Smoking Progression and Nicotine-Enhanced Reward Sensitivity Predicted by Resting-State Functional Connectivity in Salience and Executive Control Networks.

INTRODUCTION: The neural underpinnings underlying individual differences in nicotine-enhanced reward sensitivity and smoking progression are poorly understood. Thus, we investigated whether brain resting-state functional connectivity (rsFC) during smoking abstinence predicts nicotine-enhanced reward sensitivity and smoking progression in young light smokers. We hypothesized that high rsFC between brain areas with high densities of nicotinic receptors (insula, anterior cingulate cortex [ACC], hippocampus, thalamus) and areas involved in reward-seeking (nucleus accumbens [NAcc], prefrontal cortex [PFC]) would predict nicotine-enhanced reward sensitivity and smoking progression. METHODS: Young light smokers (N=64, age 18-24, M = 1.89 cigarettes/day) participated in the study. These individuals smoked between 5 to 35 cigarettes per week and lifetime use never exceeded 35 cigarettes per week. Their rsFC was assessed using functional magnetic resonance imaging after 14-hour nicotine-deprivation. Subjects also completed a probabilistic reward task after smoking a placebo on one day and a regular cigarette on another day. RESULTS: The probabilistic-reward-task assessed greater nicotine-enhanced reward sensitivity was associated with greater rsFC between the right anterior PFC and right NAcc, but with reduced rsFC between the ACC and left inferior prefrontal gyrus and the insula and ACC. Decreased rsFC within the salience network (ACC and insula) predicted increased smoking progression across 18 months and greater nicotine-enhanced reward sensitivity. CONCLUSIONS: These findings provide the first evidence that differences in rsFCs in young light smokers are associated with nicotine-enhanced reward sensitivity and smoking progression. IMPLICATIONS: Weaker rsFC within the salience network predicted greater nicotine-enhanced reward sensitivity and smoking progression. These findings suggest that salience network rsFC and drug-enhanced reward sensitivity may be useful tools and potential endophenotypes for reward sensitivity and drug-dependence research.

The effect of 22.5 kHz low-frequency contact ultrasound debridement (LFCUD) on lower extremity wound healing for a vascular surgery population: A randomised controlled trial.

The aim of this study was to compare changes in wound size and appearance and health complication rates in patients with vasculopathy and lower-extremity wounds treated with or without low-frequency contact ultrasound debridement (LFCUD) This study was a randomised controlled trial. The study was conducted in a vascular surgery service, including outpatient wound clinic and inpatient ward, in a tertiary care academic centre. In total, 70 patients with vasculopathy and lower-extremity wounds of mixed aetiology were enrolled in the trial; 68 completed the study. Patients were randomised to receive LFCUD plus usual care (n = 33) or usual care (n = 37) at 4 weekly visits, and were followed thereafter for up to 12 wk. The main outcome measures included closed wounds, change in wound surface area (WSA), and wound appearance by the revised Photographic Wound Assessment Tool (revPWAT). After 4 weekly LFCUD treatments, patients in the LFCUD group had significantly better wound appearance (total revPWAT score) compared with the control group treated only with usual care (P = <0.05). LFCUD-treated wounds also had a significant reduction in WSA over 4 wk that was not found in the UC group. LFCUD treatment was also associated with a greater number of healed wounds, odds ratio 5.00 (95% CI 1.24-20.25), and fewer instances of wound deterioration. Weekly LFCUD applications to patients with significant vasculopathy resulted in superior healing outcomes when compared with current usual wound care practice.

Mutations affecting the SAND domain of DEAF1 cause intellectual disability with severe speech impairment and behavioral problems.

Recently, we identified in two individuals with intellectual disability (ID) different de novo mutations in DEAF1, which encodes a transcription factor with an important role in embryonic development. To ascertain whether these mutations in DEAF1 are causative for the ID phenotype, we performed targeted resequencing of DEAF1 in an additional cohort of over 2,300 individuals with unexplained ID and identified two additional individuals with de novo mutations in this gene. All four individuals had severe ID with severely affected speech development, and three showed severe behavioral problems. DEAF1 is highly expressed in the CNS, especially during early embryonic development. All four mutations were missense mutations affecting the SAND domain of DEAF1. Altered DEAF1 harboring any of the four amino acid changes showed impaired transcriptional regulation of the DEAF1 promoter. Moreover, behavioral studies in mice with a conditional knockout of Deaf1 in the brain showed memory deficits and increased anxiety-like behavior. Our results demonstrate that mutations in DEAF1 cause ID and behavioral problems, most likely as a result of impaired transcriptional regulation by DEAF1.

γ-secretase binding sites in aged and Alzheimer's disease human cerebrum: the choroid plexus as a putative origin of CSF Aß.

Deposition of ß -amyloid (Aß) peptides, cleavage products of ß-amyloid precursor protein (APP) by ß-secretase-1 (BACE1) and γ-secretase, is a neuropathological hallmark of Alzheimer's disease (AD). γ-Secretase inhibition is a therapeutical anti-Aß approach, although changes in the enzyme's activity in AD brain are unclear. Cerebrospinal fluid (CSF) Aß peptides are thought to derive from brain parenchyma and thus may serve as biomarkers for assessing cerebral amyloidosis and anti-Aß efficacy. The present study compared active γ-secretase binding sites with Aß deposition in aged and AD human cerebrum, and explored the possibility of Aß production and secretion by the choroid plexus (CP). The specific binding density of [(3) H]-L-685,458, a radiolabeled high-affinity γ-secretase inhibitor, in the temporal neocortex and hippocampal formation was similar for AD and control cases with similar ages and post-mortem delays. The CP in post-mortem samples exhibited exceptionally high [(3) H]-L-685,458 binding density, with the estimated maximal binding sites (Bmax) reduced in the AD relative to control groups. Surgically resected human CP exhibited APP, BACE1 and presenilin-1 immunoreactivity, and ß-site APP cleavage enzymatic activity. In primary culture, human CP cells also expressed these amyloidogenic proteins and released Aß40 and Aß42 into the medium. Overall, our results suggest that γ-secretase activity appears unaltered in the cerebrum in AD and is not correlated with regional amyloid plaque pathology. The CP appears to be a previously unrecognised non-neuronal contributor to CSF Aß, probably at reduced levels in AD.

Symbol relations training improves cognitive functioning in students with neurodevelopmental disorders.

Students with neurodevelopmental disorders [Specific Learning Disorders (SLD), Attention Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD)] often experience learning challenges due to underlying weaknesses in cognitive processes. As these are some of the most common conditions to impact functioning, the development of effective treatments is a priority for neuropsychologists. However, the task of designing effective cognitive interventions has proven one of the most difficult challenges for our field. The Arrowsmith Program uses a novel approach compared to other cognitive intervention programs. We hypothesized that intensive practice of one aspect of this program would lead to improved cognitive functions in students with neurodevelopmental disorders. Twenty-seven students with neurodevelopmental disorders (ages 9.4-18.4 years) were recruited from Arrowsmith schools. Cognitive baseline and post-intervention data were gathered using components of the Woodcock-Johnson IV Tests of Cognitive Abilities. The intervention consisted of 6 weeks of intensive practice of the Symbol Relations Task. W-scores were used in a paired sample t-test analysis to determine if cognitive skill improvement occurred. Significant improvements were found in several measures of neuropsychological assessment, in particular in the Cattell-Horn-Carroll broad abilities These results provide a foundation for further work examining the utility of this novel approach to cognitive intervention.

Applications of Carbon Dots for the Treatment of Alzheimer's Disease.

There are currently approximately 50 million victims of Alzheimer's disease (AD) worldwide. The exact cause of the disease is unknown at this time, but amyloid plaques and neurofibrillary tangles in the brain are hallmarks of the disease. Current drug treatments for AD may slow the progression of the disease and improve the quality of life of patients, but they are often only minimally effective and are not cures. A major obstacle to developing and delivering more effective drug therapies is the presence of the blood-brain barrier (BBB), which prevents many compounds with therapeutic potential from reaching the central nervous system. Nanotechnology may provide a solution to this problem. Among the medical nanomaterials currently being studied, carbon dots (CDs) have attracted widespread attention because of their ability to cross the BBB, non-toxicity, and potential for drug/gene delivery.

Cardiac complications in patients with community-acquired pneumonia: a systematic review and meta-analysis of observational studies.

BACKGROUND: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality. CAP can trigger acute cardiac events. We sought to determine the incidence of major cardiac complications in CAP patients to characterize the magnitude of this problem. METHODS AND FINDINGS: Two investigators searched MEDLINE, Scopus, and EMBASE for observational studies of immunocompetent adults with clinical and radiological evidence of CAP that reported any of the following: overall cardiac complications, incident heart failure, acute coronary syndromes (ACS), or incident cardiac arrhythmias occurring within 30 days of CAP diagnosis. At a minimum, studies had to establish enrolment procedures and inclusion and exclusion criteria, enroll their patients sequentially, and report the incidence of cardiac complications as a function of their entire cohorts. Studies with focus on nosocomial or health care-associated pneumonia were not included. Review of 2,176 citations yielded 25 articles that met eligibility and minimum quality criteria. Seventeen articles (68%) reported cohorts of CAP inpatients. In this group, the pooled incidence rates for overall cardiac complications (six cohorts, 2,119 patients), incident heart failure (eight cohorts, 4,215 patients), acute coronary syndromes (six cohorts, 2,657 patients), and incident cardiac arrhythmias (six cohorts, 2,596 patients), were 17.7% (confidence interval [CI] 13.9-22.2), 14.1% (9.3-20.6), 5.3% (3.2-8.6), and 4.7% (2.4-8.9), respectively. One article reported cardiac complications in CAP outpatients, four in low-risk (not severely ill) inpatients, and three in high-risk inpatients. The incidences for all outcomes except overall cardiac complications were lower in the two former groups and higher in the latter. One additional study reported on CAP outpatients and low-risk inpatients without discriminating between these groups. Twelve studies (48%) asserted the evaluation of cardiac complications in their methods but only six (24%) provided a definition for them. Only three studies, all examining ACS, carried out risk factor analysis for these events. No study analyzed the association between cardiac complications and other medical complications or their impact on other CAP outcomes. CONCLUSIONS: Major cardiac complications occur in a substantial proportion of patients with CAP. Physicians and patients need to appreciate the significance of this association for timely recognition and management of these events. Strategies aimed at preventing pneumonia (i.e., influenza and pneumococcal vaccination) in high-risk populations need to be optimized. Further research is needed to understand the mechanisms underlying this association, measure the impact of cardiac complications on other CAP outcomes, identify those patients with CAP at high risk of developing cardiac complications, and design strategies to prevent their occurrence in this population.

Knowledge-based surveillance for preventing postoperative surgical site infection.

At least one out of every twenty people admitted to a Canadian hospital will acquire an infection. These hospital-acquired infections (HAIs) take a profound individual and system-wide toll, resulting in thousands of deaths and hundreds of millions of dollars in additional expenses each year. Surveillance for HAIs is essential to develop and evaluate prevention and control efforts. In nearly all healthcare institutions, however, surveillance for HAIs is a manual process, requiring highly trained infection control practitioners to consult multiple information systems and paper charts. The amount of effort required for discovery and integration of relevant data from multiple sources limits the current effectiveness of HAIs surveillance. In this research, we apply knowledge modeling and semantic technologies to facilitate the integration of disparate data and enable automatic reasoning with these integrated data to identify events of clinical interest. In this paper, we focus on Surgical Site Infections (SSIs), which account for a relatively large fraction of all hospital acquired infections.

Altered hippocampal astroglial metabolism is associated with aging and preserved spatial learning and memory.

An age-related decrease in hippocampal metabolism correlates with cognitive decline. Hippocampus-dependent learning and memory requires glutamatergic neurotransmission supported by glutamate-glutamine (GLU-GLN) cycling between neurons and astrocytes. We examined whether GLU-GLN cycling in hippocampal subregions (dentate gyrus and CA1) in Fischer 344 rats was altered with age and cognitive status. Hippocampal slices from young adult, aged cognitively-unimpaired (AU) and aged cognitively-impaired (AI) rats were incubated in artificial cerebrospinal fluid (aCSF) containing 1-13C-glucose to assess neural metabolism. Incorporation of 13C-glucose into glutamate and glutamine, measured by mass spectroscopy/liquid chromatography tandem mass spectroscopy, did not significantly differ between groups. However, when 13C-acetate, a preferential astrocytic metabolite, was used, a significant increase in 13C-labeled glutamate was observed in slices from AU rats. Taken together, the data suggest that resting state neural metabolism and GLU-GLN cycling may be preserved during aging when sufficient extracellular glucose is available, but that enhanced astroglial metabolism can occur under resting state conditions. This may be an aging-related compensatory change to maintain hippocampus-dependent cognitive function.

APOE genotype influences P3b amplitude and response to smoking abstinence in young adults.

RATIONALE: There is strong evidence that nicotine can enhance cognitive functions and growing evidence that this effect may be larger in young healthy APOE ε4 carriers. However, the moderating effects of the APOE ε4 allele on cognitive impairments caused by nicotine deprivation in chronic smokers have not yet been studied with brain indices. OBJECTIVE: We sought to determine whether young female carriers of the APOE ε4 allele, relative to noncarriers, would exhibit larger abstinence-induced decreases in P3b amplitude during a two-stimulus auditory oddball task. METHODS: We compared parietal P3bs in female chronic smokers with either APOE ε3/ε3 (n = 54) or ε3/ε4 (n = 20) genotype under nicotine-sated conditions and after 12-17-h nicotine deprivation. RESULTS: Nicotine deprivation significantly reduced P3b amplitudes in APOE ε4 carriers, but not in APOE-ε3/ε3 individuals, such that the difference seen prior to nicotine deprivation was eliminated. CONCLUSIONS: The results suggest that subjects with the APOE ε4 allele are more sensitive to nicotine, which could influence smoking patterns, the risk for nicotine dependence, and the cognitive effects of nicotine use in these individuals.

Impaired memory and marble burying activity in deformed epidermal autoregulatory factor 1 (Deaf1) conditional knockout mice.

Deleterious mutations within the DNA binding domain of the transcription factor deformed epidermal autoregulatory factor 1 (DEAF1) result in a phenotypic spectrum of neurodevelopmental disorders including intellectual disabilities and autism spectrum disorders. While whole animal deletion of Deaf1 in mice is lethal, mice with conditional disruption of the gene in neuronal precursor cells can display memory deficits and increased anxiety-like behavior. This study aimed to further characterize learning and memory alterations and assess changes in marble burying activity and hippocampal size in mice with conditional deletion of Deaf1. Mice lacking DEAF1 in the CNS (NKO) displayed reduced memory in both contextual fear conditioning and a 3-day massed trials Morris water maze paradigm. NKO mice had reduced marble burying activity in full cage marble burying tests. Using a half-cage marble test, NKO mice again buried fewer marbles and spent significantly more time on the side of the cage away from the marbles compared to control animals. The area of the dorsal hippocampus of NKO mice was decreased compared to control and animals with a single Deaf1 allele. These results continue to establish the importance of DEAF1 in cognitive behavior and provide new evidence that DEAF1 regulates hippocampal morphology.

Butein attenuates the cytotoxic effects of LPS-stimulated microglia on the SH-SY5Y neuronal cell line.

Neuroinflammation is involved in brain aging and neuronal cell death in neurodegenerative diseases such as Alzheimer's disease (AD). Butein has been suggested to have anti-inflammatory, anti-apoptotic, and anti-cancer effects. However, few studies have been done to evaluate whether butein exerts protective effects on neurons, and the potential mechanism for this effect has not been studied. Here, we examined the effect of butein on SH-SY5Y neuroblastoma cells grown with conditioned medium from BV2 microglia cells that had been activated by lipopolysaccharide (LPS) as a neuroinflammation model. We found butein pretreatment significantly increased SH-SY5Y cell viability in a dose-dependent manner by inhibiting the apoptosis normally induced by microglia-conditioned medium. SH-SY5Y cells treated with microglia-conditioned medium showed upregulated ERK signaling pathway-related mRNA expression and protein phosphorylation, which was dose-dependently reversed by butein. Immunocytochemistry and Western blot results showed that BV2-LPS conditioned medium-induced Nuclear factor kappaB (NF-κB) transactivational activity in SH-SY5Y cells, but this was attenuated by butein treatment of the BV2 cells prior to their exposure to LPS. Collectively, our results indicate that butein effectively mitigates inflammatory injury caused by LPS-conditioned medium from microglia, possibly due to reductions in the transactivational activity of NF-κB p65 and ERK signaling pathway activation, and provide evidence for a neuroprotective role of butein through blocking negative consequences of microglial activation.

High-throughput single-cell activity-based screening and sequencing of antibodies using droplet microfluidics.

Mining the antibody repertoire of plasma cells and plasmablasts could enable the discovery of useful antibodies for therapeutic or research purposes1. We present a method for high-throughput, single-cell screening of IgG-secreting primary cells to characterize antibody binding to soluble and membrane-bound antigens. CelliGO is a droplet microfluidics system that combines high-throughput screening for IgG activity, using fluorescence-based in-droplet single-cell bioassays2, with sequencing of paired antibody V genes, using in-droplet single-cell barcoded reverse transcription. We analyzed IgG repertoire diversity, clonal expansion and somatic hypermutation in cells from mice immunized with a vaccine target, a multifunctional enzyme or a membrane-bound cancer target. Immunization with these antigens yielded 100-1,000 IgG sequences per mouse. We generated 77 recombinant antibodies from the identified sequences and found that 93% recognized the soluble antigen and 14% the membrane antigen. The platform also allowed recovery of ~450-900 IgG sequences from ~2,200 IgG-secreting activated human memory B cells, activated ex vivo, demonstrating its versatility.

Author Correction: High-throughput single-cell activity-based screening and sequencing of antibodies using droplet microfluidics.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Impaired Glucose Tolerance and Reduced Plasma Insulin Precede Decreased AKT Phosphorylation and GLUT3 Translocation in the Hippocampus of Old 3xTg-AD Mice.

Several studies have demonstrated that mouse models of Alzheimer's disease (AD) can exhibit impaired peripheral glucose tolerance. Further, in the APP/PS1 mouse model, this is observed prior to the appearance of AD-related neuropathology (e.g., amyloid-ß plaques; Aß) or cognitive impairment. In the current study, we examined whether impaired glucose tolerance also preceded AD-like changes in the triple transgenic model of AD (3xTg-AD). Glucose tolerance testing (GTT), insulin ELISAs, and insulin tolerance testing (ITT) were performed at ages prior to (1-3 months and 6-8 months old) and post-pathology (16-18 months old). Additionally, we examined for altered insulin signaling in the hippocampus. Western blots were used to evaluate the two-primary insulin signaling pathways: PI3K/AKT and MAPK/ERK. Since the PI3K/AKT pathway affects several downstream targets associated with metabolism (e.g., GSK3, glucose transporters), western blots were used to examine possible alterations in the expression, translocation, or activation of these targets. We found that 3xTg-AD mice display impaired glucose tolerance as early as 1 month of age, concomitant with a decrease in plasma insulin levels well prior to the detection of plaques (∼14 months old), aggregates of hyperphosphorylated tau (∼18 months old), and cognitive decline (≥18 months old). These alterations in peripheral metabolism were seen at all time points examined. In comparison, PI3K/AKT, but not MAPK/ERK, signaling was altered in the hippocampus only in 18-20-month-old 3xTg-AD mice, a time point at which there was a reduction in GLUT3 translocation to the plasma membrane. Taken together, our results provide further evidence that disruptions in energy metabolism may represent a foundational step in the development of AD.

Hippocampal expression analyses reveal selective association of immediate-early, neuroenergetic, and myelinogenic pathways with cognitive impairment in aged rats.

Although expression of some genes is known to change during neuronal activity or plasticity, the overall relationship of gene expression changes to memory or memory disorders is not well understood. Here, we combined extensive statistical microarray analyses with behavioral testing to comprehensively identify genes and pathways associated with aging and cognitive dysfunction. Aged rats were separated into cognitively unimpaired (AU) or impaired (AI) groups based on their Morris water maze performance relative to young-adult (Y) animals. Hippocampal gene expression was assessed in Y, AU, and AI on the fifth (last) day of maze training (5T) or 21 d posttraining (21PT) and in nontrained animals (eight groups total, one array per animal; n = 78 arrays). ANOVA and linear contrasts identified genes that differed from Y generally with aging (differed in both AU and AI) or selectively, with cognitive status (differed only in AI or AU). Altered pathways/processes were identified by overrepresentation analyses of changed genes. With general aging, there was downregulation of axonal growth, cytoskeletal assembly/transport, signaling, and lipogenic/uptake pathways, concomitant with upregulation in immune/inflammatory, lysosomal, lipid/protein degradation, cholesterol transport, transforming growth factor, and cAMP signaling pathways, primarily independent of training condition. Selectively, in AI, there was downregulation at 5T of immediate-early gene, Wnt (wingless integration site), insulin, and G-protein signaling, lipogenesis, and glucose utilization pathways, whereas Notch2 (oligodendrocyte development) and myelination pathways were upregulated, particularly at 21PT. In AU, receptor/signal transduction genes were upregulated, perhaps as compensatory responses. Immunohistochemistry confirmed and extended selected microarray results. Together, the findings suggest a new model, in which deficient neuroenergetics leads to downregulated neuronal signaling and increased glial activation, resulting in aging-related cognitive dysfunction.

Atovaquone-proguanil resistance in imported falciparum malaria in a young child.

We discuss a case of atovaquone-proguanil treatment failure in a child from Mozambique, recently arrived in North America. Four weeks after completing therapy, symptomatic parasitemia recurred, caused by Plasmodium falciparum parasites bearing a Tyr268Ser mutation in cytochrome b. We review the literature concerning atovaquone-proguanil resistance, and emphasize the importance of follow-up and consideration of resistance where patients have relapsed symptoms.

Evidence for altered insulin receptor signaling in Alzheimer's disease.

Epidemiological data have shown that metabolic disease can increase the propensity for developing cognitive decline and dementia, particularly Alzheimer's disease (AD). While this interaction is not completely understood, clinical studies suggest that both hyper- and hypoinsulinemia are associated with an increased risk for developing AD. Indeed, insulin signaling is altered in post-mortem brain tissue from AD patients and treatments known to enhance insulin signaling can improve cognitive function. Further, clinical evidence has shown that AD patients and mouse models of AD often display alterations in peripheral metabolism. Since insulin is primarily derived from the periphery, it is likely that changes in peripheral insulin levels lead to alterations in central nervous system (CNS) insulin signaling and could contribute to cognitive decline and pathogenesis. Developing a better understanding of the relationship between alterations in peripheral metabolism and cognitive function might provide a foundation for the development of better treatment options for patients with AD. In this article we will begin to piece together the present data defining this relationship by briefly discussing insulin signaling in the periphery and CNS, its role in cognitive function, insulin's relationship to AD, peripheral metabolic alterations in mouse models of AD and how information from these models helps understand the mechanisms through which these changes potentially lead to impairments in insulin signaling in the CNS, and potential ways to target insulin signaling that could improve cognitive function in AD. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'