Especially in the case of amide peptide bonds, the amount of cis conformations is quite limited thus hampering systematic studies, until recently. However, lately the emerging population of databases with more 3D structures of proteins has produced a considerable number of sequences containing non-proline cis formations (cis-nonPro).In peptides and proteins, only a small percentile of peptide bonds adopts the cis-nonPro formations. For this purpose, three types of pattern discovery are performed: i) exact pattern discovery, ii) pattern discovery using a chemical equivalency set, and iii) pattern discovery using a structural equivalency set. Afterwards, using each pattern as predicate, we search the Eukaryotic Linear Motif (ELM) resource to identify potential functional implications of regions with cis-nonPro peptide bonds. The patterns extracted from each type of pattern discovery are further employed, in order to formulate a pattern-based classifier, which is used to discriminate between cis-nonPro and trans-nonPro formations.In our work, we extract regular expression-type patterns that are descriptive of regions surrounding the cis-nonPro peptide bonds towards ligand/binding functionalities. As for the pattern-based classification scheme, the highest results were obtained using the structural equivalency set, which yielded 70% accuracy, 77% sensitivity and 63% specificity.In terms of functional implications, we observe a significant association of  Hence, the incorporation of these biologically inspired equivalency sets might provide adequate reasoning and insight into the molecular basis of cis-nonPro formations.The employment of substitution groups during pattern discovery is likely to uncover underlying patterns present in regions containing cis-nonPro regions, each extracted pattern is evaluated to quantify how generic it is by comparing it against major biological datasets and representative negative control sets. This is due to the fact that the extracted patterns have been derived from a single-class dataset (i.e. CNP), leading to questionable selectivity that needs to be further validated. Specifically, for each extracted pattern the log-likelihood is calculated using the "evaluate3plets" module in TEIRESIAS, representing the likelihood of the extracted pattern occurring by chance  character class which accounts for several occurrences of aspargine and aspartic acid. Another frequent character class is [FHWY] featuring aromatic residues; it is worth noticing that even though the character class itself is quite abundant, all the individual residues are scarcely observed in any type of pattern discovery. Hence, there is a clear association between aromatic residues as a whole and cis regions which contribute towards the stabilization of the cis peptide bond  has the highest frequency of occurrence and [AG] follows; on the contrary [QN] exhibits one of the smallest frequencies. Judging from the prevalent character class [ILMV] and more specifically from residues isoleucine, leucine and valine we observe a high propensity towards aliphatic residues. Character class [AG] appears with high frequency, which is in accordance with the previous observation for the individual residues alanine and glycine, and is further reinforced by the abundant occurrence of their combination as a character class. As for the structural equivalency set, character class [ITV] is the most frequent along with glycine; [DLN] and [FHWY] also show considerable representation in the retained patterns. The frequent occurrence of [ITV] character class shows a significant propensity of orted in , especial et al.  have alside bond , same asro bonds . This prro bonds . Regardicis-nonPro bonds across the 20 amino acids, in order to identify potential propensities towards specific residues; the respective frequencies are shown in Table cis--nonPro formation.We have also assessed the distribution of cis peptide bond towards certain amino acids, particularly for glycine   9] aim acis-nonPro formations. The elicitation of regular expression-type patterns from these regions has been motivated by the limited amount of available cis amide peptide bonds and to this end aims to facilitate the extrapolation and generalization of gained knowledge about these formations, in a more systematic manner. The resulting list of patterns contains approximately 200 patterns achieving 100% coverage of cis-nonPro bonds and FDR around 0.03% for trans-nonPro bonds. The retained patterns are subsequently evaluated in terms of their predictive potential towards discriminating between cis-nonPro and trans-nonPro peptide bonds, yielding quite encouraging results. Especially favorable for predictive purposes are the pattern sets obtained using the chemical and structural equivalencies among amino acids. Our findings confirmed that regions containing cis-nonPro peptide bonds appear replete with glycine as well as leucine and alanine, which facilitate the formation of the cis bond given their refined volume; a considerable propensity was also observed towards aromatic residues which possibly act as a wrench for the stabilization of the adjacent bond. Among the retained patterns we observed lack of cysteine and methionine which can be attributed to the sulfur atom and subsequently the highly reactive sulfhydryl group. Moreover, regarding the functional associations of cis-nonPro bonds we observed a high prevalence for ligand/binding sites.We presented a methodological analysis for extracting and annotating protein patterns. Specifically, the study focused on regions surrounding the scarce, yet highly important http://sites.google.com/site/cnppatterns/.For reproducibility reasons, all datasets and algorithms employed in this work, as well as extensive results and links to relevant resources, have been deposited and are available in the following URL: KPE conceived, designed and implemented the study, working towards his PhD thesis. TPE and CP provided valuable comments and discussions. GR has contributed to the implementation of the scripts and algorithms. DIF supervised the study and provided substantial advice and guidance during all phases. All authors have read and approved the final manuscript.


An expansion of glutamine repeats in the N-terminal domain of the huntingtin protein leads to Huntington's disease (HD), a neurodegenerative condition characterized by the presence of involuntary movements, dementia, and psychiatric disturbances. Evaluation of postmortem HD tissue indicates that the most prominent cell loss occurs in cerebral cortex and striatum, forebrain regions in which cortical pyramidal neurons (CPNs) and striatal medium spiny neurons (MSNs) are the most affected. Subsequent evidence obtained from HD patients and especially from transgenic mouse models of HD indicates that long before neuronal death, patterns of communication between CPNs and MSNs become dysfunctional. In fact, electrophysiological signaling in transgenic HD mice is altered even before the appearance of the HD behavioral phenotype, suggesting that dysfunctional cortical input to the striatum sets the stage for the emergence of HD neurological signs. Striatal MSNs, moreover, project back to cortex via multi-synaptic connections, allowing for even further disruptions in cortical processing. An effective therapeutic strategy for HD, therefore, may lie in understanding the synaptic mechanisms by which it dysregulates the corticostriatal system. Here, we review literature evaluating the molecular, morphological, and physiological alterations in the cerebral cortex, a key component of brain circuitry controlling motor behavior, as they occur in both patients and transgenic HD models. In 1872, George Huntington described a disease that affects certain families and is characterized by the presence of choreic movements that gradually increase in severity and variety; his description led to the name Huntington's disease  send massive and widespread projections to the striatum, forming the corticostriatal pathway that among other functions shapes motor behavior. Because the development of involuntary movements is a prominent feature of the HD phenotype, dysfunctional cortical input to striatum is likely to constitute a key component of HD neuropathology. In fact, emerging evidence from transgenic HD models suggests that the expression of mutant HTT alters the pattern of communication between CPNs and medium spiny neurons (MSNs) in the striatum. Striatal MSNs, moreover, send information to downstream structures that project to thalamus, which in turn projects back to cortex, allowing for even further disruptions in cortical processing. Here, our aim is to review the functional alterations in cerebral cortex in both patients and transgenic models of HD and to assess how these alterations disrupt the corticostriatal system to drive the HD phenotype.The cerebral cortex is the external sheet of neuronal tissue that covers the entire brain. In mammals, cerebral cortex folds together forming the “sulci” which compress a large portion of cortical tissue in a small area. In humans the thickness of the cerebral cortex is subject to regular local variations, but the average values range from 1.5 to 4.5 mm , premotor cortex dorsal caudal (PMdc), premotor cortex dorsal rostral (PMdr), cingulate motor area caudal (CGc), cingulate motor area rostral (CGr), premotor cortex ventral caudal (PMvc), premotor cortex ventral rostral (PMvr), pre-supplementary motor area (Pre-SMA), and supplementary motor area , positron emission tomography (PET), and single-photon-emission computed tomography (SPECT) have been used to detect brain atrophy and functional changes in pre-symptomatic HD patients. These approaches have not only confirmed the thinning of cerebral cortex, but also showed that this effect occurs early, develops progressively, and extends through the cortical mantle, although distinct grades of cortical thinning may occur  along with all or part of the exogenous human htt gene. In the knock-in model, CAG repeats are “knocked in” or directly inserted into the first exon of the endogenous Hdh gene.Transgenic mouse models of HD are often separated into three broad categories based on the genetic manipulation: truncated, full-length, and knock-in models. The truncated model expresses only the first exon of the human mutant htt gene with 82 CAG repeats   occur in the perirhinal cortex of R6/1 mice (Cummings et al., Dysfunctional interneurons also may contribute to impaired CPN activity in HD. For example, reduced GABAergic inhibitory input from interneurons occurs in HD models (Gu et al., Hdh CAG140 mice are more likely to show a decrease in correlated activity between simultaneously recorded pairs of neurons than corresponding wild-type controls (Walker et al., in vivo intracellular recordings in HD mice indicate a decreased correlation between cortical spiking and simultaneously recorded electrocorticograms relative to wild-type (Stern, Neurons communicate through the modulation of firing rate and by the generation of spike bursts, which are epochs of high firing frequency. Burst firing is relevant for the efficiency of neuronal transmission and also plays a role in neuronal plasticity Lisman, . Corticae Stern, . Importae Stern, , suggeste Stern, . Interese Stern, . In thise Stern, .in vitro, MSNs show increased excitability as indicated by a depolarized resting membrane potential and enhanced sensitivity to ionotropic glutamate receptor activation (Hodgson et al., Along with alterations in CPNs activity, striatal MSNs also show altered electrophysiological properties (reviewed by Cepeda et al., Collectively, these studies indicate that altered neuronal processing occurs in cerebral cortex of HD transgenic models, indicating that CPNs send aberrant information to MSNs. In fact, analysis of simultaneous recordings of LFPs from primary motor cortex and dorsal striatum, which receives major motor cortical input, indicates an overall reduction in the level of coherence or synchrony between these brain regions in R6/2 relative to wild-type mice across a range of behavioral episodes (Hong et al., in vitro and in vivo studies indicate that mutant HTT disrupts gene expression, calcium buffering, and mitochondrial function (Choo et al., A critical question is how mutant HTT alters corticostriatal neuronal activity. Two mechanisms have been suggested: cell-autonomous toxicity and cell–cell interaction toxicity (Gu et al., +/K+ ATPase, a key protein that helps to maintain the ionic gradient across the neuronal membrane (Bonvento et al., + gradient generated by the Na+/K+ ATPase to ensure glutamate clearance from the synapse and extracellular space. It is noteworthy that decreased glutamate uptake, a well-described feature of HD (Nicniocaill et al., Impaired energy production appears to be a key alteration in HD, as both HD transgenic models and HD patients show alteration in glycolytic and mitochondrial activity (Browne and Beal, An emerging picture of HD neuropathology includes aberrant cortical signaling that impacts striatal output systems and that then affects thalamic input back to cortex. In short, HD is characterized by dysregulated information flow through the cortico-striato-cortical pathway. This problem, moreover, emerges early in the course of HD, even before some neurological signs are present, suggesting a key role in the development and subsequent progression of the HD behavioral phenotype. Further research on alterations in cortical processing in HD, including the contribution of thalamic inputs and cortical interneurons, is emerging as fertile ground for further insight into the neuronal mechanisms underlying HD and for the development of effective therapeutic strategies.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.


Depression and suicidal thinking occur frequently alongside HIV/AIDS, triggering profound detrimental impacts on quality of life, treatment adherence, disease progression, and mortality. Yet the psychosocial factors contributing to these psychiatric comorbidities remain underexplored, particularly in the developing country context. This study thus examined different dimensions of perceived family support in relation to depression and suicidal ideation among people living with HIV/AIDS (PLWHA) in Nepal.A cross-sectional survey of 322 adult PLWHA residing in the Kathmandu Valley, Nepal was conducted. Data were analyzed using multiple logistic regressions for correlates of Beck Depression Inventory (BDI)-Ia-defined depressive symptoms and suicidal ideation in the past 2 weeks. Perceived family support, measured using the 10-item Nepali Family Support and Difficulty Scale, was entered into separate models, in turn, as a composite score, for each sub-scale , and for each individual item.Overall, 25.5% of participants registered BDI-Ia-defined depression, with significantly lower rates among those with perceived family support scores in the highest  and middle  tertiles relative to those with lowest-tertile scores. Meanwhile, 14.0% reported suicidal thinking, with significantly lower rates among those in the highest perceived family support tertile relative to the lowest . Broken down by support sub-scale, only negative support (i.e. family difficulty) was significant in its correlations with both outcomes – a trend similarly reflected in the item-wise analyses.Our findings highlight an important role for family support in determining experiences of depression and suicidality among PLWHA. Incorporating family counseling and support services – with special focus on ameliorating negative interaction and bolstering emotional support – into HIV care and treatment services may help to improve mental health along with overall wellness and treatment outcomes for HIV-positive populations in Nepal and similar settings. With the prolonged life expectancy made possible through introduction of highly active antiretroviral therapy (HAART), mental health issues have come to the fore as a critical problem in people living with HIV/AIDS (PLWHA). Especially common among the several psychiatric conditions comorbid with HIV/AIDS are depression and suicidal ideation Worldwide, mental health problems are a serious and growing public health problem, constituting the brunt of the non-fatal burden of disease in 2010. Under this umbrella, depressive disorders represent the leading cause of disability-adjusted life years (DALYs) attributable to mental, neurological, and substance use disorders in high-income and low- and middle-income countries (LMICs) alike perceived availability of social support can have a direct beneficial impact on health and mood Against the heavy burden of psychiatric comorbidities associated with a chronic illness such as HIV/AIDS, social and family support may have a moderating effect and present a promising mechanism through which the mental health needs of PLWHA might fruitfully be addressed. Social resources are generally protective against adverse psychological responses to stressful situations Among the different types of social support, family support is generally one of the most important factors affecting how patients adapt to illness negative social interactions constitute a distinct dimension of social support, with separate and potentially deleterious impacts on mental health While the beneficial impacts of support from social and family networks are widely recognized, the same intimate relationships can also be a source of tension and discord. Such Such a myopic perspective may be problematic when extrapolating to other populations, as fundamental differences in the historical, cultural, and sociological fabric of a country can come into heavy play and limit generalizability of findings. In Asian countries, for example, different risk factors are known to play a greater role in suicide, including impulsiveness, financial stress, and interpersonal conflict The aim of the present study was thus to examine factors associated with depression and suicidal ideation among PLWHA in the low-income South Asian country of Nepal, with a particular emphasis on elements of perceived family support. In particular, greater understanding of the manifestations and meanings of family support in this context could guide caregivers and policy makers in designing effective psychosocial interventions targeting PLWHA and their family members, with significant implications for the success of HIV prevention and treatment efforts. Such angles may be particularly important in a context of severely constrained resources for mental health.This cross-sectional study surveyed a community-based sample A total of 322 participants were recruited through purposive, convenience sampling techniques, as a detailed database of HIV-positive individuals was not available from which to select randomly. Referrals were obtained through staff members of five local non-governmental organizations (NGOs) working within HIV-positive communities in the study area. Individuals recruited for participation fulfilled the following inclusion criteria: (1) aged 18 to 60 years, (2) self-reported diagnosis of HIV-positive status, and (3) willing provision of written informed consent for voluntary participation.Data were collected during February and March 2010 as part of the baseline phase of an ongoing Healthy Living Intervention Study headed by the second and third authors. Trained interviewers administered the structured, pre-tested Nepali language questionnaire. Interviews were face-to-face and conducted in a private setting, with each lasting approximately 45–60 minutes.All participants were briefed on the study procedures with the aid of a prepared information sheet, after which each was asked to provide written informed consent prior to being interviewed. Numerical codes were used in place of names in all records to ensure confidentiality. Regarding sample selection procedures, the minimum age of 18 was used as the formal inclusion criterion because this is the legal age of majority in Nepal. Ultimately, however, the youngest participant was 20 years old. Both the Research Ethics Committee of the Graduate School of Medicine at the University of Tokyo and the Nepal Health Research Council reviewed and approved all study protocols and procedures.Perceived family support. Perceived family support is defined herein as the felt provision of different forms of emotional and instrumental services and assistance from family members, along with negative, or unsupportive, forms of family interaction, within the past year, as measured using the 10-item Nepali Family Support and Difficulty Scale . For each item, participants were asked to rate how true each statement was for their own family on a four-point Likert scale ranging from “Not at all” (0) to “All the time” (3). The scale was developed specifically for use in Nepal. After reversing the scores for negatively formulated items , the total score was derived by summing all items, with higher scores indicating greater perceived family support (instrument range: 0–30). For the analysis, total scores were categorized into low (0–22), moderate (23–26), and high (27–30) levels of perceived support by tertiles.emotional support , instrumental support , and negative interaction . For the analysis, total sub-scores within each support category were again classified as low, medium, or high by tertiles.Total sub-scores for each of the different types of family support measured three dimensions of social exchange: The 21-item BDI-Ia, Nepali version Assessment of suicidal ideation was based on BDI-Ia item #9 , which was used as a dichotomous variable indicating the presence or absence of suicidal thoughts or wishes. Suicidal ideation endorsement was defined as responding to BDI-Ia item #9 with either (1) “I have thoughts of killing myself but I would not carry them out,” (2) “I would like to kill myself,” or (3) “I would kill myself if I had the chance”. Also included on the questionnaire were items asking about ever-experience of suicidal ideation and number of suicide attempts (if any) since being diagnosed with HIV.Measures of key sociodemographic, HIV-specific clinical, and psychosocial variables were included in the analyses as control variables.2 according to the WHO BMI classification standard for Asians Standard single questionnaire items assessed basic sociodemographic, psychosocial, and HIV-specific clinical variables. Body mass index (BMI) was calculated from the measurement of height and body weight, with underweight defined as a BMI of less than 18.5 kg/mFelt sad, down or depressed; Felt nervous or anxious; and Difficulty falling or staying asleep) were omitted for the purposes of this study to focus on the somatic aspect and avoid overlap with the measure of depressive symptoms. Participants reported whether each symptom was present, and if so, whether it was bothersome, by using a five-point Likert scale ranging from “I do not have this symptom” (0) to “I have it and it bothers me a lot” (4). Each item was dichotomized into absent/not bothersome (0–2) vs. present and bothersome (3–4) and the resulting scores summed to obtain a bothersome symptom count, with a possible range of 0–17 A modified 17-item version of the HIV Symptom Index (HSI) A modified 7-item version of the AIDS-related Stigma Scale Descriptive statistics were calculated for demographic and other relevant characteristics of the study sample. Multiple logistic regression analysis was then used to examine factors associated with depressive symptoms and suicidal ideation, with particular emphasis on the association between level of perceived family support and the two mental health outcomes. Separate multivariate models were also separately constructed to assess potential effects of each of the family support sub-scores and individual scale items on depression and suicidal ideation among the participants, adjusting for the same set of potential confounders. Additional logistic regression analysis was performed to explore factors associated with family support, with total family support collapsed into a dichotomous categorical variable based on the overall median score (25).Independent variables were entered into each regression using a direct (simultaneous) entry method. All major sociodemographic characteristics and other factors having previously established or theoretically feasible associations with the dependent variables were included as covariates or potential confounders in the analyses. Additionally, interactions between perceived family support and each of the other variables included as covariates were tested by evaluating the statistical significance of the corresponding first-order cross product terms in separate corresponding models; as none of the interaction terms was statistically significant, they were excluded from the final models. Variance inflation factors (VIFs) were low (<2.0) in all cases, indicating no problematic multicollinearity among independent variables. All statistical tests were 2-sided, evaluated as significant at the p<0.05 level, and executed using SPSS version 18.0 for Macintosh .ever thought about ending their lives and 17% had actually attempted suicide since being diagnosed with HIV, with 35 individuals reporting more than one such suicide attempt  and suicidal ideation (BDI-Ia item #9>0) from multivariate regression models are presented in Higher rates of depression were also associated with higher levels of internalized AIDS stigma  and being underweight . Older-age participants were similarly inclined toward greater rates of depressive symptoms, but the association did not reach statistical significance.Feeling shown love and caring by family  and Feeling exploited (for housework and farming) by family . Additionally, rates of depression were lower among those who endorsed Feeling able to share feelings with family , while rates of suicidal ideation were higher among those who endorsed Feeling disliked by family  and Feeling  distant from family .Only two family support elements were significantly associated with both mental health outcomes: Four variables were significantly associated with perceived family support among participants: HIV symptom burden, internalized AIDS stigma, education level, and gender. Namely, those suffering from higher levels of internalized AIDS stigma  and higher bothersome HIV symptom counts  were less likely to report higher levels of family support. On the other side, those educated to the primary level or higher  and men  were more likely to report higher family support levels.This study is among the first to shed light on important and distinct roles played by both positive and negative elements of perceived family support in determining the experience of serious psychological distress in the context of HIV/AIDS in a low-income Asian country. Against heavy burdens of BDI-Ia-defined depression (26%) and suicidal ideation (14%) among PLWHA in the Kathmandu Valley of Nepal, positive forms of family support – especially in the emotional realm – appeared to have a protective effect and negative family interactions an even stronger contributing effect toward both outcomes. Meanwhile, rates of depression and suicidal thoughts were elevated among those in the earlier stages of ART, those experiencing heavier burdens of HIV symptoms or stigma, those who had recently used illicit drugs, and those without employment.Among the central findings of this study, perceived family support as a composite construct emerged as a major correlate of both depression and suicidal ideation. Indeed, those participants reporting the highest level of perceived family support were over five times less likely than those at the lowest level to register BDI-Ia-defined depression and four times less likely to endorse suicidal ideation. This result uniquely extends theory on the link between perceived family support and psychological distress to an HIV-specific population, elucidating the strong and potentially protective effect of perceived family support in terms of depression and suicidality risks. Although families generally function differently depending on cultural context, these findings point to overarching commonalities regarding the influence of perceived family support in an individual, regardless of the specific setting or the particular nature of the stressors.negative support domain, particularly with regard to suicidal ideation – an especially dangerous manifestation of psychological distress. Specifically, feelings of being exploited, rejected, and emotionally distant from family members played heavily into experiences of depression and suicidal ideation. One explanation for this may be that negative interactions are less frequently encountered and hence more saliently felt relative to positive ones. This may be particularly true in the case of family relationships. Moreover, negative interactions can potentially undermine an individual’s sense of personal control or self-worth, erode motivation to engage in positive health behaviors, and provoke adverse physiological responses Yet, based on item-wise multivariate analysis of the perceived family support scale in relation to depression and suicidal ideation, some elements of family support appear to be more important than others to the lived experience of HIV/AIDS. Namely, consistent with certain under-explored threads in research on social support and psychological well-being Emotional support and nurturance elements of feeling loved, cared for, and understood also emerged as important correlates in buffering against negative psychological states, whereas instrumental support factors appeared not to be as critical in determining mental health among the PLWHA surveyed. Among the positive forms of social support, emotional support is generally reported to be the most important for its clear links to health in terms of direct and buffering effects Beyond family support, four further independent variables had significant associations with both depression and suicidal ideation after adjustment: HIV symptom burden, ART treatment status, reporting any recent illicit drug use, and being unemployed. In particular, those reporting a greater number of bothersome HIV symptoms in the present study were roughly four times more likely not only to be depressed, but also to harbor suicidal thoughts. This expands significantly on prior studies of symptom-related negative mental health correlates among PLWHA In addition to the potential psychological impacts of generalized somatic HIV-related symptoms, the results suggest that PLWHA treated with ART are more susceptible than those not on treatment to both depressive symptoms and suicidal ideation, particularly in the earlier treatment stages – perhaps when patients have not yet had time to adjust to the unique strains of treatment or to develop effective coping mechanisms that lead to reduced depression and suicidality risk over time. The observed association supports the depression-inducing potential of such treatment regimens among PLWHA, offering valuable insights into frequently overlooked psychosocial aspects of ART treatment. The undisputed benefits of ART notwithstanding, previous studies have shown that neuropsychiatric side-effects including depression are seen in up to 73% of HIV-infected patients on treatment regimens In a similar vein, both recent illicit drug use and employment status also emerged as significant correlates of both depression and suicidal ideation among the PLWHA surveyed. While such relationships with depression have previously been suggested in the general population Finally, depressive symptoms, though not suicidal ideation, were positively linked with both higher levels of internalized AIDS stigma and being underweight among PLWHA in this study. The correlation uncovered between depression and low BMI among PLWHA in a low-income South Asian country expands on similar findings in a study of HIV-positive men who have sex with men in the United States Several study limitations should be taken into account when interpreting these results. First, although a relatively large number of participants from multiple NGO outreach networks across the Kathmandu Valley were surveyed, findings are specifically representative of PLWHA falling within the network of partnering NGOs. Second, this study relies on self-reported measures, leaving room for several sources of bias; a social desirability bias may have been introduced, for instance, in the face-to-face interview format, though a confidential and sensitive approach to survey administration was designed to limit any such tendency. Third, this study measured perceived family support rather than actual support, though research has suggested that perceived support may be even more important than objective received support or network size in its associations with health and adjustment criteria Notwithstanding such limitations, the present study has clear value in testing a novel hypothesis with implications for research at the intersection of HIV/AIDS and mental health and in its use of well-validated research measures. To our knowledge, this is the first study to report the distinct effects of a set of perceived family support items – encompassing both positive  and negative facets – on both depression and suicidal ideation among PLWHA in Nepal or elsewhere. The findings have strong implications for the development of targeted intervention and prevention efforts to address the heavy burden of psychological distress among PLWHA in such contexts. Critically, identified associations highlight the potential of programs to minimize the harmful psychological impacts of HIV-related stressors through enhancing supportive family interactions while mitigating unsupportive ones.Among PLWHA in the Kathmandu Valley of Nepal, the burden of depression and suicidal ideation is heavy and positively associated with perceived family support, among other established sociodemographic, clinical, and psychosocial correlates. Such findings underscore a need to work within a context of limited mental health resources in Nepal and similar settings by developing innovative psychosocial interventions incorporating family counseling and support elements as an integral component of HIV prevention, care, and treatment efforts. In particular, future programs should work with PLWHA to navigate the double-edged sword of family support – identifying and improving family relationships that are the source of negative exchanges while engaging positive family support structures to buffer against psychiatric comorbidities, especially in times of life stress. Given the identified correlates of perceived family support, such interventions would perhaps be most fruitful by focusing especially on female gender and low levels of education as risk factors for poor family support, and devoting special attention to those with heavy symptom burdens and high levels of internalized stigma. Coupled with this is a need for community-level anti-stigma programs to decrease the stigma and discrimination experienced both within and outside of families, thus helping to foster an environment more conducive to positively supportive interactions.


Neuroprotection aims to prevent salvageable neurons from dying. Despite showing efficacy in experimental stroke studies, the concept of neuroprotection has failed in clinical trials. Reasons for the translational difficulties include a lack of methodological agreement between preclinical and clinical studies and the heterogeneity of stroke in humans compared to homogeneous strokes in animal models. Even when the international recommendations for preclinical stroke research, the Stroke Academic Industry Roundtable (STAIR) criteria, were followed, we have still seen limited success in the clinic, examples being NXY-059 and haematopoietic growth factors which fulfilled nearly all the STAIR criteria. However, there are a number of neuroprotective treatments under investigation in clinical trials such as hypothermia and ebselen. Moreover, promising neuroprotective treatments based on a deeper understanding of the complex pathophysiology of ischemic stroke such as inhibitors of NADPH oxidases and PSD-95 are currently evaluated in preclinical studies. Further concepts to improve translation include the investigation of neuroprotectants in multicenter preclinical Phase III-type studies, improved animal models, and close alignment between clinical trial and preclinical methodologies. Future successful translation will require both new concepts for preclinical testing and innovative approaches based on mechanistic insights into the ischemic cascade. Ischemic stroke, caused by a clot occluding a blood vessel leading to or within the brain, results in impaired blood flow, which produces neuronal cell death. Ischemic stroke is the third greatest cause of mortality and the leading cause of disability in the western world. With an ageing population, putative treatments for ischemic stroke are required to limit the extent of stroke-induced morbidity and mortality. Unfortunately, only one pharmacological agent is routinely administered for acute ischemic stroke, recombinant tissue plasminogen activator (rtPA), a thrombolytic that restores blood flow to the ischemic brain . CurrentThe center of the brain region with diminished blood flow following cerebral ischemia is the ischemic core. In this region, blood flow is depleted and neurons undergo irreversible death within minutes. Surrounding the core is the penumbra , a regio2+ influx into cells, mitochondrial dysfunction, activation of many intracellular enzymes, free radical production, nitric oxide production, apoptosis, and inflammation [Neuroprotection is specifically defined as the “protection of neurons” and is a strategy used to potentially protect the brain in a number of different cerebral conditions including Parkinson’s disease, traumatic brain injury and ischemic stroke –6. Whileammation . Unfortuammation .In pre-clinical studies, many different methods are used to assess neuroprotection. The predominant method is usually estimating the size of the cerebral infarction volume using histology or magnetic resonance imaging following a model of ischemic stroke such as middle cerebral artery occlusion (MCAO). In light of the fact that assessment of neurological outcome is the primary endpoint in clinical stroke studies, recent trends have been to use functional or behavioral indices to assess neurological deficit in pre-clinical studies . This coet al. [As shown by the comprehensive review of neuroprotective compounds by O’Collins et al. , there iet al. , based oet al. ,13. It iet al. , but incet al. . These dNeuroprotection for ischemic stroke from a translational standpoint has recently been reviewed . The preet al. identified publications on 1026 candidate stroke drugs of which about two thirds were superior to control treatments [The process of developing new neuroprotective stroke treatments usually progresses from preclinical to clinical studies. In animal models a treatment’s mechanisms of action and its efficacy regarding infarct size reduction and functional outcome are investigated. As described above, numerous potential targets for neuroprotective strategies for stroke were identified including inflammation, neuronal apoptosis, free radical damage, excitotoxicity, and calcium influx into cells. Among these impeding excitotoxicity was the most targeted mechanism in animal experimental stroke . More theatments . Despiteeatments . PromisiSince neuroprotection for ischemic stroke was first studied, there have been nearly 200 clinical trials using potential neuroprotective agents for ischemic stroke. As described earlier, not one treatment has proven to be effective at providing functional benefit to ischemic stroke patients, even though many of these agents had varying mechanisms of action by targeting different aspects of the ischemic cascade. Despite this apparent failure of clinical neuroprotection, there are a number of ongoing clinical trials investigating promising neuroprotectants that have shown pre-clinical efficacy , of whicOne of the most hopeful neuroprotective strategies that is currently under clinical investigation is hypothermia, the act of cooling the brain temperature down. Hypothermia has shown significant pre-clinical efficacy in animal models of cerebral ischemia , and hasDespite the failure of NXY-059 (discussed later in the article), two free radical scavengers are currently being investigated in clinical trials for neuroprotection for stroke. Ebselen, a glutathione-peroxidase mimic reduced infarct volume by 27% on average in nine focal ischemia studies with 10 of the 16 experimental contrasts showing protection ,29, and Other selected neuroprotective strategies that are currently undergoing investigation include magnesium sulphate, statins, DP-b99, minocycline, and albumin. Magnesium produced significant protection in preclinical animal models of stroke  by inhibStatins block the rate-limiting enzyme of cholesterol production hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, but also improve blood flow through increased nitric oxide availability as well as anti-inflammatory and antioxidant effects . Now, a As mentioned above, a wide variety of candidate neuroprotectants was shown to be beneficial in preclinical studies, whereas none were demonstrated to be superior to placebo in clinical trials . Here weN-tert-butylnitrone (NXY-059) act as a free radical trap that could potentially inhibit ischemic cell death [Free radicals have long been established as a mediator of ischemic injury . Many nill death . Many prll death , with a ll death . To mimill death . NXY-059ll death  and a poll death . These rThere have been a number of reasons given as to why NXY-059 efficacy could not be translated to human ischemic stroke. Pre-clinically, it was shown that NXY-059 may cross the BBB in only small quantities suggesting that its action on the neurovascular unit may mediate its protective effect rather than in the brain parenchyma ,63. OverThe well-known and eponymous function of haematopoietic growth factors is to regulate the mobilization, proliferation, maturation and the survival of bone marrow-derived cells . RecentlIn a pilot clinical trial EPO was safe in stroke patients and there was some evidence that EPO might improve outcome . These iA phase IIa clinical trial showed that G-CSF was safe in stroke patients even at high doses . In thisThe two case examples of failed neuroprotective treatments for stroke patients outlined the problems associated with translation. Reasons for translational difficulties have been discussed exhaustively but include variable outcome measures, clinical trial design flaws, delayed treatment time window, small sample sizes, and failure to achieve sufficient plasma levels of treatments ,84,85. INew concepts to improve translation from animal experimental studies to clinic comprise applying the process of clinical drug development to the preclinical situation . This inOther strategies to improve outcome after stroke include treatments that promote neurological recovery by remodeling of brain tissue (for a review see ). By conDespite all the disappointments there are still potential neuroprotective compounds that are currently being investigated for the treatment of acute stroke . Here weFree radical formation including ROS (reactive oxygen species) contributes to secondary infarct growth –101. HowAnother promising approach includes the inhibition of the NMDA receptor associated protein PSD-95 (postsynaptic density protein-95). This protein binds both NMDA receptors and neuronal nitric oxide synthase (nNOS) at excitatory synapses and assembles them into a signaling complex . ActivatAnother attractive target could be the activation and stabilization of hypoxia-inducible factor (HIF). HIF (isoforms 1–3) are activated under conditions of low oxygen tension and stimulate many biological processes such as vascular tone, erythopoiesis and angiogenesis . Under nAnother potential therapeutic approach is targeting inflammation following ischemic stroke. Cytokines such as interleukin-1 (IL-1) have been implicated in neuronal injury following ischemic stroke as well as traumatic brain injury and excitotoxicity . ExogenoThe failed translation from animal experimental stroke studies to clinical studies has created a great deal of pessimism over the neuroprotection hypothesis. Although animal stroke research has not directly yielded new clinical drugs, it has provided important mechanistic insights into the complex pathophysiology of ischemic stroke which will pave the way for future therapies. Moreover, we have learnt that the implementation of quality standards in experimental studies is not a panacea, but future neuroprotection experiments should nevertheless adhere to these methodological standards. Suggested multicenter preclinical Phase III-type studies might be a further concept to improve the evaluation of candidate neuroprotectants before moving to clinical trials. However, one has to keep the balance between high quality on the one hand, and practicability for preclinical research groups on the other hand. The validation of results from rodent experiments in higher-order primates sounds reasonable and might close the gap between rodent and human studies. Primate experiments, however, raise ethical concerns considering stroke is such an injuring and disabling condition. Practical concerns exist due to the high costs of primates and only a few primate facilities exist across Europe . Future