Pregnancy and birth cohorts have been utilised extensively to investigate thedevelopmental origins of health and disease, particularly in relation to understanding theaetiology of obesity and related cardiometabolic disorders. Birth and pregnancy cohortshave been utilised extensively to investigate this area of research. The aim of thepresent review was twofold: first to outline the necessity of measuring cardiometabolicrisk in children; and second to outline how it can be assessed. The major outcomes thoughtto have an important developmental component are CVD, insulin resistance and relatedmetabolic outcomes. Conditions such as the metabolic syndrome, type 2 diabetes and CHD alltend to have peak prevalence in middle-aged and older individuals but assessments ofcardiometabolic risk in childhood and adolescence are important to define early causalfactors and characterise preventive measures. Typically, researchers investigatingprospective cohort studies have relied on the thesis that cardiovascular risk factors,such as dyslipidaemia, hypertension and obesity, track from childhood into adult life. Thepresent review summarises some of the evidence that these factors, when measured inchildhood, may be of value in assessing the risk of adult cardiometabolic disease, and assuch proceeds to describe some of the methods for assessing cardiometabolic risk inchildren. Following earlier speculation that this may reflect maternal/infantnutrition at critical stages of development, David Barker's team went on to report evidencethat lower birth weight was an independent risk factor for later CHD and the metabolicsyndrome. In this context, low birth weight represents a tangible, albeit multifactorial,reflection of a suboptimal in utero environment. The resultingdevelopmental origins of health and disease (DOHaD) paradigm proposed that a range ofmetabolic, immunological and physiological adaptations to suboptimal antenatal conditionsacts in concert with postnatal conditions to modify subsequent disease risk . Fiin utero environment is influenced by broad-rangingmaternal environmental factors, maternal general health and fixed genetic variability.Experimentally, maternal environmental influences which have been studied includenutritional status  and during pregnancy), physical activity, pharmacological agents (prescribed and illicit),patterns of microbial diversity, smoking and pollutants. Some of these have been shown tohave epigenetic effects on diverse aspects of fetal development. A similar set of influencesoperates, variably, in the postnatal environment, also interacting with the genetic andepigenetic processes to affect developmental processes. Within the schema shown in The quality of the  and have an increased risk of metabolic disease. This suggests that early life effects  could be an important factor in the rising obesity ratesbeing observed worldwide.The growing global burden of obesity is now affecting all regions of the world, andassociated cardiometabolic disorders are among the greatest threats to human health. Toaddress this public health crisis, it is important to understand why obesity has developedso rapidly in such a short space of time. Obese women and those who develop gestationaldiabetes are more likely to have offspring who themselves are obese which have provided strong evidence of a causal relationship betweenearly-life exposure and metabolic risk in later life. Early-life exposures in humans aremuch more complex and multifactorial, with exposures such as smoking, drug exposure, stressand toxins at play. Despite these limitations, it is critical that the observed effects onfetal programming are replicated in human studies. Further, it is important to rigorouslyascertain whether interventions aimed at favourably altering fetal programming are effectivein humans.Studies of short-lived animals, which can be readily undertaken across the entire lifespan(from before conception to the disease end point of interest), have consistently providedsupport for the DOHaD concept. This is far more challenging in human studies which requirelong-term longitudinal follow-up. There are further differences between animal and humanstudies. Most of the animal models rely on controlled nutritionalinterventions(–) and almost all intervention studies(–) involve offspring who have not yet reached old age, or even middle age.As a consequence, they often do not as yet have definitive CVD endpoints (such as CHD andstroke). So far, the reported outcomes from these prospective human studies are lessdefinitive ‘risk’-associated parameters measured from childhood, adolescence or young adultlife (see below). These prospective mother–offspring studies per se willnot be able to establish direct cause-and-effect relationships between specific exposuresand clinical outcomes. Nevertheless they  will play a key role in building the overall picture of therole of DOHaD in human populations.Human DOHaD research has been conducted in many prospective mother–offspring cohorts and ina broad range of early-life intervention studies. Most current prospective populationstudies(–). Specifically, many studies demonstrate that a spectrum ofcardiovascular risk factors including hypertension, dyslipidaemia, obesity and the metabolic syndrome track from childhood into adulthood. For example, in the Bogalusa HeartStudy, twice the expected number of subjects whose blood pressure levels were in the highestquintile of blood pressure in childhood remained in the highest part of the distribution 15years later. Similarly, overweight 2- to 5-year-olds in the Bogalusa study were morethan four times more likely to become overweight adults, compared with children classifiedwith BMI less than the 50th centile. In the Fels study, a child or adolescent with a high BMI percentile forage remained at high risk of being overweight or obese at 35 years of age. Interestingly,this risk increased in magnitude with increasing age. A systematic review has shown that all included studies consistentlyreport an increased risk of overweight and obese youth becoming overweightadults.The utility of cardiovascular risk markers depends on evidence that these ‘track’ fromadolescent/childhood through to adult life and, by extrapolation, that those with elevatedrisk measures earlier in life are also more likely to suffer CVD later inlife and early childhood obesity may be on the pathway between early-lifefactors and cardiovascular outcomes. As such, childhood obesity and insulin resistance canbe utilised as both determinants of cardiovascular risk and/or as outcomes inepidemiological models. Clearly, childhood obesity is a major health issue in its own rightwith a broad range of immediate health risks, in addition to the long-term risk of CVD andmany non-communicable diseases.Several key postnatal factors, in particular postnatal weight gain, have been shown topredict cardiovascular risk, independent of birth sizeAlongside the virtually universal measures of BMI, prospective cohort studies often includeother anthropometric measures including waist circumference, skinfold thicknesses, andsometimes measurements of body composition from DOHaD  and bioimpedance methodologies.. More refined methods of measuring adiposity and body composition inchildhood may have utility in dissecting the role of the contribution of DOHaD mechanismsto ultimate cardiovascular risk. A long-recognised and consistent finding is that lowbirth weight followed by postnatal weight gain is associated with a central distributionof adiposity, increased percentage of body fat and increased skin folds. High birth weight is also associated with later obesity risk. Thissuggests that both impaired and excessive growth in utero have effects onprogramming for obesity. Therefore, measuring body composition may provide greatersensitivity to understanding the early programming of obesity. The most commonly used ofthese techniques include DXA, bioelectrical impedance, air displacement plethysmography, MRI and magnetic resonancespectroscopy (MRS). There is emerging evidence that ectopic fat deposits such as in therenal sinus, myocardial region and peripancreatic regions are best quantified usingMRI. Bioelectric impedance is portable and relatively inexpensive, but notas accurate as DXA or MRI. Bioelectric impedance is particularly prone to inaccuracieswith changes in body water:adipose ratio, as could occur with illness anddehydration. When employing techniques such as MRI, MRS and DXA in large-scalelongitudinal studies, considerations of cost and time commitment to the participants arenecessary, particularly if these measurements are to be repeated at several follow-ups.DXA cannot distinguish between visceral and subcutaneous fat.In infants and children BMI is generally a less predictive measure of overall adipositythan in adults, and methods for assessing adiposity in cohort studies have recently beenreviewed, are likely to be superior to BMI, at least in adults.In the literature on adults, there has been much debate about the anthropometric measuresthat best predict cardiovascular risk in cross-sectional and longitudinal studies. It isgenerally agreed that measures of central adiposity and abdominal visceral fat deposition,such as waist:hip ratio and waist circumferenceZ score. In contrast to adults, waist:hip ratio in children does not predictblood lipids, blood pressure and traditional cardiovascular risk factors. However, thereare some metabolic risk markers, namely fasting TAG and homeostatic model assessment ofinsulin resistance (HOMA-IR), that do appear to be associated with anthropometric measuressuch as BMI or waist circumference. Furthermore, cholesterol and LDL are inversely associated withheight. In childhood, there may be no ‘best’ cross-sectional measure of cardiovascularrisk, and the choice of optimal cross-sectional anthropometric measure should depend onthe research question being asked.However, the role of these measures in childhood is less definitive. Rather, there issome evidence that measures of central obesity in children are not more predictive ofcardiometabolic risk than BMI Fortunately most birth cohorts have repeat measures of anthropometry which provide theopportunity for longitudinal statistical modelling to be applied to obesity measures.Longitudinal measures may have more value than cross-sectional measures in answeringDOHaD-related questions. The present review is not intended as a comprehensive review ofstatistical longitudinal methods or of relative efficiencies of each method, but considershow these measures may be most relevant to investigating DOHaD phenomena. Suffice to say,there are many techniques for investigating longitudinal measures including linearmixed-effects model, linear mixed-effects model with skew-t random errors, semi-parametriclinear mixed models, latent class models and non-linear mixed-effects modelling. Carefulselection of the most appropriate statistical tool to answer each different life-coursequestion is critical.(–) particularly as they assume and identify different, and potentiallycausal, pathways to obesity. For example, there is evidence that childhood obesity canoccur through DOHaD effects related to large-for-gestational-age neonates who are exposedto the in utero effects of gestational diabetes and maternalobesity. By contrast, childhood obesity can also be driven by starvationin utero as occurred to fetuses exposed during the Dutch HungerWinter.Pathways to childhood obesity are likely to be heterogeneous, and under the influence ofa number of maternal and childhood factors acting at different time points . LongituZ scores of blood pressure specific for age, sex and height of the childare most appropriate for evaluation of high blood pressure in childhood. Likewise, age, sex and puberty all affect fasting total cholesterol,LDL, HDL, TAG and insulin levels through childhood.Obesity does not usually occur in isolation, but generally occurs within a cluster ofabnormalities that includes hypertension, dyslipidaemia and insulin resistance. There aresome points to note, specific to children, when interpreting these individual risk factors.. Defining the metabolic syndrome in children is problematic. In adults,the definition is based upon arbitrary cut-offs with three main consensus definitions, WHO and the International DiabetesFederation (IDF)). Consensus definitions all vary slightly in terms of the cut-off limitsused, and it is important to emphasise that these apply a bimodal approach to risk factorsthat generally have continuous relationships with disease across the range. They also varywith ethnicity, and adult definitions are not appropriate to translate to studies ofchildren. At present, in children, there is no consensus around definitions of the metabolicsyndrome. As an illustration of this controversy, in 2008, in excess of forty uniquepaediatric definitions of the metabolic syndrome in children had been used in theliterature. Two of the more recent major definitions were compared with differentgroups being identified in the same population. The IDF metabolic syndrome criterionrepresents a more stringent definition that was adapted from the NCEPdefinition.The co-occurrence of these risk factors, ‘Syndrome X’, is a phenomenon identified by Reavenin 1988, and subsequently recognised by various different names, most commonly now as themetabolic syndrome.To overcome some of these issues of definition in children, one approach is to use‘data-driven’ methods to avoid use of arbitrary cut-offs. This involves methods that canidentify natural groupings within a population. For example, cluster analysis is adata-driven method that identifies groups maximising within-group similarities andmaximising between-group differences using a variety of statisticalalgorithms, 24% and 19% of the population, respectively, were identified as in the ‘highmetabolic risk’ cluster. These groups were highly divergent for traditional risk factors Study. Specifically,cluster analysis was undertaken using continuous variables  to identify a group of children with features similar to themetabolic syndrome. At ages 8, 14 and 17 years, 29% factors, and incAlthough data-driven cluster analysis can be used within a specified population, it doesnot necessarily define cut-offs that can be translated to another population. Forcross-cohort comparisons, a consensus definition based on cut-offs is still required. Assuch, there remains a need for expert committees to define consensus statements.. Therefore, clustering of risk factors in childhood is predictive ofrisk of development of the metabolic syndrome in subsequent adult lifeCurrently there is insufficient longitudinal data to know what cut-offs predict futuredisease. Nevertheless, despite the varying definitions, overall stability of risk factorclustering is seen from childhood into adult lifeDetecting risk of CVD in children, before the expression of overt cardiovascular endpoints,has been achieved via other methods. These methods include assessments of vascular structureand function, inflammatory and epigenetic biomarkers, non-alcoholic fatty liver disease(NAFLD) and the retinal vasculature. In making a decision about which of these diversemethods are best employed in any particular study, two factors should be considered. Thefirst is that methods may potentially target different pathways in the evolution and theeventual development of CVD. Ideally the technique(s) chosen should link to the researchquestion being asked. The second consideration is a practical one. Some methods are moretime intensive, expensive and demanding of greater expertise, and need to be justified interms of the greater burdens placed upon study participants and resources.Vascular structure and function can be measured by intima media thickness (IMT), pulsewave velocity (PWV) and flow-mediated dilatation (FMD).. Evidence of atherosclerosis was directly observed even at theserelatively young ages, in the form of fatty streaks and narrowing of coronary vessels.This has driven the development of non-invasive techniques that can be used to detectevidence of early atherosclerosis in childhood and later cardiovascular risk. These areindirect measures of subclinical atherosclerosis and interpretation of these results inchildren needs to be undertaken carefully.Atherosclerosis is present in youth, beginning as deposits of cholesterol and its estersin the endothelial wall. The Pathobiological Determinants of Atherosclerosis in Youth(PDAY) study performed autopsies on 3000 individuals aged 15 to 34 years dying ofunrelated causes(–). Jarvisalo et al. showed that, at an average age of 11 years, children with type 1diabetes and hypercholesterolaemia had higher IMT compared with a control group. Childrenwith hypertension (at a mean age of 13·9 years) also had significantly greater carotid IMTthickness than unaffected children. Finally, overweight children have been shown to have significantlyincreased carotid IMT, even for mild to moderate degrees of obesity. Lower maternal energy intake during pregnancy has also been shown tobe associated with increased carotid IMT in 9-year-old children.One method, established in children, for assessing early morphological changes in thevessel wall is measurement of aortic and carotid IMT. This technique has confirmed thattraditional cardiovascular risk factors  in childhood are associated with the formation of early atheroscleroticlesions, type 2 diabetes and familial hypercholesterolaemia. In the Raine study, we have seen that the high ‘metabolic riskcluster’ participants have higher PWV in both sexes. In males, those in the highermetabolic cluster had higher augmentation index  in males, but not in females.Arterial compliance or stiffness is another non-invasive measure of later cardiovascularrisk. Three non-invasive methods of measuring arterial stiffness are used: (1) measuringPWV; (2) relating change in diameter (or area) of an artery to distending flow; and (3)assessing arterial pressure waveforms. Using these measures, cardiovascular risk can beobjectively and non-invasively quantified using applanation tonometry (Sphygmocor) whichmeasures arterial stiffness. Measures of PWV and augmentation index predict cardiovascularevents and mortality independent of other traditional risk factors in adults. Increasedarterial stiffness has been found in high-risk groups of children such as those withobesityMethods of FMD and PWV measure dynamic changes in the vasculature. Therefore,experimental conditions need to be controlled for effects such as exposure to cigarettesmoke and for menstrual cycle phase for adolescent girls. Notably, IMT measures astructural change and is not sensitive to these immediate influences.. This has also been seen in children, which shows that elevated CRPlevels are associated with increased metabolic risk, arterial changes in healthy children and eventual CVD. Mendelian randomisation approaches suggest that these associationsmay not be causal.C-reactive protein (CRP) is the most studied of the inflammatory markers in relation tocardiovascular risk. It is a non-specific measure of systemic inflammation, and adultstudies show that elevated CRP is associated with an increased risk of subsequentcardiovascular risk and all-cause mortality. In adolescents, plasma leptin has been associated with insulinresistance.Adipokines are cytokines produced by adipose tissue and might provide a mechanistic linkbetween obesity and CVD. Adipokines include adiponectin and leptin. Plasma leptinconcentrations correlate with body fat and BMI and may play a role in the aetiology ofhyperinsulinaemia and the insulin resistance syndromeγ.In adults, high levels of plasma IL-18 are associated with centralobesity, the metabolic syndrome and CVD. In adolescents, IL-18 has been associated with BMI and insulinresistance.Other circulating cytokines associated with cardiovascular risk in childhood andadolescence include IL-18, soluble TNF receptors (TNFR) and interferon-α are mediated by two specific receptors, a 55 kDaprotein (TNFR1) and a 75 kDa protein (TNFR2). Soluble forms of both receptors are detectable in plasma and havebeen used as proxies for TNF-α activity. Elevated plasma levels of TNFR have been associated with childhoodobesity and cardiovascular events.The effects of TNF-γ-induced protein of 10 kDa (IP-10) is a pro-inflammatorychemokine generated by monocytes to promote the recruitment of lymphocytes and monocytesto sites of inflammation. It is expressed in human atheroscleroticplaques and plasma levels have been correlated with waist circumference andBMI in adolescents.Interferon-. As yet there are few data for more direct measures of cardiovascularrisk, but it is of note that there is now evidence that some differentially methylated CpGsites are temporally stable between the ages of 5–7 and 14 years.Recent studies suggest that epigenetic marks in proxy tissues may reflect mechanisticpathways linking the early environment with later adiposity and differential risk ofCVDZ score, waist circumference, HOMA and systolic bloodpressure. An evolving area of interest is that of the microbiome. The effectsof diet on metabolic liver disease may be mediated, at least in part, by themicrobiome. Ongoing and future mother–birth cohort studies will be analysing themicrobiome at different time points.As discussed above, obesity is a spectrum from isolated overweight to the full cluster ofco-morbidities, but typically seen in the metabolic syndrome. Similarly, the metabolicsyndrome is also associated with other conditions such as NAFLD, the most prevalentchronic liver condition worldwide. The development of NAFLD is associated with keycomponents of the metabolic syndrome. Individuals with NAFLD typically have greater levelsof BMI .Population studies that are large scale and performed on healthy participants will haveethical constraints for obtaining ‘gold standard’ liver histology by liver biopsy.Therefore, non-invasive methods for assessing NAFLD are utilised, and MRI is now acceptedas producing reliable assessments of liver fat. Many population studies have used liverultrasound. Assessment by ultrasound may potentially introduce false negatives, but isfeasible in population studiesAssessing cardiometabolic risk in children is important in understanding developmentalprogramming and how these pathways may be addressed for disease prevention. Thesecardiometabolic risk factors can either be predictors or outcomes in analyses. Current datasuggest that early measures of cardiometabolic risk do track into adulthood and predictcardiovascular outcomes. When assessing the role of adiposity in children, longitudinalstatistical techniques and measures of body composition are likely to be useful. Data-driventechniques, such as cluster analysis, should be considered when assessing the metabolic riskmarkers in children. The development of more sophisticated cardiovascular risk markers inchildren is constantly evolving. It is important that there is considered use of thesetechniques in the context of the pathogenic pathways being examined. These approaches willadd valuable knowledge to the expanding frontier of developmental medicine (DOHaD), which isultimately the most logical target for preventing disease and curtailing the rising burdenof CVD and other non-communicable disorders.


While HIV incidence has stabilized in many settings, increases in health and wellbeing among many people living with HIV/AIDS suggest that the number of HIV-serodiscordant relationships is growing. Given the deficit of reviews addressing social and behavioural characteristics of HIV-serodiscordant couples within high-income settings, our objective was to understand the scope of the published literature, identify evidence gaps, and suggest future research needs.Ten electronic databases were searched. Studies were included if they were reported in English, used primary data, were from the combination antiretroviral (cART) era (>1996), reported on social or behavioural aspects, included any fraction of primary  relationships, and were conducted in high-income settings. Studies that identified their unit of analysis as either the dyad or individual member of the couple were included. Studies were coded according to a thematic framework.Included studies (n = 154) clustered into eight themes: risk behaviours (29%), risk management (26%), reproductive issues (12%), relationship quality (9%), serostatus disclosure (7%), adherence to antiretroviral therapy (7%), vulnerability (5%), and social support (3%). The proportion of studies conducted among heterosexual couples, same-sex male couples, and mixed cohorts were 42%, 34%, and 24%, respectively. Most studies (70%) were conducted in the United States, 70% of all studies were quantitative (including interventions), but only one-third were focused on couples (dyads) where both partners are recruited to a study. Over 25% of studies focused on sexual risk among same-sex male couples.Future research efforts should focus on the interrelationship of risk management strategies and relationship quality, social determinants of health and wellbeing, HIV testing, vulnerable populations, reproductive issues among same-sex couples, disclosure of serodiscordant status to social networks, dyadic studies, population-based studies, and interventions to support risk management within couples. Additional population-based studies and studies among marginalized groups would be helpful for targeting research and interventions to couples that are most in need. As HIV-positive partners are typically the link to services and research, innovative ways are needed for reaching out to HIV-negative partners. Our review suggests that significantly more research is needed to understand the social and behavioural contexts of HIV-serodiscordant relationships.The online version of this article (doi:10.1186/s12889-015-1488-9) contains supplementary material, which is available to authorized users. Advances in HIV treatment and prevention have helped to stabilize HIV incidence in many countries. Concomitant increases in life expectancy and stabilized prevalence suggest that the number of primary HIV-serodiscordant couples  will increase ,2. EstimAlthough combination antiretroviral therapy (cART) has been shown to reduce the rate of new HIV infections within serodiscordant couples by 96% ,8, the sOverall, there are no reviews that have synthesized knowledge in this area with the aim of identifying major gaps in evidence. Therefore, our main objective was to conduct a scoping review of the published literature in order to identify key evidence gaps and suggest future research needs in the field of HIV-serodiscordance.Scoping reviews are used to map a field of study and to determine the value in undertaking further systematic reviews or studies by helping to identify important evidence gaps . For thiOne of two reviewers (SM or JP) made exclusion decisions. Citations for which exclusion criteria were inconclusive were noted and discussed. Where agreement could not be reached, the opinion of a third reviewer (JM) was solicited. The references cited list of all included articles identified within the original search of health science databases were checked for additional relevant citations. Following a framework analytic approach , we undeSearches yielded a total of 2,133 citations, of which 154 were included in this review  but not relationship type  . In a FrIn some studies, couples appeared to manage and reduce risky sex when compared with other groups. For example, American MSM in primary seroconcordant relationships reported significantly more UAI and were more likely to have sex outside of their relationships when compared with those in primary serodiscordant relationships; yet, the impact of the level of intimacy on risky sex was moderated by drug use before sex and the partners’ HIV status -38. In sAmong women, those who were HIV-positive and in primary partnerships were more likely to have unprotected sex than HIV-positive women without partners in the US . Women wThe “risk management” theme was assigned to studies that focused on efforts to avoid or manage the risk of infection and included work on condom use, PrEP, viral load knowledge, negotiated safety agreements, seroadaptation , HIV testing, and serostatus disclosure.California Partners II study, HIV-negative partners estimated a lower likelihood of HIV transmission and had riskier sex if they thought that their partner was on cART and had an undetectable viral load [Given that it is now accepted that an undetectable viral load reduces the risk of infection, investigations into the effects of actual and perceived viral load are of particular interest. An online survey that studied the impact of viral load discussions on risky sex among American MSM found that UAI occurred within 25% of primary serodiscordant couples who had discussed their viral load together . A studyral load ,52. Favoral load . In an Aral load .Negotiated safety agreements  and seroadaptation were the most commonly discussed behavioural risk management strategies within the surveyed literature . BetweenIn studies that explored associations between risk management and HIV serostatus disclosure, knowledge of a heterosexual partner's HIV status was associated with condom use among those who had disclosed their serostatus . FrequenFour studies reported on interventions that aimed to reduce sexual risk behaviours. In a cluster randomized trial of a risk reduction intervention for African-American serodiscordant couples that addressed stigma and psychological distress, barriers to condom use, support from community organizations, and relationship skills, a lower adjusted mean number of unprotected sex acts was found in the intervention group . In a noStudies were assigned the “reproductive issues” theme if they focused primarily on any social or behavioural aspect of reproduction or fertility. Notably, studies classified within this theme were conducted exclusively among heterosexual serodiscordant couples. In one study of American couples’ desire to conceive through assisted reproduction where the majority of men in the study had previously been diagnosed with HIV, participants were most concerned about the risk of transmission within the family, premature death of the HIV-positive partner, disclosure of HIV status to children, and the potential desire for additional children if assisted reproduction proved successful on the first attempt . In a quStudies were assigned the “relationship quality” theme if they explored relationship satisfaction or outcomes of serodiscordant relationships. Two-thirds (11/18) of these studies used qualitative methods. The “Straightpoz” study, an Australian longitudinal cohort of serodiscordant couples, found that HIV-positive partners felt that their identities were “redeemed” by their seronegative partners and revealed tensions within the couple surrounding communication about serodiscordance ,77. AmonStudies were assigned to the “serostatus disclosure” theme if the primary finding was related to disclosure of serostatus to partners, family, or wider social networks. Serostatus disclosure, however, typically referred to individual disclosure of HIV status to partners. The finding that 41% and 47% of HIV-positive men and women engaged in a serodiscordant couple, respectively, had not disclosed their status to their partner ,80 was cStudies were classified within the “adherence” theme if their main finding was related to cART adherence. Studies found that strong social support was linked to better adherence by the HIV-positive partner within serodiscordant couples. In a pilot-study of 40 couples based in the United States, higher adherence levels were associated with less risk attribution to unprotected sex by seronegative partners, better perceived treatment efficacy, good knowledge of treatment, and the perceived negative consequences of poor adherence . HighligThe “vulnerability” theme was assigned when the primary contribution was a focus on understudied or highly marginalized groups such as migrants, those living in poverty, or those who had suffered from abuse. Although IDUs are highly vulnerable, these studies were typically assigned to other themes, and secondarily coded within the vulnerability theme. Among immigrant women from sub-Saharan Africa who were receiving HIV treatment in the United Kingdom, vulnerability was described by women as an interplay between migration, HIV status, and poverty . A qualiIn qualitative studies of social support, partners were the primary source of support among same-sex male serodiscordant couples, while less support was received from families . In a smThrough the process of reviewing the 154 included citations and assigning them to eight thematic categories, this scoping review identified key gaps in the social and behavioural evidence-base for HIV-serodiscordant couples. Designing studies that will contribute to evidence in these areas should inform future research. The social and behavioural aspects of biomedical prophylaxis , and impacts on relationship quality and satisfaction were generally underexplored. Moreover, although intimate couple dynamics and emotional needs were important for understanding patterns of risk in qualitative studies, these factors were seldom addressed in quantitative work ,54,64,66There is a considerable amount of work that has investigated sexual risk behaviours or management of sexual risk, without taking account of the socio-structural factors that affect these outcomes. The social determinants of health are “core social processes and arrangements – reflective of social and cultural norms, values, networks, structures and institutions – that operate in concert with individual behaviours and practices to influence HIV epidemics in particular settings” , p. S294The only quantitative study focused on HIV-testing among HIV-negative partners was conducted in the Unites States prior to a change in national guidelines that recommended that higher risk individuals receive an annual HIV test. This study found that nearly three-quarters of HIV-negative partners in same-sex serodiscordant relationships had tested for HIV in the previous year ,108,109.Eban study that assessed the impact of a behavioural intervention on HIV risk behaviours within multiple urban settings in the United States [Highly vulnerable non-IDU populations, including transgender persons and migrants, have been inadequately studied ,111,112.d States ,21. The d States , underscStudies of reproductive issues among same-sex serodiscordant couples were entirely absent, despite the fact that 19% of same-sex couples in the United States were estimated to have children as of 2011 . AlthougCurrently, very few studies have investigated barriers to disclosing a serodiscordant relationship to family and social networks, and the impacts of these decisions on the relationship. These impacts could be psychosocial, or may affect access to supportive services. In one of the very few studies on the subject, better perceived social integration facilitated a better likelihood of relationship disclosure by HIV-positive partners to their social networks when compared with their seronegative partners . Given tOnly one-third of included studies recruited dyads, defined as both partners within a serodiscordant relationship. Therefore, the majority of studies relied on the responses of a single partner. Given the importance of interpersonal dynamics within a relationship, studies that recruit both partners of a serodiscordant couple are crucial for understanding the management of risk, the cultivation of intimacy within the couple, and changes over time. Dyadic studies also enhance the validity of outcome variables by devising ways of operationalizing the responses of both partners through techniques such as agreement scores. If couples-based approaches are to be employed within HIV prevention interventions, more studies focused on the dyad as the unit of analysis will be needed. Given the challenges of recruiting representative cohorts of HIV-serodiscordant dyads, methodological work that describes challenges and solutions would be helpful.Population-based cohort studies would also help to increase our understanding of the epidemiological profile of serodiscordant couples, and would help to develop targeted programs that deliver single or combination HIV prevention interventions to couples that are most in need. Given the preponderance of studies focused on sexual risk behaviour and the movement away from viewing all unprotected anal or vaginal intercourse, or sex without condoms, as risky , a review of the ways in which the evidence base has typically operationalized “risky sexual behaviour” would be a strong contribution to the literature. Finally, a major weakness of the literature was in the aggregation of results in studies that recruited mixed populations of couples  without presenting stratified results. This aggregation complicated comparability and synthesis of data. Therefore, if primary couples are to be considered different with respect to risk, they should be properly distinguished and discussed within larger studies.Only eight intervention studies met the inclusion criteria for this scoping review. Published trials included behavioural interventions to reduce sexual risk -24, a psThere were strengths and limitations to this review. Strengths included the thorough database searching and broad inclusion criteria . Limitations included the omission of grey literature and reports published in languages other than English. Work that includes mixed cohorts, such as serodiscordant and seroconcordant couples, or primary and casual relationships, should identify these sample proportions clearly, provide consistent definitions, and conduct stratified analyses. Consistently defined outcomes and populations will facilitate helpful meta-analyses, the highest form of evidence.In summary, our findings highlight where future research on HIV-serodiscordant relationships may be directed, including the effects of risk management strategies on relationship quality, the social determinants of health for serodiscordant couples, dynamics around HIV testing, reproductive issues among same-sex couples, disclosure of serodiscordant status to social networks, dyadic studies, population-based studies and studies among vulnerable populations. Importantly, as HIV-positive partners are often the link to services and research, innovative ways are needed to reach out to HIV-negative partners in the context of research studies and supportive services. Overall, filling these gaps will be important for improving the health and quality of life for HIV-positive and HIV-negative partners engaged in serodiscordant relationships.


Drosophila have yielded numerous substantial successes in modeling congenital disorders or inborn errors of human development, as well as neurodegenerative disease and cancer. Moreover, although our ability to generate sequence datasets continues to outpace our ability to analyze these datasets, the development of high-throughput analysis platforms in Drosophila has provided access through the bottleneck in the identification of disease gene candidates. In this Review, we describe both the traditional and newer methods that are facilitating the incorporation of Drosophila into the human disease discovery process, with a focus on the models that have enhanced our understanding of human developmental disorders and congenital disease. Enviable features of the Drosophila experimental system, which make it particularly useful in facilitating the much anticipated move from genotype to phenotype (understanding and predicting phenotypes directly from the primary DNA sequence), include its genetic tractability, the low cost for high-throughput discovery, and a genome and underlying biology that are highly evolutionarily conserved. In embracing the fly in the human disease-gene discovery process, we can expect to speed up and reduce the cost of this process, allowing experimental scales that are not feasible and/or would be too costly in higher eukaryotes.Fly models that faithfully recapitulate various aspects of human disease and human health-related biology are being used for research into disease diagnosis and prevention. Established and new genetic strategies in  Drosophila Collection: This Review highlights several Drosophila models of human inborn errors of development, with particular emphasis on the strategies geneticists have developed to break through the current genotype-to-phenotype bottleneck. Estimasary see . It is vDrosophila melanogaster, coupled with the broad repertoire of genetic approaches to which Drosophila is amenable, make this organism a uniquely powerful model system for understanding the basic biological etiology of human disease and development  in the injected plasmid and the phage attachment site (attP) in the genome.CRISPR/Cas9: method of inducing targeted double-stranded breaks in the genome. CAS9 binds to RNA (termed guide RNA) that pairs with genomic DNA and induces a double-stranded DNA break. Improper repair at these breakpoints in cells that give rise to the germline can lead to mutations that can be isolated in the next generation. Additionally, double-stranded DNA breaks can induce the incorporation of foreign DNA containing homology arms surrounding the break point. This system has been utilized to generate novel mutations in genes as well as facilitate targeted knock-in strategies.Forward genetic screen: random, genome-wide mutagenesis to generate progeny with an aberrant phenotype(s). Identification of individual mutated genes leads to the discovery of genes involved in any given process. Identification of different genes with shared loss-of-function phenotypes leads to the discovery of genetic pathways. Traditional forward genetic screens in Drosophila using X-ray, chemical and transposon mutagenesis have uncovered numerous genetic pathways involved in development. These pathways and their function in development are often conserved in humans.GeneSwitch: method to control induction of gene expression spatially and temporally. This method utilizes a GAL4–progesterone-receptor chimera protein that can be activated by the hormone progesterone.Modifier screen: random mutagenesis performed in a mutant background  to identify mutations that enhance or suppress a mutant phenotype. Modifier screens yield additional genes involved in a given process/pathway, including both integral and modulatory pathway components.Mosaic analysis with a repressible cell marker (MARCM): system to generate labeled mutant mitotic clones within a field of wild-type cells. This system requires the use of: (1) the inducible gene expression system in which GAL4 protein activates transcription at upstream activation sites (UAS), (2) the repressor of GAL4 induction, GAL80, (3) spatiotemporally controlled expression of the DNA recombinase Flipase (FLP), and (4) a marker  downstream of the UAS. The mutant allele of interest and the GAL80 transgene are recombined onto homologous chromosome arms containing FRT sites (the site at which FLP-mediated recombination will occur). FLP-induced mitotic recombination in cells heterozygous for the GAL80 transgene and the mutant allele of interest yields recombinant daughter cells that inherit either two copies of the mutant allele or two copies of the GAL80 transgene. Daughter cells lacking GAL80 and harboring the homozygous mutant allele will express the marker in a field of unmarked cells that did not undergo recombination or are homozygous for GAL80.Reverse genetic screen: targeted mutagenesis of any given gene designed to understand the gene's biological function. Mutagenesis can be accomplished via numerous mechanisms, such as RNAi or CRISPR/Cas9.RNA interference (RNAi): method of depleting a cell of a specific target mRNA. This is typically accomplished by expressing cytoplasmic double-stranded RNA that is subsequently processed by the cell into small single-stranded RNA molecules that are then used as templates to target and degrade complementary mRNA in the cell.Temporal and regional gene expression targeting (TARGET): method to control induction of gene expression spatially and temporally. This method utilizes the UAS/GAL4 system in conjunction with a temperature-sensitive GAL80 to repress GAL4 activity at permissive temperatures.Drosophila has a rich experimental history in genetics and development, beginning with the observation that genes are organized on chromosomes and leading to Thomas Hunt Morgan's 1933 Nobel Prize in Medicine (http://www.nobelprize.org/nobel_prizes/medicine/laureates/1933/). Later in the 20th century, burgeoning molecular genetic analyses thrust Drosophila into a new age of discovery by enabling systematic spatiotemporal control of transgenes , modulates the activity of the Twist transcription factor via activation of NFκB  in early development in both flies and humans (CBP or by hemizygosity for Twist itself) manifests as genetically related autosomal dominant developmental syndromes, either the rare syndrome Rubinstein-Taybi   cofactor   or the m births) . These t births) .Drosophila] has numerous conserved roles during embryonic patterning and development: in the dorsoventral (DV) axis, and in the eye, heart and otic vesicle  superfamily comprises a large group of structurally related secreted signaling molecules that belong – based on similarities in sequence and function – to three subfamilies: the bone morphogenetic proteins (BMPs), the activin/inhibins, and the TGF-β proteins . TGF-β s vesicle . Given tDrosophila , was first identified in the Heidelberg screens for lethal patterning defects  has severe developmental consequences that mirror human holoprosencephaly (HPE), a common forebrain defect resulting from the failure of the cerebral hemispheres to separate. Few HPE fetuses survive to birth, but nonetheless the disorder is diagnosed in 1:20,000 live births (Our understanding of the Hedgehog (Hh) signaling pathway [called Sonic hedgehog (SHH) in mammals], and how it contributes to congenital conditions, also has its foundations in  defects  and was  defects . Many otd cloned . The obse births .SHH, but mutation of other pathway components  have also been causally linked to the disorder (in vivo modifier screens and quantitative (high-throughput) functional genomic assays in cell culture are invaluable for a comprehensive understanding of pathways as well as for a fuller understanding of loci contributing to dysmorphic disease susceptibility in the long term  , a condiferation .Notch alleles (in flies with notched wings) almost 100 years ago , More generally, the Notch signaling pathway plays a conserved role in organ development in all metazoa – ranging from insect to nematode to echinoderm to human; effects of pathway mutation are pleiotropic and dependent on dose and context . AdditioDrosophila, mutations in several human genes cause predictable, analogous defects. For example, in both flies and humans, mutations in HOX genes and Hox family members alter spatial identities: mutations in the Hox family member Pax6 [called eyeless (ey) in Drosophila] eliminates eyes; mutations in SALL1  disrupt eye and auditory elements (respectively); and mutations in Nkx2-5 [called tinman (tin) in Drosophila] lead to heart defects. In all cases, these genes encode transcription factors that are components of conserved In accordance with their developmental roles in Drosophila biological systems  that illustrate how forward genetic methods have been useful not only for organizing human developmental disorders on the basis of signal transduction pathways, but also for validating models of development on the basis of conserved complex GRNs.Below we discuss three model Drosophila compound and mammalian camera eyes have actually diverged in evolution  not only in flies and humans, but also in zebrafish, frogs, chicks and mice  and Sox2 , along with the lens-specific DC5 enhancer (defined in chick), form a conserved regulatory circuit responsible for secretion of crystalline, an essential lens protein ; MEF2 and Hand , GATA ; and Tbx (at least seven homologs in humans: Midline and H15 in Drosophila)  . MEF2, wn record . It is en record .NKX2-5) are associated with cardiac conduction abnormalities, as well as ventricular and atrial septal defects , has been particularly well studied in model systems, including Drosophila  to express GFP in the hearts of mutants, and conventional A lack of analysis . Second,analysis . FinallyDrosophila  and tango (tgo)] that each encode a basic helix-loop-helix (bHLH) protein (for which vertebrate counterparts remain unidentified). The subsequent elongation (in both flies and humans) of these branches depends on the Sprouty and FGF proteins, with Sprouty negatively regulating FGF10 [called Branchless (Bnl) in Drosophila]  have their foundation in traditional loss-of-function studies of osophila . The Dro tissues . The pri tissues . The simsophila] . Drosophn normal ; in mammal tubes .Drosophila embryonic development, specialized cells within the tracheal system, called terminal cells, undergo dramatic morphogenetic changes by extending numerous thinly branched cytoplasmic projections  to study human congenital disease . These reports provide a universal/less-specialized entry point for both Drosophila and non-Drosophila researchers interested in fly models of disease (The OMIM (Online Mendelian Inheritance in Man) database is a valuable resource that can point the translational scientist to rare congenital disease candidate genes that have likely orthologs in  disease . Conserv disease .Fig. 2.Drosophila using reverse genetic approaches. One expedient way to do this is through the use of temporally and spatially controlled RNA interference (RNAi) using the UAS:GAL4 system  at Harvard University has undertaken an effort to generate and utilize RNAi constructs for various research applications. With the aim of understanding the function of genes suspected of causing Drosophila orthologs of human genes linked to disease (Drosophila orthologs (http://www.flyrnai.org/HuDis). TRiP lines are readily available (from DRSC and Bloomington Stock Center). The Vienna Drosophila RNAi Collection (VDRC) currently boasts a set of almost 32,000 Drosophila transgenic RNAi lines, corresponding to an estimated 90% of the entire fly genome (Drosophila (with some examples briefly described here) that is less costly and less time consuming than reverse genetic validation strategies in vertebrate model systems  gene, which encodes a protein that is required for the proper folding of alpha-tubulin subunits and thus for the formation of alpha-beta-tubulin heterodimers  and hereditary spastic paraplegia  syndrome, which is also diagnosed as Sanjad-Sakati or Richardson-Kirk syndrome, is a rare, autosomal recessive inherited condition characterized by congenital hypothyroidism, mental retardation, and growth failure associated with facial dysmorphia . HRD resrodimers . The mecraplegia . The DroDrosophila are also being used to model CHARGE syndrome, a common autosomal dominant disorder  associated with wide-ranging congenital dysmorphologies, including malformations of the nasal cavity, heart, inner ear and retina   . However disease , but a gmb group . In thesDrosophila). 60% of cases occur in infants with no previous family history of the disease, and are thus thought to arise de novo. Treacher Collins syndrome has been successfully modeled in flies through the disruption of Nopp140, which encodes a 140-kDa nucleolar and Cajal body phosphoprotein that is thought to be a ribosome assembly factor, although its specific function remains unknown  is an autosomal dominant craniofacial dysmorphology disorder caused by mutations affecting the protein TCOF1 . In humans, mutations in SLC35c1, the human Gfr ortholog, cause the rare autosomal recessive congenital disorder of glycosylation, type IIc (CDG). Affected individuals exhibit severe mental retardation, short stature and characteristic facial dysmorphia, in addition to immune dysfunction  in flies]. Flies null for salm, a target of the Dpp and Hh signaling pathways, suffer embryonic lethality  in mosaic flies that carry both wild-type and mutant cells revealed that these flies manifest antennae and genitalia defects. In addition, electrophysiological assays confirm that these flies are also deaf (Townes-Brocks' syndrome (TBS) is a rare autosomal dominant inherited malformation syndrome that is characterized by anal, renal, limb and ear abnormalities, and is uniquely associated with mutations in the ethality . Howeverlso deaf . Thus, also deaf .Drosophila experimental system also allows researchers to ‘knock-in’ genes of interest  using traditional transgenesis protocols. Most examples of the technique's utility for disease modeling in the fly comes from the analyses of neurodegenerative conditions, perhaps because these disorders share a common pathological denominator, protein misfolding. The subsequent formation of aberrant protein aggregates with toxic conformers selectively damage neuronal populations. In the case of Alexander disease, the autosomal dominantly inherited GFAP  for which there is no ortholog in flies. Nonetheless, glial expression of human mutant GFAP in transgenic flies induces the formation of Rosenthal fibers (inclusions that serve as markers of the human condition) and promotes glial-mediated neurodegeneration  cause the remainder , results only from a small set of PTPN11 missense mutations, which are believed to be associated with the loss, rather than with the gain, of SHP2 function  in Drosophila]} to create humanized models of LEOPARD syndrome. Ubiquitous expression of either allele leads to ectopic wing venation and, in the case of Y279C, to rough eyes and increased numbers of the R7 photoreceptor – all readouts of increased RAS/MAPK signaling  or juvenile myelomonocytic leukemia (E76K) (a (E76K)  have alsDrosophila has gained traction as a repurposed tool to investigate congenital disorders of metabolism, such as diabetes  offering unique opportunities to model human disease and development: the embryo is useful for the study of development; Drosophila larvae are useful for studying physiological processes and some simple behaviors (e.g. foraging); studies in pupae have been instrumental in investigating hormonal processes , and sleep and seizure disorders, as well as into cognitive/psychosis and affective disorders, cancer, cardiovascular disease, inflammation and infectious disease, and metabolic diseases, including diabetes . FMR1 mutation results from expansion of its CGG triplet, of which there are five to 40 repeats in wild-type alleles and 55 to 200 repeats in mutant alleles, and consequent silencing of the FMR1 gene  to assess function of the candidate disease genes that are frequently identified in neonate whole-genome sequencing studies . The mod


Inhibitory neuronal activity is critical for the normal functioning of the brain, but is thought to go awry during neurological disorders such as epilepsy. Animal models have suggested both decreased and increased inhibition as possible initiators of epileptic activity, but it is not known if, or how, human inhibitory neurons shape seizures. Here, using large-scale recordings of neocortical single neurons in patients with secondarily generalized tonic-clonic seizures, we show that fast-spiking (FS) inhibitory activity first increases as a seizure spreads across the neocortex, impeding and altering the spatial flow of fast epileptic traveling waves. Unexpectedly, however, FS cells cease firing less than half-way through a seizure. We use biophysically-realistic computational models to show that this cessation is due to FS cells entering depolarization block as a result of extracellular potassium accumulation during the seizure and not because they are inhibited by other inhibitory subtypes. Strikingly, this absence of FS inhibitory activity is accompanied by dramatic increases in local seizure amplitude along with unobstructed traveling waves and is seen during all secondarily generalized seizures examined, independent of etiology or focus. FS cessation also leads to prominent spike-and-wave events, suggesting that FS cell dynamics control the transition between the tonic and clonic phases of these seizures. Thus, it may be possible to curtail human seizures by preventing inhibitory neurons from entering potassium-dependent depolarization block, a novel and potentially powerful therapeutic avenue in treating multiple kinds of epilepsies.


Chronic alcohol-related neuroadaptations in key neural circuits of emotional and cognitive control play a critical role in the development of, and recovery from, alcoholism. Converging evidence in the neurobiological literature indicates that neuroplastic changes in the prefrontal–striatal–limbic circuit, which governs emotion regulation and decisionmaking and controls physiological responses in the autonomic nervous system and hypothalamic–pituitary–adrenal axis system, contribute to chronic alcoholism and also are significant predictors of relapse and recovery. This paper reviews recent evidence on the neuroplasticity associated with alcoholism in humans, including acute and chronic effects, and how these neurobiological adaptations contribute to alcohol recovery, along with the discussion of relevant clinical implications and future research directions. Recovery from alcoholism is a complex and long-term process with high relapse rates. Therefore, understanding why people relapse has been critically important to improving treatment outcomes. To that end, researchers are looking for clinical and biological markers that predict relapse after treatment and to use those risk factors to develop effective treatments to reduce relapse rates. One promising research area is examining how alcohol changes structure and function in the brain, affecting what neuroscience calls neuroplasticity and causing neuroadaptations that can affect the brain’s reward and decision-making centers and, in turn, affect relapse and recovery.Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM–IV). According to the survey, during the preceding year, of those 4,422 alcohol-dependent people, 35.9 percent achieved either low-risk drinking (17.7 percent) or abstinence (18.2 percent)  psychologically and physiologically recuperate from the deleterious effects of alcohol exposure by achieving complete abstinence or low-level, nonhazardous alcohol intake. The National Epidemiologic Survey of Alcohol-Related Conditions (NESARC) conducted 43,093 in-person interviews with a national sample of adults and found that 4,422 subjects, at some point prior to the past year, met the criteria for alcohol dependence, as defined by the percent) . The stupercent) . Additiopercent) .In an effort to identify clinical and biological markers that predict relapse risk, researchers have looked toward the brain and alcohol-related changes in the brain that might make it more difficult for people with AUD to recover successfully. In particular, recent research has capitalized on advances in neuroimaging techniques to examine neuroplastic changes that may increase vulnerability to alcoholism and alcohol relapse . In factThese chronic alcohol-related neuronal changes and their co-occurring symptoms, such as stress, may serve as markers of alcohol relapse and long-term recovery but are not currently addressed in most AUD treatment programs. Already there is evidence that people who maintain long-term abstinence show functional differences in resting-state brain synchrony relative to those with short-term abstinence .This paper reviews the evidence for neuronal changes associated with alcoholism in humans, including those resulting from acute and chronic effects of alcohol, and how these changes contribute to alcohol relapse. To help understand alcohol recovery in a clinical research setting, the review will specifically focus on neuroplastic changes associated with alcohol relapse immediately following treatment. This paper also reviews the effects of stress on alcohol-related neuroplasticity and alcohol recovery, along with relevant clinical implications and future research directions. Elucidating the link between neuroplastic changes and alcohol recovery will contribute to our understanding of complex alcohol-related symptomatology and provide insights into the development of effective treatments to improve recovery from alcoholism.Neuroplasticity refers to changes in the nervous system that occur in response to various stimuli or experiences and include structural and functional re-organization . These nIn studies of alcoholism, substantial evidence indicates short-term and long-term pharmacological effects of alcohol on the nervous system and related neurophysiological dysfunction . SpecifiOne way this circuit could interact with alcohol to influence these phases of alcoholism is through a part of the PSL circuit called the ventromedial prefrontal cortex (VmPFC), a brain region critical for emotional and behavioral control and that regulates the ANS and hypothalamic–pituitary–adrenal (HPA) axis systems . If repeAlcohol has clear and immediate pharmacological effects on the brain  studies report acute effects of alcohol on reducing anxious and negative emotion and increasing alcohol craving by modulating limbic-striatal activity. In one study , researcSeveral fMRI studies also have reported an influence of alcohol on cognitive function and decisionmaking. Alcohol consumption in healthy individuals resulted in impaired episodic memory encoding, which, in turn, was associated with reduced activity in the lateral PFC . In addiTaken together, neuroimaging studies demonstrate the significant influence of alcohol in healthy individuals via alterations in the PSL circuit, including reduced limbic response to negative emotional stimuli , enhanceNot surprisingly, just as acute alcohol consumption affects the brain, so does chronic, heavy alcohol consumption. In fact, studies consistently report alcohol-related neuroadaptive changes in the PSL circuit, along with related allostatic changes in physiological functions, including ANS and HPA axis systems . The braBlunted dopamine release and other types of dopamine dysfunction in the striatum may be a biomarker indicating increased vulnerability to alcohol and other substance use ;Chronic alcohol abuse and exposure result in alterations in reward brain regions, such as the ventral striatum, leading to disrupted dopamine transmission and striatal activity .Detoxified AUD patients show signs of altered reward responses, such that enhanced ventral striatal activity is more biased toward alcohol cues than other reward cues, such as money ; andPeople with AUD had reduced levels of dopamine D2 receptors in their frontal-striatal regions compared with control subjects .Several lines of research link changes in the striatum and, therefore, the brain’s reward system to chronic alcohol use:Decreased levels of striatal dopamine D2 receptor persisted in AUD patients and did not recover up to 4 months after alcohol detoxification .123I] iodobenzamide (IBZM) single-photon emission computerized tomography (SPECT)  .AUD patients who relapsed within 3 months of becoming abstinent showed increased activity in part of the striatum, called the ventral putamen, when viewing visual alcohol cues during the early weeks of abstinence (at least 1 week after detoxification) .On the other hand, recently detoxified (1 to 3 weeks) alcoholic patients with a blunted striatal response to positive emotional pictures relative to neutral pictures had a greater number of drinking days and a higher amount of alcohol consumed during the 6-month followup .Researchers have suggested that repeated alcohol use gradually enhances incentive salience and craving response toward alcoholic beverages by altering the reward pathways and triggering more alcohol craving and drug seeking . AlteredThese studies suggest that striatal reward system function plays a key role in the development of alcoholism and continues to influence the course of alcoholism by affecting alcohol recovery. Continued alcohol use seems to sensitize striatal reward function and increase incentive salience toward alcohol stimuli. In AUD patients, this altered striatal system may further intensify craving responses and trigger withdrawal symptoms during alcohol-free periods, increasing risk for relapse .As excessive alcohol use continues, alterations in the reward system could result in allostatic changes in other brain regions closely connected with the striatum, including the limbic regions and the PFC . In partStress is a critical factor in increasing alcohol craving and compulsive alcohol consumption , as evidThe brain’s stress response involves activation of the ANS and HPA axis systems to promote regulation of physiological arousal and also facilitate adaptive coping . ChronicIn terms of brain regions involved, researchers postulate that neuroadaptations in the amygdala may influence negatively reinforced craving and alcohol seeking . The amyDuring stress, ANS and HPA axis function are under the regulatory control of the VmPFC . PreclinAlthough further work still is needed to fully understand the associations between stress-related neural response during abstinence, treatment, and early alcohol recovery, available data suggest that neuroadaptations in the peripheral and CNS involved in stress modulation play a significant role in recovery from chronic alcoholism. Altered emotional and stress responses and poor abilities to cope under stress observed in people with AUD may increase vulnerability to high-stress–related craving, relapse, and alcohol drinking, especially under challenging life circumstances.If repeated alcohol exposure disrupts the limbic-striatal system, the result could progressively debilitate prefrontal executive functions . ChronicStructural imaging studies, for example, find reduced gray matter volume in the medial PFC/OFC and its surrounding regions in AUD patients, and this is associated with poor treatment outcome. One study  examinedFunctional neuroimaging studies also have reported connections between alcoholism, alcohol recovery, and altered activity in the medial PFC, OFC, and striatum. In AUD individuals, PET imaging studies found decreased glucose metabolism in the frontal cortex during alcohol withdrawal (for review, see Recent evidence in humans suggests that excessive, chronic alcohol consumption may lead to hyperexcitability of neurons in the CNS, which, in turn, plays a role in alcohol addiction and recovery . Indeed,Alcoholism is a chronic illness, characterized by high relapse risk. Research now suggests that underlying this chronic relapse risk may be negative neuroplastic changes in the brain caused by the cycle of continued alcohol abuse and repeated brief alcohol abstinence and/or alcohol withdrawal. These neuroplastic changes occur in the PSL circuit, which regulates emotions and decisionmaking, which, in turn, influence alcohol recovery . Within The neuroadaptive patterns in this circuit may serve as a set of neurobiological markers of alcohol relapse and recovery. Future research can validate these patterns and investigate their use to help predict relapse vulnerability and to identify people with the greatest challenge to alcohol recovery in the clinical setting.Researchers could develop and test novel treatment strategies that target these validated biomarkers and attempt to reverse these neuroadaptations and significantly improve the chances of recovery from alcoholism. Already evidence supports a mediating role of neuroplasticity in the PSL circuit in improving treatment outcome. A study  with deeResearchers could develop treatments that target withdrawal symptoms and stress-related pathology, such as stress-induced craving and alcohol seeking, implicated by the alcohol-related neuroadaptations in the PSL circuit. For instance, alpha1-adrenergic antagonists, such as Prazosin, show promise for improving stress-induced deficits and impaired PFC function from chronic stress (for a review, see The evidence supporting a role of the neuroadaptative changes in the PSL circuit in alcohol recovery points to important clinical implications:In conclusion, current neurobiological research in humans has identified neuroplasticity in the PSL circuit and its related dysfunctions as key factors increasing relapse risk and jeopardizing alcohol recovery. Further development of biomarkers for these alcohol-related neuroadaptive changes and new treatments that aim to restore the brain have the potential to influence the development of new treatment strategies to promote alcohol recovery and reduce the global burden associated with alcoholism.


The zebrafish (Danio rerio), a vertebrate species with high genetic and physiological homology to humans, is an excellent organism for innovative central nervous system (CNS) drug discovery and small molecule screening. Here, we outline new strategies for developing higher-throughput zebrafish screens to test neuroactive drugs and predict their pharmacological mechanisms. With the growing application of automated 3D phenotyping, machine learning algorithms, movement pattern- and behavior recognition, and multi-animal video-tracking, zebrafish screens are expected to markedly improve CNS drug discovery.The high prevalence of brain disorders and the lack of their efficient treatments necessitate improved  Come on, feel the noiseSo jump a little higher,Jump, jump a little higher…Scooter, “We Take You Higher” (1996)in-vivo models for drug discovery  is rapidly emerging as an excellent model to address these needs  for drug targets and potential therapies  behavioral endpoints in adult zebrafish  assays markedly facilitate the collection and computer processing of data -induced  enables both automated quantification of fish locomotion and interpretation of complex zebrafish behaviors  to deliver behavioral stimuli, such as punishment or reward. Exposing fish to predator or conspecific images on a computer screen (Luca and Gerlai, in-vivo assays, allowing comprehensive coverage of the biological mechanisms of complex brain disorders, and leading to innovative CNS drug discovery.Fully automated robot-based screening platforms for larval and, eventually, adult zebrafish will soon become routine in zebrafish neurophenotyping studies. The HTS systems developed specifically for CNS drugs that affect complex behaviors will increase both the “width” and the “depth” of such screens Figures . CoupledThe Review Editor Dr. Caroline Helen Brennan declares that, despite having collaborated with the author Dr. Allan V. Kalueff, the review process was handled objectively. 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.


Here, we review BVCs influence on bacterial adaptation to their environment and discuss the biological relevance of recently reported inter- and intra-species bacterial interactions mediated by BVCs.Bacteria produce and release a large diversity of small molecules including organic and inorganic volatile compounds, hereafter referred to as bacterial volatile compounds (BVCs). Whereas BVCs were often only considered as wasted metabolic by-product sometimes perceived by animal olfactory systems, it is increasingly clear that they can also mediate cross-kingdom interactions with fungi, plants and animals. Recently,  Figure 1; While the contribution of diffusible soluble secondary metabolites in bacterial ability to communicate, compete or cooperate with neighboring microorganisms has been actively investigated, bacteria also produce and release a wide diversity of volatile compounds that can be readily detected in the bacterial headspace . NeverthBacillus, Pseudomonas, Serratia, or Streptomyces affecting bacterial growth. For instance, dimethyl disulfide emitted from Pseudomonas fluorescens and Serratia plymuthica displays bacteriostatic effects against two plant bacterial pathogens, Agrobacterium tumefaciens and A. vitis   are also able to inhibit growth of several enteropathogens (ia coli) , and alsfringens . Althougfragilis  and sevefragilis  suggestiCollimonas pratensis increased production of secondary metabolites in P. fluorescens that showed antimicrobial activity against Bacillus sp   . Recent . aureus . Whereas harveyi , it trigucleatum , S. wood. woodyi , S. enteenterica , and Neiorrhoeae . In P. aifestyle .E. coli, ammonia mode of action involved its import through the AmtB channel followed by an increase in polyamine synthesis leading to modulation of antibiotic resistance profiles , confers multidrug resistance upon different pathogens  under aerobic conditions via the mitigation of oxidative stress induced by antibiotic treatment upon suppression of DNA-damaging Fenton reaction . Indeed, several soil-associated bacteria were not only shown to have positive effects on plant resistance but also to control plant diseases by exhibiting antibacterial activity against plant pathogens (P. aeruginosa) or by affecting host cell functions  are potentially occurring in environments such as soil or mammalian intestines, the high solubility of BVCs in the liquids present in these environments raises the question of the true aerial nature of BVC-mediated impact on bacteria. Future work will therefore have to clarify the role played by BVCs in bacterial ability to adapt and/or respond to their environments by determining the physiological concentrations of relevant BVCs in diverse environments and to establish, preferentially 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.


Sedation in the ICU is crucial in reduction of patients' discomfort, in particular in patients undergoing mechanical ventilation to help tolerate intubation and reduce pain and anxiety. Propofol (Pr) is a widely used option, but other viable alternatives for short-term sedation  include benzodiazepines (BDZ) and dexmedetomidine (Dx). We aimed at pooling all available evidence on the comparative effects of Pr in terms of awakening and recovery times after STS in mechanically ventilated ICU patients.We planned a systematic literature review searching Medline and Scopus and performed a meta-analysis on direct comparisons reporting on weaning time (Tw), duration of mechanical ventilation (Tmv), time to extubation (Tex) and length of stay in the ICU (Ticu). The primary analysis considered only data from RCTs, while in a secondary analysis observational studies were also included.The literature search identified 15 relevant RCTs, of which 11 versus BDZ, and a further five observational studies, of which one versus BDZ. When compared with BDZ, Pr associated with significantly reduced Tw , Tmv , and Ticu ; no statistically significant difference resulted when comparing Pr and Dx. When nonrandomized evidence was included, results did not change significantly.In conclusion, Pr is associated with shorter awakening and recovery times after STS than BDZ, while no difference could be shown when Pr was compared with Dx.


Plasmodium falciparum transmission, most of the childhood anaemia disease burden is being attributed to malaria. The pathogenesis of malaria anaemia, which may well be the single most frequent cause for childhood mortality worldwide, has been debated for many decades.Anaemia is a major health burden in sub-Saharan Africa. With an estimated two-thirds of children being affected, childhood anaemia causes poor cognitive development, reduced growth and impaired immune functions associated with increased mortality. In malaria-endemic regions, particularly in those with perennial In order to identify underlying mechanisms for malaria anaemia two studies were evaluated: a cohort study including 465 children that were followed weekly over eight months and a severe malaria case-control study including >4,500 children, both carried out in a hyperendemic malaria area of Ghana, West Africa. Human genetic polymorphisms of candidate genes were genotyped and tested for association with malaria anaemia in both studies.We found several genotype-phenotype associations, which had differing effects after stratifying for anaemia with and without complications. For instance, uncomplicated anaemia was found associated with the A allele of rs196854, which was associated previously with an increased expression of interleukin-6, a key mediator of the systemic inflammatory response.Our results suggest that there are at least two different underlying mechanisms of malaria anaemia, uncomplicated anaemia characterized by a slow and continuous development towards a deficit of red blood cells, and anaemia with complications characterized by a rapid and substantial loss of red blood cells. The uncomplicated form appears to be caused by chronic systemic inflammatory processes rather than malaria episodes or parasite densities, similar to what is found in other forms of anaemia of chronic disease (ACD).


Arabidopsis petioles, cells adjacent to procambium cells (stem cell-like cells) are dedifferentiated and survive more easily than other cell types. This finding indicates that stem cells or stem cell-like cells may influence the dedifferentiating niche. In this paper, we provide a brief overview of stem cell maintenance and dedifferentiation regulation. We also summarize current knowledge of genetic and epigenetic mechanisms underlying the balance between differentiation and dedifferentiation. Furthermore, we discuss the correlation of stem cells or stem cell-like cells with dedifferentiation.Dedifferentiation is the transformation of cells from a given differentiated state to a less differentiated or stem cell-like state. Stem cell-related genes play important roles in dedifferentiation, which exhibits similar histone modification and DNA methylation features to stem cell maintenance. Hence, stem cell-related factors possibly synergistically function to provide a specific niche beneficial to dedifferentiation. During callus formation in  Stem cells are a major research hotspot because of their therapeutic potential in several applications, such as human tissue replacement and drug development . Stem cePlant stem cells are maintained in primary and secondary meristems. Primary meristems possess three parts: apical meristem (shoots and roots), intercalary meristem, and floral meristem. Secondary meristems comprise lateral meristems, which include cambium and phellogen, and traumatic  meristem . IntercaProcambium/cambium cells satisfy the criteria for stem cells because of their capacity for long-term self-renewal and ability to differentiate into one or more specialized cell types; as such, these tissues serve as niches for plant stem cells . SeveralCallus is predominantly formed from a pre-existing population of stem cells , 2011 anDedifferentiation is the transformation of cells from a given differentiated state to a less differentiated or stem cell-like state and leads to reacquisition of pluripotency; dedifferentiation is a cellular process associated with reentry into the cell cycle, trans/redifferentiation, or even cell death . This prPlant cellular dedifferentiation is manifested by transition of differentiated cells into protoplasts  and featA study revealed that cell dedifferentiation in animals is triggered by signals from the stem cell niche and leads to dynamic cellular rearrangements. This process possibly involves Janus kinase–signal transducer and activator of transcription signaling pathway because its downregulation leads to inhibition of dedifferentiation . In addiDedifferentiation is a complex process related to the expression and regulation of specific genes. Several studies investigated the relationship between genes and dedifferentiation . SeveralWUSCHEL (WUS) and NO APICAL MERISTEM (NAM) gene families are strongly expressed in petiole dedifferentiation , an LBD family member, is involved in hormone-mediated pericycle cell dedifferentiation and promotes initial cell division  and its close homologs, including WIND2 to WIND4, induce wounding and promote cell dedifferentiation in bidopsis . A similalophila . Howeverormation . As suchormation .The types and levels of cell differentiation differ in explants. Specific cells, such as differentiated cells, switch fate during dedifferentiation, whereas other cells, such as stem cells, are not affected by differentiation. However, not all parenchymal cells in explants can reach a stem cell-like status because some of these cells may die. Hence, when the explants encounters a cell fate decision, a certain signal should indicate which cells should survive. This signal may be secreted by the cell itself to determine autonomous events in each cell. Moreover, signal communication may exhibit similar characteristics to the mode used by stem cells to decide their number in the microenvironment. In several cases and in organisms ranging from bacteria to humans, cells adopt a particular fate stochastically without apparent regard to the environment or history . In the Dedifferentiation is controlled by various epigenetic mechanisms, including chromatin structural changes, as well as DNA and gene methylation. Epigenetic changes in stem cells are reversible and provide plasticity in plants; plasticity allows differentiated cells to recover totipotency under certain physiological and environmental conditions.Open chromatin conformation characterizes dedifferentiated cells in plants and animals . This chArabidopsis protoplasts, the acquisition of pluripotency is associated with chromatin reorganization in specific domains ; this finding indicates that DNMT1-like methyltransferases are related to dedifferentiation process-callus formation  is responsible for self-renewal and differentiation of stem cells, as well as self-renewal of mammalian somatic tissues . Similarbidopsis . Root exormation . Active ormation .KYP)/SUVH4 mutants, which encode a histone H3 lysine 9 (H3K9) methyltransferase, produces defects during stem cell proliferation and callus formation , also known as Arabidopsis transcription activation factor (ATAF1)] is associated with widespread decondensation of pericentric chromatin  in the vascular bundle in any wound of a leaf. These observations imply that the retained stem cells or stem cell-like cells may initiate asexual reproduction of plants , more easily survive than other cells . Pre-exiDrosophila, airway stem cells can influence the dedifferentiation of airway epithelial cells into stable and functional basal stem cells in vivo and ex vivo (In  ex vivo . These fSignificant advances have been achieved in stem cell research. Accumulating evidence suggests that a complicated regulatory network contributes to modulated plant stem cell maintenance, although the detailed mechanisms have not been completely revealed. This complicated regulatory network may include genes, hormones, and epigenetic factors, which play significant roles in dedifferentiation. These factors build and maintain a specific niche. In addition, stem cells or stem cell-like cells may influence the dedifferentiating niche. Studies documented that stem cells retained in the tissues contribute to callus formation under certain environmental conditions. Moreover, plant cells that underwent stress or senescence present a dedifferentiation patter similar to the stem cell-like state prior to entry into new cell fates. Stem cells may communicate with neighboring cells by releasing specific signals during dedifferentiation of neighboring cells. This communication process may be enhanced by adding stem cells. However, further research must be performed to confirm this assumption. Elucidating signals/factors involved in the governing dedifferentiating niche, including stem cells, can provide insights into designing sophisticated and specific molecular tools to systematically manipulate organ regeneration.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.