Important Role of Ion Flux Regulated by Separators in Lithium Metal Batteries

Polyolefin separators are the most common separators used in rechargeable lithium (Li)-ion batteries. However, the influence of different polyolefin separators on the performance of Li metal batteries (LMBs) has not been well studied. By performing particle injection simulations on the reconstructed three-dimensional pores of different polyethylene separators, it is revealed that the pore structure of the separator has a significant impact on the ion flux distribution, the Li deposition behavior, and consequently, the cycle life of LMBs. It is also discovered that the homogeneity factor of Li-ion toward Li metal electrode is positively correlated to the longevity and reproducibility of LMBs. This work not only emphasizes the importance of the pore structure of polyolefin separators but also provides an economic and effective method to screen favorable separators for LMBs.

Atherosclerotic Cardiovascular Disease in Women: Providing Protection With Lipid-altering Agents

PURPOSE

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death in women, yet it remains underdiagnosed, undertreated, and understudied in women compared with men. Although estrogen has provided observational evidence of cardioprotection, randomized controlled trials using hormone replacement therapy have generally produced unfavorable results.

METHODS

For this narrative review, a literature search was performed using the key words cardiovascular disease, women, and dyslipidemia in PubMed and Google Scholar with no date limitations. References within each article were also reviewed for additional relevant articles.

FINDINGS

Sex-specific risk factors and underrecognized conditions more predominant in women elevate ASCVD risk, creating further clinical challenges, such as the need for accurate risk stratification, compared with in men. Dyslipidemia frequently manifests or worsens during the menopausal transition. Therefore, identification during midlife and implementing lipid-lowering strategies to reduce ASCVD risk is imperative. Women have historically been poorly represented in cardiovascular (CV) outcome trials. However, more recent studies and meta-analyses have indicated that lipid-lowering therapies are equally effective in women and produce similar reductions in CV events and total mortality. Major cholesterol guidelines address many of the challenges that clinicians face when assessing ASCVD risk in women. Key points specific to women include obtaining a detailed history of pregnancy-related conditions, identification of common autoimmune disorders associated with systemic inflammation, and use of 10-year ASCVD risk calculators and imaging modalities (coronary artery calcium) to optimize ASCVD assessment. In terms of treatment, similar to men, women with existing ASCVD or high-risk primary prevention patients should be treated aggressively to achieve ≥50% LDL-C reductions and/or LDL-C goals as low as <55 mg/dL. Appropriate lipid-lowering therapies include high-intensity statins with or without ezetimibe and proprotein convertase subtilisin kexin/type 9 inhibitors. Women with lower ASCVD risk may be considered for low- to moderate-intensity statin therapy (approximately 30%-50% LDL-C reduction). All women, regardless of ASCVD risk category, should implement therapeutic lifestyle changes, which improve many common age-related cardiometabolic conditions.

IMPLICATIONS

Although ASCVD and current risk factor trends in women are concerning, numerous evidence-based approaches are available to protect women with ASCVD risk from life-changing CV events.

Financial Toxicity and Patient Experience Outcomes on a Multi-Institutional Phase I Single Fraction Stereotactic Partial Breast Irradiation Protocol for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

Given the demonstrated financial toxicity (FT) of radiation treatment on breast cancer patients shown in both conventional and our recent 5 fraction stereotactic APBI (S-PBI) study, we assessed the FT, as well as patient-reported utility, quality-of-life and patient experience measures, on patients treated in our phase I single fraction S-PBI trial.

MATERIALS/METHODS

A phase I single fraction dose escalation trial of S-PBI for early-stage breast cancer was conducted. Women with in-situ or stage I-II (AJCC 6) invasive breast cancer following breast conserving surgery were treated with S-PBI in 1 fraction to a total dose of 22.5, 26.5 or 30 Gy (Clinical trials.gov ID NCT02685332). At one month follow-up, patients were asked to complete our novel "Patient Perspective Cost and Convenience of Care Questionnaire". Patients also completed the EQ-5D-5L, including the visual analogue scale of overall health (VAS), at enrollment, 6, 12-, 24-, 36-, and 48-month follow-up.

RESULTS

Of 29 patients enrolled and treated, questionnaire data was available for all patients. Our trial encompassed a wide range of annual household incomes, education, and employment status. Overall, 44.8% (n = 13/29) of patients reported that radiation treatment presented a financial burden. Interestingly, no demographic information, such as patient race, marital status, education, household income, or employment during treatment predicted perceived FT. Patients reporting FT trended towards younger age (median 64 vs 70.5) and having a cancer related co-pay similar to our 5 fraction S-PBI FT trial; however, due to the small size of this study, this did not reach significance (p = 0.24 and 0.10, respectively). VAS and utility scores were calculated per the EQ-5D-5L and remained unchanged from baseline through 4-year follow-up. Likewise, there was no difference in the utility or VAS between patients who reported FT and those who did not. Interestingly, while patient reported cosmesis was similar for all patients at enrollment, patients who reported FT noted significantly worse cosmesis scores (fair/poor vs good/excellent) at 6 month and 2-year follow-ups (p = 0.01 and 0.04, respectively). Finally, patients were surveyed on treatment related disruption to their daily activities and enjoyment of life. The median values were 0 (scale 0-10, with 0 being no disruption) regardless of perceived FT. Patients were also uniformly satisfied with treatment time with a median score of 10 (scale 0-10, 10 being most satisfied).

CONCLUSION

Here, we show that despite using SPBI in a single fraction, nearly half of the patients treated still reported FT of treatment. Importantly, single fraction S-PBI has no negative impact on patient VAS or utility scores, and all patients were uniformly satisfied with treatment time without significant disruption to their life.

An assessment of animal welfare impacts in wild Norway rat (Rattus norvegicus) management

Norway rats (Rattus norvegicus) are considered one of the most significant vertebrate pests globally, because of their impacts on human and animal health. There are legal and moral obligations to minimise the impacts of wildlife management on animal welfare, yet there are few data on the relative welfare impacts of rat trapping and baiting methods used in the UK with which to inform management decisions. Two stakeholder workshops were facilitated to assess the relative welfare impacts of six lethal rat management methods using a welfare assessment model. Fifteen stakeholders including experts in wildlife management, rodent management, rodent biology, animal welfare science, and veterinary science and medicine, participated. The greatest welfare impacts were associated with three baiting methods, anticoagulants, cholecalciferol and non-toxic cellulose baits (severe to extreme impact for days), and with capture on a glue trap (extreme for hours) with concussive killing (mild to moderate for seconds to minutes); these methods should be considered last resorts from a welfare perspective. Lower impacts were associated with cage trapping (moderate to severe for hours) with concussive killing (moderate for minutes). The impact of snap trapping was highly variable (no impact to extreme for seconds to minutes). Snap traps should be regulated and tested to identify those that cause rapid unconsciousness; such traps might represent the most welfare-friendly option assessed for killing rats. Our results can be used to integrate consideration of rat welfare alongside other factors, including cost, efficacy, safety, non-target animal welfare and public acceptability when selecting management methods. We also highlight ways of reducing welfare impacts and areas where more data are needed.

Efficacy and safety of rucaparib in previously treated, locally advanced or metastatic urothelial carcinoma from a phase 2, open-label trial (ATLAS)

BACKGROUND

ATLAS evaluated the efficacy and safety of the PARP inhibitor rucaparib in patients with previously treated locally advanced/unresectable or metastatic urothelial carcinoma (UC).

METHODS

Patients with UC were enrolled independent of tumor homologous recombination deficiency (HRD) status and received rucaparib 600 mg BID. The primary endpoint was investigator-assessed objective response rate (RECIST v1.1) in the intent-to-treat and HRD-positive (loss of genome-wide heterozygosity ≥10%) populations. Key secondary endpoints were progression-free survival (PFS) and safety. Disease control rate (DCR) was defined post-hoc as the proportion of patients with a confirmed complete or partial response (PR), or stable disease lasting ≥16 weeks.

RESULTS

Of 97 enrolled patients, 20 (20.6%) were HRD-positive, 30 (30.9%) HRD-negative, and 47 (48.5%) HRD-indeterminate. Among 95 evaluable patients, there were no confirmed responses. However, reductions in the sum of target lesions were observed, including 6 (6.3%) patients with unconfirmed PR. DCR was 11.6%; median PFS was 1.8 months (95% CI, 1.6-1.9). No relationship was observed between HRD status and efficacy endpoints. Median treatment duration was 1.8 months (range, 0.1-10.1). Most frequent any-grade treatment-emergent adverse events were asthenia/fatigue (57.7%), nausea (42.3%), and anemia (36.1%). Of 64 patients with data from tumor tissue samples, 10 (15.6%) had a deleterious alteration in a DNA damage repair pathway gene, including four with a deleterious BRCA1 or BRCA2 alteration.

CONCLUSIONS

Rucaparib did not show significant activity in unselected patients with advanced UC regardless of HRD status. The safety profile was consistent with that observed in patients with ovarian or prostate cancer.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov (NCT03397394). Date of registration: 12 January 2018. This trial was registered in EudraCT (2017-004166-10).

Comparison of Brain Morphology in Alzheimer’s Dementia in the General Population and Demented Subjects with Down’s Syndrome

Aim:

To compare Magnetic Resonance Imaging (MRI) findings in Alzheimer's dementia (AD) in the general population with Down's syndrome dementia.

Background review: AD is characterised by cognitive dysfunction interfering with activities of daily living. Mild cognitive impairment (MCI) is an intermediate state between normal aging and dementia. People with Down's syndrome have an increased risk of developing AD. AD pathology initially appears in the entorhinal cortex, followed by the hippocampus and later in the temporal lobes. These areas are critical for memory functioning.

Method:

Volumetric analysis was performed on MRI brain scans using Measure software. Manual tracing was undertaken for the hippocampus, temporal lobes and lateral ventricles as well as the total brain volume of the cerebral hemispheres and cerebellum. Brain volumes were normalised as a percentage of traced intracranial volumes. Freesurfer software was used to obtain entorhinal cortical thickness measures. Statistical analysis was undertaken using SPSS15.

Results:

Subjects with AD (n=46), MCI (n=28) and controls (n=39) were compared with Down's syndrome demented subjects (DS+, n=20), non-demented subjects with Down's syndrome (DS-, n=45) and age-matched controls (n=43). Hippocampi, entorhinal cortex and temporal lobes were significantly reduced in AD and DS+ compared to controls. Lateral ventricles were significantly increased in AD and DS+ compared to controls. MCI and DS- produced findings between those of dementia and controls.

Conclusions:

Critical memory regions atrophy in dementia corresponding to decreased cognitive functioning. DS+ morphology is comparable to AD in the general population but the atrophy is less pronounced.

Functional MRI investigation of verbal working memory in adults with anorexia nervosa

Literature regarding verbal working memory (vWM) in anorexia nervosa (AN) has been inconsistent due to a misunderstanding of the key components of vWM and introduction of confounding stimuli. Furthermore, there are no studies looking at how brain function in people with AN relates to vWM performance. The present study used functional magnetic resonance imaging (fMRI) with a letter n-back paradigm to study the effect of increasing vWM task difficulty on cortical functioning in the largest AN sample to date (n = 31). Although the AN group had low BMI and higher anxious and depressive symptomology compared to age-matched controls (HC), there were no between-group differences in accuracy and speed at any task difficulty. fMRI data revealed no regions exhibiting significant differences in activation when groups were compared at each difficulty separately and no regions showing group x condition interaction. Although there was a trend towards lower accuracy as duration of illness increased, this was not correlated with activity in regions associated with vWM. These findings indicate that vWM in AN is as efficient and performed using the same cognitive strategy as HC, and that there may not be a need for therapies to pursue remediation of this particular neurocognitive faculty.

Acute cardiac tamponade secondary to ruptured pericardial cyst: Case report and literature review

Pericardial cysts are a rare disorder with an incidence of about 1 in 100,000, the majority of which are benign and incidentally identified. Pericardial cyst causing cardiac tamponade is an extremely rare phenomenon. The exact incidence of cardiac tamponade secondary to pericardial cyst is unknown. To the best of our knowledge limited case reports showing this association have been published. We have summarized cases showing this association in a tabular fashion. We present a case of a 36-year-old male who presented with symptoms of shortness of breath, chest pain, and fevers found to have ruptured pericardial cyst causing cardiac tamponade. <Learning objective: The majority of pericardial cysts are diagnosed incidentally and have benign course. Pericardial cyst causing cardiac tamponade is an extremely rare phenomenon. Ruptured pericardial cysts should be considered in the differential diagnosis of cardiac tamponade in patients with history of pericardial cyst. Interventions such as immediate pericardiocentesis, sternotomy, and surgical resection of cyst can be life-saving.>.

Altered fear processing in adolescents with a history of severe childhood maltreatment: an fMRI study

BACKGROUND

Children with a history of maltreatment suffer from altered emotion processing but the neural basis of this phenomenon is unknown. This pioneering functional magnetic resonance imaging (fMRI) study investigated the effects of severe childhood maltreatment on emotion processing while controlling for psychiatric conditions, medication and substance abuse.

METHOD

Twenty medication-naive, substance abuse-free adolescents with a history of childhood abuse, 20 psychiatric control adolescents matched on psychiatric diagnoses but with no maltreatment and 27 healthy controls underwent a fMRI emotion discrimination task comprising fearful, angry, sad happy and neutral dynamic facial expressions.

RESULTS

Maltreated participants responded faster to fearful expressions and demonstrated hyper-activation compared to healthy controls of classical fear-processing regions of ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex, which survived at a more lenient threshold relative to psychiatric controls. Functional connectivity analysis, furthermore, demonstrated reduced connectivity between left vmPFC and insula for fear in maltreated participants compared to both healthy and psychiatric controls.

CONCLUSIONS

The findings show that people who have experienced childhood maltreatment have enhanced fear perception, both at the behavioural and neurofunctional levels, associated with enhanced fear-related ventromedial fronto-cingulate activation and altered functional connectivity with associated limbic regions. Furthermore, the connectivity adaptations were specific to the maltreatment rather than to the developing psychiatric conditions, whilst the functional changes were only evident at trend level when compared to psychiatric controls, suggesting a continuum. The neurofunctional hypersensitivity of fear-processing networks may be due to childhood over-exposure to fear in people who have been abused.

Grey matter volume and thickness abnormalities in young people with a history of childhood abuse

BACKGROUND

Childhood abuse is associated with abnormalities in brain structure and function. Few studies have investigated abuse-related brain abnormalities in medication-naïve, drug-free youth that also controlled for psychiatric comorbidities by inclusion of a psychiatric control group, which is crucial to disentangle the effects of abuse from those associated with the psychiatric conditions.

METHODS

Cortical volume (CV), cortical thickness (CT) and surface area (SA) were measured in 22 age- and gender-matched medication-naïve youth (aged 13-20) exposed to childhood abuse, 19 psychiatric controls matched for psychiatric diagnoses and 27 healthy controls. Both region-of-interest (ROI) and whole-brain analyses were conducted.

RESULTS

For the ROI analysis, the childhood abuse group compared with healthy controls only, had significantly reduced CV in bilateral cerebellum and reduced CT in left insula and right lateral orbitofrontal cortex (OFC). At the whole-brain level, relative to healthy controls, the childhood abuse group showed significantly reduced CV in left lingual, pericalcarine, precuneus and superior parietal gyri, and reduced CT in left pre-/postcentral and paracentral regions, which furthermore correlated with greater abuse severity. They also had increased CV in left inferior and middle temporal gyri relative to healthy controls. Abnormalities in the precuneus, temporal and precentral regions were abuse-specific relative to psychiatric controls, albeit at a more lenient level. Groups did not differ in SA.

CONCLUSIONS

Childhood abuse is associated with widespread structural abnormalities in OFC-insular, cerebellar, occipital, parietal and temporal regions, which likely underlie the abnormal affective, motivational and cognitive functions typically observed in this population.

Comparison of neural substrates of temporal discounting between youth with autism spectrum disorder and with obsessive-compulsive disorder

BACKGROUND

Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) share abnormalities in hot executive functions such as reward-based decision-making, as measured in the temporal discounting task (TD). No studies, however, have directly compared these disorders to investigate common/distinct neural profiles underlying such abnormalities. We wanted to test whether reward-based decision-making is a shared transdiagnostic feature of both disorders with similar neurofunctional substrates or whether it is a shared phenotype with disorder-differential neurofunctional underpinnings.

METHODS

Age and IQ-matched boys with ASD (N = 20), with OCD (N = 20) and 20 healthy controls, performed an individually-adjusted functional magnetic resonance imaging (fMRI) TD task. Brain activation and performance were compared between groups.

RESULTS

Boys with ASD showed greater choice-impulsivity than OCD and control boys. Whole-brain between-group comparison revealed shared reductions in ASD and OCD relative to control boys for delayed-immediate choices in right ventromedial/lateral orbitofrontal cortex extending into medial/inferior prefrontal cortex, and in cerebellum, posterior cingulate and precuneus. For immediate-delayed choices, patients relative to controls showed reduced activation in anterior cingulate/ventromedial prefrontal cortex reaching into left caudate, which, at a trend level, was more decreased in ASD than OCD patients, and in bilateral temporal and inferior parietal regions.

CONCLUSIONS

This first fMRI comparison between youth with ASD and with OCD, using a reward-based decision-making task, shows predominantly shared neurofunctional abnormalities during TD in key ventromedial, orbital- and inferior fronto-striatal, temporo-parietal and cerebellar regions of temporal foresight and reward processing, suggesting trans-diagnostic neurofunctional deficits.

Brexit: what does it mean for the veterinary profession?

ALICK SIMMONS: , chair of the BVA's Brexit working group, discusses the implications of Brexit for the veterinary profession and the opportunities it might provide.

West Nile virus-infected human dendritic cells fail to fully activate invariant natural killer T cells

West Nile virus (WNV) infection is a mosquito-borne zoonosis with increasing prevalence in the United States. WNV infection begins in the skin, and the virus replicates initially in keratinocytes and dendritic cells (DCs). In the skin and cutaneous lymph nodes, infected DCs are likely to interact with invariant natural killer T cells (iNKTs). Bidirectional interactions between DCs and iNKTs amplify the innate immune response to viral infections, thus controlling viral load and regulating adaptive immunity. iNKTs are stimulated by CD1d-bound lipid antigens or activated indirectly by inflammatory cytokines. We exposed human monocyte-derived DCs to WNV Kunjin and determined their ability to activate isolated blood iNKTs. DCs became infected as judged by synthesis of viral mRNA and Envelope and NS-1 proteins, but did not undergo significant apoptosis. Infected DCs up-regulated the co-stimulatory molecules CD86 and CD40, but showed decreased expression of CD1d. WNV infection induced DC secretion of type I interferon (IFN), but no or minimal interleukin (IL)-12, IL-23, IL-18 or IL-10. Unexpectedly, we found that the WNV-infected DCs stimulated human iNKTs to up-regulate CD69 and produce low amounts of IL-10, but not proinflammatory cytokines such as IFN-γ or tumour necrosis factor (TNF)-α. Both CD1d and IFNAR blockade partially abrogated this iNKT response, suggesting involvement of a T cell receptor (TCR)-CD1d interaction and type I interferon receptor (IFNAR) signalling. Thus, WNV infection interferes with DC-iNKT interactions by preventing the production of proinflammatory cytokines. iNKTs may be a source of IL-10 observed in human flavivirus infections and initiate an anti-inflammatory innate response that limits adaptive immunity and immune pathology upon WNV infection.

A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis

Protein-truncating variants protective against human disease provide in vivo validation of therapeutic targets. Here we used targeted sequencing to conduct a search for protein-truncating variants conferring protection against inflammatory bowel disease exploiting knowledge of common variants associated with the same disease. Through replication genotyping and imputation we found that a predicted protein-truncating variant (rs36095412, p.R179X, genotyped in 11,148 ulcerative colitis patients and 295,446 controls, MAF=up to 0.78%) in RNF186, a single-exon ring finger E3 ligase with strong colonic expression, protects against ulcerative colitis (overall P=6.89 × 10(-7), odds ratio=0.30). We further demonstrate that the truncated protein exhibits reduced expression and altered subcellular localization, suggesting the protective mechanism may reside in the loss of an interaction or function via mislocalization and/or loss of an essential transmembrane domain.

The effects of acute fluoxetine administration on temporal discounting in youth with ADHD

BACKGROUND

Serotonin is under-researched in attention deficit hyperactivity disorder (ADHD), despite accumulating evidence for its involvement in impulsiveness and the disorder. Serotonin further modulates temporal discounting (TD), which is typically abnormal in ADHD relative to healthy subjects, underpinned by reduced fronto-striato-limbic activation. This study tested whether a single acute dose of the selective serotonin reuptake inhibitor (SSRI) fluoxetine up-regulates and normalizes reduced fronto-striato-limbic neurofunctional activation in ADHD during TD.

METHOD

Twelve boys with ADHD were scanned twice in a placebo-controlled randomized design under either fluoxetine (between 8 and 15 mg, titrated to weight) or placebo while performing an individually adjusted functional magnetic resonance imaging TD task. Twenty healthy controls were scanned once. Brain activation was compared in patients under either drug condition and compared to controls to test for normalization effects.

RESULTS

Repeated-measures whole-brain analysis in patients revealed significant up-regulation with fluoxetine in a large cluster comprising right inferior frontal cortex, insula, premotor cortex and basal ganglia, which further correlated trend-wise with TD performance, which was impaired relative to controls under placebo, but normalized under fluoxetine. Fluoxetine further down-regulated default mode areas of posterior cingulate and precuneus. Comparisons between controls and patients under either drug condition revealed normalization with fluoxetine in right premotor-insular-parietal activation, which was reduced in patients under placebo.

CONCLUSIONS

The findings show that a serotonin agonist up-regulates activation in typical ADHD dysfunctional areas in right inferior frontal cortex, insula and striatum as well as down-regulating default mode network regions in the context of impulsivity and TD.

Effect of high-potency cannabis on corpus callosum microstructure

BACKGROUND

The use of cannabis with higher Δ9-tetrahydrocannabinol content has been associated with greater risk, and earlier onset, of psychosis. However, the effect of cannabis potency on brain morphology has never been explored. Here, we investigated whether cannabis potency and pattern of use are associated with changes in corpus callosum (CC) microstructural organization, in patients with first-episode psychosis (FEP) and individuals without psychosis, cannabis users and non-users.

METHOD

The CC of 56 FEP (37 cannabis users) and 43 individuals without psychosis (22 cannabis users) was virtually dissected and segmented using diffusion tensor imaging tractography. The diffusion index of fractional anisotropy, mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity was calculated for each segment.

RESULTS

Across the whole sample, users of high-potency cannabis had higher total CC MD and higher total CC AD than both low-potency users and those who never used (p = 0.005 and p = 0.004, respectively). Daily users also had higher total CC MD and higher total CC AD than both occasional users and those who never used (p = 0.001 and p < 0.001, respectively). However, there was no effect of group (patient/individuals without psychosis) or group x potency interaction for either potency or frequency of use. The within-group analysis showed in fact that the effects of potency and frequency were similar in FEP users and in users without psychosis.

CONCLUSIONS

Frequent use of high-potency cannabis is associated with disturbed callosal microstructural organization in individuals with and without psychosis. Since high-potency preparations are now replacing traditional herbal drugs in many European countries, raising awareness about the risks of high-potency cannabis is crucial.

Practical cut-offs for visual rating scales of medial temporal, frontal and posterior atrophy in Alzheimer's disease and mild cognitive impairment

BACKGROUND

Atrophy in the medial temporal lobe, frontal lobe and posterior cortex can be measured with visual rating scales such as the medial temporal atrophy (MTA), global cortical atrophy - frontal subscale (GCA-F) and posterior atrophy (PA) scales, respectively. However, practical cut-offs are urgently needed, especially now that different presentations of Alzheimer's disease (AD) are included in the revised diagnostic criteria.

AIMS

The aim of this study was to generate a list of practical cut-offs for the MTA, GCA-F and PA scales, for both diagnosis of AD and determining prognosis in mild cognitive impairment (MCI), and to evaluate the influence of key demographic and clinical factors on these cut-offs.

METHODS

AddNeuroMed and ADNI cohorts were combined giving a total of 1147 participants (322 patients with AD, 480 patients with MCI and 345 control subjects). The MTA, GCA-F and PA scales were applied and a broad range of cut-offs was evaluated.

RESULTS

The MTA scale showed better diagnostic and predictive performances than the GCA-F and PA scales. Age, apolipoprotein E (ApoE) ε4 status and age at disease onset influenced all three scales. For the age ranges 45-64, 65-74, 75-84 and 85-94 years, the following cut-offs should be used. MTA: ≥1.5, ≥1.5, ≥2 and ≥2.5; GCA-F, ≥1, ≥1, ≥1 and ≥1; and PA, ≥1, ≥1, ≥1 and ≥1, respectively, with an adjustment for early-onset ApoE ε4 noncarrier AD patients (MTA: ≥2, ≥2, ≥3 and ≥3; and GCA-F: ≥1, ≥1, ≥2 and ≥2, respectively).

CONCLUSIONS

If successfully validated in clinical settings, the list of practical cut-offs proposed here might be useful in clinical practice. Their use might also (i) promote research on atrophy subtypes, (ii) increase the understanding of different presentations of AD, (iii) improve diagnosis and prognosis and (iv) aid population selection and enrichment for clinical trials.

From Phineas Gage and Monsieur Leborgne to H.M.: Revisiting Disconnection Syndromes

On the 50th anniversary of Norman Geschwind's seminal paper entitled ‘Disconnexion syndrome in animal and man’, we pay tribute to his ideas by applying contemporary tractography methods to understand white matter disconnection in 3 classic cases that made history in behavioral neurology. We first documented the locus and extent of the brain lesion from the computerized tomography of Phineas Gage's skull and the magnetic resonance images of Louis Victor Leborgne's brain, Broca's first patient, and Henry Gustave Molaison. We then applied the reconstructed lesions to an atlas of white matter connections obtained from diffusion tractography of 129 healthy adults. Our results showed that in all 3 patients, disruption extended to connections projecting to areas distant from the lesion. We confirmed that the damaged tracts link areas that in contemporary neuroscience are considered functionally engaged for tasks related to emotion and decision-making (Gage), language production (Leborgne), and declarative memory (Molaison). Our findings suggest that even historic cases should be reappraised within a disconnection framework whose principles were plainly established by the associationist schools in the last 2 centuries.

Investigating virtual reality navigation in amnestic mild cognitive impairment using fMRI

Spatial navigation requires a well-established network of brain regions, including the hippocampus, caudate nucleus, and retrosplenial cortex. Amnestic Mild Cognitive Impairment (aMCI) is a condition with predominantly memory impairment, conferring a high predictive risk factor for dementia. aMCI is associated with hippocampal atrophy and subtle deficits in spatial navigation. We present the first use of a functional Magnetic Resonance Imaging (fMRI) navigation task in aMCI, using a virtual reality analog of the Radial Arm Maze. Compared with controls, aMCI patients showed reduced activity in the hippocampus bilaterally, retrosplenial cortex, and left dorsolateral prefrontal cortex. Reduced activation in key areas for successful navigation, as well as additional regions, was found alongside relatively normal task performance. Results also revealed increased activity in the right dorsolateral prefrontal cortex in aMCI patients, which may reflect compensation for reduced activations elsewhere. These data support suggestions that fMRI spatial navigation tasks may be useful for staging of progression in MCI.

Plasma protein biomarkers of Alzheimer's disease endophenotypes in asymptomatic older twins: early cognitive decline and regional brain volumes

There is great interest in blood-based markers of Alzheimer's disease (AD), especially in its pre-symptomatic stages. Therefore, we aimed to identify plasma proteins whose levels associate with potential markers of pre-symptomatic AD. We also aimed to characterise confounding by genetics and the effect of genetics on blood proteins in general. Panel-based proteomics was performed using SOMAscan on plasma samples from TwinsUK subjects who are asymptomatic for AD, measuring the level of 1129 proteins. Protein levels were compared with 10-year change in CANTAB-paired associates learning (PAL; n = 195), and regional brain volumes (n = 34). Replication of proteins associated with regional brain volumes was performed in 254 individuals from the AddNeuroMed cohort. Across all the proteins measured, genetic factors were found to explain ~26% of the variability in blood protein levels on average. The plasma level of the mitogen-activated protein kinase (MAPK) MAPKAPK5 protein was found to positively associate with the 10-year change in CANTAB-PAL in both the individual and twin difference context. The plasma level of protein MAP2K4 was found to suggestively associate negatively (Q < 0.1) with the volume of the left entorhinal cortex. Future studies will be needed to assess the specificity of MAPKAPK5 and MAP2K4 to eventual conversion to AD.

Disorder-specific grey matter deficits in attention deficit hyperactivity disorder relative to autism spectrum disorder

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are two common childhood disorders that exhibit genetic and behavioural overlap and have abnormalities in similar brain systems, in particular in frontal and cerebellar regions. This study compared the two neurodevelopmental disorders to investigate shared and disorder-specific structural brain abnormalities.

METHOD

Forty-four predominantly medication-naïve male adolescents with ADHD, 19 medication-naïve male adolescents with ASD and 33 age-matched healthy male controls were scanned using high-resolution T1-weighted volumetric imaging in a 3-T magnetic resonance imaging (MRI) scanner. Voxel-based morphometry (VBM) was used to test for group-level differences in structural grey matter (GM) and white matter (WM) volumes.

RESULTS

There was a significant group difference in the GM of the right posterior cerebellum and left middle/superior temporal gyrus (MTG/STG). Post-hoc analyses revealed that this was due to ADHD boys having a significantly smaller right posterior cerebellar GM volume compared to healthy controls and ASD boys, who did not differ from each other. ASD boys had a larger left MTG/STG GM volume relative to healthy controls and at a more lenient threshold relative to ADHD boys.

CONCLUSIONS

The study shows for the first time that the GM reduction in the cerebellum in ADHD is disorder specific relative to ASD whereas GM enlargement in the MTG/STG in ASD may be disorder specific relative to ADHD. This study is a first step towards elucidating disorder-specific structural biomarkers for these two related childhood disorders.

Disorder-dissociated effects of fluoxetine on brain function of working memory in attention deficit hyperactivity disorder and autism spectrum disorder

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are often co-morbid and share performance and brain dysfunctions during working memory (WM). Serotonin agonists modulate WM and there is evidence of positive behavioural effects in both disorders. We therefore used functional magnetic resonance imaging (fMRI) to investigate shared and disorder-specific brain dysfunctions of WM in these disorders, and the effects of a single dose of the selective serotonin reuptake inhibitor (SSRI) fluoxetine.

METHOD

Age-matched boys with ADHD (n = 17), ASD (n = 17) and controls (n = 22) were compared using fMRI during an N-back WM task. Patients were scanned twice, under either an acute dose of fluoxetine or placebo in a double-blind, placebo-controlled randomized design. Repeated-measures analyses within patients assessed drug effects on performance and brain function. To test for normalization effects of brain dysfunctions, patients under each drug condition were compared to controls.

RESULTS

Under placebo, relative to controls, both ADHD and ASD boys shared underactivation in the right dorsolateral prefrontal cortex (DLPFC). Fluoxetine significantly normalized the DLPFC underactivation in ASD relative to controls whereas it increased posterior cingulate cortex (PCC) deactivation in ADHD relative to control boys. Within-patient analyses showed inverse effects of fluoxetine on PCC deactivation, which it enhanced in ADHD and decreased in ASD.

CONCLUSIONS

The findings show that fluoxetine modulates brain activation during WM in a disorder-specific manner by normalizing task-positive DLPFC dysfunction in ASD boys and enhancing task-negative default mode network (DMN) deactivation in ADHD.

The influence of negative life events on hippocampal and amygdala volumes in old age: a life-course perspective

BACKGROUND

Psychosocial stress has been related to changes in the nervous system, with both adaptive and maladaptive consequences. The aim of this study was to examine the relationship of negative events experienced throughout the entire lifespan and hippocampal and amygdala volumes in older adults.

METHOD

In 466 non-demented old adults (age range 60-96 years, 58% female), hippocampal and amygdala volumes were segmented using Freesurfer. Negative life events and the age at which these events occurred were assessed by means of a structured questionnaire. Using generalized linear models, hippocampal and amygdala volumes were estimated with life events as independent variables. The statistical analyses were adjusted for age, gender, intracranial volume, lifestyle factors, cardiovascular risk factors, depressive symptoms, and cognitive functioning.

RESULTS

Total number of negative life events and of late-life events, but not of early-life, early-adulthood, or middle-adulthood events, was related to larger amygdala volume. There were interactions of early-life events with age and gender. Participants who reported two or more early-life events had significantly smaller amygdala and hippocampal volumes with increasing age. Furthermore, smaller hippocampal volume was found in men who reported two or more early-life events, but not in women.

CONCLUSIONS

These results suggest that the effect of negative life events on the brain depends on the time when the events occurred, with the strongest effects observed during the critical time periods of early and late life.

Random Forest ensembles for detection and prediction of Alzheimer's disease with a good between-cohort robustness

Computer-aided diagnosis of Alzheimer's disease (AD) is a rapidly developing field of neuroimaging with strong potential to be used in practice. In this context, assessment of models' robustness to noise and imaging protocol differences together with post-processing and tuning strategies are key tasks to be addressed in order to move towards successful clinical applications. In this study, we investigated the efficacy of Random Forest classifiers trained using different structural MRI measures, with and without neuroanatomical constraints in the detection and prediction of AD in terms of accuracy and between-cohort robustness. From The ADNI database, 185 AD, and 225 healthy controls (HC) were randomly split into training and testing datasets. 165 subjects with mild cognitive impairment (MCI) were distributed according to the month of conversion to dementia (4-year follow-up). Structural 1.5-T MRI-scans were processed using Freesurfer segmentation and cortical reconstruction. Using the resulting output, AD/HC classifiers were trained. Training included model tuning and performance assessment using out-of-bag estimation. Subsequently the classifiers were validated on the AD/HC test set and for the ability to predict MCI-to-AD conversion. Models' between-cohort robustness was additionally assessed using the AddNeuroMed dataset acquired with harmonized clinical and imaging protocols. In the ADNI set, the best AD/HC sensitivity/specificity (88.6%/92.0% - test set) was achieved by combining cortical thickness and volumetric measures. The Random Forest model resulted in significantly higher accuracy compared to the reference classifier (linear Support Vector Machine). The models trained using parcelled and high-dimensional (HD) input demonstrated equivalent performance, but the former was more effective in terms of computation/memory and time costs. The sensitivity/specificity for detecting MCI-to-AD conversion (but not AD/HC classification performance) was further improved from 79.5%/75%-83.3%/81.3% by a combination of morphometric measurements with ApoE-genotype and demographics (age, sex, education). When applied to the independent AddNeuroMed cohort, the best ADNI models produced equivalent performance without substantial accuracy drop, suggesting good robustness sufficient for future clinical implementation.

Alterations in brain structure in adults with anorexia nervosa and the impact of illness duration

BACKGROUND

Brain structure alterations have been reported in anorexia nervosa, but findings have been inconsistent. This may be due to inadequate sample size, sample heterogeneity or differences in methodology.

METHOD

High resolution magnetic resonance images were acquired of 33 adult participants with anorexia nervosa and 33 healthy participants, the largest study sample to date, in order to assess whole-brain volume, ventricular cerebrospinal fluid, white matter and grey matter volume. Voxel-based morphometry was conducted to assess regional grey matter volume. Levels of depression, anxiety, obsessionality and eating disorder-related symptoms were measured and used to explore correlations with brain structure.

RESULTS

Participants with anorexia nervosa had smaller brain volumes as well as a global decrease in grey matter volume with ventricular enlargement. Voxel-based morphometry revealed a decrease in grey matter volume spanning across the cerebellum, temporal, frontal and occipital lobes. A correlation was found between grey matter volume loss and duration of illness in the cerebellum and mesencephalon. No correlations were found with clinical measures.

CONCLUSIONS

Findings are in accordance with several previous studies on brain structure and match functional studies that have assessed the symptomatology of anorexia nervosa, such as body image distortion and cognitive bias to food. The correlation with duration of illness supports the implication of cerebellar atrophy in the maintenance of low weight and disrupted eating behaviour and illustrates its role in the chronic phase of anorexia nervosa. The lack of other correlations suggests that these findings are not related to the presence of co-morbid disorders.

Feasibility of event-related potential methodology to evaluate changes in cortical processing after rehabilitation in children with cerebral palsy: a pilot study

This study examined the feasibility of using event-related potentials (ERPs) to measure changes in cortical processing following an established rehabilitative intervention (constraint-induced movement therapy, CIMT) for children with cerebral palsy (CP). Sixteen participants with a diagnosis of hemiparetic CP, with a median age of 6 years, were assessed pre and immediately post CIMT and at 6-month follow-up, using a picture-word match/mismatch discrimination task and standard neurobehavioral measures. Intervention effects were evident in improved performance on behavioral tests of sensory and motor function and the increased mean ERP amplitude of the N400 match/mismatch response on the side ipsilateral to the lesion. These effects were maintained 6 months after the intervention. No such changes were observed on the side contralateral to the lesion. This research suggests that ERPs can measure rehabilitation-induced changes in neural function in children with CP.

Influence of age, disease onset and ApoE4 on visual medial temporal lobe atrophy cut-offs

BACKGROUND

Visual assessment of medial temporal lobe atrophy (MTA; range 0-4, from no atrophy to increasing atrophy of the choroid fissure, temporal horns and hippocampus) is a sensitive radiological marker of Alzheimer's disease (AD). One of the critical elements for visual MTA assessment is the cut-off score that determines deviation from normality.

METHODS

In this study, we assessed the sensitivity and specificity of different MTA cut-off scores to classify control subjects, individuals with mild cognitive impairment (MCI) and AD patients from two large independent cohorts, AddNeuroMed and Alzheimer's Disease Neuroimaging Initiative. Of note, we evaluated the effects of clinical, demographic and genetic variables on the classification performance according to the different cut-offs.

RESULTS

A cut-off of ≥1.5 based on the mean MTA scores of both hemispheres showed higher sensitivity in classifying patients with AD (84.5%) and MCI subjects (75.8%) who converted to dementia compared to an age-dependent cut-off. The age-dependent cut-off showed higher specificity or ability to correctly identify control subjects (83.2%) and those with MCI who remained stable (65.5%). Increasing age, early-onset disease and absence of the ApoE ε4 allele had a stronger influence on classifications using the ≥1.5 cut-off. Above 75 years of age, an alternative cut-off of ≥2.0 should be applied to achieve a classification accuracy for both patients with AD and control subjects that is clinically useful.

CONCLUSION

Clinical, demographic and genetic variables can influence the classification of MTA cut-off scores, leading to misdiagnosis in some cases. These variables, in addition to the differential sensitivity and specificity of each cut-off, should be carefully considered when performing visual MTA assessment.

Examination of the predictive value of structural magnetic resonance scans in bipolar disorder: a pattern classification approach

BACKGROUND

Bipolar disorder (BD) is one of the leading causes of disability worldwide. Patients are further disadvantaged by delays in accurate diagnosis ranging between 5 and 10 years. We applied Gaussian process classifiers (GPCs) to structural magnetic resonance imaging (sMRI) data to evaluate the feasibility of using pattern recognition techniques for the diagnostic classification of patients with BD.

METHOD

GPCs were applied to gray (GM) and white matter (WM) sMRI data derived from two independent samples of patients with BD (cohort 1: n = 26; cohort 2: n = 14). Within each cohort patients were matched on age, sex and IQ to an equal number of healthy controls.

RESULTS

The diagnostic accuracy of the GPC for GM was 73% in cohort 1 and 72% in cohort 2; the sensitivity and specificity of the GM classification were respectively 69% and 77% in cohort 1 and 64% and 99% in cohort 2. The diagnostic accuracy of the GPC for WM was 69% in cohort 1 and 78% in cohort 2; the sensitivity and specificity of the WM classification were both 69% in cohort 1 and 71% and 86% respectively in cohort 2. In both samples, GM and WM clusters discriminating between patients and controls were localized within cortical and subcortical structures implicated in BD.

CONCLUSIONS

Our results demonstrate the predictive value of neuroanatomical data in discriminating patients with BD from healthy individuals. The overlap between discriminative networks and regions implicated in the pathophysiology of BD supports the biological plausibility of the classifiers.

Drug-specific laterality effects on frontal lobe activation of atomoxetine and methylphenidate in attention deficit hyperactivity disorder boys during working memory

BACKGROUND

The catecholamine reuptake inhibitors methylphenidate (MPH) and atomoxetine (ATX) are the most common treatments for attention deficit hyperactivity disorder (ADHD). This study compares the neurofunctional modulation and normalization effects of acute doses of MPH and ATX within medication-naive ADHD boys during working memory (WM).

METHOD

A total of 20 medication-naive ADHD boys underwent functional magnetic resonance imaging during a parametric WM n-back task three times, under a single clinical dose of either MPH, ATX or placebo in a randomized, double-blind, placebo-controlled, cross-over design. To test for normalization effects, brain activations in ADHD under each drug condition were compared with that of 20 age-matched healthy control boys.

RESULTS

Relative to healthy boys, ADHD boys under placebo showed impaired performance only under high WM load together with significant underactivation in the bilateral dorsolateral prefrontal cortex (DLPFC). Both drugs normalized the performance deficits relative to controls. ATX significantly enhanced right DLPFC activation relative to MPH within patients, and significantly normalized its underactivation relative to controls. MPH, by contrast, both relative to placebo and ATX, as well as relative to controls, upregulated the left inferior frontal cortex (IFC), but only during 2-back. Both drugs enhanced fronto-temporo-striatal activation in ADHD relative to control boys and deactivated the default-mode network, which were negatively associated with the reduced DLPFC activation and performance deficits, suggesting compensation effects.

CONCLUSIONS

The study shows both shared and drug-specific effects. ATX upregulated and normalized right DLPFC underactivation, while MPH upregulated left IFC activation, suggesting drug-specific laterality effects on prefrontal regions mediating WM.

CERAD Neuropsychological Total Scores Reflect Cortical Thinning in Prodromal Alzheimer's Disease

Background

Sensitive cognitive global scores are beneficial in screening and monitoring for prodromal Alzheimer's disease (AD). Early cortical changes provide a novel opportunity for validating established cognitive total scores against the biological disease markers.

Methods

We examined how two different total scores of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery and the Mini-Mental State Examination (MMSE) are associated with cortical thickness (CTH) in mild cognitive impairment (MCI) and prodromal AD. Cognitive and magnetic resonance imaging (MRI) data of 22 progressive MCI, 78 stable MCI, and 98 control subjects, and MRI data of 103 AD patients of the prospective multicenter study were analyzed.

Results

CERAD total scores correlated with mean CTH more strongly (r = 0.34-0.38, p < 0.001) than did MMSE (r = 0.19, p = 0.01). Of those vertex clusters that showed thinning in progressive MCI, 60-75% related to the CERAD total scores and 3% to the MMSE.

Conclusion

CERAD total scores are sensitive to the CTH signature of prodromal AD, which supports their biological validity in detecting early disease-related cognitive changes.

Classification and prediction of clinical diagnosis of Alzheimer's disease based on MRI and plasma measures of α-/γ-tocotrienols and γ-tocopherol

BACKGROUND

The aim of this study was to evaluate the accuracy of combined structural magnetic resonance imaging (MRI) measures and plasma levels of vitamin E forms, including all eight natural vitamin E congeners (four tocopherols and four tocotrienols) and markers of vitamin E oxidative/nitrosative damage, in differentiating individuals with Alzheimer's disease (AD) and mild cognitive impairment (MCI) from cognitively intact control (CTL) subjects.

METHODS

Overall, 81 patients with AD, 86 with MCI and 86 CTL individuals were enrolled from the longitudinal multicentre AddNeuroMed study. MRI and plasma vitamin E data were acquired at baseline. MRI scans were analysed using Freesurfer, an automated segmentation scheme which generates regional volume and cortical thickness measures. Orthogonal partial least squares to latent structures (OPLS), a multivariate data analysis technique, was used to analyse MRI and vitamin E measures in relation to AD and MCI diagnosis.

RESULTS

The joint evaluation of MRI and plasma vitamin E measures enhanced the accuracy of differentiating individuals with AD and MCI from CTL subjects: 98.2% (sensitivity 98.8%, specificity 97.7%) for AD versus CTL, and 90.7% (sensitivity 91.8%, specificity 89.5%) for MCI versus CTL. This combination of measures also identified 85% of individuals with MCI who converted to clinical AD at follow-up after 1 year.

CONCLUSIONS

Plasma levels of tocopherols and tocotrienols together with automated MRI measures can help to differentiate AD and MCI patients from CTL subjects, and to prospectively predict MCI conversion into AD. Our results suggest the potential role of nutritional biomarkers detected in plasma-tocopherols and tocotrienols-as indirect indicators of AD pathology, and the utility of a multimodality approach.

Abstract 30: Behavioral Change after Heart Disease Risk Assessment in Women

Background: Heart disease is the leading killer of women in the United States. Unfortunately, most women are unaware of their individual risk. Studies have shown that awareness of cardiovascular (CV) disease risks correlates with positive behavior changes, including increased physical activity and weight loss.

Methods: The Change of Heart (COH) Program is a university hospital based CV disease risk assessment program. The assessment included baseline weight, height, blood pressure, lipid profile, fasting glucose, and Framingham risk score in women 18 years of age and older. A 90-minute individual discussion of risk and recommendations for healthy lifestyle changes were given. Follow up questionnaires and newsletters designed to assess and encourage heart-healthy behavioral changes were given at 3 and 6 months after the initial visit to participants. We compared baseline vs. follow up self-reported activity levels and readiness for change.

Results: At baseline, participants’ average age was 50.6 years, they exercised between 1 to 3 hours each week, and most had either never smoked or had quit smoking. When asked what they thought a woman’s greatest health problem was, 62% answered Heart Disease/Heart Attack. Additionally, 59% of participants felt moderately informed about women’s heart disease and 54% would call 911 if they thought they were having a heart attack. We found a statistically significant improvement in willingness to increase physical activity (p < 0.001), practice good eating habits (p < 0.001), avoid smoking (p <0.01), lose or maintain healthy weight (p <0.001), lower and maintain cholesterol levels (p < 0.001) and blood pressure (p < 0.001) over the course of the study.

Conclusion: In a population of women who felt that they were moderately well informed on heart disease, only 62% knew that a woman’s greatest health risk was heart disease or a heart attack. Most women showed improvements in readiness for positive heart-healthy behavioral changes. This emphasizes the ability for a cardiovascular risk reduction program to positively influence a woman’s willingness for behavioral change.

Abstract 98: Personal and Community Barriers to a Heart-healthy Lifestyle in Women

Background: Though heart disease is the leading killer of women in the United States, many of them are unaware of their individual risks. Studies have shown that awareness of cardiovascular disease risk correlates with positive behavior changes, including increased physical activity and weight loss, leading to a heart-healthy lifestyle. The purpose of this study was to assess women’s awareness of their heart disease risk and barriers to starting heart healthy behaviors, such as improved diet and exercise.

Methods: The Change of Heart (COH) Program at the University of Kansas Hospital conducted a self-reported assessment on women’s perceived barriers to leading heart-healthy lifestyle. Participants (N = 157) of this study were recruited from Mid-America Cardiology and their age ranged from 29 to 78 years (M = 53 years). Additionally, participants had an average education level of college and above and the median income was greater than $60,000. The assessment included questions regarding family and other care giving responsibilities, personal perception of heart disease risk, availability of indoor exercise facilities, and community access to fresh fruit and vegetables.

Results: The three most common personal barriers amongst this population were family and other care giving obligations (87%), not perceiving oneself to be at risk for heart disease (63%), and feeling too stressed to accomplish one’s tasks (51%). Additionally, the three most common community barriers were a lack of nutritional information posted on restaurant menus (32%), not having access to indoor exercising facilities (17%), and not having access to support groups, such as weight management, smoking cessation (13%). When participants were asked what their intentions to make lifestyle changes to lower heart disease risk, 66% answered either an 8 or 9 on a scale of 0 (no intention) to 10 (most intention); however, 21% of women did not or occasionally did not believe they had control over their health conditions. The majority of participants had access to fresh fruits and vegetables (66%), to smoke free restaurants and public facilities (75%), and to safe, outside, public exercises areas (61%).

Conclusion: In this well-educated cohort of women, the most common barrier to leading a heart-healthy lifestyle was lack of time due to family obligations. Most women were aware that women in general needed to make healthy changes in their lives, but they did not personalize their risk. This study suggests that women, even with available resources, need to be assessed, reminded, and encouraged to develop behavioral skills and strategies (e.g. time management) to incorporate heart healthy behaviors into their lifestyle.

An MRI-based index to measure the severity of Alzheimer's disease-like structural pattern in subjects with mild cognitive impairment

BACKGROUND

Structural magnetic resonance imaging (MRI) is sensitive to neurodegeneration and can be used to estimate the risk of converting to Alzheimer's disease (AD) in individuals with mild cognitive impairment (MCI). Brain changes in AD and prodromal AD involve a pattern of widespread atrophy. The use of multivariate analysis algorithms could enable the development of diagnostic tools based on structural MRI data. In this study, we investigated the possibility of combining multiple MRI features in the form of a severity index.

METHODS

We used baseline MRI scans from two large multicentre cohorts (AddNeuroMed and ADNI). On the basis of volumetric and cortical thickness measures at baseline with AD cases and healthy control (CTL) subjects as training sets, we generated an MRI-based severity index using the method of orthogonal projection to latent structures (OPLS). The severity index tends to be close to 1 for AD patients and 0 for CTL subjects. Values above 0.5 indicate a more AD-like pattern. The index was then estimated for subjects with MCI, and the accuracy of classification was investigated.

RESULTS

Based on the data at follow-up, 173 subjects converted to AD, of whom 112 (64.7%) were classified as AD-like and 61 (35.3%) as CTL-like.

CONCLUSION

We found that joint evaluation of multiple brain regions provided accurate discrimination between progressive and stable MCI, with better performance than hippocampal volume alone, or a limited set of features. A major challenge is still to determine optimal cut-off points for such parameters and to compare their relative reliability.

Proton magnetic resonance spectroscopy of the striatum in Parkinson's disease patients with motor response fluctuations

We have performed proton magnetic resonance spectroscopy centred on the putamen contralateral to the worst affected side in 10 patients with idiopathic Parkinson's disease (PD) and motor response fluctuations and seven age matched healthy controls. In PD, there was striking reduction in the N-acetylaspartate (NAA) and creatine and NAA/choline ratios compared to controls. This pilot study provides in vivo evidence of striatal neuronal dysfunction in PD and further studies are in progress to establish if the observed changes are due to the disease process itself or due to chronic levodopa therapy.

Jak-STAT regulation of cyst stem cell development in the Drosophila testis

Establishment and maintenance of functional stem cells is critical for organ development and tissue homeostasis. Little is known about the mechanisms underlying stem establishment during organogenesis. Drosophila testes are among the most thoroughly characterized systems for studying stem cell behavior, with germline stem cells (GSCs) and somatic cyst stem cells (CySCs) cohabiting a discrete stem cell niche at the testis apex. GSCs and CySCs are arrayed around hub cells that also comprise the niche and communication between hub cells, GSCs, and CySCs regulates the balance between stem cell maintenance and differentiation. Recent data has shown that functional, asymmetrically dividing GSCs are first established at ∼23 h after egg laying during Drosophila testis morphogenesis (Sheng et al., 2009). This process correlates with coalescence of the hub, but development of CySCs from somatic gonadal precursors (SGPs) was not examined. Here, we show that functional CySCs are present at the time of GSC establishment, and that Jak-STAT signaling is necessary and sufficient for CySC maintenance shortly thereafter. Furthermore, hyper-activation of Jak in CySCs promotes expansion of the GSC population, while ectopic Jak activation in the germline induces GSC gene expression in GSC daughter cells but does not prevent spermatogenic differentiation. Together, these observations indicate that, similar to adult testes, Jak-STAT signaling from the hub acts on both GSCs and CySC to regulate their development and differentiation, and that additional signaling from CySCs to the GSCs play a dominant role in controlling GSC maintenance during niche formation.

Sudden cardiac death in women

Women are at lower risk for development of sudden cardiac death (SCD) as compared with men. Women with SCD tend to have less structural heart disease and preserved left ventricular systolic function. Coronary artery disease (CAD) is the most common predictor of SCD in women, as it is in men. However, women with SCD are less likely to have underlying CAD than men, suggesting the need to identify risk factors other than CAD or systolic dysfunction for its prediction in women. SCD risk factors in women include heart failure with preserved left ventricular systolic function, abnormal sympathetic uptake as assessed by meta-iodobenzylguanidine uptake, depression, and/or use of antidepressants. This article reviews SCD in women and discusses areas for future research.

Genome-wide association with MRI atrophy measures as a quantitative trait locus for Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with considerable evidence suggesting an initiation of disease in the entorhinal cortex and hippocampus and spreading thereafter to the rest of the brain. In this study, we combine genetics and imaging data obtained from the Alzheimer's Disease Neuroimaging Initiative and the AddNeuroMed study. To identify genetic susceptibility loci for AD, we conducted a genome-wide study of atrophy in regions associated with neurodegeneration in this condition. We identified one single-nucleotide polymorphism (SNP) with a disease-specific effect associated with entorhinal cortical volume in an intron of the ZNF292 gene (rs1925690; P-value=2.6 × 10(-8); corrected P-value for equivalent number of independent quantitative traits=7.7 × 10(-8)) and an intergenic SNP, flanking the ARPP-21 gene, with an overall effect on entorhinal cortical thickness (rs11129640; P-value=5.6 × 10(-8); corrected P-value=1.7 × 10(-7)). Gene-wide scoring also highlighted PICALM as the most significant gene associated with entorhinal cortical thickness (P-value=6.7 × 10(-6)).

Differential corticospinal tract degeneration in homozygous 'D90A' SOD-1 ALS and sporadic ALS

BACKGROUND

The homogeneous genotype and stereotyped phenotype of a unique familial form of amyotrophic lateral sclerosis (ALS) (patients homozygous for aspartate-to-alanine mutations in codon 90 (homD90A) superoxide dismutase 1) provides an ideal model for studying genotype/phenotype interactions and pathological features compared with heterogeneous apparently sporadic ALS. The authors aimed to use diffusion tensor tractography to quantify and compare changes in the intracerebral corticospinal tracts of patients with both forms of ALS, building on previous work using whole-brain voxelwise group analysis.

METHOD

21 sporadic ALS patients, seven homD90A patients and 20 healthy controls underwent 1.5&emsp14;T diffusion tensor MRI. Patients were assessed using 'upper motor neuron burden,' El Escorial and ALSFR-R scales. The intracranial corticospinal tract was assessed using diffusion tensor tractography measures of fractional anisotropy (FA), mean diffusivity, and radial and axial diffusivity obtained from its entire length.

RESULTS

Corticospinal tract FA was reduced in sporadic ALS patients compared with both homD90A ALS patients and controls. The diffusion measures in sporadic ALS patients were consistent with anterograde (Wallerian) degeneration of the corticospinal tracts. In sporadic ALS, corticospinal tract FA was related to clinical measures. Despite a similar degree of clinical upper motor neuron dysfunction and disability in homD90A ALS patients compared with sporadic ALS, there were no abnormalities in corticospinal tract diffusion measures compared with controls.

CONCLUSIONS

Diffusion tensor tractography has shown axonal degeneration within the intracerebral portion of the corticospinal tract in sporadic ALS patients, but not those with a homogeneous form of familial ALS. This suggests significant genotypic influences on the phenotype of ALS and may provide clues to slower progression of disease in homD90A patients.

No effect of 5HTTLPR or BDNF Val66Met polymorphism on hippocampal morphology in major depression

Neuroimaging research implicates the hippocampus in the aetiology of major depressive disorder (MDD). Imaging genetics studies have investigated the influence of the serotonin transporter-linked polymorphic region (5HTTLPR) and brain-derived neurotrophic factor (BDNF) Val66Met polymorphism on the hippocampus in healthy individuals and patients with depression (MDD). However, conflicting results have led to inconclusive evidence about the effect of 5HTTLPR or BDNF on hippocampal volume (HCV). We hypothesized that analysis methods based on three-dimensional (3D) hippocampal shape mapping could offer improved sensitivity to clarify these effects. Magnetic resonance imaging data were collected in parallel samples of 111 healthy individuals and 84 MDD patients. Manual hippocampal segmentation was conducted and the resulting data used to investigate the influence of 5HTTLPR and BDNF Val66Met genotypes on HCV and 3D shape within each sample. Hippocampal volume normalized by intracranial volume (ICV) showed no significant difference between 5HTTLPR S allele carriers and L/L homozygotes or between BDNF Met allele carriers and Val/Val homozygotes in the group of healthy individuals. Moreover, there was no significant difference in normalized HCV between 5HTTLPR diallelic and triallelic classifications or between the BDNF Val66Met genotypes in MDD patients, although there was a relationship between BDNF Val66Met and ICV. Shape analysis detected dispersed between-group differences, but these effects did not survive multiple testing correction. In this study, there was no evidence of a genetic effect for 5HTTLPR or BDNF Val66Met on hippocampal morphology in either healthy individuals or MDD patients despite the relatively large sample sizes and sensitive methodology.