Elevated activity of the sympathetic nervous system is related to diminished practice effects in memory:A pilot study

BACKGROUND: Reductions in memory practice effects have gained interest as risk factor for future cognitive decline. Practice effects vary with age and can be moderated by factors such as individual variability in arousal or stress experience acting as an additional cognitive load. OBJECTIVE: In the current pilot study, we examined whether sympathetic nervous system activation moderates the relationship between age and practice effects. METHODS: Thirty cognitively healthy individuals aged 40–70 years performed a mnemonic discrimination task twice. Salivary alpha amylase (sAA) samples were obtained at different time points as a proxy of sympathetic activity. Spearman correlations examined the relation between practice effects and sAA. Subsequently, age by sAA interactions on practice scores were explored with bootstrapped linear regression models. Additionally, participants were divided in learners (exhibiting practice effects) and non-learners based on the difference in mnemonic discrimination performance. RESULTS: Higher age and baseline SNS activity were independently related to lower practice effects. The non-learners showed significantly higher sAA scores at all time points compared to learners. Among the learners, baseline-adjusted lower levels of sAA after encoding were associated with greater practice effects, particularly in middle-aged individuals. No such interaction was observed for non-learners. CONCLUSION: These results show that higher baseline sympathetic activation is associated with worse practice effects independently of age. Additionally, in a subgroup of middle-aged learners practice effects were observed when sympathetic activity remained low during learning. These findings suggest that elevated sympathetic nervous system activation may be a promising indicator of imminent cognitive decline

The impact of ageing reveals distinct roles for human dentate gyrus and CA3 in pattern separation and object recognition memory

© 2017 The Author(s). Both recognition of familiar objects and pattern separation, a process that orthogonalises overlapping events, are critical for effective memory. Evidence is emerging that human pattern separation requires dentate gyrus. Dentate gyrus is intimately connected to CA3 where, in animals, an autoassociative network enables recall of complete memories to underpin object/event recognition. Despite huge motivation to treat age-related human memory disorders, interaction between human CA3 and dentate subfields is difficult to investigate due to small size and proximity. We tested the hypothesis that human dentate gyrus is critical for pattern separation, whereas, CA3 underpins identical object recognition. Using 3 T MR hippocampal subfield volumetry combined with a behavioural pattern separation task, we demonstrate that dentate gyrus volume predicts accuracy and response time during behavioural pattern separation whereas CA3 predicts performance in object recognition memory. Critically, human dentate gyrus volume decreases with age whereas CA3 volume is age-independent. Further, decreased dentate gyrus volume, and no other subfield volume, mediates adverse effects of aging on memory. Thus, we demonstrate distinct roles for CA3 and dentate gyrus in human memory and uncover the variegated effects of human ageing across hippocampal regions. Accurate pinpointing of focal memory-related deficits will allow future targeted treatment for memory loss

Antimicrobial and antioxidant properties of methanol extract, fractions and compounds from the stem bark of Entada abyssinica Stend ex A. Satabie

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the antimicrobial and antioxidant activities of the methanol extract, fractions and isolated compounds from <it>Entada abyssinica </it>stem bark, plant used traditionally against gastrointestinal infections.</p> <p>Methods</p> <p>The methanol extract of <it>E. abyssinica </it>stem bark was pre-dissolved in a mixture of methanol and water, and then partitioned between <it>n</it>-hexane, ethyl acetate and <it>n</it>-butanol. The ethyl acetate portion was fractionated by column chromatography and the structures of isolated compounds elucidated by analysis of spectroscopic data and comparison with literature data. Antimicrobial activity was assayed by broth microdilution techniques on bacteria and yeasts. The antioxidant activity was determined by DPPH radical scavenging method.</p> <p>Results</p> <p>Four known compounds [(5<it>S</it>,6<it>R</it>,8a<it>R</it>)-5-(carboxymethyl)-3,4,4a,5,6,7,8,8a-octahydro-5,6,8a-trimethylnaphthalenecarboxylic acid (<b>1</b>), methyl 3,4,5-trihydroxybenzoate (<b>2</b>), benzene-1,2,3-triol (<b>3</b>) and 2,3-dihydroxypropyltriacontanoate (<b>4</b>)] were isolated. Compared to the methanol extract, fractionation increased the antibacterial activities of the <it>n</it>-hexane and ethyl acetate fractions, while the antifungal activities increased in ethyl acetate, <it>n</it>-butanol and aqueous residue fractions. The isolated compounds were generally more active on bacteria (9.7 to 156.2 μg/ml) than yeasts (78.1 to 312.5 μg/ml). Apart from compound <b>1</b>, the three others displayed DPPH^·scavenging activity (RSa), with RSa₅₀values of 1.45 and 1.60 μg/ml.</p> <p>Conclusion</p> <p>The results obtained from this study support the ethnomedicinal use of <it>E. abyssinica </it>in the treatment of gastrointestinal infections and the isolated compounds could be useful in the standardisation of antimicrobial phytomedicine from this plant.</p

Cortical Thinning in Patients with Recent Onset Post-Traumatic Stress Disorder after a Single Prolonged Trauma Exposure

Most of magnetic resonance imaging (MRI) studies about post-traumatic stress disorder (PTSD) focused primarily on measuring of small brain structure volume or regional brain volume changes. There were rare reports investigating cortical thickness alterations in recent onset PTSD. Recent advances in computational analysis made it possible to measure cortical thickness in a fully automatic way, along with voxel-based morphometry (VBM) that enables an exploration of global structural changes throughout the brain by applying statistical parametric mapping (SPM) to high-resolution MRI. In this paper, Laplacian method was utilized to estimate cortical thickness after automatic segmentation of gray matter from MR images under SPM. Then thickness maps were analyzed by SPM8. Comparison between 10 survivors from a mining disaster with recent onset PTSD and 10 survivors without PTSD from the same trauma indicates cortical thinning in the left parietal lobe, right inferior frontal gyrus, and right parahippocampal gyrus. The regional cortical thickness of the right inferior frontal gyrus showed a significant negative correlation with the CAPS score in the patients with PTSD. Our study suggests that shape-related cortical thickness analysis may be more sensitive than volumetric analysis to subtle alteration at early stage of PTSD

Long-Stay Psychiatric Patients: A Prospective Study Revealing Persistent Antipsychotic-Induced Movement Disorder

OBJECTIVE: The purpose of this study was to assess the frequency of persistent drug-induced movement disorders namely, tardive dyskinesia (TD), parkinsonism, akathisia and tardive dystonia in a representative sample of long-stay patients with chronic severe mental illness. METHOD: Naturalistic study of 209, mainly white, antipsychotic-treated patients, mostly diagnosed with psychotic disorder. Of this group, the same rater examined 194 patients at least two times over a 4-year period, with a mean follow-up time of 1.1 years, with validated scales for TD, parkinsonism, akathisia, and tardive dystonia. RESULTS: The frequencies of persistent movement disorders in the sample were 28.4% for TD, 56.2% for parkinsonism, 4.6% for akathisia and 5.7% for tardive dystonia. Two-thirds of the participants displayed at least one type of persistent movement disorder. CONCLUSIONS: Persistent movement disorder continues to be the norm for long-stay patients with chronic mental illness and long-term antipsychotic treatment. Measures are required to remedy this situation

The new molecular markers DDIT3, STT3A, ARG2 and FAM129A are not useful in diagnosing thyroid follicular tumors

Preoperative characterization of thyroid follicular lesions is challenging. Fine-needle aspiration specimens cannot differentiate follicular carcinomas from benign follicular neoplasias. Recently, promising markers have been detected using modern molecular techniques. We conducted a retrospective study to confirm the usefulness of immunohistochemical staining for the protein markers, DDIT3, STT3A (ITM1), ARG2 and FAM129A (C1orf24) in separating benign and malignant thyroid follicular lesions. Formalin-fixed, paraffin-embedded thyroid tissue from 30 in-house cases (15 follicular carcinomas and 15 follicular adenomas), as well as 8 follicular carcinomas and 21 follicular adenomas on tissue microarray slides were stained immunohistochemically for DDIT3, STT3A, ARG2 and FAM129A expression. Control tissue consisted of thyroid parenchyma adjacent to the tumors and 11 separate cases of normal thyroid parenchyma. All in-house cases of follicular adenomas, follicular carcinomas and adjacent normal thyroid tissue showed positive immunostaining with anti-DDIT3 and anti-STT3A. Anti-ARG2 and anti-FAM129A polyclonal antibodies showed positive staining in 20 and 60% of in-house follicular adenomas, and 40 and 87% of in-house follicular carcinomas, respectively. Monoclonal anti-FAM129A demonstrated positive staining in 13 and 33% of in-house follicular adenomas and follicular carcinomas, respectively. Polyclonal anti-DDIT3, -STT3A and -FAM129A antibodies showed positive staining in all tissue microarray slides of follicular carcinoma and in 76, 85 and 81% of the follicular adenomas, respectively. Monoclonal anti-STT3A stained 81% of the follicular adenoma cores. Anti-ARG2 stained positive in 13% of follicular carcinomas and 10% of follicular adenomas on the tissue microarray slides. In conclusion, DDIT3, STT3A, ARG2 and FAM129A immunohistochemistry does not appear to be useful in the diagnosis of thyroid follicular neoplasias, as they do not reliably distinguish follicular thyroid carcinoma from follicular thyroid adenoma

Slow wave sleep and accelerated forgetting

We investigated whether the benefit of slow wave sleep (SWS) for memory consolidation typically observed in healthy individuals is disrupted in people with accelerated long-term forgetting (ALF) due to epilepsy. SWS is thought to play an active role in declarative memory in healthy individuals and, furthermore, electrographic epileptiform activity is often more prevalent during SWS than during wakefulness or other sleep stages. We studied the relationship between SWS and the benefit of sleep for memory retention using a word-pair associates task. In both the ALF and the healthy control groups, sleep conferred a memory benefit. However, the relationship between the amount of SWS and sleep-related memory benefits differed significantly between the groups. In healthy participants, the amount of SWS correlated positively with sleep-related memory benefits. In stark contrast, the more SWS, the smaller the sleep-related memory benefit in the ALF group. Therefore, contrary to its role in healthy people, SWS-associated brain activity appears to be deleterious for memory in patients with ALF

Systematic review of interventions for treating or preventing antipsychotic-induced tardive dyskinesia

Background: Antipsychotic medication can cause tardive dyskinesia (TD) – late-onset, involuntary, repetitive movements, often involving the face and tongue. TD occurs in > 20% of adults taking antipsychotic medication (first-generation antipsychotics for > 3 months), with this proportion increasing by 5% per year among those who continue to use these drugs. The incidence of TD among those taking newer antipsychotics is not different from the rate in people who have used older-generation drugs in moderate doses. Studies of TD have previously been found to be limited, with no treatment approach shown to be effective. Objectives: To summarise the clinical effectiveness and safety of treatments for TD by updating past Cochrane reviews with new evidence and improved methods; to undertake public consultation to gauge the importance of the topic for people living with TD/the risk of TD; and to make available all data from relevant trials. Data sources: All relevant randomised controlled trials (RCTs) and observational studies. Review methods: Cochrane review methods, network meta-analysis (NMA). Design: Systematic reviews, patient and public involvement consultation and NMA. Setting: Any setting, inpatient or outpatient. Participants: For systematic reviews, adults with TD who have been taking a stable antipsychotic drug dose for > 3 months. Interventions: Any, with emphasis on those relevant to UK NHS practice. Main outcome measures: Any measure of TD, global assessments and adverse effects/events. Results: We included 112 studies (nine Cochrane reviews). Overall, risk of bias showed little sign of improvement over two decades. Taking the outcome of ‘TD symptoms improved to a clinically important extent’, we identified two trials investigating reduction of antipsychotic dose [n = 17, risk ratio (RR) 0.42, 95% confidence interval (CI) 0.17 to 1.04; very low quality]. Switching was investigated twice in trials that could not be combined (switching to risperidone vs. antipsychotic withdrawal: one RCT, n = 42, RR 0.45, 95% CI 0.23 to 0.89; low quality; switching to quetiapine vs. haloperidol: one RCT, n = 45, RR 0.80, 95% CI 0.52 to 1.22; low quality). In addition to RCTs, six observational studies compared antipsychotic discontinuation with decreased or increased dosage, and there was no clear evidence that any of these strategies had a beneficial effect on TD symptoms (very low-quality evidence). We evaluated the addition to standard antipsychotic care of several treatments, but not anticholinergic treatments, for which we identified no trials. We found no clear effect of the addition of either benzodiazepines (two RCTs, n = 32, RR 1.12, 95% CI 0.6 to 2.09; very low quality) or vitamin E (six RCTs, n = 264, RR 0.95, 95% CI 0.89 to 1.01; low quality). Buspirone as an adjunctive treatment did have some effect in one small study (n = 42, RR 0.53, 95% CI 0.33 to 0.84; low quality), as did hypnosis and relaxation (one RCT, n = 15, RR 0.45, 95% CI 0.21 to 0.94; very low quality). We identified no studies focusing on TD in people with dementia. The NMA model found indirect estimates to be imprecise and failed to produce useful summaries on relative effects of interventions or interpretable results for decision-making. Consultation with people with/at risk of TD highlighted that management of TD remains a concern, and found that people are deeply disappointed at the length of time it has taken researchers to address the issue. Limitations: Most studies remain small and poorly reported. Conclusions: Clinicians, policy-makers and people with/at risk of TD are little better informed than they were decades ago. Underpowered trials of limited quality repeatedly fail to provide answers. Future work: TD reviews have data from current trials extracted, tabulated and traceable to source. The NMA highlights one context in which support for this technique is ill advised. All relevant trials, even if not primarily addressing the issue of TD, should report appropriate binary outcomes on groups of people with this problem. Randomised trials of treatments for people with established TD are indicated. These should be large (> 800 participants), necessitating accrual through accurate local/national registers, including an intervention with acceptable treatments and recording outcomes used in clinical practice. Study registration: This study is registered as PROSPERO CRD4201502045. Funding: The National Institute for Health Research Health Technology Assessment programme