A Metabolomics Analysis of a Novel Phenotype of Older Adults at Higher Risk of Dementia

Background

Older adults presenting with dual-decline in cognition and walking speed face a 6-fold higher risk for dementia compared with those showing no decline. We hypothesized that the metabolomics profile of dual-decliners would be unique even before they show signs of decline in cognition and gait speed.

Objective

The objective of this study was to determine if plasma metabolomics signatures can discriminate dual-decliners from no decliners, purely cognitive decliners, and purely motor decliners prior to decline.

Methods

A retrospective cross-sectional study using baseline plasma for untargeted metabolomics analyses to investigate early signals of later dual-decline status in study participants (n = 76) with convenient sampling. Dual-decline was operationalized as decline in gait speed (>10 cm/s) and cognition (>2 points decline in Montreal Cognitive Assessment score) on at least two consecutive 6-monthly assessments. The participants' decliner status was evaluated 3 years after the blood sample was collected. Pair-wise comparison of detected compounds was completed using principal components and hierarchical clustering analyses.

Results

Analyses did not detect any cluster separation in untargeted metabolomes across baseline groups. However, follow-up analyses of specific molecules detected 4 compounds (17-Hydroxy-12-(hydroxymethyl)-10-oxo-8 oxapentacyclomethyl hexopyranoside, Fleroxacin, Oleic acid, and 5xi-11,12-Dihydroxyabieta-8(14),9(11),12-trien-20-oic acid) were at significantly higher concentration among the dual-decliners compared to non-decliners. The pure cognitive decliner group had significantly lower concentration of six compounds (1,3-nonanediol acetate, 4-(2-carboxyethyl)-2-methoxyphenyl beta-D-glucopyranosiduronic acid, oleic acid, 2E-3-[4-(sulfo-oxy)phenyl] acrylic acid, palmitelaidic acid, and myristoleic acid) compared to the non-decliner group.

Conclusions

The unique metabolomics profile of dual-decliners warrants follow-up metabolomics analysis. Results may point to modifiable pathways.

Proceedings from the Albert Charitable Trust Inaugural Workshop on white matter and cognition in aging

This third in a series of vascular cognitive impairment (VCI) workshops, supported by "The Leo and Anne Albert Charitable Trust," was held from February 8 to 12 at the Omni Resort in Carlsbad, CA. This workshop followed the information gathered from the earlier two workshops suggesting that we focus more specifically on brain white matter in age-related cognitive impairment. The Scientific Program Committee (Frank Barone, Shawn Whitehead, Eric Smith, and Rod Corriveau) assembled translational, clinical, and basic scientists with unique expertise in acute and chronic white matter injury at the intersection of cerebrovascular and neurodegenerative etiologies. As in previous Albert Trust workshops, invited participants addressed key topics related to mechanisms of white matter injury, biomarkers of white matter injury, and interventions to prevent white matter injury and age-related cognitive decline. This report provides a synopsis of the presentations and discussions by the participants, including the existing knowledge gaps and the delineation of the next steps towards advancing our understanding of white matter injury and age-related cognitive decline. Workshop discussions and consensus resulted in action by The Albert Trust to (1) increase support from biannual to annual "White Matter and Cognition" workshops; (2) provide funding for two collaborative, novel research grants annually submitted by meeting participants; and (3) coordinate the formation of the "Albert Research Institute for White Matter and Cognition." This institute will fill a gap in white matter science, providing white matter and cognition communications, including annual updates from workshops and the literature and interconnecting with other Albert Trust scientific endeavors in cognition and dementia, and providing support for newly established collaborations between seasoned investigators and to the development of talented young investigators in the VCI-dementia (VCID) and white matter cognition arena.

A functional-structural model of ephemeral seagrass growth influenced by environment

Background and Aims

Ephemeral seagrasses that respond rapidly to environmental changes are important marine habitats. However, they are under threat due to human activity and are logistically difficult and expensive to study. This study aimed to develop a new functional-structural environmentally dependent model of ephemeral seagrass, able to integrate our understanding of ephemeral seagrass growth dynamics and assess options for potential management interventions, such as seagrass transplantation.

Methods

A functional-structural plant model was developed in which growth and senescence rates are mechanistically linked to environmental variables. The model was parameterized and validated for a population of Halophila stipulacea in the Persian Gulf.

Key Results

There was a good match between empirical and simulated results for the number of apices, net rhizome length or net number of internodes using a 330 d simulation. Simulated data were more variable than empirical data. Simulated structural patterns of seagrass rhizome growth qualitatively matched empirical observations.

Conclusions

This new model successfully simulates the environmentally dependent growth and senescence rates of our case-study ephemeral seagrass species. It produces numerical and visual outputs that help synthesize our understanding of how the influence of environmental variables on plant functional processes affects overall growth patterns. The model can also be used to assess the potential outcomes of management interventions like seagrass transplantation, thus providing a useful management tool. It is freely available and easily adapted for new species and locations, although validation with more species and environments is required.

In Vitro Validation of Intratumoral Modulation Therapy for Glioblastoma

BACKGROUND/AIM

This proof-of-concept study evaluated the antitumor impact of a direct electrical stimulation technique, termed intratumoral modulation therapy (IMT) on glioblastoma (GBM) cells.

MATERIALS AND METHODS

An in vitro IMT model comprised of a calibrated electrode to deliver continuous, low-intensity stimulation within GBM preparations. Viability and apoptosis assays were performed in treated immortalized and patient-derived GBM cells, and post-mitotic neurons. IMT was delivered alone and with temozolomide, or gene silencing of the tumor-promoting chaperone, heat-shock protein 27 (HSP27).

RESULTS

GBM cells, but not neurons, exhibited >40% loss of viability, caspase-3 activation and apoptosis with IMT. Cell death was modest with temozolomide alone (30%) but increased significantly with concomitant IMT (70%). HSP27 silencing alone produced 30% viability loss, with significant enhancement of target knockdown and GBM cell death (65%), when combined with IMT.

CONCLUSION

These findings warrant further evaluation of IMT as a potential novel therapeutic strategy for GBM.

Elucidating the clinical characteristics of patients captured using different definitions of massive transfusion

BACKGROUND AND OBJECTIVES

The type and clinical characteristics of patients identified with commonly used definitions of massive transfusion (MT) are largely unknown. The objective of this study was to define the clinical characteristics of patients meeting different definitions of MT for the purpose of patient recruitment in observational studies.

MATERIALS AND METHODS

Data were extracted on all patients who received red blood cell (RBC) transfusions in 2010 at three tertiary Australian hospitals. MT patients were identified according to three definitions: ≥10 units RBC in 24 h (10/24 h), ≥6 units RBC in 6 h (6/6 h) and ≥5 units RBC in 4 h (5/4 h). Clinical coding data were used to assign bleeding context. Data on in-hospital mortality were also extracted.

RESULTS

Five hundred and forty-two patients met at least one MT definition, with 236 (44%) included by all definitions. The most inclusive definition was 5/4 h (508 patients, 94%) followed by 6/6 h (455 patients, 84%) and 10/24 h (251 patients, 46%). Importantly, 40-55% of most types of critical bleeding events and 82% of all obstetric haemorrhage cases were excluded by the 10/24 h definition. Patients who met both the 5/4 h and 10/24 h definitions were transfused more RBCs (19 vs. 8 median total RBC units; P < 0·001), had longer ventilation time (120 vs. 55 h; P < 0·001), median ICU (149 vs. 99 h; P < 0·001) and hospital length of stay (23 vs. 18 h; P = 0·006) and had a higher in-hospital mortality rate (23·3% vs. 16·4%; P = 0·050).

CONCLUSION

The 5/4 h MT definition was the most inclusive, but combination with the 10/24 h definition appeared to identify a clinically important patient cohort.

A computational simulation study of the influence of helmet wearing on head injury risk in adult cyclists

Evidence for the effectiveness of cycle helmets has relied either on simplified experiments or complex statistical analysis of patient cohorts or populations. This study directly assesses the effectiveness of cycle helmets over a range of accident scenarios, from basic loss of control to vehicle impact, using computational modelling. Simulations were performed using dynamics modelling software (MADYMO) and models of a 50% Hybrid III dummy, a hybrid cross bicycle and a car. Loss of control was simulated by a sudden turn of the handlebars and striking a curb, side and rear-on impacts by a car were also simulated. Simulations were run over a representative range of cycle speeds (2.0-14.0 m s(-1)) and vehicle speeds (4.5-17.9 m s(-1)). Bicycle helmets were found to be effective in reducing the severity of head injuries sustained in common accidents. They reduced the risk of an AIS>3 injury, in cases with head impacts, by an average of 40%. In accidents that would cause up to moderate (AIS=2) injuries to a non-helmeted rider, helmets eliminated the risk of injury. Helmets were also found to be effective in preventing fatal head injuries in some instances. The effectiveness of helmets was demonstrated over the entire range of cycle speeds studied, up to and including 14 m s(-1). There was no evidence that helmet wearing increased the risk of neck injury, indeed helmets were found to be protective of neck injuries in many cases. Similarly, helmets were found to offer an increase in protection even when an increase in cycle speed due to risk compensation was taken into consideration.

Piloting the use of 2D barcode and patient safety-software in an Australian tertiary hospital setting

OBJECTIVES

Errors in administration of blood products can lead to poor patient outcomes including fatal ABO incompatible transfusions. This pilot study sought to establish whether the use of two-dimensional (2D) barcode technology combined with patient identification software designed to assist in blood administration improves the bedside administration of transfusions in an Australian tertiary hospital.

STUDY DESIGN AND METHODS

The study was conducted in a Haematology/Oncology Day Clinic of a major metropolitan hospital, to evaluate the use of 2D barcode technology and patient safety-software and hand-held PDAs to assist nursing staff in patient identification and blood administration. Comparative audits were conducted before and after the technology's implementation.

RESULTS

The preimplementation transfusion practice audits demonstrated a poor understanding of the blood checking process, with focus on the product rather than patient identification. Following the implementation of 2D barcode technology and patient safety-software, there was significant improvement in administration practice. Positive, verbal patient identification improved from 57% (51/90) to 94% (75/80). Similarly, the cross-referencing of the patient's identification with the patient's wristband improved from 36% (32/90) to 94% (75/80), and the cross-referencing of patient ID on the compatibility tag to wristbands improved from 48% (43/90) to 99% (79/80). Importantly, the 2D barcode technology and patient safety-software saw 100% (80/80) of checks being conducted at the patient bedside, compared with 76% (68/90) in the preimplementation audits.

CONCLUSION

This pilot study demonstrates that 2D barcode technology and patient safety-software significantly improves the bedside check of patient and blood product identification in an Australian setting.

Neuropilin 1 directly interacts with Fer kinase to mediate semaphorin 3A-induced death of cortical neurons

Neuropilins (NRPs) are receptors for the major chemorepulsive axonal guidance cue semaphorins (Sema). The interaction of Sema3A/NRP1 during development leads to the collapse of growth cones. Here we show that Sema3A also induces death of cultured cortical neurons through NRP1. A specific NRP1 inhibitory peptide ameliorated Sema3A-evoked cortical axonal retraction and neuronal death. Moreover, Sema3A was also involved in cerebral ischemia-induced neuronal death. Expression levels of Sema3A and NRP1, but not NRP2, were significantly increased early during brain reperfusion following transient focal cerebral ischemia. NRP1 inhibitory peptide delivered to the ischemic brain was potently neuroprotective and prevented the loss of motor functions in mice. The integrity of the injected NRP1 inhibitory peptide into the brain remained unchanged, and the intact peptide permeated the ischemic hemisphere of the brain as determined using MALDI-MS-based imaging. Mechanistically, NRP1-mediated axonal collapse and neuronal death is through direct and selective interaction with the cytoplasmic tyrosine kinase Fer. Fer RNA interference effectively attenuated Sema3A-induced neurite retraction and neuronal death in cortical neurons. More importantly, down-regulation of Fer expression using Fer-specific RNA interference attenuated cerebral ischemia-induced brain damage. Together, these studies revealed a previously unknown function of NRP1 in signaling Sema3A-evoked neuronal death through Fer in cortical neurons.

The Sea Empress oil spill (Wales, UK): effects on Common Scoter Melanitta nigra in Carmarthen Bay and status ten years later

Carmarthen Bay, UK, regularly supports internationally important numbers (>16,000) of non-breeding Common Scoters Melanitta nigra. The spill of 72,000 tonnes of crude oil from the Sea Empress in 1996 affected birds both through direct mortality and likely pollution of key food resources. Numbers were greatly reduced following the spill, whilst changes in the distribution of birds within Carmarthen Bay suggested that potentially sub-optimal foraging zones were used. However, ten years after the incident, numbers of Common Scoter were no different to those recorded immediately before the spill. Compared to some other spills, rapid revival is evident. Numbers increased to pre-spill levels within three winters and distributional changes suggested a concurrent return to previously contaminated feeding areas, implying that the ecosystem had regenerated sufficiently to support its top predator. The importance of prolonged, standardised monitoring of bird numbers and distribution as indicators of ecological recovery from environmental damage is emphasised.

A 3-year prospective study of the effects of adjuvant treatments on cognition in women with early stage breast cancer

The neuropsychological performance of 85 women with early stage breast cancer scheduled for chemotherapy, 43 women scheduled for endocrine therapy and/or radiotherapy and 49 healthy control subjects was assessed at baseline (T1), postchemotherapy (or 6 months) (T2) and at 18 months (T3). Repeated measures analysis found no significant interactions or main effect of group after controlling for age and intelligence. Using a calculation to examine performance at an individual level, reliable decline on multiple tasks was seen in 20% of chemotherapy patients, 26% of nonchemotherapy patients and 18% of controls at T2 (18%, 14 and 11%, respectively, at T3). Patients who had experienced a treatment-induced menopause were more likely to show reliable decline on multiple measures at T2 (OR=2.6, 95% confidence interval (CI) 0.823–8.266 P=0.086). Psychological distress, quality of life measures and self-reported cognitive failures did not impact on objective tests of cognitive function, but were significantly associated with each other. The results show that a few women experienced objective measurable change in their concentration and memory following standard adjuvant therapy, but the majority were either unaffected or even improve over time.

Recovery from post-operative anaemia

Acceptance of lower transfusion thresholds and shorter post-operative stays results in patients leaving hospital after surgery with lower haemoglobin (Hb) than previously. We undertook a prospective observational study to assess the haematological response to post-operative anaemia and to determine the utility of quality of life (QoL) measures in assessing the impact of anaemia on such patients. Thirty patients undergoing unilateral hip arthroplasty had blood samples taken and QoL questionnaires administered pre-operatively and at 7, 28 and 56 days post-operatively. Increased erythropoiesis was evident at day 7 post-operatively. Approximately two-thirds of the post-operative Hb deficit was corrected by day 28. There was evidence of functional iron deficiency in more than one-quarter of patients at day 56. QoL scores used did not show any relationship with Hb in the post-operative period. Red cell 2,3-diphosphoglycerate (2,3DPG) levels increased in proportion to the degree of post-operative anaemia. We concluded that substantial recovery of Hb occurs between day 7 and day 28 post-operatively. Complete recovery of Hb may be delayed beyond day 56 due to development of iron deficiency. Patients are at significant risk of developing post-operative iron deficiency depending on operative blood loss and pre-operative iron stores. Increased red cell 2,3DPG may offset the effect of anaemia on oxygen delivery. We found no evidence that anaemia produces a measurable effect on chosen QoL scores in the post-operative period.

Interaction Between a Rat Model of Cerebral Ischemia and β-Amyloid Toxicity

Background and Purpose— Clinical data suggest that Alzheimer disease (AD) and stroke together potentiate cognitive impairment. Our rat model demonstrates that this interaction may be mediated through inflammatory cells and pathways. Thus, anti-inflammatory agents such as Triflusal, a nonsteroidal anti-inflammatory agent (NSAID), may provide neuroprotection for susceptible neurons in AD and cerebral ischemia.

Methods— AD was modeled by cerebroventricular injections of β-amyloid (Aβ25–35) and subcortical lacunar infarcts by striatal endothelin injections. Inflammatory mechanisms were examined by immunohistochemical analysis. Behavioral tasks were assessed with the Montoya staircase test.

Results— Triflusal reduced pathologic and inflammatory markers and functional deficits in rats receiving Aβ or endothelin alone but was less effective in the more severe pathology of the combined Aβ/endothelin model.

Conclusions— Higher doses or more prolonged treatment with NSAIDs may be required for more effective neuroprotection in combined AD and stroke conditions.

Genome sequence of the enterobacterial phytopathogen Erwinia carotovora subsp. atroseptica and characterization of virulence factors

The bacterial family Enterobacteriaceae is notable for its well studied human pathogens, including Salmonella, Yersinia, Shigella, and Escherichia spp. However, it also contains several plant pathogens. We report the genome sequence of a plant pathogenic enterobacterium, Erwinia carotovora subsp. atroseptica (Eca) strain SCRI1043, the causative agent of soft rot and blackleg potato diseases. Approximately 33% of Eca genes are not shared with sequenced enterobacterial human pathogens, including some predicted to facilitate unexpected metabolic traits, such as nitrogen fixation and opine catabolism. This proportion of genes also contains an overrepresentation of pathogenicity determinants, including possible horizontally acquired gene clusters for putative type IV secretion and polyketide phytotoxin synthesis. To investigate whether these gene clusters play a role in the disease process, an arrayed set of insertional mutants was generated, and mutations were identified. Plant bioassays showed that these mutants were significantly reduced in virulence, demonstrating both the presence of novel pathogenicity determinants in Eca, and the impact of functional genomics in expanding our understanding of phytopathogenicity in the Enterobacteriaceae.

The complete genome sequence and analysis of Corynebacterium diphtheriae NCTC13129

Corynebacterium diphtheriae is a Gram-positive, non-spore forming, non-motile, pleomorphic rod belonging to the genus Corynebacterium and the actinomycete group of organisms. The organism produces a potent bacteriophage-encoded protein exotoxin, diphtheria toxin (DT), which causes the symptoms of diphtheria. This potentially fatal infectious disease is controlled in many developed countries by an effective immunisation programme. However, the disease has made a dramatic return in recent years, in particular within the Eastern European region. The largest, and still on-going, outbreak since the advent of mass immunisation started within Russia and the newly independent states of the former Soviet Union in the 1990s. We have sequenced the genome of a UK clinical isolate (biotype gravis strain NCTC13129), representative of the clone responsible for this outbreak. The genome consists of a single circular chromosome of 2 488 635 bp, with no plasmids. It provides evidence that recent acquisition of pathogenicity factors goes beyond the toxin itself, and includes iron-uptake systems, adhesins and fimbrial proteins. This is in contrast to Corynebacterium's nearest sequenced pathogenic relative, Mycobacterium tuberculosis, where there is little evidence of recent horizontal DNA acquisition. The genome itself shows an unusually extreme large-scale compositional bias, being noticeably higher in G+C near the origin than at the terminus.

'Tag and label' system for checking and recording of blood transfusions

Guidelines for checking and recording of blood transfusion mandate the use of a blood transfusion compatibility form. We have introduced and assessed a 'tag and label' system that does away with the compatibility form. A compatibility tag with a peel-off self-adhesive label is attached to the unit for transfusion. No compatibility form is issued to the site of the transfusion. The peel-off label is signed and fixed in patient notes at the time of transfusion. We have found the system easier to use and to be preferred by nursing staff administering transfusions. During 2 years, we have transfused over 100,000 blood components, including 70,000 units of red cells, and have not recognized any episode during which the wrong blood was transfused to a patient. Recording in the patient notes of units transfused has significantly improved compared with local and national figures in a previous survey. We conclude that it is possible to dispense with the compatibility form without compromising the safety of the transfusion process.

Sequence of Plasmodium falciparum chromosomes 1, 3-9 and 13

Since the sequencing of the first two chromosomes of the malaria parasite, Plasmodium falciparum, there has been a concerted effort to sequence and assemble the entire genome of this organism. Here we report the sequence of chromosomes 1, 3-9 and 13 of P. falciparum clone 3D7--these chromosomes account for approximately 55% of the total genome. We describe the methods used to map, sequence and annotate these chromosomes. By comparing our assemblies with the optical map, we indicate the completeness of the resulting sequence. During annotation, we assign Gene Ontology terms to the predicted gene products, and observe clustering of some malaria-specific terms to specific chromosomes. We identify a highly conserved sequence element found in the intergenic region of internal var genes that is not associated with their telomeric counterparts.