproteinase MMP-8, interleukin IL-1 probing .The bacterium utilizes amino acids as energy and carbon sources and incorporates them mainly as dipeptides. Therefore, a wide variety of dipeptide production processes mediated by dipeptidyl peptidases (DPPs) could be beneficial for the organism . Porphyromonas gingivalis does not produce siderophores. Instead, it employs specific outer membrane receptors, proteases (particularly gingipains), and lipoproteins to acquire iron/heme. Specific proteins involved in iron and heme capture have been described [Iron utilized by this pathogen in the form of heme has been shown to play an essential role in its growth and virulence.escribed . Porphyromonas gingivalis, such as fimA fimbrilin (a subunit of major fimbriae), 75-kDa protein (a subunit of minor fimbriae), hemagglutinins, and the hemoglobin receptor protein, which are important for the bacterium to colonize and proliferate in the gingival crevice and to invade the periodontium. These findings strongly point out the critical roles of gingipain R and gingipain K in the virulence of Porphyromonas gingivalis [ Porphyromonas gingivalis strains is a complex of a 60-kDa catalytic protein with hemagglutinin/adhesins. Molecular cloning and structural characterization of the gingipain R and gingipain K genes has shown that they code for 1704 and 1722 amino-acid residue preproenzymes, respectively [Additionally, the proteolytic activities of gingipain R and gingipain K contribute to processing/maturation of various cell-surface proteins ofngivalis . Proteasectively . The vir Porphyromonas gingivalison diverse surfaces are facilitated by a repertoire of adhesins including fimbriae, hemagglutinins, and proteinases [ Porphyromonas gingivalis hemagglutinin B (HagB) and attenuates HagB-induced chemokine responses in human myeloid dendritic cells. Thus histatin 5 is capable of attenuating chemokine responses which may help control oral inflammation [Retention and growth ofteinases . Histatiammation .Porphyromonas gingivalis produces large amounts of arginine- and lysine-specific cysteine proteinases in cell-associated and secretory forms [ry forms . Porphyromonas gingivalis W83, is comparable to the previously determined structures of homologues K2 and K3, all three being representative members of the cleaved adhesin domain family. In the structure of K1, the conformation of the most extensive surface loop is unexpectedly perturbed, perhaps by crystal packing, and is displaced from the previously reported arginine-anchored position observed in K2 and K3. This displacement allows the loop to become free to interact with other proteins; the alternate flipped-out loop conformation is a novel mechanism for interacting with target host proteins, other bacteria, or other gingipain protein domains. Furthermore, the K1 adhesin module, like others, is found to be hemolytic in vitro and thus functions in erythrocyte recognition contributing to the hemolytic function of Kgp. K1 was also observed to selectively bind to hemalbumin with high affinity, suggesting this domain may be involved in gingipain-mediated hem acquisition from hemalbumin. Consequently, it is most likely that all cleaved adhesin domains of Kgp contribute to the pathogenicity of Porphyromonas gingivalis in more complex ways than simply mediating bacterial adherence [These enzymes, referred to as gingipains, cleave protein and peptide substrates after arginine (gingipain R) and lysine residues (gingipain K), and it has been found  that neidherence . Porphyromonas gingivalis-specific virulence factor arginine gingipainB was screened by ELISA method. Significantly higher anti-RgpB antibody levels were detected in the periodontitis subset, compared to the nonperiodontitis control subset. Significantly increased anti-RgpB antibody levels in periodontitis serum, compared to nonperiodontitis serum, may suggest that elevated anti-RgpB IgG levels can be used as a proxy for chronic periodontitis in studies where the periodontal status is of interest but unknown [The presence of antibodies to the unknown .Porphyromonas gingivalis HmuY hemophore-like protein binds heme and scavenges heme from host hemoproteins to further deliver it to the cognate heme receptor HmuR. The characterization of structural features of HmuY variants in the presence and absence of heme with respect to roles of tryptophan residues in conformational stability is the aim of the further research [research .Porphyromonas gingivalis contains exceedingly high concentrations of cysteine proteinases with trypsin-like activity which has been implicated as a virulence factor in adult-onset periodontitis [ Porphyromonas gingivalis: hemagglutinins and collagenases [dontitis . Severaldontitis  have sugagenases . Porphyromonas gingivalis have contact with host tissues and cells because of the outermost cell elements. As a result, such components of Porphyromonas gingivalis are potentially important in the occurrence of periodontal diseases [ Porphyromonas gingivalis fimbriae are a critical factor for mediation of interaction of this bacterial organism with host tissues, as Porphyromonas gingivalis promotes both bacterial adhesion to and invasion of targeted sites. Porphyromonas gingivalis fimbriae are likely to interrupt the cellular signaling via extracellular matrix proteins/integrins in periodontal regions. Fimbriae are also thought to be critically important in invasive events of this bacterial organism to host cells [Surface components ofdiseases . Porphyrst cells .Porphyromonas gingivalis fimbriae are capable of binding to salivary enzymes, extracellular matrix proteins, and commensal bacteria as well as also strongly adhering to cellular alpha5beta1-integrin [ Porphyromonas gingivalis is captured by cellular pseudopodia which enable invagination through an actin-mediated pathway. The invasive event has been reported to require host cellular dynamin, actin fibers, microtubules, and lipid rafts [ Porphyromonas gingivalis pathogen impairs cellular function. Porphyromonas gingivalis fimbriae are classified into 6 genotypes (types I to V and Ib) based on the diversity of the fimA genes encoding each fimbria subunit. Intracellular Porphyromonas gingivalis with type II fimbriae has been found to clearly degrade integrin-related signaling molecules, paxillin and focal adhesion kinase which disables cellular migration and proliferation of the host cells [ Porphyromonas gingivalis, followed by type IV; type II fimA fimbriae of Porphyromonas gingivalis were found significantly more often in patients with more severe forms of periodontitis [ Porphyromonas gingivalis fimbriae act as an important virulence factor in atherosclerosis progression. Regulatory T cells (Tregs) may play a crucial role in autoimmune response during this process. However, whether Porphyromonas gingivalis infection is associated with Tregs dysregulation during atherosclerosis is still unknown and the prevalence of different Porphyromonas gingivalis FimA genotypes during this process is unclear. Porphyromonas gingivalis infection reduced Tregs in atherosclerotic patients [integrin . Followiid rafts . Followist cells . A majordontitis . Porphyrpatients . Porphyromonas gingivalis is a key factor in the development of periodontitis. Gingival fibroblasts, which are the major constituents of gingival connective tissue, may directly interact with Porphyromonas gingivalis and its bacterial products, including lipopolysaccharide, in periodontitis lesions [The lipopolysaccharide of lesions . Due to  lesions . Plasmin lesions .Porphyromonas gingivalis lipopolysaccharide increases the expression of EphB4 while inhibiting the expression of EphrinB2 [ Porphyromonas gingivalis LPS induces proinflammatory cytokines, such as IL-1β, IL-6, and IL-8, which induce periodontal tissue destruction. Periodontal ligament stem cells (PDLSCs) play an important role in periodontal tissue regeneration and are expected to have future applications in cellular therapies for periodontitis. Porphyromonas gingivalis LPS inhibited the alkaline phosphatase activity, collagen type 1 Alpha 1, and osteocalcin production and mineralization in the PDLSCs which are positive for STRO-1 and SSEA-4. Porphyromonas gingivalis LPS also promoted cell proliferation and produced IL-1β, IL-6, and IL-8 [EphrinB2 . Porphyrand IL-8 . Porphyromonas gingivalis LPS was compared with that of Toll-like receptor 2 agonist synthetic triacylated lipoprotein Pam3-Cys-Ser-(Lys)4 (Pam3CSK4). Gene and protein expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin could be measured using RT-PCR and flow cytometry, respectively. Porphyromonas gingivalis LPS stimulates the expression levels of all adhesion molecules in a dose-dependent manner [The effect oft manner . Porphyromonas gingivalis are extracellular products of an important etiological agent in periodontal diseases. Many of the in vitro actions of these enzymes are consistent with the observed deregulated inflammatory and immune features of the disease [The cysteine proteases of disease . They ar disease . These e disease . The uti disease . Porphyromonas gingivalis fimbriae bind CD14 and activate Toll-like receptor 2 (TLR2) and phosphatidylinositol 3-kinase-mediated signaling leading to induction of the high-affinity conformation of CR3 in leukocytes. Although this TLR2 proadhesive signaling pathway may normally be involved in enhancing leukocyte-endothelial cell interactions and transendothelial migration, intriguing evidence [ Porphyromonas gingivalis has co-opted this pathway for enhancing the interaction of its cell surface fimbriae with CR3. Indeed, activated CR3 interacts with Porphyromonas gingivalis fimbriae and induces downregulation of interleukin-12 p70, a key cytokine involved in intracellular bacterial clearance. Moreover, the interaction of activated CR3 with Porphyromonas gingivalis leads to the internalization of the pathogen by macrophages. Since CR3 does not readily activate microbicidal mechanisms and constitutes a “preferred receptor” for certain intracellular pathogens, possible exploitation of CR3 by Porphyromonas gingivalis for evading innate immune clearance might be a plausible hypothesis [The complement system is an important host response to invading bacteria. Activation of the complement leads to deposition of C3b on the bacterial surface and phagocytosis of the opsonized bacteria by host cells. Alternatively, the entire complement pathway, including terminal components C5b-9, may be activated on the cell surface which gives rise to generation and insertion of the membrane attack complex into the bacterial membrane and cell lysis. Bacterial resistance to complement may be by enzyme digestion of complement components or by the generation or acquisition from the host of cell surface molecules which allow the organism to adopt host complement control proteins . The proevidence  suggestspothesis . Porphyromonas gingivalis expresses C5 convertase-like enzymatic activity and adeptly exploits complement-TLR crosstalk to subvert host defenses and escape elimination. Intriguingly, this defective immune surveillance leads to the remodeling of the periodontal microbiota to a dysbiotic state that causes inflammatory periodontitis. Understanding the mechanisms by which Porphyromonas gingivalis modulates complement function to cause dysbiosis offers new targets for complement therapeutics [Signaling crosstalk between complement and Toll-like receptors (TLRs) normally serves to coordinate host immunity. However, the periodontal bacteriumapeutics . Porphyromonas gingivalis, have developed different strategies to perturb the structural and functional integrity of the gingival epithelium. Porphyromonas gingivalis adheres to, invades, and replicates within human epithelial cells [Periodontopathogens, such asal cells . Periodoal cells . Porphyromonas gingivalis gingipains may present a novel mechanism by which Porphyromonas gingivalis manipulates the host innate immune response helping to establish chronic periodontal inflammation [The triggering receptor expressed on myeloid cells 1 (TREM-1) is a cell surface receptor of the immunoglobulin superfamily with the capacity to amplify proinflammatory cytokine production and regulate apoptosis. Polymorphonuclear neutrophils (PMNs) are the first line of defense against infection and a major source of TREM-1. The differential regulation of TREM-1 by theammation .Porphyromonas gingivalis can modulate eukaryotic cell signal transduction pathways, directing its uptake by gingival epithelial cells. Within this privileged site, Porphyromonas gingivalis can replicate and impinge upon components of the innate host defense [ Porphyromonas gingivalis. Genotypic characterization of Porphyromonas gingivalis strains has revealed extensive heterogeneity in natural populations of this bacterium [ Porphyromonas gingivalis may occur by a negative regulator as has been described in other pathogenic organisms [ defense . Elucidaacterium . Regulatrganisms . Porphyromonas gingivalis. The gingival epithelial cells express functional A2a receptor and Porphyromonas gingivalis may use the A2a receptor coupled “Danger Signals” adenosine signaling as a means to establish successful persistence in the oral mucosa, possibly via downregulation of the proinflammatory response [Extracellular signaling during inflammation and chronic diseases involves molecules referred to as “Danger Signals,” including the small molecule adenosine. The primary gingival epithelial cells express a family of G-protein coupled receptors known as adenosine receptors, including the high-affinity receptors A1 and A2a and low-affinity receptors A2b and A3. A2a receptor antagonism and knockdown via RNA interference significantly reduced metabolically active intracellularresponse . Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, as they are the major causes of gingivitis. Their specific aims include seeing what components are shuttled between the bacteria as it has already been proven that neither bacterial species can survive without the other [Currently, researchers are trying to find exactly how the symbiosis among the bacterial populations within the mouth works, specifically betweenhe other . Also, mhe other . Anotherhe other . Aggregatibacter actinomycetemcomitans may give insight into novel prevention strategies for Aggregatibacter actinomycetemcomitans-associated periodontitis. Since Porphyromonas gingivalis infection is related to a typical periodontal ecopathology, the susceptibility to person-to-person transmission of Porphyromonas gingivalis pathogen may be controlled by periodontal treatment and emphasizing the significance of high standard oral hygiene [Future research aiming at finding the reasons which cause the changes in the oral homeostasis to allow the growth of hygiene . Porphyromonas gingivalis, the major etiologic factor in periodontitis, facilitates the development and progression of collagen induced arthritis [Recent clinical and epidemiological studies have provided strong evidence for a significant association between rheumatoid arthritis and periodontitis. Moreover, our findings show thatrthritis .Porphyromonas gingivalis, a major cause of chronic periodontitis, has also been implicated in the etiology of rheumatoid arthritis, specifically in anti-citrullinated protein/peptide antibody positive, based on its unique property among pathogens to express a citrullinating peptidylarginine deiminase enzyme [ Porphyromonas gingivalis peptidyl-arginine deiminase has the ability to convert arginine residues in proteins to citrulline. Protein citrullination alters protein structure and function; hence, peptidyl-arginine deiminase may be involved in deregulation of the host's signaling network and immune evasion. Furthermore, accumulating evidence suggests a role for autoimmunity against citrullinated proteins in the development of rheumatoid arthritis [e enzyme . Porphyrrthritis . Porphyromonas gingivalis, a major pathogen of periodontal disease, shows that catechin epigallocatechin gallate destroys established Porphyromonas gingivalis biofilms and inhibits biofilm formation [The research of the effects of tea catechin epigallocatechin gallate on established biofilms and biofilm formation byormation . Porphyromonas gingivalis, the EphB4 receptor on osteoblasts and the EphrinB2 ligand on osteoclasts may generate bidirectional antiosteoclastogenic and pro-osteoblastogenic signaling into respective cells and potentially facilitate the transition from bone resorption to bone formation. In bone remodeling, the Eph family is involved in regulating the process of osteoclast and osteoblast coordination in order to maintain bone homeostasis [The results from current research indicate that, when treated with LPS fromeostasis . Porphyromonas gingivalis lipopolysaccharide. The expression of Toll-like receptor 2 (TLR2), TLR4, TNF-α, and inducible NO synthase was mainly detected in the gingival macrophages of chronic periodontitis patients. The leptomeninges serve as an important route for transducing inflammatory signals from macrophages to microglia by secretion of proinflammatory mediators during chronic periodontitis [The leptomeningeal cells transduce inflammatory signals from peripheral macrophages to brain-resident microglia in response todontitis .Porphyromonas gingivalis is a major pathogen of severe adult periodontitis. Alveolar bone resorption is one of the most important factors in denture construction. Porphyromonas gingivalis causes alveolar bone resorption and morphologic measurements are the most frequent methods to identify bone resorption in periodontal studies [ Porphyromonas gingivalis, an etiological agent in severe forms of periodontitis (a chronic inflammatory disease), is a prominent component of the oral microbiome and a successful colonizer of the oral epithelium [ studies . The micithelium .Porphyromonas gingivalis lipopolysaccharide circulates systemically in over 50% of periodontal disease patients and is associated with increased matrix metalloproteinase. The low systemic lipopolysaccharide stimulates an inflammatory response in the left ventricle through metalloproteinase leading to a decrease in cardiac function [ Porphyromonas gingivalis contain virulence factors such as lipopolysaccharide and gingipains. The sera from periodontitis patients had significantly stronger reactivity against an outer membrane vesicles-producing strain than the isogenic outer membrane vesicles-depleted strain. The gingipain-laden outer membrane vesicles may contribute to tissue destruction in periodontal diseases by serving as a vehicle for the antigens and active proteases [ Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans can be transmitted from family member to family member and may cause periodontitis in the recipient individual [function . In the roteases . Porphyrdividual . Porphyromonas gingivalis may lead to the development of novel strategies for eradication of Porphyromonas gingivalis and treatment for periodontal diseases in the future.Recent advances in the understanding of the pathomechanisms of Porphyromonas gingivalis, a well-adapted opportunistic pathogen of the oral mucosa and prominent constituent of oral biofilms, best known for its involvement in periodontitis, may be an important mediator in the development of a number of multifactorial and seemingly unrelated chronic diseases, such as rheumatoid arthritis and orodigestive cancers. Orodigestive cancers represent a large proportion of the total malignancies worldwide and include cancers of the oral cavity, gastrointestinal tract, and pancreas. For prevention and/or enhanced prognosis of these diseases, a good understanding of the pathophysiological mechanisms and the interaction between Porphyromonas gingivalis and host is much needed [The past decades of biomedical research have yielded massive evidence for the contribution of the microbiome in the development of a variety of chronic human diseases. There is emerging evidence thath needed . Porphyromonas gingivalis, an etiological agent in severe forms of periodontitis, is a prominent component of the oral microbiome and a successful colonizer of the oral epithelium. This Gram-negative anaerobe can also exist within the host epithelium without the existence of overt disease. Porphyromonas gingivalis seems to be a highly adapted pathogen of the oral microbiome. The latest studies tend to focus on the research of its possible direct and indirect influence on certain systemic diseases such as atherosclerosis and reumatoid arthritis. Mutual relations between Porphyromonas gingivalis and other pathogens of the oral cavity are another subject of intensive studies.The authors have used both latest as well as older reviews and studies to compile a comprehensive overview of this key periodontal pathogen.


Among women dually infected with malaria and HIV, high-density malaria  was associated with increased risk for perinatal MTCT (ARR 2.0), compared to low-density malaria. The interaction between placental malaria and MTCT appears to be variable and complex: placental malaria that is controlled at low density may cause an increase in broad-based immune responses that protect against MTCT; uncontrolled, high-density malaria may simultaneously disrupt placental architecture and generate substantial antigen stimulus to HIV replication and increase risk for MTCT.To determine whether maternal placental malaria is associated with an increased risk for perinatal mother-to-child HIV transmission (MTCT), we studied HIV-positive women in western Kenya. We enrolled 512 mother-infant pairs; 128 (25.0%) women had malaria, and 102 (19.9%) infants acquired HIV perinatally. Log Malaria during pregnancy is a serious problem in sub-Saharan Africa, affecting an estimated 24 million pregnant women; malaria prevalence may exceed 50% among primigravid and secundigravid women in malaria-endemic areas , a large publicly funded hospital in Kisumu  in western Kenya. Malaria transmission within Kisumu is perennial, and >32 weeks’ gestation , resided within the Kisumu municipality, and had no known underlying chronic illness. Following informed consent, a structured questionnaire was administered in the local language (Dholuo or Kiswahili) to obtain information on sociodemographic, health, and obstetric factors.Pregnant women were enrolled from June 1996 through May 2000. Screening procedures have been described previously  on an electronic balance , and gestational age was assessed by using the Ballard method  and the Kenya Medical Research Institute ethical review committee were strictly followed. Mothers of enrolled infants signed an additional informed consent form for infant participation.The study protocol was approved in 1995 by the institutional review boards of the Kenya Medical Research Institute; CDC, Atlanta, Georgia, USA; and the Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands, and was reviewed annually by the participating institutions. This study occurred during a changing environment in preventing perinatal HIV transmission, with results of studies in other countries demonstrating the benefits of short-course AZT use . Capillary blood was collected from infants by a heel prick on the day of delivery and then monthly thereafter for HIV testing. Plasma was separated from blood samples and stored at –70°C.Infant HIV testing was done by polymerase chain reaction (PCR) of proviral DNA extracted from peripheral blood mononuclear cells  and standard fluorescent-activated cell sorting  analysis following whole-blood lysis  slide test . Hemoglobin was measured to the nearest 0.1 g/dL using a Hemocue machine .>2,500 g, regardless of gestational age, and low birth weight if they weighed <2,500 g. Preterm delivery was defined as occurring at <37 weeks of gestation. Small for gestational age was defined as sex-specific birth weight <10th percentile for weight-for-gestational-age . Placental parasitemia was defined as any plasmodial asexual form detected on a thick film. Maternal HIV infection was defined as a positive result on both rapid tests; women not reactive with the initial Serostrip HIV-1/2 test were considered HIV uninfected. Women whose serostatus could not be determined  were excluded from analysis. Newborns were classified as normal birth weight if they weighed >2 consecutive positive HIV PCR tests, the first of which was at <4 months of age; 2) were lost to follow-up but had had >3 consecutive positive PCR results, the first of which was at <4 months of age; 3) remained alive with continued and consistent positive PCR results, the first of which was at <4 months of age. Infants were considered negative for perinatally acquired HIV if they had >3 PCR tests performed on them, and all tests were negative, with at least one of the negative tests at >4 months of age. Because infants had to be >4 months old to be classified as uninfected, those who died or were lost to follow-up before 4 months of age were excluded. Infants who acquired HIV at >5 months of age were considered to have acquired HIV postnatally and were included as nontransmitters from the perinatal perspective. Infants for whom we had insufficient PCR data to determine their status were classified as indeterminate and were excluded. Mothers of infected infants were classified as transmitters and those of uninfected infants as nontransmitters.An algorithm was developed to describe the perinatal HIV infection status of infants. Infants were classified as having acquired HIV infection perinatally  if they met the following conditions: 1) died and by the time of death had 10-transformed. We defined high-density placental parasitemia as >10,000 parasites/μL, which corresponded approximately to the uppermost quintile of parasite density. Univariate analyses were performed by using χ2 or Fisher exact tests  to compare proportions for categorical variables; t tests were used to compare normally distributed continuous variables. Relative risks (RRs) were computed with their 95% confidence interval (CI) to measure the strength of the associations between potential risk factors and perinatal MTCT.Plasma virus levels load below the limit of quantification (400 copies/mL) were assigned a value of 200 copies/μL; plasma viral load results were then logTo evaluate the effect of placental malaria on perinatal MTCT, a Poisson log-linear model containing placental malaria and maternal viral load as primary predictor variables was constructed by using backward elimination; adjusted RRs were computed. An interaction term between placental malaria density and maternal viral load was significant (p = 0.02) and was retained in the model. Because women with and without placental malaria may have different risk factors for perinatal MTCT, we fit three separate multivariate models: all study women, women without placental malaria, and women with placental malaria. All tests were two-sided; p values <0.05 were considered significant. Analysis was done using STATA  and SAS .<2 versus >3), and rates of episiotomy or perineal tear. However, excluded women were more likely to have infants born with low birth weight . The baseline characteristics of the 512 women included in the analysis are shown in A total of 829 mother-infant pairs were enrolled; 317 (38.2%) infants with incomplete follow-up or indeterminate HIV status were excluded, leaving 512 mother-infant pairs. Included and excluded women did not differ in age, level of education, mean maternal viral load, mean CD4+ counts, malaria rates, high-density malaria rates, proportion of low birth order  and low CD4+ count (<200 cells/μL) were significantly associated with perinatal MTCT  transmitted HIV to their infants perinatally. High maternal viral load , who represented approximately one fifth of women with malaria. Among women with viral load below the detection level, perinatal MTCT occurred in none of 35 mothers with malaria, compared to 10 (8.7%) of 115 mothers without malaria (p = 0.12).Maternal peripheral parasitemia at delivery was not associated with MTCT; however, placental malaria was associated with a 40% reduction in the risk for perinatal MTCT  . Compare<2, and low birth weight in the newborn were significant risk factors or markers for perinatal MTCT. Among women with malaria , high maternal viral load, episiotomy or perineal tear, and high-density placental infection were significant risk factors for perinatal MTCT  malaria was an independent protective factor for perinatal MTCT. Among women without microscopically detectable malaria, high maternal viral load, gravidity tal MTCT . In bothIn further examination of the interaction between maternal viral load and placental malaria, we found no significant differences in the frequency of episiotomy or perineal tear, mean CD4+ count, mean maternal hemoglobin level, mean birth weight, and frequency of small-for-gestational-age neonates among women without malaria, those with low-density placental malaria, and those with high-density placental malaria. Women with placental malaria were of lower mean gravidity than women without malaria . Geometric mean maternal viral load was slightly higher in women with low-density placental malaria  and was nearly twofold higher in women with high-density placental malaria  than the viral load in women without placental malaria ; however, these differences were not significant (p = 0.14). Viral load was significantly higher among women with peripheral malaria parasitemia at delivery  than among women without . As shown in These associations were further evaluated in models comparing the relative risk for perinatal transmission between the three groups with placental malaria at various levels of maternal viral load. Low-density placental parasitemia was associated with significant protection for perinatal MTCT at the lower viral load levels, but not at higher viral load levels . When wo,This evaluation of perinatal HIV transmission in a malarious area of western Kenya demonstrated that approximately 20% of infants born to HIV-infected mothers acquired HIV by 4 months of age, similar to rates reported in other sub-Saharan African settings , it restricted our study population to the “healthiest” women with HIV and likely resulted in an underestimate of the overall rate of perinatal MTCT in our study area. Some infants categorized as having acquired HIV through perinatal transmission may have actually acquired it through early breastfeeding transmission. However, including these infants would likely bias the results toward underestimating the magnitude of the observed risks. Our measurement of malaria was limited to microscopy examination of placental smears and could have been inexact; those with no evidence of malaria may have had very low-density infection and may have been misclassified as having no malaria. Such misclassification would be expected to bias our findings toward the null hypothesis. Because placental malaria can cause an inflammatory response in the placenta, the use of leukocyte count to calculate parasite density may have resulted in an underestimation. However, our cutoff of 10,000 parasites/μL for high-density placental parasitemia is essentially a relative measure based on the upper quintile of densities; therefore, we do not think that our estimation technique would have introduced any bias. Finally, in a study such as ours, loss to follow-up always has the potential to introduce bias. Approximately one third of infants enrolled in our study were lost to follow-up. However, as noted, these mothers and infants were generally similar to the study population included in our analysis, and we were unable to detect biases that would have affected our analysis.Our observation of an association between low-density placental malaria and reduced perinatal MTCT has several possible explanations. First, over 16% of women reported self-treatment  with chloroquine during pregnancy. High-grade chloroquine resistance in this area is widespread, and its use is unlikely to clear placental infections but may reduce parasite densities. Chloroquine is known to have anti-HIV properties and to reduce HIV-1 replication and viral loads in adults (A more likely explanation is that a balance exists in the uterine-placental-fetal environment among malaria-induced antigen stimulation, HIV viral replication, maternal host immune response to both malaria and HIV, and the likelihood of MTCT. Although high viral load has been shown to increase the risk for MTCT, no more than half of exposed infants, even at high maternal viral load, become infected with HIV-1. These data suggest that other systemic or placental factors must be important in preventing HIV-1 transmission. Recent studies suggest that selected cytokines and hormones potentially affect HIV-1 transplacental transmission and that both innate and acquired protection play a role in MTCT (The finding of reduced perinatal MTCT in the presence of low-density, but not high-density, placental malaria does not suggest altering existing recommendations for the use of intermittent preventive antimalarial treatment in pregnant women in malarious areas of Africa (As noted earlier, this study was carried out in Kenya in a changing environment of perinatal HIV and malaria prevention and has been transformed into a program delivering short-course antenatal antiretroviral therapy to HIV-infected women and a system to support providing intermittent preventive antimalarial treatment during pregnancy according to the newly adopted national policy (


The heart is also occasionally involved in acquired serum amyloid A type (AA) amyloidosis and other rare hereditary types. Clinical phenotype varies greatly between different types of amyloidosis, and even the cardiac presentation has a great spectrum. The incidence of amyloidosis is uncertain, but it is thought that the most frequently diagnosed AL amyloidosis has an annual incidence of 6 to 10 cases per million population in the United Kingdom and United States. Amyloidosis due to transthyretin deposition (ATTR) can be wild-type transthyretin amyloid deposits, which predominantly accumulate in the heart and are very common at autopsy in the elderly. Although the associated clinical syndrome known as senile systemic amyloidosis is diagnosed rarely in life,2 there is increasing evidence that this disorder is much underdiagnosed and that with increasing longevity and improved diagnostic methods it may be identified as a substantial public health problem.Systemic amyloidosis is a relatively rare multisystem disease caused by the deposition of misfolded protein in various tissues and organs. It may present to almost any specialty, and diagnosis is frequently delayed.3This review focuses on recent progress in the field: novel diagnostic and surveillance approaches using imaging , biomarkers , new histological typing techniques, and current and future treatments, including approaches directly targeting the amyloid deposits.4 Amyloid deposits also contain minor nonfibrillary constituents, including serum amyloid P component (SAP), apolipoprotein E, connective tissue components , and basement membrane components .8 Amyloid deposits can be massive, and cardiac or other tissues may become substantially replaced. Amyloid fibrils bind Congo red stain, yielding the pathognomonic apple-green birefringence under cross-polarized light microscopy that remains the gold standard for identifying amyloid deposits.Amyloidosis is caused by the extracellular deposition of autologous protein in an abnormal insoluble β-pleated sheet fibrillary conformation—that is, as amyloid fibrils. More than 30 proteins are known to be able to form amyloid fibrils in vivo, which cause disease by progressively damaging the structure and function of affected tissues.1 Key “red flags” to possible systemic amyloidosis include nephrotic syndrome, autonomic neuropathy , soft-tissue infiltrations , bleeding , malnutrition/cachexia and genetic predisposition . Initial presentations may be cardiac, with progressive exercise intolerance and heart failure. Other organ involvement, particularly in AL amyloidosis, may cloud the cardiac presentation . Pulmonary edema is not common early in the disease process,9 but pleural and pericardial effusions and atrial arrhythmias are often seen.11 Syncope is common and a poor prognostic sign.12 It is typically exertional or postprandial as part of restrictive cardiomyopathy, sensitivity to intravascular fluid depletion from loop diuretics combined with autonomic neuropathy, or conduction tissue involvement  or ventricular arrhythmia.15 The latter may rarely cause recurrent syncope. Disproportionate septal amyloid accumulation mimicking hypertrophic cardiomyopathy with dynamic left ventricular (LV) outflow tract obstruction19 is rare but well documented. Myocardial ischemia can result from amyloid deposits within the microvasculature.21 Atrial thrombus is common, particularly in AL amyloidosis, sometimes before atrial fibrillation occurs.22 Intracardiac thrombus can embolize, causing transient ischemic attacks or strokes, and may be an early or even presenting feature.23 Anticoagulation is therefore important in the appropriate clinical situation, but careful consideration must be given to patients with extensive systemic AL amyloidosis who may have an elevated bleeding risk due to factor X deficiency or in some cases with gastrointestinal involvement.24 The Table gives an outline of the clinical phenotypes of the common amyloid subtypes.Cardiac amyloidosis, irrespective of type, presents as a restrictive cardiomyopathy characterized by progressive diastolic and subsequently systolic biventricular dysfunction and arrhythmia.25 Cardiac AL amyloidosis may be rapidly progressive. Low QRS voltages, particularly in the limb leads, are common. Thickening of the LV wall is typically mild to moderate and is rarely >18 mm even in advanced disease. Cardiac AL amyloid deposition is accompanied by marked elevation of the biomarkers BNP and cardiac troponin, even at an early stage. Involvement of the heart is the commonest cause of death in AL amyloidosis and is a major determinant of prognosis; without cardiac involvement, patients with AL amyloidosis have a median survival of around 4 years,26 but the prognosis among affected patients with markedly elevated BNP and cardiac troponin (Mayo stage III disease)27 is on the order of 8 months.AL amyloidosis is caused by deposition of fibrils composed of monoclonal immunoglobulin light chains and is associated with clonal plasma cell or other B-cell dyscrasias. The spectrum and pattern of organ involvement is very wide, but cardiac involvement occurs in half of cases and is sometimes the only presenting feature.Mutations in several genes, such as transthyretin, fibrinogen, apolipoprotein A1, and apolipoprotein A2 can be responsible for hereditary amyloidosis, but by far the most common cause is variant ATTR amyloidosis (variant ATTR) caused by mutations in the transthyretin gene causing neuropathy and, often, cardiac involvement.29 In a large autopsy study that included individuals with cardiac amyloidosis, the TTR Val122Ile allele was present in 3.9% of all African Americans and 23% of African Americans with cardiac amyloidosis. Penetrance of the mutation is not truly known and is associated with a late-onset cardiomyopathy that is indistinguishable from senile cardiac amyloidosis. Although the prevalence of disease caused by this mutation is unknown, it is almost certainly underdiagnosed, because the wall thickening is often incorrectly attributed to hypertensive heart disease. Neuropathy is not generally a feature of this ATTR due to Val122Ile.The TTR gene is synthesized in the liver, and several point mutations are described (see the Table 1), but the most common is the Val122Ile mutation.30 For example, cardiac involvement is rare in variant ATTR associated with Val30Met , but it is almost universal and develops early in individuals with variant ATTR due to Thr60Ala mutation (a mutation common in Ireland).More than 100 genetic variants of TTR are associated with amyloidosis. Most present as the clinical syndrome of progressive peripheral and autonomic neuropathy. Unlike wild-type ATTR or variant ATTR Val122Ile, the features of other variant ATTR include vitreous amyloid deposits or, rarely, deposits in other organs. Cardiac involvement in variant ATTR varies by mutations and can be the presenting or indeed the only clinical feature.31Mutations in apolipoprotein A1 gene can cause systemic amyloidosis, typically causing renal and hepatic involvement—although cardiac involvement is well recognized.34 The prevalence of wild-type TTR deposits leading to the clinical syndrome of wild-type ATTR cardiac amyloidosis remains to be ascertained, but the syndrome is distinct and clearly far rarer. Wild-type ATTR is a predominantly cardiac disease, and the only other significant extracardiac feature is a history of carpal tunnel syndrome, often preceding heart failure by 3 to 5 years.35 Extracardiac involvement is most unusual.Wild-type TTR amyloid deposits are found at autopsy in about 25% of individuals >80 years of age, but their clinical significance has not been clear.9 Wild-type ATTR has a strong male predominance, and the natural history remains poorly understood, but studies suggest a median survival of about 7 years from presentation.33 The true incidence of wild-type ATTR is probably underestimated, and recent developments in cardiac magnetic resonance (CMR), which have greatly improved detection of cardiac amyloid during life, suggest that wild-type ATTR is more common than previously thought: It accounted for 0.5% of all patients seen at the UK amyloidosis center until 2001 but now accounts for 7% of 1100 cases with amyloidosis seen since the end of 2009 (unpublished data). There appears to be an association between wild-type ATTR and history of myocardial infarctions, G/G  exon 24 polymorphism in the alpha2-macroglobulin , and the H2 haplotype of the tau gene36; the association of tau with Alzheimer's disease raises interesting questions as both are amyloid-associated diseases of aging. Although the echocardiographic manifestations of cardiac ATTR may be indistinguishable from advanced AL amyloidosis, patients with the former typically have fewer symptoms and better survival.37Both wild-type ATTR and ATTR due to Val122Ile are diseases of the >60-year age group and are often misdiagnosed as hypertensive heart disease.38 and become ubiquitous with age, being present at autopsy in 80% of people >70 years of age.40 The significance and causality of atrial natriuretic peptide amyloid deposits remain unknown. Amyloid of as yet unknown fibril type is also common in explanted cardiac valves.42 Systemic AA amyloidosis complicating chronic inflammatory diseases, in which the amyloid fibrils are derived from the acute-phase reactant serum amyloid A protein, involves the heart in about 2% of cases with systemic AA amyloidosis. Incidence of AA amyloidosis is generally in decline, likely reflecting better treatment for rheumatological disorders with biological agents.Localized atrial amyloid deposits derived from atrial natriuretic peptide are associated with atrial fibrillation, notably postoperatively,43 The combination of low ECG voltage with concentrically increased wall thickness is highly suspicious for cardiac amyloidosis (see 44 Other findings include first-degree atrioventricular block (21%), nonspecific intraventricular conduction delay (16%), second- or third-degree atrioventricular block (3%), atrial fibrillation/flutter (20%), and ventricular tachycardia (5%).44 Left and right bundle branch block can also occur.18 ECG patterns can provide clues to differentiate between AL and TTR amyloidosis: Left bundle branch block is seen in 40% of patients with wild-type ATTR but is rare in AL (4%), whereas typical low QRS voltages are seen in 40% wild-type ATTR versus 60% AL.45 There has been little recent study of ECG correlation with cardiac biomarkers, treatment toxicity, and mortality. Progressive ECG changes may be useful in assessing silent cardiac progression.46 Changes in ECG abnormalities after treatment in AL amyloidosis remain poorly studied but can occur—more often little improvement is seen. Holter ECG monitoring identifies asymptomatic arrhythmias in >75% of cardiac AL patients (mainly supraventricular tachyarrhythmias and some nonsustained ventricular tachycardia).47Low QRS voltages  with poor R-wave progression in the chest leads (pseudoinfarction pattern) occur in up to 50% of patients with cardiac AL amyloidosis.osis see , but vol50 Typical findings include concentric ventricular thickening with right ventricular involvement, poor biventricular long-axis function with normal/near-normal ejection fraction,52 and valvular thickening (particularly in wild-type or variant ATTR).45 Diastolic dysfunction is the earliest echocardiographic abnormality and may occur before cardiac symptoms develop.54 As with all investigations, echocardiography must be interpreted within the clinical context; a speckled or granular myocardial appearance, although characteristic of amyloid, is an inexact finding, which is dependent on machine gain settings. Biatrial dilatation in presence of biventricular, valvular, and interatrial septal thickening 53 is a useful clue to the diagnosis.All patients with suspected amyloidosis should undergo echocardiography. Findings are characteristic in advanced disease but are harder to elicit earlier on and have prognostic as well as diagnostic significance.56 Strain and strain rate imaging, derived from speckle tracking , but the significance and cause are unclear.69Measurements of BNP, its more stable N-terminal fragment (NT-proBNP), and cardiac troponins are extremely informative in AL amyloidosis, which is the only type in which they have been systematically studied to date. Their value in TTR amyloidosis is yet to be determined. BNP/NT-proBNP is cleared by the kidneys , confounding evaluation of patients with kidney involvement. Elevated NT-proBNP levels in systemic AL amyloidosis are a sensitive marker of cardiac involvement, with a cutoff >152 pmol/L being associated with higher mortality rate (72% vs 7.6% per year).71 but extravascular contrast agents based on chelated gadolinium provide the key information. The appearance ,ance see  of globa76 Late gadolinium enhancement imaging in amyloidosis is inherently challenging because amyloid infiltration within the interstitium of the heart reduces the differences in contrast signal between blood and myocardium such that the two compartments may null together or even be reversed and effusions may cause considerable ghosting artifact, although these both can be a strong clue to the underlying diagnosis ; therapies that suppress production of the respective amyloid fibril precursor protein ; and novel strategies to inhibit amyloid fibril formation or to directly target the amyloid deposits or stabilize the precursor protein . Cardiac transplantation, although rarely feasible, can be very successful in carefully selected patients.93 especially the latter, which can lead to rapid worsening. Careful monitoring is needed to avoid significant drug interactions, for example, β-blockers with thalidomide used in chemotherapy of AL amyloidosis causing bradycardia.94Standard heart-failure therapy may be of limited benefit or even detrimental in cardiac amyloidosis. There is scant evidence for the use (or not) of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or β-blockers. These may be poorly tolerated and may worsen postural hypotension or renal function. Restrictive cardiomyopathy leads to a heart-rate–dependent cardiac output in some cases, and some such patients may find difficulty in tolerating β-blockers. Digitalis and calcium channel blockers may be selectively concentrated in amyloidotic tissue and are relatively contraindicated on grounds of increased toxicity,95Maintenance of adequate filling pressures is vital because of the restrictive physiology, balancing peripheral edema and renal impairment with salt/water restriction and judicious use of diuretics. Patient education and participation, ideally with backup from a heart failure team, are critical to successful management. Contrary to standard heart failure management, maintenance of adequate blood pressure with an α-agonist such as midodrine may permit higher doses of loop diuretics, especially in patients with autonomic neuropathy.96 In the absence of evidence, pacing indications remain within current standard guidelines. High defibrillator thresholds may be encountered, and the benefits of such devices remain uncertain.98 Biventricular pacing appears to play little role but may be the ideal pacing option to avoid decompensation of the stiffened ventricle as a result of induced dyssynchrony from right ventricular pacing.99Pacemakers or implantable cardioverter defibrillators may not prevent sudden cardiac death, because this is thought to often be due to electromechanical dissociation.100 Dexamethasone, although a very useful agent in all patients with AL amyloidosis, including those with cardiac involvement, has to be used with great caution in patients with cardiac amyloidosis because of a high risk of fluid overload in absence of adequate and rapid changes to diuretic therapy. Close coordination between the treating hematology and cardiology teams is critical to steer the patient successfully through the treatment course.101 High-dose melphalan followed by autologous stem-cell transplantation is generally contraindicated in patients with advanced cardiac amyloidosis. Although it has been argued that autologous stem cell transplantation is the best treatment for suitable patients,104 its role in the era of novel agents, discussed below, is less certain.Treatment of amyloidosis is currently based on the concept of reducing the supply of the respective amyloid fibril precursor protein. In AL amyloidosis, therapy is directed toward the clonal plasma cells using either cyclical combination chemotherapy or high-dose therapy with autologous stem cell transplantation. Most chemotherapy regimes in AL amyloidosis comprise dexamethasone combined with an alkylator . Addition of thalidomide, for example, in the risk-adapted cyclophosphamide, thalidomide, and dexamethasone regime used widely in the United Kingdom, improves response rates but probably at cost of greater toxicity.105 and the newer immunomodulatory drugs lenalidomide and pomalidomide. Bortezomib combinations appear to be especially efficient in amyloidosis with high rates of near-complete clonal responses, which appear to translate into early cardiac responses.108 Phase II (bortezomib in combination with cyclophosphamide or doxorubicin) and phase III  trials are underway.The newer treatment options include bortezomib (a proteosome inhibitor)AA amyloidosis is the only other type of amyloidosis in which production of the fibril precursor protein can be effectively suppressed by currently available therapies. Anti-inflammatory therapies, such as anti-tumor necrosis factor agents in rheumatoid arthritis, can substantially suppress serum amyloid A protein production, but very little experience has been obtained regarding cardiac involvement, which is very rare in this particular type of amyloidosis.109 is already in phase I clinical trial. Liver transplantation has been used as a treatment for variant ATTR for 20 years, to remove genetically variant TTR from the plasma. Although this is a successful approach in ATTR Val30Met, it has had disappointing results in patients with other ATTR variants, which often involve the heart. The procedure commonly results in progressive cardiac amyloidosis through ongoing accumulation of wild-type TTR on the existing template of variant TTR amyloid.110 The role of liver transplantation in non-Val30Met–associated hereditary TTR amyloidosis thus remains very uncertain.TTR is produced almost exclusively in the liver, and TTR amyloidosis has lately become a focus for novel drug developments aimed at reducing production of TTR through silencing RNA and antisense oligonucleotide therapies. ALN-TTR01, a systemically delivered silencing RNA therapeutic,112 Studies of diflunisal in ATTR are in progress. Tafamidis is a new compound without anti-inflammatory analgesic properties that has a similar mechanism of action. Tafamidis has just been licensed for neuropathic ATTR, but its role in cardiac amyloidosis remains uncertain, and clinical trial results are eagerly awaited. Higher-affinity “superstabilizers” are also in development.113Amyloid fibril formation involves massive conformational transformation of the respective precursor protein into a completely different form with predominant β-sheet structure. The hypothesis that this conversion might be inhibited by stabilizing the fibril precursor protein through specific binding to a pharmaceutical has lately been explored in TTR amyloidosis. A key step in TTR amyloid fibril formation is the dissociation of the normal TTR tetramer into monomeric species that can autoaggregate in a misfolded form. In vitro studies identified that diflunisal, a now little used nonsteroidal anti-inflammatory analgesic, is bound by TTR in plasma, and that this enhances the stability of the normal soluble structure of the protein.114 and further studies are currently being conducted.Eprodisate is a negatively charged, sulfonated molecule with similarities to heparan sulfate, which is being pursued as a treatment for AA amyloidosis. Eprodisate is thought to inhibit the pro-amyloidogenic interactions of glycosaminoglycans with SAA during fibril formation in AA amyloidosis. A phase III trial showed benefits in terms of progression of AA-amyloid–associated renal dysfunction,Amyloid deposits are remarkably stable, but the body evidently has some limited capacity to remove them. After treatment that prevents the production of new amyloid, for example, successful chemotherapy in AL type amyloid deposits are gradually mobilized in the majority of patients, though at different rates in different organs and different individuals. Unfortunately clearance of amyloid is especially slow in the heart, and echocardiographic evidence of improvement is rare, even over several years. The concept of passive immunotherapy to enhance clearance of amyloid has proved successful in experimental models and is variously now in clinical development.3 The unprecedented capacity of this novel combined therapy to eliminate amyloid deposits in mice is encouraging and should be applicable to all forms of human systemic and local amyloidosis.The challenge of developing a therapeutic monoclonal antibody that is reactive with all types of amyloid has lately been addressed by targeting SAP because this is a universal constituent of all amyloid deposits and an excellent immunogen. Anti-SAP antibody treatment is clinically feasible because circulating human SAP can be depleted in patients by the bis-d-proline compound CPHPC, thereby enabling injected anti-SAP antibodies to reach residual SAP in the amyloid deposits.115 Cardiac transplantation followed by successful peripheral blood autologous stem cell transplantation was associated with better survival in selected patients, as reported116 from most major amyloidosis units in the United Kingdom,115 France,117 Germany,118 and the United States.119 A suitable patient with AL amyloidosis is likely to be young (<60 years); to have isolated Mayo stage III cardiac amyloidosis, NYHA III or IV symptoms after adequate diuretics, good renal/liver function, no significant autonomic neuropathy, and low-level bone marrow plasmacytosis; and to be eligible for autologous stem cell transplantation after the heart transplantation. Even in such patients, outcomes are probably inferior to other indications.120 For variant ATTR, combined cardiac and liver transplantation has been performed in a few dozen cases throughout the world.122 Although most patients with wild-type ATTR are too elderly for cardiac transplantation, the absence of extracardiac involvement renders younger patients with wild-type ATTR excellent candidates. The 2 patients with wild-type ATTR who presented to our center before age 60 survived 10 and 20 years, respectively, after cardiac transplantation.Cardiac transplantation has played a disappointingly small role, because of the multisystem nature of amyloidosis, advanced age, treatment-related complications, and rapid disease progression. Further, patients with AL amyloidosis must be deemed likely to be sufficiently fit to undergo chemotherapy afterward, to address the underlying bone marrow disorder. As a result, only a few dozen cardiac transplantations have ever been performed for amyloidosis. However, the long-term outcome can be good in highly selected patients with AL amyloidosis.Cardiac amyloidosis remains challenging to diagnose and to treat. Key “red flags” that should raise suspicion include clinical features indicating multisystem disease and concentric LV thickening on echocardiography in the absence of increased voltage on ECG; the pattern of gadolinium enhancement on CMR appears to be very characteristic. Confirmation of amyloid type is now possible in most cases through a combination of immunohistochemistry, DNA analysis, and proteomics. Unlike other causes of heart failure, supportive treatment is mainly focused on diuretics therapy. Although developments in chemotherapy have greatly improved the outlook in AL amyloidosis, the prognosis of patients with advanced cardiac involvement remains very poor. Senile cardiac amyloidosis is probably greatly underdiagnosed, but CMR and DPD scintigraphy show great potential to address this unmet need in the aging population. A variety of novel specific therapies are on the near horizon, with potential to both inhibit new amyloid formation and enhance clearance of existing deposits.


The DNA damage response (DDR) has emerged as a critical tumour suppressor pathway responding to cellular DNA replicative stress downstream of aberrant oncogene over-expression. Recent studies have now implicated the DDR as a sensor of oncogenic virus infection. In this review, we discuss the mechanisms by which tumour viruses activate and also suppress the host DDR. The mechanism of tumour virus induction of the DDR is intrinsically linked to the need for these viruses to promote an S-phase environment to replicate their nucleic acid during infection. However, inappropriate expression of viral oncoproteins can also activate the DDR through various mechanisms including replicative stress, direct interaction with DDR components and induction of reactive oxygen species. Given the growth-suppressive consequences of activating the DDR, tumour viruses have also evolved mechanisms to attenuate these pathways. Aberrant expression of viral oncoproteins may therefore promote tumourigenesis through increased somatic mutation and aneuploidy due to DDR inactivation. This review will focus on the interplay between oncogenic viruses and the DDR with respect to cellular checkpoint control and transformation. Innate tumour suppression in response to oncogenic stress includes the well-characterised ARF-mediated activation and stabilisation of p53 , which causes acute and chronic liver diseases, including cirrhosis and hepatocellular carcinoma, promotes cellular proliferation and the DDR through the pleiotropic oncoprotein HBx. Heterologous expression of HBx increases cytosolic Ca kinases  and, ultBeyond the growth suppressive functions of the DDR, DNA repair and activation of checkpoints may be beneficial for the replication of tumour viral genomes. Oncogenic viruses have therefore developed mechanisms to activate specific components of the DDR pathway, while strictly preventing downstream induction of apoptosis. Recent work indicates that SV40 large T antigen can serve as both a substrate for the ATM kinase as well as its direct upstream activator through binding the Nbs1 component of the ATM-activating Mre11/Rad50/Nbs1 complex  do they replicate genomes lytically to produce progeny virions. In order to ensure an environment that allows latent viral episome replication, viral oncoproteins promote S phase and cell proliferation. Similar to small DNA tumour viruses, these activities can lead to replicative stress and DDR activation. However, it is likely that with more complex genomes, the large DNA tumour viruses are able to attenuate the amount of replicative stress generated to maintain a successful latent infection. Such is the case for EBV, where an initial DDR-activating burst of proliferation is driven by the viral proteins EBNA2/EBNA-LP. Subsequently, expression of the EBNA3C protein attenuates EBNA2 transcriptional activity and DDR activation enabling long-term latency establishment (γ-herpesviruses (It is also worth noting that during lytic viral DNA replication, the nuclear sites of viral DNA synthesis often recruit DDR factors and also activate the DDR. These factors can either be beneficial for replication as is the case for ATM signalling in sviruses  or detriIn summary, the DDR can be activated directly by aberrant expression of oncoproteins, cellular or viral, or as a consequence of cellular proliferation-induced replicative stress. DNA tumour virus-driven cellular transformation occurs as a by-product of the virus promoting the cell cycle in order to establish an appropriate environment with the requisite DNA replication machinery and repair factors necessary for viral DNA replication. Similarly, viruses such as HTLV-1 must activate the infected T-cell in order to promote a favourable environment for proviral DNA integration. However, in the inadvertent setting such as following aberrant integration of viral genomes where loss of normal viral replication function occurs or other changes lead to increased viral oncoprotein expression, a constitutively activated DDR is triggered. DDR signalling typically limits viral oncogenesis, but also provides selective pressure for mutations in DDR signalling components that promote tumourigenesis. The delicate balance between virus replication, latency, and the extent of activation of the DDR ultimately dictates whether an infected cell will give rise to a productive cycle generating progeny virions or a tumour.