Abstract P4-06-02: The mammary ducts create a favourable microenvironment for xenografting of luminal and molecular apocrine breast tumours

This abstract was not presented at the symposium.

[Is dementia preventable through intensive vascular care? The preDIVA trial]

OBJECTIVE

To assess whether intensive vascular care in GP practices can prevent dementia in a population of community-dwelling older people.

METHOD

This pragmatic cluster-randomised open-label study (ISRCTN29711771) was conducted in persons aged 70-78 years who were registered with Dutch GP practices. The only exclusion criteria were a diagnosis of dementia and limited life expectancy. Practices were randomly assigned to an intervention arm or a control arm. Participants in the interventional arm underwent a cardiovascular check-up every 4 months for six years by a practice nurse. Primary outcomes were cumulative incidence of dementia and functional limitations. Main secondary outcomes were the incidence of cardiovascular disease and mortality.

RESULTS

Between June 2006 and March 2009, 116 GP practices (3526 participants) were recruited and randomly assigned: 63 (1890 participants) to the intervention group and 53 (1636 participants) to the control group. Primary outcome data were obtained for 3454 (98%) participants; median follow-up was 6.7 years. In this period, dementia was diagnosed in 121/1853 (6.5%) participants in the intervention group and in 112/1601 (7.0%) participants in the control group. This difference was not significant (hazard ratio 0.92, 95% CI 0.71-1.19). No differences were found with regard to functional decline, incident cardiovascular disease and mortality.

CONCLUSION

Long-term intensive vascular care for community-dwelling elderly patients, provided in a primary care setting, does not result in a reduced incidence of dementia, functional limitations or mortality. There is, however, possibly an effect in elderly patients with untreated or sub-optimally treated hypertension; this warrants further research.

[Diagnostics in memory loss: for whom, what and when?]

With the advancement of diagnostic tests, the call for an ever-earlier diagnosis of people with memory problems is becoming louder. Diagnostic tests for people with mild cognitive impairment are in fact prognostic tests, complicating the application and interpretation of test results. There is currently insufficient evidence on the incremental diagnostic (or prognostic) value of specific diagnostic tests including MRI, CSF and PET scanning in representative memory clinic populations. Labelling large groups of people who may never develop dementia as having prodromal Alzheimer's disease may be more harmful than a postponed nosological diagnosis in those with mild cognitive impairment. The current Dutch practice guideline on dementia, with a reticent attitude towards the use of diagnostic tests in patients with cognitive impairment, is appropriate and scientifically sound.

Prevalence of Equine Hepacivirus Infections in France and Evidence for Two Viral Subtypes Circulating Worldwide

Like hepatitis C virus (HCV) in humans, the newly identified equine hepacivirus (NPHV) displays a predominating liver tropism that may evolve into chronic infections. The genomes of the two viruses share several organizational and functional features and are phylogenetically closest amongst the Hepacivirus genus. A limited amount of data is available regarding the spread of hepacivirus infections in horses. In this study, we asked whether in a more representative sample the prevalence and distribution of NPHV infections in France would resemble that reported so far in other countries. A total of 1033 horses sera from stud farms throughout France were analysed by qRT-PCR to determine the prevalence of ongoing NPHV infections and viral loads; in positive samples, partial sequences of NPHV's genome (5'UTR, NS3 and NS5B genes) were determined. Serum concentrations of biliary acids, glutamate dehydrogenase (GLDH) and L-gamma-glutamyl transferase (γ-GT) were measured for most horses. We detected NPHV infections in 6.2% of the horses, a prevalence that reached 8.3% in thoroughbreds and was significantly higher than in other breeds. The presence of circulating virus was neither significantly associated with biological disturbances nor with clinical hepatic impairment. Our phylogenetic analysis was based on both neighbour-joining and maximum-likelihood approaches. Its result shows that, like almost everywhere else in the world so far, two major groups of NPHV strains infect French domestic horses. Based on genetic distances, we propose a classification into two separate NPHV subtypes. Viral loads in the serum of horses infected by the main subtype were, in average, four times higher than in those infected by the second subtype. We hypothesize that amino acid substitutions in the palm domain of NS5B between NPHV subtypes could underlie viral phenotypes that explain this result.

Psychological, behavioral and social effects of disclosing Alzheimer's disease biomarkers to research participants: a systematic review

BACKGROUND

Current Alzheimer's disease (AD) research initiatives focus on cognitively healthy individuals with biomarkers that are associated with the development of AD. It is unclear whether biomarker results should be returned to research participants and what the psychological, behavioral and social effects of disclosure are. This systematic review therefore examines the psychological, behavioral and social effects of disclosing genetic and nongenetic AD-related biomarkers to cognitively healthy research participants.

METHODS

We performed a systematic literature search in eight scientific databases. Three independent reviewers screened the identified records and selected relevant articles. Results extracted from the included articles were aggregated and presented per effect group.

RESULTS

Fourteen studies met the inclusion criteria and were included in the data synthesis. None of the identified studies examined the effects of disclosing nongenetic biomarkers. All studies but one concerned the disclosure of APOE genotype and were conducted in the USA. Study populations consisted largely of cognitively healthy first-degree relatives of AD patients. In this group, disclosure of an increased risk was not associated with anxiety, depression or changes in perceived risk in relation to family history. Disclosure of an increased risk did lead to an increase in specific test-related distress levels, health-related behavior changes and long-term care insurance uptake and possibly diminished memory functioning.

CONCLUSION

In cognitively healthy research participants with a first-degree relative with AD, disclosure of APOE ε4-positivity does not lead to elevated anxiety and depression levels, but does increase test-related distress and results in behavior changes concerning insurance and health. We did not find studies reporting the effects of disclosing nongenetic biomarkers and only one study included people without a family history of AD. Empirical studies on the effects of disclosing nongenetic biomarkers and of disclosure to persons without a family history of AD are urgently needed.

TRIAL REGISTRATION

PROSPERO international prospective register for systematic reviews CRD42016035388 . Registered 19 February 2016.

In vivo evidence of mitochondrial dysfunction and altered redox homeostasis in a genetic mouse model of propionic acidemia: Implications for the pathophysiology of this disorder

Accumulation of toxic metabolites has been described to inhibit mitochondrial enzymes, thereby inducing oxidative stress in propionic acidemia (PA), an autosomal recessive metabolic disorder caused by the deficiency of mitochondrial propionyl-CoA carboxylase. PA patients exhibit neurological deficits and multiorgan complications including cardiomyopathy. To investigate the role of mitochondrial dysfunction in the development of these alterations we have used a hypomorphic mouse model of PA that mimics the biochemical and clinical hallmarks of the disease. We have studied the tissue-specific bioenergetic signature by Reverse Phase Protein Microarrays and analysed OXPHOS complex activities, mtDNA copy number, oxidative damage, superoxide anion and hydrogen peroxide levels. The results show decreased levels and/or activity of several OXPHOS complexes in different tissues of PA mice. An increase in mitochondrial mass and OXPHOS complexes was observed in brain, possibly reflecting a compensatory mechanism including metabolic reprogramming. mtDNA depletion was present in most tissues analysed. Antioxidant enzymes were also found altered. Lipid peroxidation was present along with an increase in hydrogen peroxide and superoxide anion production. These data support the hypothesis that oxidative damage may contribute to the pathophysiology of PA, opening new avenues in the identification of therapeutic targets and paving the way for in vivo evaluation of compounds targeting mitochondrial biogenesis or reactive oxygen species production.

White Matter Hyperintensity Volume and Cerebral Perfusion in Older Individuals with Hypertension Using Arterial Spin-Labeling

BACKGROUND AND PURPOSE

White matter hyperintensities of presumed vascular origin in elderly patients with hypertension may be part of a general cerebral perfusion deficit, involving not only the white matter hyperintensities but also the surrounding normal-appearing white matter and gray matter. We aimed to study the relation between white matter hyperintensity volume and CBF and assess whether white matter hyperintensities are related to a general perfusion deficit.

MATERIALS AND METHODS

In 185 participants of the Prevention of Dementia by Intensive Vascular Care trial between 72 and 80 years of age with systolic hypertension, white matter hyperintensity volume and CBF were derived from 3D FLAIR and arterial spin-labeling MR imaging, respectively. We compared white matter hyperintensity CBF, normal-appearing white matter CBF, and GM CBF across quartiles of white matter hyperintensity volume and assessed the continuous relation between these CBF estimates and white matter hyperintensity volume by using linear regression.

RESULTS

Mean white matter hyperintensity CBF was markedly lower in higher quartiles of white matter hyperintensity volume, and white matter hyperintensity volume and white matter hyperintensity CBF were negatively related (standardized β = -0.248, P = .001) in linear regression. We found no difference in normal-appearing white matter or GM CBF across quartiles of white matter hyperintensity volume or any relation between white matter hyperintensity volume and normal-appearing white matter CBF (standardized β = -0.065, P = .643) or GM CBF (standardized β = -0.035, P = .382) in linear regression.

CONCLUSIONS

Higher white matter hyperintensity volume in elderly individuals with hypertension was associated with lower perfusion within white matter hyperintensities, but not with lower perfusion in the surrounding normal-appearing white matter or GM. These findings suggest that white matter hyperintensities in elderly individuals with hypertension relate to local microvascular alterations rather than a general cerebral perfusion deficit.

[Web-based interventions targeting cardiovascular risk factors in older people; a systematic review and meta-analysis]

OBJECTIVE

To evaluate whether web-based interventions for cardiovascular risk factor management reduce the risk of cardiovascular disease in older people.

DESIGN

Systematic review and meta-analysis.

METHOD

Embase, Medline, Cochrane Library and CINAHL were systematically searched from January 1995 to 3 November 2014. We included all randomised controlled trials for web-based interventions targeting cardiovascular risk factors in populations with a mean age of 50 and older. The outcome measures were cardiovascular risk factors (blood pressure, HbA1c, LDL cholesterol, weight, smoking status and physical activity) and the incidence of cardiovascular disease. We used random-effects models to pool the results of the studies.

RESULTS

A total of 57 studies (19,862 participants) fulfilled eligibility criteria, and 47 of these were suitable for meta-analysis. We found a significant reduction in systolic blood pressure (-2.66 mmHg, 95% CI -3.81 to -1.52), diastolic blood pressure (-1.26 mmHg, 95% CI -1.92 to -0.60), HbA1c level (-0.13%, 95% CI -0.22 to -0.05), LDL cholesterol level (-0.06 mmol/l, 95% CI -0.10 to -0.01), weight (-1.34 kg, 95% CI -1.91 to -0.77), and an increase in physical activity (standardized mean difference 0.25, 95% CI 0.10-0.39) in the intervention group when compared with the control group. Treatment effects were more pronounced in studies of short duration (< 12 months) and when combining the web-based intervention with human support by a health care professional. No difference in the incidence of cardiovascular disease was found between groups.

CONCLUSION

Web-based interventions have a beneficial effect on the cardiovascular risk profile, but this effect is modest and declines with time. Currently, there is insufficient evidence that this can prevent cardiovascular disease. A focus on long-term effects, effect-sustainability and clinical endpoints is recommended for future studies.

Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment

Search results for nucleon decays p→e^{+}X, p→μ^{+}X, n→νγ (where X is an invisible, massless particle) as well as dinucleon decays np→e^{+}ν, np→μ^{+}ν, and np→τ^{+}ν in the Super-Kamiokande experiment are presented. Using single-ring data from an exposure of  273.4  kton·yr, a search for these decays yields a result consistent with no signal. Accordingly, lower limits on the partial lifetimes of τ_{p→e^{+}X}>7.9×10^{32} yr, τ_{p→μ^{+}X}>4.1×10^{32} yr, τ_{n→νγ}>5.5×10^{32} yr, τ_{np→e^{+}ν}>2.6×10^{32}  yr, τ_{np→μ^{+}ν}>2.2×10^{32} yr, and τ_{np→τ^{+}ν}>2.9×10^{31} yr at a 90% confidence level are obtained. Some of these searches are novel.

Cerebral Perfusion Measurements in Elderly with Hypertension Using Arterial Spin Labeling

Purpose

The current study assesses the feasibility and value of crushed cerebral blood flow (CBF_crushed) and arterial transit time (ATT) estimations for large clinical imaging studies in elderly with hypertension.

Material and Methods

Two pseudo-continuous arterial spin labeling (ASL) scans with (CBF_crushed) and without flow crushers (CBF_non-crushed) were performed in 186 elderly with hypertension, from which CBF and ATT maps were calculated. Standard flow territory maps were subdivided into proximal, intermediate and distal flow territories, based on the measured ATT. The coefficient of variation (CV) and physiological correlations with age and gender were compared between the three perfusion parameters.

Results

There was no difference in CV between CBF_crushed and CBF_non-crushed (15–24%, p>0.4) but the CV of ATT (4–9%) was much smaller. The total gray matter correlations with age and gender were most significant with ATT (p = .016 and p<.001 respectively), in between for CBF_crushed (p = .206 and p = .019) and least significant for CBF_non-crushed (p = .236 and p = .100).

Conclusion

These data show the feasibility and added value of combined measurements of both crushed CBF and ATT for group analyses in elderly with hypertension. The obtained flow territories provide knowledge on vascular anatomy of elderly with hypertension and can be used in future studies to investigate regional vascular effects.

Hepatoerythropoietic Porphyria Caused by a Novel Homoallelic Mutation in Uroporphyrinogen Decarboxylase Gene in Egyptian Patients

Porphyrias are metabolic disorders resulting from mutations in haem biosynthetic pathway genes. Hepatoerythropoietic porphyria (HEP) is a rare type of porphyria caused by the deficiency of the fifth enzyme (uroporphyrinogen decarboxylase, UROD) in this pathway. The defect in the enzymatic activity is due to biallelic mutations in the UROD gene. Currently, 109 UROD mutations are known. The human disease has an early onset, manifesting in infancy or early childhood with red urine, skin photosensitivity in sun-exposed areas, and hypertrichosis. Similar defects and links to photosensitivity and hepatopathy exist in several animal models, including zebrafish and mice. In the present study, we report a new mutation in the UROD gene in Egyptian patients with HEP. We show that the homozygous c.T163A missense mutation leads to a substitution of a conserved phenylalanine (amino acid 55) for isoleucine in the enzyme active site, causing a dramatic decrease in the enzyme activity (19 % of activity of wild-type enzyme). Inspection of the UROD crystal structure shows that Phe-55 contacts the substrate and is located in the loop that connects helices 2 and 3. Phe-55 is strictly conserved in both prokaryotic and eukaryotic UROD. The F55I substitution likely interferes with the enzyme-substrate interaction.

Post-stroke cognitive decline: an update and perspectives for clinical research

The close relationship between stroke and dementia is an important health issue. Ischaemic stroke can facilitate the onset of vascular dementia as well as aggravate pre-existing cognitive decline. The onset of cognitive decline may become manifest immediately following the onset of ischaemic stroke, but often there is a delay in the development of cognitive decline after a stroke. This delay can be seen as a therapeutic time window allowing interventions to be applied to preserve cognition following stroke. Both neurodegenerative and vascular mechanisms are activated and probably result in overlapping processes within the neurovascular unit. This review focuses on the incidence and prevalence of cognitive decline following stroke, predisposing stroke aetiologies, pre-stroke decline, imaging factors and biomarkers. Outcomes are discussed in relation to timing of assessment and neuropsychological tests used for evaluation of cognitive decline in ischaemic stroke patients. Including such tests in routine evaluations of stroke patients after some weeks or months is recommended. Finally, an outlook on ongoing and planned intervention trials is added and some recommendations for future research are proposed.

[Clinical and biochemical characterization of childhood urolithiasis]

OBJECTIVES

Urolithiasis is rare in children, but the incidence has increased over the past few decades. This study aims at describing the clinical and biochemical characteristics, etiology, and treatment of urolithiasis in children.

METHODS

This was a retrospective study of all children under 16 years of age seen at the Bordeaux University Children's Hospital with a diagnosis of urolithiasis. The diagnosis was confirmed either radiologically or clinically by the expulsion of the stone.

RESULTS

A total of 186 children with a diagnosis of urolithiasis between 1994 and 2012 were included. The median age at diagnosis was 7.4 years. The male-to-female ratio was 1.9. The estimated annual incidence was around 5.5/100,000 children under 15 years of age in the past 5 years. The main presenting feature was nonspecific abdominal pain (71%). Metabolic calculi accounted for 48% of the patients with idiopathic hypercalciuria as the main cause. Genetic diseases accounted for 15% of cases. The proportion of infectious calculi was estimated at 33% and decreased in the past two decades. Stone fragments were sent for analysis in 86 children, and calcium oxalate was the major component (37%), followed by calcium phosphate (33%), purine (9%), and struvite (8%). At least 26% of patients experienced recurrence of stone passage.

CONCLUSION

This retrospective study highlighted changes in characteristics of pediatric urolithiasis over time. Childhood-onset urolithiasis requires complete etiological work-up so that a metabolic cause with a high risk of recurrence does not go unrecognized.

Search for trilepton nucleon decay via p→e+νν and p→μ+νν in the Super-Kamiokande experiment

The trilepton nucleon decay modes p→e+νν and p→μ+νν violate |Δ(B-L)| by two units. Using data from a 273.4 kt yr exposure of Super-Kamiokande a search for these decays yields a fit consistent with no signal. Accordingly, lower limits on the partial lifetimes of τp→e+νν>1.7×10(32) years and τp→μ+νν>2.2×10(32) years at a 90% confidence level are obtained. These limits can constrain Grand Unified Theories which allow for such processes.

p62/SQSTM1 upregulation constitutes a survival mechanism that occurs during granulocytic differentiation of acute myeloid leukemia cells

The p62/SQSTM1 adapter protein has an important role in the regulation of several key signaling pathways and helps transport ubiquitinated proteins to the autophagosomes and proteasome for degradation. Here, we investigate the regulation and roles of p62/SQSTM1 during acute myeloid leukemia (AML) cell maturation into granulocytes. Levels of p62/SQSTM1 mRNA and protein were both significantly increased during all-trans retinoic acid (ATRA)-induced differentiation of AML cells through a mechanism that depends on NF-κB activation. We show that this response constitutes a survival mechanism that prolongs the life span of mature AML cells and mitigates the effects of accumulation of aggregated proteins that occurs during granulocytic differentiation. Interestingly, ATRA-induced p62/SQSTM1 upregulation was impaired in maturation-resistant AML cells but was reactivated when differentiation was restored in these cells. Primary blast cells of AML patients and CD34(+) progenitors exhibited significantly lower p62/SQSTM1 mRNA levels than did mature granulocytes from healthy donors. Our results demonstrate that p62/SQSTM1 expression is upregulated in mature compared with immature myeloid cells and reveal a pro-survival function of the NF-κB/SQSTM1 signaling axis during granulocytic differentiation of AML cells. These findings may help our understanding of neutrophil/granulocyte development and will guide the development of novel therapeutic strategies for refractory and relapsed AML patients with previous exposure to ATRA.

Methylmalonic aciduria cblB type: characterization of two novel mutations and mitochondrial dysfunction studies

Methylmalonic aciduria (MMA) cblB type is caused by mutations in the MMAB gene, which codes for the enzyme adenosine triphosphate (ATP): cobalamin adenosyltransferase (ATR). This study reports differences in the metabolic and disease outcomes of two pairs of siblings with MMA cblB type, respectively harbouring the novel changes p.His183Leu/p.Arg190dup (P1 and P2) and the previously described mutations p.Ile96Thr/p.Ser174fs (P3 and P4). Expression analysis showed p.His183Leu and p.Arg190dup to be destabilizing mutations. Both were associated with reduced ATR stability and a shorter half-life than wild-type ATR. Analysis of several parameters related to oxidative stress and mitochondrial function showed an increase in reactive oxygen species (ROS) content, a decrease in mitochondrial respiration and changes in mitochondria morphology and structure in patient-derived fibroblasts compared to control cells. The impairment in energy production and the presence of oxidative stress and fission of the mitochondrial reticulum suggested mitochondrial dysfunction in cblB patients' fibroblasts. The recovery of mitochondrial function should be a goal in efforts to improve the clinical outcome of MMA cblB type.

Graduate nurses' learning trajectories and experiences of problem based learning: a focused ethnography study

BACKGROUND

Problem-based learning seeks to foster active, collaborative and self directed learning. It is increasingly utilized in health professional education; however, it is difficult to ascertain effectiveness. Empirically, student satisfaction does not match academic achievement but the reasons for this are unclear.

OBJECTIVE

To explore the experience trajectories and satisfaction of graduates who had completed an undergraduate problem-based learning nursing program.

DESIGN AND METHODS

Qualitative focused ethnography using individual and group semi-structured interviews. Categories and themes were identified using inductive constant comparison. A comparative matrix analysis of differing levels of the two core processes illuminated specific experience profiles.

PARTICIPANTS AND SETTING

Forty five program graduates who had graduated between one and nine years previously from a Western Canadian program offered at four academic sites. The sample was mostly female (n=37), aged 26-30 years (n=23) and graduated 5-8 years previously (n=20).

RESULTS

Levels of satisfaction with the program varied markedly. Two core processes contributed to this: "understanding" and "valuing" problem-based learning. Specific experience profiles included: "Happy as fish in water" which represents those who understood and valued the approach, and flourished; "I'll do it but I won't like it" reflects those who understood and could adjust to the academic context but did not particularly value it; "I just want to be a nurse" characterized those who consistently disliked and resisted the process but endured in order to graduate. Each profile was characterized by attitudes, intentions, learning preferences and program satisfaction.

CONCLUSIONS

We theorize an underlying mechanism explaining these diverse levels of satisfaction are differing orientations to studying. This approach to understanding how students typically approach learning is strongly linked to perceptions of academic quality and program satisfaction in higher education research, although it has been neglected in nursing problem-based learning research. Orientations to studying include reproductive surface learning, deep learning for understanding and meaning, and strategic approaches to maximize desired objectives. These orientations are congruent with the descriptive typologies developed in this research. This provides an effective explanation as to why some students adapt easily and flourish in problem-based learning contexts, while others continually struggle to adapt. Further research is needed to determine the relationship between deep, surface, and strategic orientations to study and student satisfaction in nursing programs.