Neuromodulation of subcortical areas of the brain as therapy to reduce Parkinsonian motor symptoms was developed in the mid-twentieth century and went through many technical and scientific advances that established specific targets and stimulation parameters. Deep Brain Stimulation (DBS) was approved by the FDA in 2002 as neuromodulation therapy for advanced Parkinson's disease, prompting several randomized controlled trials that confirmed its safety and effectiveness. The implantation of tens of thousands of patients in North America and Europe ignited research into its potential role in early disease stages and the therapeutic benefit of DBS compared to best medical therapy. In 2013 the EARLY-STIM trial provided Class I evidence for the use of DBS earlier in Parkinson's disease. This finding led to the most recent FDA approval in patients with at least 4 years of disease duration and 4 months of motor complications as an adjunct therapy for patients not adequately controlled with medications. This following review highlights the historical development and advances made overtime in DBS implantation, the current application, and the challenges that come with it. Idiopathic Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder in the western world. Dopaminergic neuronal loss begins as early as 10 years before motor symptoms appear. Diagnosis is still clinical and relies on the United Kingdom Brain Bank Criteria , 3. A muBefore the discovery of dopaminergic agents, ablative surgical intervention was the main treatment for the motor symptoms of PD. The origins of the surgical interventions for movement disorders date back to the early twentieth century when the basal ganglia was considered a potential target for surgical intervention. Dr. E. Jefferson Browder at the State University of New York described improvement of Parkinsonian symptoms with caudate nucleus extirpation; and almost two decades later in 1947 neuroscientist Ernest A. Speigel and neurosurgeon Henry T. Wycis at Temple University developed the first stereotaxic frame for humans. In parallel, the Neurophysiologist Jose Delgado at Yale University performed several experiments of deep electrical stimulation in animals and humans for behavioral control.In 1953 Dr. Cooper made an accidental ligation of the anterior choroidal artery that resulted in a reduction of the contralateral tremor and rigidity in a PD patient . He thenThe next decade was notable for an expansion of ablative surgery  as a refThe first description of chronic thalamic stimulation was made in 1965 by Carl Wilhelm Sem-Jacobsen, a Norwegian neurophysiologist and psychiatrist. However, the introduction of levodopa in 1967 by Cotzias et al.  temporarThe idea of using chronic subcortical stimulation as a permanent therapy was developed in the 1970s by Dr. Natalia Petrovna Bechtereva at the Institute of Experimental Medicine and the Academy of Medical Sciences in Leningrad. Dr. Petrovna implanted electrodes into the ventrolateral and centromedian thalamic nuclei and administered intermittent high frequency pulses over several sessions. Unfortunately, since most of her articles were written in Russian and not further translated, her work was not widely disseminated.The DBS golden era for PD was introduced to neurologists and neuroscientists by work from Dr. Benabid and his colleagues in 1987 at the Grenoble University. Their original paper highlighted the use of the traditional approach of VIM thalamotomy combined with chronic stimulation of the contralateral VIM, resulting in similar suppression of tremor in both affected sides. Afterwards, high frequency stimulation was used on 26 PD patients demonstrating improvement in tremor and rigidity, while dopaminergic medication dosage was reduced by 30% in 10 of these patients . The samIn 1997, the FDA approved for the first time the use of DBS as therapy in movement disorders, establishing the practice of VIM-DBS to treat essential tremor and tremor associated with Parkinson's disease  DBS in addition to best medical treatment (BMT) is more effective than BMT alone and (2) an earlier intervention could preserve functional capacity. Randomized controlled trials (RCT) have shown that DBS plus BMT can be superior to BMT alone, not only for improving motor function during the “off” state measured by UPDRS-III , but also by increasing quality of life (PDQ-39 self-reporting survey), maintaining activities of daily living (ADL), decreasing levodopa requirements, and expanding time spent in the “on” state without troublesome dyskinesia. Given the robust response to DBS in PD and the quest to maintain quality of life, multiple studies have addressed the issue of functional capacity and symptoms reduction with the long-term use of DBS. Nonrandomized studies have shown sustained reduction of motor symptoms and levodopa induced dyskinesia after a five-year follow-up , motor sp < 0.003); finally the DBS + BMT group significantly improved in the motor score (UPDRS-III) compared to the BMT (p = 0.02). Currently the group is preparing to launch a phase III clinical trial on early stage PD STN-DBS.Thereafter, studies by Schuepbach et al.  and CharIn 2012, a German-French group published a paper theorizing three phases of PD progression . The firThe concept of PD phases prompted the initial hypothesis that the use of DBS as an adjunctive therapy in the early stage second-phase disease could maintain quality of life and social adjustment in PD patients, leading to the EARLY-STIM trial , an earlThese two studies are the backbone of earlier intervention in PD; furthermore there were two Japanese prospective publications that reported significant improvement in ADLs and UPDRS-III with early STN-DBS implantation after 3- and 6-month follow-up , 51.Moreover a base-case analysis showed that the incremental cost-utility ratio for STN-DBS versus BMT was 22.700 euros per quality adjusted life year gained, showing that STN-DBS at earlier stages of the disease is cost-effective in patients below the age of 61 . LikewisThe above findings led to the recent FDA approval of DBS in PD levodopa-responsive patients with at least 4 years of disease duration and 4 months of motor complications not adequately controlled with medications .The implementation of this new criterion of early intervention based on the EARLY-STIM criteria requires a complete evaluation of the limitations of this study and has been the subject of extensive ethical discussion , 57. DesThe lack of a double-blinded design with sham surgery raised the concern for placebo effect in this trial. Some authors state that the placebo effect in PD trials can be as high as 39% . HoweverThe rate of progression in PD is variable –63 but aThe motor and nonmotor benefit obtained in the earlier intervention studies is at least as good as or even better than what RCTs have shown in advanced Parkinson's disease. Earlier DBS extends the possibility of maintaining functional capacity and improving the patient's quality of life earlier in the disease course.Within the movement disorders field, the concept of earlier DBS intervention has been a matter of debate among neurologists and there have been multiple challenges to implement it in the clinical scenario.For patients to be considered for early DBS implantation, they require a diagnosis of at least 4 years of disease duration and after 4 months of motor complications, which are not adequately controlled with medication. This 4-year time window has been established to avoid DBS implantation in patients with Parkinson's plus syndromes. This is supported by the literature which shows that most Parkinson's plus syndromes receive correct diagnoses within 4-5 years . In thisPreoperative indicators for good outcomes in DBS for PD include younger age, short disease duration, robust levodopa-response, few axial motor symptoms, absence of dementia, and stable psychiatric conditions . The EARPatients who will most likely benefit from early DBS intervention according to the EARLY-STIM trial subgroup analysis  are patiThe benefit to risk ratio is an important consideration; the use of earlier DBS should be considered in specific patients if the benefits of the surgical therapy are weighed against the procedure risks and the lifelong need for specialized care . DBS comTo the best of our knowledge there is no data available regarding a difference in the incidence of these adverse events with an earlier intervention. However, a recent report of the Implantable Systems Performance Registry (ISPR), a prospective, long-term multicenter registry supported by Medtronic® compared adverse events in the overall DBS cohort versus early PD-DBS patients (<7.5 years disease duration) showing no significant differences of the adverse event profile between the Earlier PD Subset and the Overall Cohort . Adversep = 0.091) ) ) .Several animal models have raised the possibility of DBS as a neuroprotective therapy. Multiple studies of STN-DBS on 6-OHDA lesioned rodents showed that rats with DBS had less dopaminergic cell loss compared with controls –85. AnotDeep Brain Stimulation for Parkinson's disease was developed based on findings from ablative surgical procedures. Research into its use decreased with the advent of levodopa but resumed in the early 1990s due to frequent motor complications and symptoms refractory to dopaminergic therapy. In 2002, DBS was approved for late stage PD with motor complications. Even more recently in 2016 Class I evidence led to the approval for earlier intervention in patients who were diagnosed for at least 4 years and exhibited at least 4 months of motor complications. Early interventions require the assessment and follow-up of an interdisciplinary and highly experienced team. Due to the recent approval of earlier intervention, we are missing knowledge regarding the patient progression and the long-term outcomes of the early DBS patients. Nonetheless, extensive education of the healthcare community, especially neurologists, is crucial in order to provide the intervention for appropriately selected candidates. Earlier DBS intervention offers the opportunity to impact PD patients' quality of life and functional ability, providing potential significant symptomatic relief over a longer period of time.


The ultimate goals for stem cell researchers are uncovering the fundamental mechanisms of cellular biology as well as developing treatments for disease and/or injury. The central nervous system (CNS) presents an unparalleled challenge for these studies due to the diversity of cell types and their interrelated functions in health and disease. Furthermore, the endpoints for determining phenotypic maturation are complicated by the fact that cells, especially neurons, express a plethora of receptors and ion channels that control excitability and plasticity which vary greatly between CNS regions. For this reason, extensive effort has been placed on developing methods to differentiate appropriate populations of cells that reside within the CNS . These studies typically employ phenotypic validation by the use of expression analysis for various protein markers of regionalized populations, with a burgeoning effort to verify functional outcomes. Much of this work has been informed by basic developmental studies that have identified cell-intrinsic and cell-extrinsic signaling mechanisms, as well as transcriptional programs involved with cell fate specification.While early work focused on the use of mesenchymal stem cells, embryonic carcinoma cells, and fetal stem cells, more recent efforts have focused on the areas of human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs). These sources typically require slightly different methods to direct differentiation to various CNS fates, although many mechanisms appear to converge on common signaling pathways. Many recent studies have even successfully uncovered cell-type specific phenotypes that are appropriate for various human diseases. However, despite these advances, limitations still hamper the application of human stem cells for CNS development/disease studies. First, most differentiation protocols lead to a heterogeneity of cells in terms of both their “regional” markers and their maturational states. Furthermore, the number and diversity of available fate-specific biomarkers remain insufficient to unambiguously identify regional and transmitter phenotypes.In this special issue, we highlight both the advancements and challenges of directed differentiation of various neuronal and glial cells from pluripotent stem cells. We hope this collection of works will provide readers with a resource to understand directed differentiation, functional maturation, and transplantation-induced changes to host environments. in vitro and in vivo development and the utility of hESCs to model human-specific signaling processes. The article concludes with a series of brief descriptions about various developmental and neurodegenerative diseases and how iPSCs have been used to model their underlying molecular and cellular pathologies.The article by P. Prajumwongs et al. reviews the current state of knowledge regarding neural induction of human pluripotent stem cells, detailing the signaling pathways and timing of critical events such as neuroepithelial differentiation. Emphasis is placed on the comparison between in vivo principles provided the basis for in vitro neural induction strategies of human pluripotent stem cells (hPSCs). The article highlights the basic stages of neural development including neural induction, neurulation, and neural patterning. Here they focus on signaling pathways, morphogenes, and patterning factors described to be crucial for the development of distinct brain regions. The authors then discuss how knowledge from in vivo brain development has been translated by many groups to direct the differentiation of hPSCs to clinically relevant region-specific neurons in vitro. Finally, they give an outlook of how human brain development data can be utilized for improving directed differentiation protocols and validating the thereof derived region-specific subpopulations of human neurons.The review article from A. Zirra et al. gives a detailed overview of the development of the neural tube and how these in vitro models for these types of studies.The article by F. Cavaliere et al. reviews the use of organotypic hippocampal slice cultures as a model for understanding neurogenesis under normal and pathological conditions. They first present a historical summary of the development of slice cultures from neonatal, and more recently adult animals, for the study of neurogenesis from both SVZ and DGZ. The article also describes results from pathological studies of slice cultures in the context of ischemia, Parkinson's, and Alzhemier's disease, as well as regeneration of neurons in the spinal cord. The authors suggest that the maintenance of the 3D architecture and cellular composition of these cultures make them unique among in vitro and in vivo models of ischemic stroke. Polyamines are low molecular weight compounds secreted in high concentrations from the brain and are important indicators of metabolic function, especially in response to injury or disease. The authors found that middle cerebral artery occlusion (MCAo) in vivo and oxygen-glucose deprivation (OGD) of a neural cell line in vitro significantly altered a plurality of polyamine levels. Importantly, the authors found that disruptions of polyamine levels by MCAo- and OGD-induced ischemic conditions could be restored to near-normal levels after introduction of human bone marrow-derived mesenchymal stem cells.The primary research article from T. H. Shin et al. tested the effects of mesenchymal stem cells on polyamine levels in both in vitro findings to in vivo data from rodent models. The author then discusses recent results modeling various neurological disorders using iPSC-derived neurons and iNs. He concludes by critically reflecting on the use of these two cell types for developmental and disease studies and provides suggestions on how to optimally determine and report neuronal function.Finally, the review article from J. P. Weick highlights the efforts by many groups to understand the functional phenotypes of pluripotent stem cell-derived neurons as well as directly converted/induced neurons (iNs). This article focuses on the assessment of developmental maturation of forebrain neurons via analysis of forebrain glutamatergic and GABAergic currents, comparing theseTogether, the articles in this special issue highlight recent advances in our understanding of the directed differentiation and functional properties of stem cells and describe several new approaches to model and develop novel therapies for neurological disease and injury.Jason P. WeickJason P. WeickJason S. MeyerJason S. MeyerJulia LadewigJulia LadewigWeixiang GuoWeixiang GuoYan LiuYan Liu


Life presumably arose in the primeval oceans  and we have combined our efforts to achieve a wider, more detailed understanding of salt tolerance in plants mediated by ion transport.At the time of compiling this Research Topic many aspects of ion transport under salinity stress are not yet well understood. The structure-function relationships of ion channels and transporters are slowly being deciphered, but essentially remain The papers in the Research Topic address the aspects of ion transport under salinity stress mentioned above: they analyse precise details of the molecular structure of ion transporters linked to the selectivity of ion transport and compare ion fluxes in different organisms. The results suggest a diversity of adaptations to salt stress and ion transport in yeast and other fungi, in algae, in agriculturally important plants and crops and further in halophytes from mangroves to recretohalophytes, which excrete salt via specialized salt glands. The topic contributions explore numerous aspects of salinity tolerance, including osmotic adjustment, oxidative stress, changes in photosynthesis and morphology of cells. The wide and comprehensive picture of the processes related to salinity tolerance is united under the heading of ion transport at the time of saline stress. The following short introduction, describing the contributing papers, provides a brief guide to the topics that have been addressed.+ fluxes and their regulation at the level of the whole plant to fluxes at the cellular and vacuolar membranes with specific ion channels and transporters. Maathuis et al. provide a solid description of the morphological structures and the molecular mechanisms important for Na+ transport. Volkov applies a quantitative approach to ion transport, initially in yeast and other small cells and then to entire plants . The current advanced methods allow us to estimate the exact number of the individual ion channels and transporters in a single yeast cell. Further, we can determine their uneven distribution in specific lipid domains with a size around hundreds of nanometers. The ion fluxes via cellular membranes are also influenced by the cell walls and by the hydrostatic pressure inside cells, adding more complexity (Volkov). A similar quantitative approach is useful for the whole plants, although much less is known about the larger organisms. In a second review, Volkov applies a systems biology approach, describing the progress in genetic and protein engineering to manipulate ion fluxes in plants (Volkov).The reviews in this topic lay out a logical pathway for understanding the ion transport and physiology of plants affected by salinity: from characterization of NaBeilby provides a comprehensive review of salinity tolerance in giant-celled algae of the Characeae, introducing this classical system and its response to salinity, measurement of ion fluxes and study of fast electric action potentials. The narrative compares the salt-tolerant Chara longifolia and Lamprothamnium species with the salt-sensitive Chara australis and discusses several electrically active states of the plasma membrane, when different sets of ion transporters determine the membrane electrophysiology. The review ponders both hyper and hypo-osmotic regulation in these unusually large cells (Beilby).The Characeae are one of the three charophyte branches of the phylogenetic tree that gave rise to land plants. Duarte et al. focus on morphological features of halophytes, particularly photosynthesis, accumulation of osmotically active substances and antioxidants protecting the plant exposed to high salinity. Yuan et al. and Dassanayake and Larkin present reviews that discuss novel advances in research on the ion transport via salt glands of excreting salt recretohalophytes. The former review focuses on the morphological structure of salt glands, methods of collection of salt gland liquid, mechanisms of ion transport including the specific ion channels and transporters involved . The latter review discusses morphology and evolution of salt glands, suggesting that the salt glands emerged independently at least 12 times in recretohalophytes. Further narrative briefly describes the present genetic resources available for genetic engineering of salt glands and ponders the strategies and complications on the way (Dassanayake and Larkin).Moving to more saline environments in a brief perspective paper on halophytes, Alemán et al.) and cation HKT  transporters. The plant transporter HAK5 is important for K+ uptake at low K+ concentrations in the soil. The mutation F130S in HAK5 from A. thaliana substituted phenylalanine to serine in a presumed pore for K+ binding of the transporter. The mutated HAK5 increased the survival of yeast cells of strain 9.3 under salinity. These yeast cells lacked their own K+ and Na+ transport systems, but expressed the mutated HAK5 from Arabidopsis . The kinetic transport properties of mutated HAK5 were also characterized in the yeast 9.3 cells. The F130S mutation surprisingly increased affinity for Rb+ (Rb+ mimicked K+ uptake) over 100 times, while reducing the inhibitory constants Ki of the Rb+ transport by Na+ or by Cs+ over 10 times. Several other HAK5 mutants also demonstrated altered kinetic properties of transport . The HKT cation transporters play a role in Na+ and K+ transport to xylem and in uptake of the ions by roots. A single amino acid change from serine to glycine (S70G) in the first pore domain of tomato HKT1;2  transporter altered the ion selectivity of transport. The mutated form of SlHKT1;2 transported K+ and Na+, instead of only Na+, but at lower rates. The selectivity of ion transport was characterized when SlHKT1;2 was expressed in oocytes of African clawed toad Xenopus laevis. The ion currents were measured by the electrophysiological method of two-electrode voltage clamp. The heterologous expression of tomato HKT1;2 in the mutant Arabidopsis athkt1;1 plants without native HKT transporter restored the K+ accumulation in the shoots. Thus the combined methods of molecular biology and electrophysiology characterized the functioning of SlHKT1;2 transporter in tomato .Research papers within the Topic feature two reports analysing macroscopic results of single amino acid substitutions within specific regions of potassium HAK5 . In barley under salinity treatment the expression of slow anion channel genes, HvSLAH1 and HvSLAC1, was up-regulated in the leaves of salt-tolerant cultivars and positively correlated with the grain yield under field conditions. Compared to sensitive varieties, the aperture of stomatal cells under salinity remained larger in the salt tolerant barley plants, although significantly decreased in comparison to control conditions . The trees of the mangrove Kandelia candel grow at the sea coast with roots in seawater and the expression of its superoxide dismutase gene KcSOD in tobacco plants increased their salt tolerance . Further, the Na+ fluxes in roots, the accumulation of ions, the activity and intracellular location of superoxide dismutase, the kinetics of reactive oxygen species and the parameters of photosynthesis or growth were characterized for the mangrove, the transgenic tobacco and the Arabidopsis plants .Two more experimental papers link expression of the individual genes with salinity tolerance and ion transport . The responses to salinity of salt-tolerant and salt-sensitive varieties of habanero pepper plants (Capsicum chinense) also differed greatly . The salt tolerant variety accumulated fifty times more osmolyte proline in roots, retained more K+ in the roots under salinity, sequestered Na+ in the cytoplasm in vacuole-like structures and not in the apoplast, compared to the salt sensitive pepper plants . The halophyte Atriplex canescens  increased the net photosynthetic rate, accumulated more proline and betaine, kept relatively stable K+ concentrations in its tissues and had higher Na+ in the salt glands under salinity than under non-saline conditions .Three experimental papers report important physiological aspects of ion transport and salinity tolerance for different plant species. The sodium accumulation in vacuoles and in the cytoplasm of distinct root zones was explored in detail for six salt-tolerant and sensitive wheat cultivars by using a sodium-sensitive fluorescent dye. Unexpectedly, the cells of root meristem in the salt-tolerant cultivars had a higher NaBacillus subtilis improved salinity tolerance of the white clover by decreasing the osmotic potential of the leaves and preserving better K+/Na+ ratio under salinity . The examination of potato plantlets, using electron microscopy, revealed unusual features of the ultrastructure of leaf mesophyll cells and their chloroplasts, which were recorded under a gradient of salinity treatments . The associated biochemical tests and X-ray microanalysis of plant tissues added more details to understanding the survival of these plantlets under saline conditions . The salt avoidance bending of growing roots, known as halotropism, was documented for Arabidopsis plants . Halotropism was influenced by the illumination stress for these roots. The illumination stress increased their growth rate, stimulated oxidative stress and influenced F-actin-dependent processes. The UVR8 light receptor relocated to nuclei in apical root cells after UV-B treatment, while the halotropism was inhibited by light .Finally, three other experimental papers elucidate several novel areas, usually not associated with salt stress. Selected strain BG03 of the soil bacterium en route to deciphering salinity tolerance, creation of salt-tolerant crops, and of growing crops in the fields irrigated with salt water.We believe that our simultaneous efforts will inspire further research and wider understanding of the ion transport in general and at the time of salinity stress. We also hope that the Research Topic lays one more foundation stone in understanding the biophysics of ion transport via ion channels and transporters All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Hypertension is one of the most frequently diagnosed chronic conditions in Germany. Targeted prevention strategies and allocation of general practitioners where they are needed most are necessary to prevent severe complications arising from high blood pressure. However, data on chronic diseases in Germany are mostly available through survey data, which do not only underestimate the actual prevalence but are also only available on coarse spatial scales. The discussion of including area deprivation for planning of healthcare is still relatively young in Germany, although previous studies have shown that area deprivation is associated with adverse health outcomes, irrespective of individual characteristics. The aim of this study is therefore to analyze the spatial distribution of hypertension at very fine geographic scales and to assess location-specific associations between hypertension, socio-demographic population characteristics and area deprivation based on health insurance claims of the AOK Nordost.To visualize the spatial distribution of hypertension prevalence at very fine geographic scales, we used the conditional autoregressive Besag–York–Mollié (BYM) model. Geographically weighted regression modelling (GWR) was applied to analyze the location-specific association of hypertension to area deprivation and further socio-demographic population characteristics.The sex- and age-adjusted prevalence of hypertension was 33.1% in 2012 and varied widely across northeastern Germany. The main risk factors for hypertension were proportions of insurants aged 45–64, 65 and older, area deprivation and proportion of persons commuting to work outside their residential municipality. The GWR model revealed important regional variations in the strength of the examined associations.Area deprivation has only a significant and therefore direct influence in large parts of Mecklenburg-West Pomerania. However, the spatially varying strength of the association between demographic variables and hypertension indicates that there also exists an indirect effect of area deprivation on the prevalence of hypertension. It can therefore be expected that persons ageing in deprived areas will be at greater risk of hypertension, irrespective of their individual characteristics. The future planning and allocation of primary healthcare in northeastern Germany would therefore greatly benefit from considering the effect of area deprivation. Hypertension belongs to one of the most frequent diagnosed chronic conditions in primary healthcare in Germany and within members of the Allgemeine Ortskrankenkasse . Current prevalence estimates range between 22% - 51%, depending on the respective study design, study area and definition of hypertension . The potAlthough lifestyle-related factors on an individual level play a substantial role for the development of chronic conditions, several studies additionally point out that area deprivation is – independent of individual factors – an important determinant for chronic conditions –15. ThesIn the German health care system, all citizens are required to be enrolled in the statutory health insurance, unless their salary exceeds a certain threshold. In this case, citizens can choose private health insurance or remain voluntarily enrolled in the statutory health insurance . ApproxiIn the case of primary care, the planning and provision of general practitioners is organized by the association of statutory health insurance physicians in accordance with the respective statutory health insurance providers . As a coHowever, analyzing the impact of socio-demographic and -economic characteristics on the prevalence of chronic diseases is challenging based on health insurance claims. Large differences exist in the socio-demographic composition of members of the various health insurance providers with the AOK having the largest proportion of members with a lower socio-economic status and therefore a higher prevalence of chronic diseases . DetaileThe goal of our study is therefore to (i) analyze the spatial distribution of hypertension based on health insurance claims of northeastern Germany’s largest health insurance provider – the AOK Nordost, (ii) identify possible associations with area deprivation and socio-demographic population characteristics and (iii) analyze how these associations vary over space.For this study, we used health insurance claims from the AOK Nordost for 2012, which covers roughly a quarter of the population in the federal states of Berlin, Brandenburg and Mecklenburg-West Pomerania. Of the 1.79 million insurants, 810 thousand (45.2%) were diagnosed with hypertension. We defined hypertension as a confirmed diagnosis with the ICD-codes (10th revision) I10 – I15 [As long as an insurant is treated for hypertension, this diagnosis remains in the insurants personal medical file. The unique insurant number was used to ensure that each insurant is included only once in the analysis.The data were aggregated to the level of municipalities and urban districts for the cartographic visualization of the sex- and age-standardized rates. Since large urban areas such as Germany’s capital Berlin count only as one municipality, we combined the municipalities with the urban districts of Rostock and the postal codes of Berlin, Potsdam, Brandenburg an der Havel, Schwerin, Frankfurt (Oder) and Cottbus to visualize intra-urban differences. Since the AOK Nordost does not cover the total population, the spatial scale of municipalities for the spatial regression analysis was considered too small. We therefore further aggregated the health insurance claims to the level of association of municipalities, which is the next largest administrative unit after municipalities. The underlying map sources for the municipalities and the association of municipalities were downloaded from the federal agency of cartography and geodesy .As the aim of our analysis was to evaluate, whether hypertension is associated with area deprivation, we used the “German Index of Multiple Deprivation” (GIMD), which was obtained from the Institute of Health Economics and Health Care Management at the Helmholtz Zentrum München, German Research Center for Environmental Health Fig. . The indTo account for the increase of hypertension in middle-aged and elderly persons, we used the proportion of insurants aged 45–64 and older than 65 as demographic variables. As several studies found an association between marital status and chronic diseases –35, we iThe proportion of persons commuting to work outside their residential municipality for the year 2012 was additionally included as possible explanatory variable as they comprise an important risk group for hypertension. Long commuting times to work – and thus lower levels of physicial activity but higher levels of stress - have been previously been identified as an important modifiable risk factor for a wide range of adverse health outcomes, including hypertension –38.This We standardized directly for sex and age, using the World Health Organization (WHO) standard population from 1976 . Our goap-value below the 0.001 threshold.As one of our goals was to detect areas with significantly elevated prevalence rates of hypertension, we applied the spatial scan statistic. Local cluster tests are a frequently used tool in public health to prioritize areas for future preventive interventions –45. In tp < 0.05) and are free from multicollinearity as measured by the variance inflation factor (VIF < 7.5) [Before creating a geographically weighted regression model, we first identified all significant explanatory variables through exploratory regression. As the ordinary least squares (OLS) regression model is a linear model, it requires a normal distribution of the dependent variable . We therF < 7.5) . We thenOur goal was not only to estimate the strength of predictors for hypertension, but also to evaluate how the strength of association between the identified explanatory variables and hypertension varies over the study area. In northeastern Germany, the socio-demographic and -economic composition of the population varies widely across the association of municipalities. Based on the results of a previous study on type 2 Diabetes Mellitus in this area , we hypoThe data input for the GWR model consisted of the same dependent and explanatory variables as in the OLS model and the centroid coordinates of the association of municipalities. We used the R package “GWmodel” for our calculations of a GWR model . In “GWmThe data and results used in this study were anonymized and do not contain any personal information. The use of anonymized data for research purposes does not require a vote by an ethics committee or an institutional research board.The overall sex- and age-adjusted hypertension prevalence was 33.1%. The lowest prevalence rates were observed in the urban areas of Berlin, Schwerin, Neubrandenburg and Cottbus Fig. . The higWe identified four variables as significant predictors of hypertension: (i) Area deprivation, (ii) proportions of insurants aged 45–64, (iii) proportion of insurants aged 65 and older and (iv), proportion of commuters. These four variables explained 67% of the spatial variation of hypertension Table . MulticoI = 0.053; p > 0.05). The GWR model outperformed the global OLS model (AICc = −1320) and explained 71% of the spatial variation of hypertension prevalence (adjusted R2 = 0.71). The associations between the explanatory variables and hypertension display clear spatial variability  of the leading institution of the German government in the field of biomedicine, the Robert Koch-Institute (RKI)  or used Third, the proportion of persons commuting to work outside their residential municipality is taken from the BBSR and is therefore only available for the whole population of the respective administrative unit. Since the AOK Nordost accounts for approximately a quarter of the population of northeastern Germany, It is currently unknown whether the proportion of commuters within members of the AOK Nordost differs from the proportion among the total population. Given the socio-economic and geographic characteristics of northeastern Germany, it can however be assumed that the proportion of commuters among the AOK Nordost insurants will not differ substantially from the general population.Fourth, by using the German Index of Multiple Deprivation, we obscured fine socio-economic population characteristics such as employment rate or type of occupation in specific age-groups, which might be potentially of more use to identify the main population at risk for hypertension. For preventive interventions where more detailed socio-economic characteristics are of interest, the analysis should be repeated with health insurance-specific socio-economic variables such as type of insurance, age-specific unemployment rate, occupation and income.Fifth, the associations examined in this study are based on an ecological study design. In how far these associations are applicable at an individual level as well is subject to further research.Sixth, the proportion of AOK Nordost insurants is heterogeneously distributed in northeastern Germany with more persons being insured in more deprived areas. It is therefore possible that the effect of area deprivation on hypertension is alleviated in our population sample, given that the proportion of AOK Nordost insurants increases with area deprivation.Seventh, although the awareness of hypertension is generally very high in Germany with over 80% , there iThis study examined the spatial distribution of hypertension based on health insurance claims at the smallest administrative units available. The results of our study clearly show that hypertension varies at the level of municipalities and urban districts in northeastern Germany and highlight the potential of “big data” from health insurance providers for planning and allocation of primary healthcare. The GWR analysis has shown that hypertension is associated with location-specific socio-demographic population characteristics and area deprivation. The future planning of healthcare should therefore be planned at smaller spatial scales than the central areas at which it is currently planned and should reflect the location-specific impact of area deprivation on the prevalence of chronic diseases.


Post treatment periapical periodontitis is usually caused by residual microbes, due to poorly treated root canals and microleakage. Our clinical case proved that orthograde, single-visit endodontic re-treatment is the first choice for the clinician. Cone Beam Computed Tomography (CBCT) images detect the presence and the real extension of the periapical periodontitis and the outcome of the endodontic treatment, in terms of healing the bone defect. Compared with the limited 2-D data obtained by using the radiograph, the CBCT shows a 3-D image of the tooth, the root canal, and the surrounding tissue. Marginal leakage may also lead to the reinfection of the endodontic system [4]. The aim of the conservative retreatment is to remove the defective restorations and to eliminate the infection in the endodontic system.Persistent microbial infection within the endodontic system causes post-treatment apical periodontitis. Other factors involved in the persistent periapical radiolucency after root canal treatment are the extraradicular infection, extruded exogenous materials  and true cysts with cholesterol crystals. A particular case is the scar tissue healing of the lesion, which is not considered a failure. The most frequent cause of persisting post treatment apical periodontitis is residual microbes in the apical region in both poorly and properly treated cases. The necrotic pulp offers the substrate for the microorganism, which is present as planktonic cells floating in the environment or organizing themselves in biofilms attached to the moist surface, in aggregates and co-aggregates . There was no reported difference in the outcome of the treatment. The risk of a fracture between appointments was decreasing. The situations in which a multiple visit treatment is required are highly infected canals, when an antimicrobial dressing is applied, excessive exudate, hemorrhage, or the impossibility to achieve complete chemo-mechanical root canal treatment due to the complex morphology or iatrogenies. Multiple visits are recommended in symptomatic retreatment cases [8].The single visit retreatment is considered efficient even though most of the studies revealed more residual microbes, compared to multiple visits treatment. The advantages of single visit are a lower rate of flare-ups and reinfections between appointments and the minimizing of the costs .Due to the higher sensitivity of CBCT and the more accurate detection of the periapical status, the success rate of the endodontic treatment is lower compared with radiographs. The modern conception states that the size decreasing of the initial lesion, associated with asymptomatic and functional tooth is considered an efficient treatment [In conclusion, the conservative single visit retreatment should be the first choice in retreatment, when confronted with poorly filled root canal with a large apical lesion. CBCT produces high-resolution images and provides more detailed information about the bone lesions and the outcome of an endodontic treatment. Compared with PA X-ray, CBCT showed a higher accuracy in detecting periapical lesions, canal anatomy, and root canal fillings.


Herniation of small bowel through the peritoneal defect of the Pouch of Douglas is extremely rare type of internal hernia, and this type of internal hernia has been described as an entity of perineal hernia. Here, we describe a case of a 26-year-old female without history of abdominal surgery presenting with incarcerated small bowel hernia through a peritoneal defect of the Pouch of Douglas. She visited an emergency department presenting with abdominal pain and distension. Without improvement symptom by conservative management, an operation was performed. During the operation, the distal ileum had been herniated through a peritoneal defect of the Pouch of Douglas, and there were no specific findings on gynecological examination. Reduction of the herniated bowel and primary repair of the peritoneal defect were performed. The case represents a very rare type of internal hernia and provides published cases of hernia through a peritoneal defect of the Pouch of Douglas.  Intestinal obstruction caused by internal hernia is rare, with an incidence of between 0.2% and 0.9% . DiverseA 26-year-old woman was admitted to the emergency department of Ilsan Paik Hospital with abdominal pain and distension lasting for 3 days. She had no history of abdominal surgery. Abdominal examination revealed mild distension and hyperactive bowel sounds. Signs of peritoneal irritation were not apparent and there were no remarkable laboratory data. Plain abdominal X-ray showed a dilated small bowel loop without free air. An emergency computed tomography (CT) revealed diffuse dilatation in proximal to mid ileal loop with abrupt luminal narrowing at distal ileum level without definite evidence of bowel ischemia . During Without improvement of symptoms and physical findings during conservative management, the patient underwent an exploratory laparotomy on 3rd hospital stay. During the operation, approximately 5 cm length of the distal ileum  had been herniated into a defect of the Pouch of Douglas, and there were no specific findings of pelvic examination . After rIn patients without history of abdominal surgery, causes of bowel obstruction such as colorectal cancer, inguinal hernia, intussusception, volvulus, and inflammatory bowel disease might be diagnosed based on physical examination and imaging studies preoperatively. However, the preoperative diagnosis of internal hernia may be difficult although preoperative diagnosis through CT has been reported , 8.Congenitally created peritoneal defect and foramen may lead to internal hernias . Among tThe Pouch of Douglas is an anterior peritoneal reflection between the uterus and the rectum which is so-called rectouterine pouch. Multiparity, old age, and history of pelvic surgery may lead to weakening or defect of the pelvic floor resulting in herniation of bowel though the Pouch of Douglas . This tyThe definitive diagnosis usually has been made during the surgery, although CT findings of hernia through a peritoneal defect of the Pouch of Douglas have been reported, in which a cluster of collapsed small bowel loops in the peritoneal defect between the rectum and the uterine cervix may be detected . In the The surgical treatments of perineal hernia consist of reduction of hernia sac, ligation, excision, and approximation of the uterosacral ligament, or obliteration of hernia sac using continuous sutures through the posterior wall of the cervix and the anterior wall of the rectum . HoweverThe preoperative diagnosis of internal hernia may be elusive because of the rarity of the disease entity, especially unusual type of internal hernia. Delayed diagnosis and treatment could result in morbidity and mortality. Thus, even though hernia through a peritoneal defect of the Pouch of Douglas is an extremely rare type of internal hernia and its preoperative diagnosis is difficult, a high degree of suspicion based on CT findings and history of abdominal surgery may be necessary for prompt management.


Cost-effective care pathways are integral to delivering sustainable healthcare programmes. Due to the overestimation of coronary artery disease using traditional risk tables, non-invasive testing has been utilised to improve risk stratification and initiate appropriate management to reduce the dependence on invasive investigations. In line with recent technological improvements, cardiac CT is a modality that offers a detailed anatomical assessment of coronary artery disease comparable to invasive coronary angiography.The recent publication of the National Institute for Health and Care Excellences (NICE) Clinical Guideline 95 update assesses the performance and cost utility of different non-invasive imaging strategies in patients presenting with suspected anginal chest pain. The low cost and high sensitivity of cardiac CT makes it the non-invasive test of choice in the evaluation of stable angina. This has now been ratified in national guidelines with NICE recommending cardiac CT as the first-line investigation for all patients presenting with chest pain due to suspected coronary artery disease. Additionally, randomised controlled trials have demonstrated that cardiac CT improves diagnostic certainty when incorporated into chest pain pathways.NICE recommend cardiac CT as the first-line test for the evaluation of stable coronary artery disease in chest pain pathways. Despite decades of investment in the delivery of effective treatment, cardiovascular disease remains responsible for the vast majority of deaths worldwide. Even prior to the recent fluctuations in the global financial climate, many modern healthcare economies had sharpened their focus on delivering healthcare that is both clinical and cost effective. Ensuring cost-effective and efficacious treatment is central to maintaining sustainable healthcare programmes as populations increase in age and access healthcare in greater numbers. In the UK, the National Institute for Health and Care Excellence (NICE) routinely reviews clinical evidence and publishes advice and recommendations based on the combination of clinical efficacy and cost effectiveness of both therapies and technologies. Established in 1997, it is now enshrined in UK law to ensure patients cared for in the English National Health Service (NHS) gain benefits from cost-effective measures, and that NHS resources are optimised.Quick Reference Guide for Clinicians recommended patients were offered treatment based on their pre-test probability of angina, and a clear history of anginal chest pain was a pre-requisite for stratifying which patients required downstream investigation [Guidelines on the investigation and management of coronary artery disease (CAD) have evolved significantly over the past two decades. In the early 1990s, Braunwald’s Since Braunwald’s early publication, the expansion of multi-modality cardiac imaging has generated a number of different testing strategies with improved sensitivity for diagnosing CAD that have been incorporated into national  and intePrior to being updated in November 2016, the UK NICE recommendations on the investigation of stable chest pain involved eliciting a careful history of symptoms and estimation of the pre-test likelihood (PTL) of significant CAD using a modified Diamond-Forrester model .Several concerns were subsequently raised about the 2010 NICE guidelines and many were fundamental to the recent revision. First, the reduction in the prevalence of CAD secondary to the increased use of therapy for risk factor modification led to the modified Diamond-Forrester model significantly overestimating the frequency of significant CAD, particularly in women . ClearlySecond, there was concern about the minimal use of anatomical assessment of CAD that was limited to CACS and ICA in those with the lowest and highest PTL. Moreover, the evidence base for CACS was based on data from asymptomatic patients, not those with symptoms . As suchThird, even in 2010, CTCA assessment was likely to be beneficial in those with both low and intermediate PTL  and funcThus, the updated 2016 NICE guideline is notable for its removal of the pre-test probability model and the use of CTCA as the first-line investigation in all patients with atypical or typical angina symptoms or those who are asymptomatic with suggested EKG changes for ischemia . It has Is this anatomical-guided strategy supported by the evidence? Historically, ICA has been the definitive test to confirm of the presence of CAD against which all other non-invasive tests have been validated. However, ICA is the most expensive diagnostic investigation and, importantly, exposes individuals to the highest risk of procedural complications . In the As part of the 2016 update, NICE evaluated the diagnostic accuracy of the main non-invasive testing strategies against the presence of obstructive coronary artery luminal stenosis on ICA. Established stress testing modalities using dobutamine or exercise stress echocardiography (DSE/ExSE), myocardial perfusion scintigraphy (MPS)–single photon emission computed tomography (SPECT), and cardiac magnetic resonance imaging (CMR) have comparable levels of diagnostic accuracy, which is reflected by the relatively few novel publications in this field. Conversely, the evolution of computed tomography (CT) has resulted in technological developments providing increased volume coverage and shorter gantry rotation times that significantly improve the diagnostic utility at much reduced levels of radiation exposure. The enhanced spatial and temporal resolution of modern cardiac CT scanners offer an extremely high sensitivity  for detecting the presence of coronary artery plaque when compared to ICA. The majority of the studies included in the NICE meta-analysis were composed of populations with a higher prevalence of coronary artery disease than is often found in the unselected population that are referred to cardiology clinics for assessment. This may account for the wider variation seen in the specificity of cardiac CT , albeit no significant bias was observed following sensitivity analysis . It is no surprise that when compared with ICA, an anatomical assessment using cardiac CT outperforms all other stress testing modalities. However, of greater importance is the ability to avoid more costly and potentially harmful invasive investigation  versus 3.2 per 10,000 (CTCA) .NICE’s cost utility analysis of a diagnostic test aims to calculate the incremental cost and benefit of care pathways using different investigation strategies. The health economics of care pathways have come under greater scrutiny due to increasing financial pressures on healthcare providers. Only two studies have been published that reflect both the UK costs of investigation for CAD and measurable health benefit by either quality-adjusted life year or correct diagnosis , 18. GenNICE has calculated that the use of CTCA as a first-line investigation will generate annual savings of £16 million in England alone, by prompt exclusion of significant CAD and more effectively use of NHS resources.  ModellinWhilst the UK NICE guidelines give a clear picture as to the most clinically and cost-effective modality based on a 50% stenosis on ICA as a gold standard, there are additional arguments for the use of CTCA as a first-line investigation in this population. The ideal diagnostic test for CAD should influence downstream decision-making to reduce cardiac death and non-fatal myocardial infarction. To facilitate a reduction in cardiac events, the first-line diagnostic test should have a high level of diagnostic accuracy, the ability to better risk stratify individuals into different treatment regimens and be integrated into a cost-effective clinical pathway.Until recently, most studies that have compared different stress imaging modalities to detect obstructive CAD have found no definitive evidence to recommend the superiority of one diagnostic test over another , 22. Diap = 0.0527). Subsequent post hoc landmark analysis from the time of clinical intervention (at 50 days), namely the point when clinicians reviewed the test result and dispensed preventive medical therapy, was associated with a halving of the rate of cardiac death and myocardial infarction  [The Prospective Multicenter Imaging Study for Evaluation of chest pain (PROMISE) trial was a pragmatic trial that recruited a large cohort from USA and Canadian centres to determine whether an initial assessment of suspected stable CAD using CTCA reduces major adverse cardiovascular events . There w= 0.020) . This siThe publication of the updated NICE guideline CG95 poses some major challenges to the cardiovascular imaging community. First, a significant increase in the availability of CTCA is required for UK centres to comply with the updated NICE recommendations. An estimate by the British Society of Cardiovascular Imaging/British Society of Cardiovascular CT (BSCI/BSCCT) is that a 700% increase in cardiac CT will be required across the UK . In ordeSecond, there will also be implications for functional imaging modalities which are more difficult to define. Concerns involve the potential disinvestment in stress imaging services in favour of CT imaging. Whilst a second-line stress test may be required in a proportion of patients who undergo CTCA, it is unknown how this will affect the service utilisation of functional imaging. The increased use of CTCA will generate greater numbers of positive and equivocal CTCA and therefore the requirement for functional imaging will likely not decline significantly.Third, in addition to increasing the volume of cardiac CT that is performed, it is essential that quality is maintained in order to maintain the high diagnostic accuracy of CTCA. This includes optimisation of image quality, providing informative reports of studies and minimising radiation dose exposure. Guidelines for the optimal acquisition of cardiac CT have been published by national and international groups, and these should be followed in order to optimise image quality in cardiac CT , 31. GuiFinally, the emergence of cardiac CT has correlated with a debate on the revision of atherosclerotic coronary artery disease classification . CategorThe update to the UK NICE guidelines recommends that cardiac CT is the first-line investigation for patients presenting with new-onset chest pain due to suspected CAD. This guideline is based primarily on the diagnostic accuracy and cost effectiveness of this strategy, using ICA stenosis as the gold-standard. In addition, the inability of cardiovascular risk assessment to adequately differentiate between groups of patients means that this has been removed from the updated NICE recommendations. An anatomical investigation strategy, such as proposed in the 2016 NICE guidelines, is supported by recent large-scale randomised controlled trials using cardiac CT in both the UK and USA. The implementation of these guidelines requires a large increase in the number of CT scans that are performed; however, the projected cost savings of $20 million per annum, in England alone, mean that the short-term investment is likely to be justified.


Hence, we review the role of CaMKII and inhibitory GPCR signaling in the effect of CART on cocaine reward and provide a new insight into the mechanism of that effect. In this article, we will first review the biological function of CART and discuss the role of CART in cocaine reward. Then, we will focus on the role of CaMKII and inhibitory GPCR signaling in cocaine reward. Furthermore, we will discuss how CaMKII and inhibitory GPCR signaling are involved in the mechanistic action of CART in cocaine reward. Finally, we will provide our opinions regarding the future directions of research on the role of CaMKII and inhibitory GPCR signaling in the effect of CART on cocaine reward.Cocaine- and amphetamine-regulated transcript (CART) peptides are neuropeptides that are expressed in brain regions associated with reward, such as the nucleus accumbens (NAc), and play a role in cocaine reward. Injection of CART into the NAc can inhibit the behavioral effects of cocaine, and injecting CART into the ventral tegmental area (VTA) reduces cocaine-seeking behavior. However, the exact mechanism of these effects is not clear. Recent research has demonstrated that Ca Cocaine is a strong psychostimulant drug that can inhibit the reuptake of serotonin, norepinephrine and dopamine (DA). This results in greater concentrations of these three neurotransmitters in the brain. The drug can easily cross the blood-brain barrier and cause the user to feel intense euphoria  and inhibitory G-protein coupled receptor (GPCR) signaling are involved in the mechanism of the effect of CART on cocaine reward, which may explain how CART inhibits the behavioral effect of DA and may help establish a more comprehensive mechanistic model of the effect of CART on cocaine reward. In the following sections, we will first review the role of CART in cocaine reward and note the shortcomings of the currently proposed mechanism for the effect of CART on cocaine reward. Then, we will focus on the role of CaMKII and inhibitory GPCR signaling in cocaine reward. In addition, we will discuss how CaMKII and inhibitory GPCR signaling are involved in the mechanism of the effect of CART on cocaine reward. Finally, we will provide our opinions regarding the future directions of research on the role of CaMKII and inhibitory GPCR signaling in the effect of CART on cocaine reward.Cocaine- and amphetamine-regulated transcript (CART) is a neuropeptide that is expressed in brain regions associated with reward, such as the nucleus accumbens (NAc). During the last two decades, increasing evidence has demonstrated that CART plays a role in cocaine reward Table . First, cart gene, which is located on the 5th chromosome in humans  response element (CRE) in the start codon of the cart gene  and D3 receptors couple to and activate the Gi/o subclass of Gα subunits and produce inhibitory signaling  and DA (D3 receptors) plays an important role in cocaine reward  blunted cocaine-seeking behavior during the presentation of cocaine-associated cues in rats  by Ca2+/CaM could enhance the binding of CaMKIIα to D3Rs, which further stimulates the phosphorylation of D3Rs and transiently inhibits the efficacy of those receptors  286 and D3R and reduces cocaine-induced LMA  286. Specifically, activated CaMKIIα can stimulate the phosphorylation of D3Rs and transiently inhibit D3R efficacy . In addition, baclofen (GABAB receptor agonist) antagonizes cocaine-induced DA release in the NAc and blocks cocaine-induced hyperlocomotion . The totality of the evidence suggests that CART not only reduces the rewarding effects of cocaine by inhibiting cocaine self-administration patterns but also prevents relapse to cocaine use; therefore, it represents an important potential target for drug treatments.Compulsive drug-taking behavior and high rates of relapse are the two main characteristics of drug addiction. Relapse is a difficult problem to solve in drug addiction treatment and occurs when the drug-seeking habit is reactivated by drug-related cues. Initially, the addict may retrieve from memory strongly compelling drug-related experiences, which then lead to further drug-seeking and drug-taking behavior. Currently, research on the effect of CART on cocaine reward mainly focuses on LMA. There are only a few studies on the effect of CART on relapse. James et al.  found thCY and XZ wrote the manuscript. ZH provided the idea for this work and designed the structure of the manuscript. The other authors revised the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Extracellular recordings are the primary tool for extracting neuronal spike trains in-vivo. One of the crucial pre-processing stages of this signal is the high-pass filtration used to isolate neuronal spiking activity. Filters are characterized by changes in the magnitude and phase of different frequencies. While filters are typically chosen for their effect on magnitudes, little attention has been paid to the impact of these filters on the phase of each frequency. In this study we show that in the case of nonlinear phase shifts generated by most online and offline filters, the signal is severely distorted, resulting in an alteration of the spike waveform. This distortion leads to a shape that deviates from the original waveform as a function of its constituent frequencies, and a dramatic reduction in the SNR of the waveform that disrupts spike detectability. Currently, the vast majority of articles utilizing extracellular data are subject to these distortions since most commercial and academic hardware and software utilize nonlinear phase filters. We show that this severe problem can be avoided by recording wide-band signals followed by zero phase filtering, or alternatively corrected by reversed filtering of a narrow-band filtered, and in some cases even segmented signals. Implementation of either zero phase filtering or phase correction of the nonlinear phase filtering reproduces the original spike waveforms and increases the spike detection rates while reducing the number of false negative and positive errors. This process, in turn, helps eliminate subsequent errors in downstream analyses and misinterpretations of the results. Extracellular recordings of neuronal activity are one of the primary research tools in systems neuroscience –5. The eSignal filtration is used for removal of unwanted components based on their spectral composition while preserving others. Filtration properties are defined by their frequency-based magnitude and phase responses. Based on their frequency magnitude response, which describes the amplification of each frequency, filters can be characterized in terms of their pass (amplification ~1) and stop (amplification ~0) bands. The phase response of the filter, which has typically received significantly less attention, describes the phase shifts of the filtered signal as a function of the frequency. Based on the phase response, filters can be classified as zero-phase (ZP), linear phase (LP) or nonlinear phase (NLP) filters . ZP filtOnline and offline filtration processes in neurophysiology generally aim to reduce the magnitude of unwanted frequencies. For example, high pass filters are commonly used preceding the process of spike sorting to reduce the magnitude of the low frequency components in the signal, and low pass filters are used for extracting the LFP signal –11. FiltThe impact of filtration-induced phase changes has been studied in different fields and contexts ,12. HoweIn this paper we focus on the temporal distortion of the spike waveform caused by the usage of NLP filters, which are the de-facto standard used in both online and offline systems in neurophysiology. We demonstrate how these distortions influence downstream analysis and affect both the extracted mean spike shape and spike train. Finally we show how these distortions can be either prevented when the raw (wide-band) signal is available, or corrected in the case of high pass filtered (narrow-band) continuous or segmented data acquisition.a wide band filter . Single unit spike times were offline extracted from this wide-band sampled signal  following an offline ZP band-pass filtration of the raw signal . Neurons were classified into different sub-populations based on their firing rate and pattern, and mean spike waveform. Spike detection and timestamp identification via spike sorting were performed once for each signal using the non-distorted signal. Thus, allowing a comparison between the mean waveforms following the different filtration procedures using the exact same spike times and numbers  filter. The application of the same filter using the signal and its reversed form provided the ZP filter used throughout the manuscript. An equivalent LP filter was used for comparison and defined as 20th order Hamming window based FIR filter with a similar bandwidth.The The mean action potential waveform represented by 88 samples (2 millisecond window) was transformed using a Discrete Fourier Transform (DFT). The coefficients of the first eight frequencies (0.5–4 KHz) representing the maximal power were used for the reconstruction of sinusoidal functions with amplitudes and phases corresponding to the spike's spectral composition. The spike shape was reconstructed by summing these 8 sinusoidal functions, corresponding to the frequencies, amplitudes and phases of the DFT product .http://ibglab.org/software/phaseDistortion.html)The MATLAB source code and dataset used in this manuscript is fully available online as supplementary material  of the pure sinusoidal signals constituting the spike waveform , top. ThThis non-linearity of the phase response lead to a differential distortion of the spike waveforms depending on their constituent frequencies. We studied the distortion of spikes using simulated signals. The NLP filter induced more pronounced waveform distortions for wider spike waveforms  since moWaveform distortions thus led to a significant reduction in the waveform amplitude and to a reduction in the SNR, which hindered the process of threshold based spike detection. To examine the effect of filtration induced waveform distortion on the detection of action potentials we compared the rate of false negative (β) and false positive (α) errors in the spike detection for different SNRs in simulated signals compared to the known spike times. For each simulated signal, we used different thresholds for spike detection and calculated the probabilities for α and β errors. These probabilities were then used for the computation of ROC curves, P(1-β) as a function of P(α), for different SNRs. The reduction in SNR following NLP filtration resulted in increased α & β errors  leading Online ZP filtration of the signal during acquisition is not feasible due to its dependency on future inputs. LP filters are typically complex and lead to significant time delays which are intolerable in cases when online processing and feedback are required. Thus, currently, the vast majority of acquisition systems use NLP filters for online filtration. These filters serve to acquire either a wide-band of frequencies, including the classical range of both LFP and spikes , or a narrow-band of frequencies which separates the high frequencies of the signal including primarily the spiking activity  . FollowiIn many cases the continuous signal is never acquired but rather only short segments which cross a specific threshold. In these cases of segmented-data acquisition, a retrospect correction of the extracted spike train is not possible. Rather, a partial correction of the waveform by a phase reversal process within the segment is possible . ReconstIn this manuscript we showed that the signal filtration typical of multiple applications in neurophysiology leads to waveform distortions due to nonlinear phase shifts in the filtered signal. This distortion causes a significant change in spike shape and a reduction in the SNR. The reduction of SNR, in turn, leads to errors in spike detection which consequently result in further errors in any analysis that relies on the identification quality. NLP filtration-induced waveform distortion is a significant problem with high impact on both studies interpreting action potential waveforms as well as works analyzing the identified spike trains. Since most acquisition systems and offline analysis software packages use NLP filters, filtration-induced waveform distortion is a widespread problem that should be accounted for in the analysis of extracellularly recorded signals.Signal distortions caused by nonlinear phase shifts can be either prevented by using LP or ZP filters or retrospectively corrected by deconvolution of the reversed signal using the same filter as when the continuous spiking signal was acquired. However, the acquisition of segmented spiking data is currently the de-facto standard in many applications. Modern multichannel electrode recordings produce large amounts of data requiring excessive storage and processing resources. The amount of stored data may be reduced by an order of magnitude by using online detection and segmentation of the signal. The distortion of the segmented signal as a result of this process is unavoidable and can only be partially remedied retrospectively. Our results show that segmentation and detection based on the distorted signal yields significantly inferior results, primarily due to the reduction in the SNR.In addition to its use in extraction of spike times from the continuous signal, the action potential waveform is one of the features used for the classification of neurons into different sub-populations ,20,26,27NLP filters have been addressed extensively in the general signal analysis literature . In neurMany researchers in the neurophysiology community are currently oblivious to the impact of the problem created by phase distorting filters on the spiking data that they collect. Thus, while paying close attention to the magnitude modulation of the filters, they are typically unaware of the phase distortions that can have such far reaching consequences. Most of the hardware and software based filtration procedures in both online and offline applications use NLP filters by default, thereby hiding the original waveforms and perpetuating the use of the distorted waveforms. Here we provide a clear description of this problem and emphasize its significance. We present concrete solutions to overcome this problem, which affects the vast majority of neurophysiological studies examining spiking activity through extracellular recordings.


The current field of posterior pole and retinal imaging of the human eye has expanded into detailed analyses of the macula, retinal periphery, individual retinal layers, vitreoretinal interface, imaging of the choroid and the optic nerve head. The challenge in retinal imaging is the enduring pursuit of deeper penetration into tissues, increased resolution to the cellular level, and interpretation of observations. How much deeper can we go and with what resolution and reproducibility? These are fundamental questions for experts in search of novel imaging modalities. New discoveries may resolve existing controversies, but inevitably stimulate new questions. Emerging technologies in retinal imaging include adaptive optics retinal imaging and optical coherence tomography-based retinal angiography.In this review, the focus of our discussion will be the discrepancy between the findings (interpretation) of one imaging technology that do not agree or are not even found with a complementary technology. If a clearly seen abnormality is present with one technology but absent in another, what are the possible explanations? Following is a summary of key concepts of retinal and optic nerve imaging modalities and current controversies regarding their interpretation and/or limitations. The two most common imaging modalities utilized to detect macular edema due to various etiologies include fluorescein angiography (FA) and optical coherence tomography (OCT). Fluorescein angiography for clinical use was first described by Novotny and Alvis in 1961 .Since its introduction, optical coherence tomography has rapidly assumed an important and indispensable role as a noninvasive diagnostic and monitoring imaging modality in numerous diseases of the retina and the choroid . OpticalBoth FA and high-definition OCT imaging are used to illustrate different pathologic aspects. FA identifies the anatomical location and pattern of vascular leakage, and is generally a qualitative and functional study, whereas OCT allows a morphological and quantitative assessment of pathology such as macular edema (ME) by producing two or three-dimensional images of the retinal tissue. While both FA and OCT are used extensively to detect and characterize the same pathology, in some instances OCT and FA may yield discrepant findings in the same patient , 7. In tAge-related macular degeneration (AMD) is the leading cause of severe visual impairment in elderly people in the developed world; however, the management of this condition has been radically altered by the introduction of anti-vascular endothelial growth factor therapy . The visToday, spectral domain OCT (SD-OCT) and non-invasive fundus autofluorescence imaging can provide additional anatomical information beyond the FA, including visualization of the layer of the retina and choroid involved with the neovascular membrane , 10. OCTOn the other hand, CNV activity may be seen on FA and not be apparent on SD-OCT; this occurs if only intraretinal cystoid spaces and subretinal fluid accumulation are considered to represent CNV activity on SD-OCT. Other findings were found to indicate CNV activity, including intraretinal hyper-reflective flecks and fluid accumulation in the sub-RPE space, such as serous components of a pigment epithelial detachment (PED) .Kozak et al. also reported a discrepancy in the detection of macular edema in various retinovascular diseases including AMD. They observed in 1,272 eyes that 94.97 % had the finding of ME or subretinal fluid confirmed by both techniques. There were 3.86 % of eyes in whom the FA showed dye leakage in the macular area and OCT demonstrated a normal foveal contour. Conversely, in 1.17 %, OCT showed intraretinal and subretinal fluid, which was not revealed by FA . In theiThe use of OCT has increased dramatically during the past decade, whereas use of FA had declined considerably . DespiteThe American Academy of Ophthalmology AMD Preferred Practice Pattern advocates the use of intravenous fundus FA when a patient complains of new metamorphopsia or has unexplained blurred vision; it can also be used when the clinical examination reveals elevation of the RPE or the retina, subretinal blood, hard exudates, or subretinal fibrosis. Fluorescein angiography is also indicated in the following situations: to detect the presence of and determine the extent, type, size, and location of CNV; to detect persistent or recurrent CNV following treatment and to assist in determining the cause of visual loss that is not explained by the clinical examination , 16. TheMacular edema is one of the most common vision threatening complications of uveitis and can affect patients with different types of ocular inflammation . CystoidSeveral studies evaluated the agreement between FA and OCT when diagnosing macular edema in patients with uveitis. Kempen et al. found that OCT and FA offered only moderate agreement regarding macular edema status in uveitis cases. The discrepancy noted in some cases was attributed to the difference in what FA and OCT measure. Macular leakage detected by FA and macular thickness as measured by OCT are caused by the same pathology but have different impacts on our diagnosis and treatment . LeakageWhile OCT seemed like the most appropriate first test to evaluate the macula in patients with uveitis, FA was found more sensitive in detecting CNV secondary to inflammatory conditions such as multifocal choroiditis . AnotherPrior to the development and widespread use of OCT technology in ophthalmology, clinical examination with contact lens and FA were employed commonly in diabetic patients to evaluate, plan treatment, and to monitor diabetic macular edema (DME). Because clinical detection of macular edema may be possible only if severe macular involvement has already developed, it is then mandatory to image the macula in suspicious cases since early diagnosis of macular edema leads to more effective treatment. Both imaging modalities, FA and OCT, are complementary investigations, each revealing different aspects of the pathophysiologic aspects of DME . Fundus In a comparison of FA and OCT for detection of ME in diabetic patients, Ozdek et al. found that the sensitivity of OCT was higher than that of FA, especially for the cystoid pattern of ME . AccordiSome reports, however, favor SD-OCT over fundus FA because of sensitivity. Jittpoonkuson et al. reported that SD-OCT gave earlier macular edema diagnosis than FA in 3.53 % of eyes in their study and that residual macular edema at follow-up visits was missed by FA in 1.18 % of eyes . In a stPathologic myopia, a major cause of visual impairment and legal blindness, is associated with progressive elongation of the globe. It may be accompanied by degenerative changes in the sclera, choroid, Bruch's membrane, retinal pigment epithelium (RPE), and neurosensory retina. Choroidal neovascularization at the macula is the most common vision-threatening complication of pathologic myopia . The diaLeveziel et al. found no agreement regarding signs of active CNV between OCT and FA. Exudative features of myopic CNV were more obvious on FA (82 %) than on SD OCT (48.6 %). They suggested that fluorescein angiography should be performed when new-onset myopic CNV was suspected. One possible explanation of the little information that can be obtained from OCT in cases of myopic CNV is the less exudative behavior of the new vessels associated with myopic CNV compared with those associated with neovascular AMD . AnotherDespite proclaimed superiority of FA in cases of myopic CNV, Milani et al. found that, on the basis of FA alone, active myopic CNV can be misdiagnosed and they suggested the use of SD-OCT in combination with FA . In a reGaucher et al. described the OCT finding of a characteristic bulge of the macular retina, RPE, and choroid within the concavity of the moderate posterior staphyloma in myopic eyes. In their study, FA showed atrophic changes in the macular retinal pigment epithelium (RPE) in all eyes, combined with focal points of leakage in some eyes. The dome-shaped macula often is associated with RPE atrophic changes and foveal retinal detachment, which may explain the visual impairment in those eyes .Pseudophakic cystoid macular edema  is a swelling of the fovea due to fluid accumulation occurring a few weeks to months after cataract surgery. It is one of the most important causes of visual impairment after cataract surgery. The prevalence of pseudophakic CME varies from study to study depending on the method used in its detection. By using fluorescein angiography, a prevalence of up to 20 % has been reported. However, with inclusion of loss of vision as a requirement to establish the diagnosis, the prevalence of pseudophakic CME was found to be only 2 %. Its incidence has also decreased with less invasive cataract surgery .Fundus FA in cases of pseudophakic CME can reveal capillary dilatation and leakage from small perifoveal capillaries in the early phase of the angiogram. In later phases, pooling in the outer plexiform layer results in the classic perifoveal ‘petaloid’ staining pattern in addition to staining of the optic nerve due to capillary leakage . In caseIn cases of difficult venous access, oral fluorescein administration is an alternative for obtaining a retinal angiogram. Barteselli et al. found that oral FA had better sensitivity compared with spectral-domain OCT for detection of pseudophakic CME . The genCentral serous chorioretinopathy (CSCR) is characterized by one or more serous detachments of the neurosensory retina, commonly associated with retinal pigment epithelium (RPE) detachments. The diagnosis of CSCR is mainly based on clinical diagnosis but may be aided by FA and OCT. Fluorescein angiography classically shows the leakage of dye from the choroid through a focal RPE defect and its pooling in the subretinal space in acute CSCR. Alternatively, OCT is used to quantify the amount and extent of the subretinal fluid, demonstrate thickening of the neural retina and is commonly used for monitoring during the follow-up and also for diagnosing the changes in the neurosensory retina –46.Fluorescein angiography is essential for the identification of the leakage site for appropriate treatment with laser photocoagulation while OCT should be used for follow-up and evaluations of retinal thickness. On the other hand, SD-OCT can be crucial in detecting small amounts of fluid in chronic CSCR where the signal from depigmented RPE can make it difficult to discern such fluid. It is also useful in detecting CNV associated with CSCR .OCT-based angiography is an emerging in vivo imaging modality that images retinal vessels and their filling without the use of intravenous dye injection. It captures physiological and pathological blood vessels at different layers of the retina by separating static/tissue from motion/blood flow signals . The detImaging for glaucoma has been a topic of intense research, and has gained a prime position in the management of patients with glaucomatous optic neuropathy. Disc photographs have been considered the gold standard for documenting the optic nerve appearance. The limitations of photographs are the lack of quantitative data to demonstrate progression and the inability to provide early detection of glaucoma. Photography of the retinal nerve fiber layer (RNFL) has been proposed as a tool for detecting glaucoma. However, it was fraught with issues in developing the images to demonstrate the RNFL and has not evolved much in the digital age. Regardless, the ability to see the RNFL is important in assessing the amount of axonal loss due to ganglion cell death , 51. IniAs the SLO, OCT and polarimetry were each used to image the RNFL, the initial winner was the nerve fiber analysis with polarimetry. The algorithms and normative database enhanced the usability of the instrument . PolarimOptic nerve photos provide images of the cup-to-disc in single plane image or stereo-images. Even amongst experts the cup appearance did not always match the level of visual field damage. Methods for detecting focal rim changes have included the “ISNT” rule . StudiesFor many years, many have agreed that ganglion cell loss seems to be the source of optic cupping and RNFL loss due to glaucoma. Because the macula gives the impression of having an abundance of ganglion cells, this was the location of initial efforts at looking for glaucoma-induced cell loss. The first generations of OCT did not have the resolution to discriminate the ganglion cell layer very well . With thDiabetic retinopathy has been considered primarily a retinal microvascular disorder caused by the direct effects of hyperglycemia and by the metabolic pathways it activates . HoweverAdaptive optics is a relatively new tool that makes it possible for the ophthalmologist to evaluate the retina at a cellular level. Adaptive optics technology aims to correct the ocular aberrations and enhance performance of the optical system . In addiOptical coherence tomography angiography is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. It allows the visualization of retinal microvasculature by detecting intravascular blood flow, using a split-spectrum amplitude-decorrelation angiography (SSADA) algorithm, without any dye injection . OCT angIn conclusion, FA and OCT are complementary investigations. OCT provides detailed imaging of anatomical retinal layers, allows detection of microstructural changes, and helps perform quantitative assessment during follow up. FA is used to evaluate retinal vascular perfusion and the integrity of the inner blood-retinal barrier. Therefore, the use of either or both imaging modalities is advisable for the most accurate diagnosis and the proper management of retinal diseases.


This study investigated nose profile morphology and its relationship to the skull in Scottish subadult and Indonesian adult populations, with the aim of improving the accuracy of forensic craniofacial reconstruction. Samples of 86 lateral head cephalograms from Dundee Dental School  and 335 lateral head cephalograms from the Universitas Padjadjaran Dental Hospital, Bandung, Indonesia (mean age 24.2 years), were measured. The method of nose profile estimation based on skull morphology previously proposed by Rynn and colleagues in 2010 (FSMP 6:20–34) was tested in this study. Following this method, three nasal aperture-related craniometrics and six nose profile dimensions were measured from the cephalograms. To assess the accuracy of the method, six nose profile dimensions were estimated from the three craniometric parameters using the published method and then compared to the actual nose profile dimensions.In the Scottish subadult population, no sexual dimorphism was evident in the measured dimensions. In contrast, sexual dimorphism of the Indonesian adult population was evident in all craniometric and nose profile dimensions; notably, males exhibited statistically significant larger values than females. The published method by Rynn and colleagues  performed better in the Scottish subadult population  compared to the Indonesian adult population .In addition, regression formulae were derived to estimate nose profile dimensions based on the craniometric measurements for the Indonesian adult population. The published method is not sufficiently accurate for use on the Indonesian population, so the derived method should be used. The accuracy of the published method by Rynn and colleagues  was sufficiently reliable to be applied in Scottish subadult population. In order to establish the identity of severely damaged human remains, in which the primary methods such as dental, DNA and finger print identification have failed, craniofacial reconstruction may offer a solution in facilitating familial recognition. Thereafter, the primary identification methods can be attempted again to reaffirm the identity –4. To acAnatomical patterning is a term used here to describe where the shape of the individual skull overrules the ASTD pattern. This occurs in three main areas. Firstly, the bone beneath the superficial masticatory muscles . If these areas are more deeply concave than usual, with a raised zygomatic arch, it dictates bulkier muscles, hence deeper than average tissue. Secondly, if areas such as the brow ridge or the zygomatic bones are more prominent than usual, slightly deeper than average tissue should be applied . Even ifAlthough the literature is very limited, researchers have attempted to provide guidelines that will permit the accurate estimation of soft tissue anatomy for the nose from the skulls of both adults and children , 7–13. TThe aim of this study was to investigate the accuracy of the Rynn method  on samplTo test for sexual dimorphism in nasal dimensionsTo quantify the error of the published method  by compaIf necessary, to derive more accurate regression formulae for use on different populations and different age groups.The objectives of this study:Eighty-six lateral cephalograms were collected from the archive of orthodontic patients at the Dental School University of Dundee, Scotland. The East of Scotland Research Ethics Service granted the ethical approval for this study in December 2015 . The Health Research Ethics Committee, Universitas Padjadjaran, provided the ethical approval for this study (Number 812/UN6.C1.3.2/KEPK/PN/2015). The samples were derived from orthodontic patients prior to orthodontic treatment .The collected samples of the two populations were representative of the natural population of the radiography archive. Patients with facial syndrome were already excluded from the sample.X), rhinion-subspinale (Y) and nasion-subspinale (Z) were measured , pronasal projection height (PV), pronasal projection in the Frankfurt horizontal plane (PFHP), nasal length (NL), nasal height (NH) and nasal depth (ND)  were used in rescaling the images. The enlargement of the X-ray compared to the real cranial size was less than 10%. Thus, the image adjustment effect did not impair the image quality, and in turn, image quality did not compromise point identification and therefore these measurements can be deemed to be accurate. Distances between nasion-acanthion  tests were used to analyse the results. All variables showed a very high level of both reliability and repeatability with ICC scores above 0.87 Table .Table 1It test showed that there were no significant differences in both aspects of craniometrics and nose profile dimensions between the sexes (p > .05). Therefore, in the following analysis, male and female groups were pooled. In contrast, an independent t test verified the presence of sexual dimorphism in the Indonesian adult population in all three craniometrics and six nose profile dimensions (p < .001).In the Scottish subadult population, an independent t tests were performed in the Scottish subadult population to determine whether there was a statistically significant mean difference between the actual and estimated nose profile dimensions using the published method [Paired sample d method   in the Scottish subadult population compared to the Indonesian adult population. The similarity in ancestry group between the source sample of the published method  and the Three studies from various geographical regions in Europe examining nasal dimensions were compared to the current study Table . The curThis study demonstrates that the relationship between the morphology of the nasal aperture and that of the nose profile is different between the Indonesian population and the predominantly Caucasoid population from which the published method  was deri