Rethinking global health from south and north: A social medicine approach to global health education.

This study examines efforts to integrate social medicine into global health education and its potential to guide the new practice of structural competency. The methods employ participant observation and interviews with program coordinators and participants in a social medicine course. Areas of success included: pedagogical innovation, conscientizing course participants, decentralising global health practice, and promoting reflexivity. Accompanying these successes were points of friction, including: inequities in personal risk and mobility limitations among course participants, as well as complexities and nuances in unintentionally reproducing hierarchies of knowledge. Specifically, further recommendations from our research include: (1) incorporating innovative pedagogical approaches, which highlight social medicine practices outside the global north, prioritising opportunities for cross-collaboration among practitioners from the global south; (2) framing social theory as a bidirectional flow: global south traditions must be included in teaching social theory; (3) practising structural humility by highlighting the perspectives and expertise of communities experiencing social and structural marginalisation, while including strategies in organising and direct pathways to political engagement. These conclusions highlight how social medicine-based training can both build from and move beyond the competencies explicitly specified by the structural competency model to create a global health practice inclusive of diverse thought from around the world.

COVID-19 reveals weak health systems by design: Why we must re-make global health in this historic moment.

The COVID-19 pandemic demonstrates the critical need to reimagine and repair the broken systems of global health. Specifically, the pandemic demonstrates the hollowness of the global health rhetoric of equity, the weaknesses of a health security-driven global health agenda, and the negative health impacts of power differentials not only globally, but also regionally and locally. This article analyses the effects of these inequities and calls on governments, multilateral agencies, universities, and NGOs to engage in true collaboration and partnership in this historic moment. Before this pandemic spreads further - including in the Global South - with potentially extreme impact, we must work together to rectify the field and practice of global health.

A computational neurodegenerative disease progression score: method and results with the Alzheimer's disease Neuroimaging Initiative cohort.

While neurodegenerative diseases are characterized by steady degeneration over relatively long timelines, it is widely believed that the early stages are the most promising for therapeutic intervention, before irreversible neuronal loss occurs. Developing a therapeutic response requires a precise measure of disease progression. However, since the early stages are for the most part asymptomatic, obtaining accurate measures of disease progression is difficult. Longitudinal databases of hundreds of subjects observed during several years with tens of validated biomarkers are becoming available, allowing the use of computational methods. We propose a widely applicable statistical methodology for creating a disease progression score (DPS), using multiple biomarkers, for subjects with a neurodegenerative disease. The proposed methodology was evaluated for Alzheimer's disease (AD) using the publicly available AD Neuroimaging Initiative (ADNI) database, yielding an Alzheimer's DPS or ADPS score for each subject and each time-point in the database. In addition, a common description of biomarker changes was produced allowing for an ordering of the biomarkers. The Rey Auditory Verbal Learning Test delayed recall was found to be the earliest biomarker to become abnormal. The group of biomarkers comprising the volume of the hippocampus and the protein concentration amyloid beta and Tau were next in the timeline, and these were followed by three cognitive biomarkers. The proposed methodology thus has potential to stage individuals according to their state of disease progression relative to a population and to deduce common behaviors of biomarkers in the disease itself.

Comparative effectiveness of care coordination interventions in the emergency department: a systematic review.

STUDY OBJECTIVE: To conduct a systematic review on the effectiveness of emergency department (ED)-based care coordination interventions. METHODS: We reviewed any randomized controlled trial or quasi-experimental study indexed in MEDLINE, CINAHL, Web of Science, Cochrane, or Scopus that evaluated the effectiveness of ED-based care coordination interventions. To be included, interventions had to incorporate information from previous visits, provide educational services on continuing care, provide post-ED treatment plans, or transfer information to continuing care providers. Studies had to quantify information transfer or report ED revisits, hospitalizations, or follow-up rates. Randomized controlled trial quality was assessed with the Jadad score. RESULTS: Of 23 included articles, 14 were randomized controlled trials and 9 were quasi-experimental studies. Randomized controlled trial quality ranged from 2 to 3 on a 5-point scale. The majority of the studies (17) were conducted at a single center. Of nineteen studies that developed post-ED plans, 12 were effective in improving follow-up rates or reducing repeated ED visits. Four studies found paradoxically higher ED visit rates. Of 4 that used educational services for continuing care, 2 were effective. Of the 2 evaluating information transfer, 1 was effective. One study assessed incorporating information from other sites and found higher rates of information transfer, but utilization was not studied. CONCLUSION: The majority of ED-based care coordination interventions focus on interfacing with outpatient providers, and about two thirds have been effective in increasing follow-up rates or reducing repeated ED utilization. Other types of interventions have shown similar effectiveness, but fewer have been studied.

Disease progression modeling using Hidden Markov Models.

The development of novel treatments for many slowly progressing diseases, such as Alzheimer's disease (AD), is dependent on the ability to monitor and detect changes in disease progression. In some diseases the distinct clinical stages of the disease progress far too slowly to enable a quick evaluation of the efficacy of a given proposed treatment. To help improve the assessment of disease progression, we propose using Hidden Markov Models (HMM's) to model, in a more granular fashion, disease progression as compared to the clinical stages of the disease. Unlike many other applications of Hidden Markov Models, we train our HMM in an unsupervised way and then evaluate how effective the model is at uncovering underlying statistical patterns in disease progression by considering HMM states as disease stages. In this study, we focus on AD and show that our model, when evaluated on the cross validation data, can identify more granular disease stages than the three currently accepted clinical stages of "Normal", "MCI" (Mild Cognitive Impairment), and "AD".

Meta-analysis for genome-wide association study identifies multiple variants at the BIN1 locus associated with late-onset Alzheimer's disease.

Recent GWAS studies focused on uncovering novel genetic loci related to AD have revealed associations with variants near CLU, CR1, PICALM and BIN1. In this study, we conducted a genome-wide association study in an independent set of 1034 cases and 1186 controls using the Illumina genotyping platforms. By coupling our data with available GWAS datasets from the ADNI and GenADA, we replicated the original associations in both PICALM (rs3851179) and CR1 (rs3818361). The PICALM variant seems to be non-significant after we adjusted for APOE e4 status. We further tested our top markers in 751 independent cases and 751 matched controls. Besides the markers close to the APOE locus, a marker (rs12989701) upstream of BIN1 locus was replicated and the combined analysis reached genome-wide significance level (p = 5E-08). We combined our data with the published Harold et al. study and meta-analysis with all available 6521 cases and 10360 controls at the BIN1 locus revealed two significant variants (rs12989701, p = 1.32E-10 and rs744373, p = 3.16E-10) in limited linkage disequilibrium (r²â€Š =  0.05) with each other. The independent contribution of both SNPs was supported by haplotype conditional analysis. We also conducted multivariate analysis in canonical pathways and identified a consistent signal in the downstream pathways targeted by Gleevec (P = 0.004 in Pfizer; P = 0.028 in ADNI and P = 0.04 in GenADA). We further tested variants in CLU, PICALM, BIN1 and CR1 for association with disease progression in 597 AD patients where longitudinal cognitive measures are sufficient. Both the PICALM and CLU variants showed nominal significant association with cognitive decline as measured by change in Clinical Dementia Rating-sum of boxes (CDR-SB) score from the baseline but did not pass multiple-test correction. Future experiments will help us better understand potential roles of these genetic loci in AD pathology.

Disease progression model for cognitive deterioration from Alzheimer's Disease Neuroimaging Initiative database.

BACKGROUND: A mathematical model was developed to describe the longitudinal response in Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog) obtained from the Alzheimer's Disease Neuroimaging Initiative. METHODS: The model was fit to the longitudinal ADAS-cog scores from 817 patients. Risk factors (age, apolipoprotein ɛ4 [APOE ɛ4] genotype, gender, family history of AD, years of education) and baseline severity were tested as covariates. RESULTS: Rate of disease progression increased with baseline severity. Age, APOE ɛ4 genotype, and gender were identified as potential covariates influencing disease progression. The rate of disease progression in patients with mild to moderate AD was estimated as approximately 5.5 points/yr. CONCLUSIONS: A disease progression model adequately described the natural decline of ADAS-cog observed in Alzheimer's Disease Neuroimaging Initiative. Baseline severity is an important covariate to predict a curvilinear rate of disease progression in normal elderly, mild cognitive impairment, and AD patients. Age, APOE ɛ4 genotype, and gender also influence the rate of disease progression.

Hallucinogen-like effects of N,N-dipropyltryptamine (DPT): possible mediation by serotonin 5-HT1A and 5-HT2A receptors in rodents.

N,N-dipropyltryptamine (DPT) is a synthetic tryptamine hallucinogen which has been used psychotherapeutically in humans, but has been studied preclinically only rarely. In the present studies, DPT was tested in a drug-elicited head-twitch assay in mice, and in rats trained to discriminate lysergic acid diethylamide (LSD), N,N-dimethyl-4-phosphoryloxytryptamine (psilocybin), or 3,4-methylenedioxymethamphetamine (MDMA). A separate group of rats was also trained to recognize DPT itself as a discriminative stimulus, and in all cases, the behavioral effects of DPT were challenged with the selective serotonin (5-HT)2A antagonist M100907, the 5-HT1A selective antagonist WAY-100635, or their combination. In the head-twitch assay, DPT elicited dose-dependent effects, producing a biphasic dose-effect curve. WAY-100635 produced a parallel rightward shift in the dose-effect curve for head twitches, indicative of surmountable antagonism, but the antagonist effects of M100907 were functionally insurmountable. DPT produced partial to full substitution when tested in rats trained to discriminate LSD, psilocybin or MDMA, and served as a discriminative stimulus. In all cases, the antagonist effects of M100907 were more profound than were those of WAY-100635. DPT is thus active in two rodent models relevant to 5-HT2 agonist activity. The effectiveness with which M100907 antagonizes the behavioral actions of this compound strongly suggest that the 5-HT2A receptor is an important site of action for DPT, but the modulatory actions of WAY-100635 also imply a 5-HT1A-mediated component to the actions of this compound.

Modulation of glycine potency in rat recombinant NMDA receptors containing chimeric NR2A/2D subunits expressed in Xenopus laevis oocytes.

Heteromeric NMDARs are composed of coagonist glycine-binding NR1 subunits and glutamate-binding NR2 subunits. The majority of functional NMDARs in the mammalian central nervous system (CNS) contain two NR1 subunits and two NR2 subunits of which there are four types (A-D). We show that the potency of a variety of endogenous and synthetic glycine-site coagonists varies between recombinant NMDARs such that the highest potency is seen at NR2D-containing and the lowest at NR2A-containing NMDARs. This heterogeneity is specified by the particular NR2 subunit within the NMDAR complex since the glycine-binding NR1 subunit is common to all NMDARs investigated. To identify the molecular determinants responsible for this heterogeneity, we generated chimeric NR2A/2D subunits where we exchanged the S1 and S2 regions that form the ligand-binding domains and coexpressed these with NR1 subunits in Xenopus laevis oocytes. Glycine concentration-response curves for NMDARs containing NR2A subunits including the NR2D S1 region gave mean glycine EC(50) values similar to NR2A(WT)-containing NMDARs. However, receptors containing NR2A subunits including the NR2D S2 region or both NR2D S1 and S2 regions gave glycine potencies similar to those seen in NR2D(WT)-containing NMDARs. In particular, two residues in the S2 region of the NR2A subunit (Lys719 and Tyr735) when mutated to the corresponding residues found in the NR2D subunit influence glycine potency. We conclude that the variation in glycine potency is caused by interactions between the NR1 and NR2 ligand-binding domains that occur following agonist binding and which may be involved in the initial conformation changes that determine channel gating.

Cerebral glucose metabolism in obsessive-compulsive hoarding.

OBJECTIVE: Compulsive hoarding and saving symptoms, found in many patients with obsessive-compulsive disorder (OCD), are part of a discrete clinical syndrome that includes indecisiveness, disorganization, perfectionism, procrastination, and avoidance and has been associated with poor response to medications and cognitive behavior therapy. The authors sought to identify cerebral metabolic patterns specifically associated with the compulsive hoarding syndrome using positron emission tomography (PET). METHOD: [(18)F]Fluorodeoxyglucose PET scans were obtained for 45 adult subjects who met DSM-IV criteria for OCD (12 of whom had compulsive hoarding as their most prominent OCD symptom factor) and 17 normal comparison subjects. All subjects had been free of psychotropic medication for at least 4 weeks. Regional cerebral glucose metabolism was compared between the groups. RESULTS: In relation to the comparison subjects, the patients with compulsive hoarding syndrome had significantly lower glucose metabolism in the posterior cingulate gyrus and cuneus, whereas the nonhoarding OCD patients had significantly higher glucose metabolism in the bilateral thalamus and caudate. In relation to nonhoarding OCD patients, compulsive hoarders had significantly lower metabolism in the dorsal anterior cingulate gyrus. Across all OCD patients, hoarding severity was negatively correlated with glucose metabolism in the dorsal anterior cingulate gyrus. CONCLUSIONS: OCD patients with the compulsive hoarding syndrome had a different pattern of cerebral glucose metabolism than nonhoarding OCD patients and comparison subjects. Obsessive-compulsive hoarding may be a neurobiologically distinct subgroup or variant of OCD whose symptoms and poor response to anti-obsessional treatment are mediated by lower activity in the cingulate cortex.