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An improved understanding of diagnostic and treatment practices for patients with rare primary mitochondrial disorders can support benchmarking against guidelines and establish priorities for evaluative research. We aimed to describe physician care for patients with mitochondrial diseases in Canada, including variation in care.
We conducted a cross-sectional survey of Canadian physicians involved in the diagnosis and/or ongoing care of patients with mitochondrial diseases. We used snowball sampling to identify potentially eligible participants, who were contacted by mail up to five times and invited to complete a questionnaire by mail or internet. The questionnaire addressed: personal experience in providing care for mitochondrial disorders; diagnostic and treatment practices; challenges in accessing tests or treatments; and views regarding research priorities.
We received 58 survey responses (52% response rate). Most respondents (83%) reported spending 20% or less of their clinical practice time caring for patients with mitochondrial disorders. We identified important variation in diagnostic care, although assessments frequently reported as diagnostically helpful (e.g., brain magnetic resonance imaging, MRI/MR spectroscopy) were also recommended in published guidelines. Approximately half (49%) of participants would recommend “mitochondrial cocktails” for all or most patients, but we identified variation in responses regarding specific vitamins and cofactors. A majority of physicians recommended studies on the development of effective therapies as the top research priority.
While Canadian physicians’ views about diagnostic care and disease management are aligned with published recommendations, important variations in care reflect persistent areas of uncertainty and a need for empirical evidence to support and update standard protocols.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
Background: Spinal muscular atrophy (SMA) is a children’s neuromuscular disorder. Although motor neuron loss is a major feature of the disease, we have identified fatty acid abnormalities in SMA patients and in preclinical animal models, suggesting metabolic perturbation is also an important component of SMA. Methods: Biochemical, histological, proteomic, and high resolution respirometry were used. Results: SMA patients are more susceptible to dyslipidemia than the average population as determined by a standard lipid profile in a cohort of 72 pediatric patients. As well, we observed a non-alcoholic liver disease phenotype in apreclinical mouse model. Denervation alone was not sufficient to induce liver steatosis, as a mouse model of ALS, did not develop fatty liver. Hyperglucagonemia in Smn2B/-mice could explain the hepatic steatosis by increasing plasma substrate availability via glycogen depletion and peripheral lipolysis. Proteomic analysis identified mitochondrion and lipid metabolism as major clusters. Alterations in mitochondrial function were revealed by high-resolution respirometry. Finally, low-fat diets led to increased survival in Smn2B/-mice. Conclusions: These results provide strong evidence for lipid metabolism defects in SMA. Further investigation will be required to establish the primary mechanism of these alterations and understand how they lead to additional co-morbidities in SMA patients.
Malnutrition remains a leading contributor to the morbidity and mortality of children under the age of 5 years and can weaken the immune system and increase the severity of concurrent infections. Livestock milk with the protective properties of human milk is a potential therapeutic to modulate intestinal microbiota and improve outcomes. The aim of this study was to develop an infection model of childhood malnutrition in the pig to investigate the clinical, intestinal and microbiota changes associated with malnutrition and enterotoxigenic Escherichia coli (ETEC) infection and to test the ability of goat milk and milk from genetically engineered goats expressing the antimicrobial human lysozyme (hLZ) milk to mitigate these effects. Pigs were weaned onto a protein–energy-restricted diet and after 3 weeks were supplemented daily with goat, hLZ or no milk for a further 2 weeks and then challenged with ETEC. The restricted diet enriched faecal microbiota in Proteobacteria as seen in stunted children. Before infection, hLZ milk supplementation improved barrier function and villous height to a greater extent than goat milk. Both goat and hLZ milk enriched for taxa (Ruminococcaceae) associated with weight gain. Post-ETEC infection, pigs supplemented with hLZ milk weighed more, had improved Z-scores, longer villi and showed more stable bacterial populations during ETEC challenge than both the goat and no milk groups. This model of childhood disease was developed to test the confounding effects of malnutrition and infection and demonstrated the potential use of hLZ goat milk to mitigate the impacts of malnutrition and infection.
Jumping to conclusions (JTC), which is the proneness to require less information before forming beliefs or making a decision, has been related to formation and maintenance of delusions. Using data from the National Institute of Health Research Biomedical Research Centre Genetics and Psychosis (GAP) case–control study of first-episode psychosis (FEP), we set out to test whether the presence of JTC would predict poor clinical outcome at 4 years.
One-hundred and twenty-three FEP patients were assessed with the Positive and Negative Syndrome Scale (PANSS), Global Assessment of Functioning (GAF) and the probabilistic reasoning ‘Beads’ Task at the time of recruitment. The sample was split into two groups based on the presence of JTC bias. Follow-up data over an average of 4 years were obtained concerning clinical course and outcomes (remission, intervention of police, use of involuntary treatment – the Mental Health Act (MHA) – and inpatient days).
FEP who presented JTC at baseline were more likely during the follow-up period to be detained under the MHA [adjusted OR 15.62, 95% confidence interval (CI) 2.92–83.54, p = 0.001], require intervention by the police (adjusted OR 14.95, 95% CI 2.68–83.34, p = 0.002) and have longer admissions (adjusted IRR = 5.03, 95% CI 1.91–13.24, p = 0.001). These associations were not accounted for by socio-demographic variables, IQ and symptom dimensions.
JTC in FEP is associated with poorer outcome as indicated and defined by more compulsion police intervention and longer periods of admission. Our findings raise the question of whether the implementation of specific interventions to reduce JTC, such as Metacognition Training, may be a useful addition in early psychosis intervention programmes.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
The preceding chapters in this book have provided ample evidence for the growing maturity of planetary ring studies. The wealth of data, particularly from spacecraft observations, has resulted in the discovery of new phenomena and a total reevaluation of our knowledge of ring systems. Therefore, this seems like an appropriate point at which to assess progress and speculate on the future direction of research in this field.
Planetary ring systems are among the most beautiful and iconic structures in the solar system, and continue to play a unique role as vehicles for discovery. This occurs in at least three ways: (i) as detectors of their environment, (ii) as records of the history and origin of their planetary system, and (iii) as natural laboratories for understanding astrophysical disks.
The main rings of each of the giant planets are extensive but delicate systems, with surface areas that are far larger than those of neighboring moons. Therefore, while the surfaces of moons in outer planet systems provide a more permanent record of impacts and internal processes, rings can catch and amplify traces of planetary and interplanetary processes. Transient ejecta clouds provide direct evidence of the population of external impactors (Chapters 3 and 9), and corrugations in the rings of Jupiter and Saturn provide longer-lived records of larger impactors (Chapters 6 and 12). Patterns in dusty rings also give information regarding the nearby planetary magnetic fields (Chapters 12 and 14). Finally, spiral waves in dense rings impart detailed information about the moons that raise them (Chapter 3), and the precession of narrow rings yields some of the most accurate current knowledge of the internal structure of the giant planets (Chapter 11).
Whether rings represent the material left over from the planetary formation process or the debris from a tidally disrupted object, they still provide invaluable evidence of the history and origin of their respective planetary systems. At Uranus, the apparently sourceless ν ring and the closely packed orbits of nearby small moons seem to tell of an eventful history for that planetary system (Chapter 4). Particle mass and size distributions and accompanying spectral data, including local variations across a ring system (see Chapter 3), constrain source materials and evolutionary histories while a proper understanding of all the dynamical processes at work is key to obtaining accurate estimates of the age of a ring system (Chapter 18).
A major focus for improving the diets in many less developed countries (LDCS) is the provision of rumen fermentable nitrogen (N) using protein supplements to complement N-deficient foods. However, in vitro digestibility methods usually use N-rich environments for the degradation of single foods. This conventional approach may give data which do not reflect the nutritive value of the N-deficient diets often on offer in LDCS, neither is it appropriate for using in vitro gas production to study protein supplementation. Our earlier study indicated that, by using a N-free medium, the gas production technique responded to added ammonium sulphate and urea. The ADAS standardized methodology, which used 10 ml of inoculum instead of the 5 ml used in the earlier study, was found not to be very responsive to N supplementation. The ADAS methodology was therefore investigated in order to develop a modified protocol for fermenting foods in an N-limited environment. The study involved using inocula diluted to different extents in N-free medium for fermenting N-deficient substrates in N-free and N-rich media. The modified protocol was then used for investigating the interactions between N-rich and N-deficient foods from north-west India.
Ruminants in many less developed countries may consume poor quality roughages such as straws, stovers and senescent native pasture as a major part of their diet, particularly during the dry season when high-quality forages are in short supply. The majority of these roughages are high in fibre, low in protein and the intake of digestible nutrients often is not enough to meet maintenance requirements. Intake and digestibility of poor-quality roughages may be increased by supplementation. The response to supplementation can be attributed to an increase in the supply of nitrogen and/or readily fermentable carbohydrate, resulting in an increase in rumen cellulolytic micro-organisms and therefore enhanced fibre degradation.
The fibrous forage high temperature dried (HT) alfalfa has been fed to horses for a number of years because of its consistently high nutritive value. It is common practise in the UK to combine HT alfalfa either chopped or in a ground and pelleted form with sugar beet pulp (SB) as this is regarded as a nutritious feed for horses. Synergistic effects of sugar beet when added to fibre-based diets have been observed in other species (Longland et al., 1994) whereby the digestibility of graminaceous forages has been increased. However, such effects have been little examined in horses and there is a lack of information in the literature on the effects of SB on the digestibility of leguminous forages. Thus, the effect of sugar beet on the in vitro fermentation of ground and chopped HT alfalfa by an equid hind-gut microflora using the pressure transducer technique of Theodorou et al. (1994) was investigated.
Feeding horses high levels of cereal starch can result in diet-related azoturia, laminitis and colic, whereas high fibre, forage-based diets do not generally elicit these conditions. Therefore, it would be advantageous to develop fibrous feeds with increased digestibilities, permitting horses with high energy demands to be sustained on greater forage: cereal starch ratios. High temperature dried (HT) alfalfa has been fed to horses for a number of years and it is common practise to combine this with sugar beet pulp (SB) another nutritious fibrous feed for horses. Synergistic effects of SB when added to fibre-based diets have been observed in other species in vivo (Longland et al., 1994) whereby the digestibility of graminaceous feeds has been increased. However, such effects have been little examined in horses fed a leguminous-forage diet. The aim of this study therefore, was to determine if SB enhanced the digestibility of alfalfa, a forage legume that is increasingly being fed to equines in the UK.
There is a dearth of information available on the effects of donor animal on the fermentative capacity of equine faecal inocula for use in in vitro digestibility determinations. Furthermore, there is little knowledge of the degradation characteristic of feedstuffs incubated with equine faecal inocula. As such this study aimed to elucidate the effect of donor animal on the fermentation of feedstuffs in vitro and to assess the in vitro degradation characteristics of three commonly fed components of horse diets incubated with equine faecal inocula.
A range of endophenotypes characterise psychosis, however there has been limited work understanding if and how they are inter-related.
This multi-centre study includes 8754 participants: 2212 people with a psychotic disorder, 1487 unaffected relatives of probands, and 5055 healthy controls. We investigated cognition [digit span (N = 3127), block design (N = 5491), and the Rey Auditory Verbal Learning Test (N = 3543)], electrophysiology [P300 amplitude and latency (N = 1102)], and neuroanatomy [lateral ventricular volume (N = 1721)]. We used linear regression to assess the interrelationships between endophenotypes.
The P300 amplitude and latency were not associated (regression coef. −0.06, 95% CI −0.12 to 0.01, p = 0.060), and P300 amplitude was positively associated with block design (coef. 0.19, 95% CI 0.10–0.28, p < 0.001). There was no evidence of associations between lateral ventricular volume and the other measures (all p > 0.38). All the cognitive endophenotypes were associated with each other in the expected directions (all p < 0.001). Lastly, the relationships between pairs of endophenotypes were consistent in all three participant groups, differing for some of the cognitive pairings only in the strengths of the relationships.
The P300 amplitude and latency are independent endophenotypes; the former indexing spatial visualisation and working memory, and the latter is hypothesised to index basic processing speed. Individuals with psychotic illnesses, their unaffected relatives, and healthy controls all show similar patterns of associations between endophenotypes, endorsing the theory of a continuum of psychosis liability across the population.
There is no consensus as to whether magnetic resonance imaging (MRI) should be used as part of the initial clinical evaluation of patients with first-episode psychosis (FEP).
(a) To assess the logistical feasibility of routine MRI; (b) to define the clinical significance of radiological abnormalities in patients with FEP.
Radiological reports from MRI scans of two FEP samples were reviewed; one comprised 108 patients and 98 healthy controls recruited to a research study and the other comprised 241 patients scanned at initial clinical presentation plus 66 healthy controls.
In the great majority of patients, MRI was logistically feasible. Radiological abnormalities were reported in 6% of the research sample and in 15% of the clinical sample (odds ratio (OR) = 3.1, 95% CI 1.26–7.57, χ2(1) = 6.63, P = 0.01). None of the findings necessitated a change in clinical management.
Rates of neuroradiological abnormalities in FEP are likely to be underestimated in research samples that often exclude patients with organic abnormalities. However, the majority of findings do not require intervention.
Fe deficiency in early childhood is associated with long-term consequences for cognitive, motor and behavioural development; however explorations in healthy children from low risk, high-resource settings have been limited. We aimed to explore associations between Fe status and neurodevelopmental outcomes in low risk, healthy 2-year-olds. This study was a secondary analysis of a nested case–control subgroup from the prospective, maternal-infant Cork Babies after Screening for Pregnancy Endpoints: Evaluating the Longitudinal Impact using Neurological and Nutritional Endpoints (BASELINE) Birth Cohort Study. At 2 years, serum ferritin, Hb and mean corpuscular volume (MCV) were measured and neurodevelopment was assessed using the Bayley Scales of Infant and Toddler Development (n 87). Five children had Fe deficiency (ferritin <12 µg/l) and no child had Fe deficiency anaemia (Hb<110 g/l+ferritin<12 µg/l). Children with microcytosis (MCV<74 fl, n 13) had significantly lower mean cognitive composite scores (88·5 (sd 13·3) v. 97·0 (sd 7·8), P=0·04, Cohen’s d effect size=0·8) than those without microcytosis. The ferritin concentration which best predicted microcytosis was calculated as 18·4 µg/l (AUC=0·87 (95% CI 0·75, 0·98), P<0·0001, sensitivity 92 %, specificity 75 %). Using 18·5 µg/l as a threshold, children with concentrations <18·5 µg/l had significantly lower mean cognitive composite scores (92·3 (sd 10·5) v. 97·8 (sd 8·1), P=0·012, Cohen’s d effect size=0·6) compared with those with ferritin ≥18·5 µg/l. All associations were robust after adjustment for potential confounding factors. Despite a low prevalence of Fe deficiency using current diagnostic criteria in this healthy cohort, microcytosis was associated with lower cognitive outcomes at 2 years. This exploratory study emphasises the need for re-evaluation of the diagnostic criteria for Fe deficiency in young children, with further research in adequately powered studies warranted.
Understanding the benefits and outcomes of Canada's public investment in Arctic science and associated community–researcher partnerships represents a significant challenge for government. This paper presents a capital assets-based approach to conceptualising northern research partnership development processes and assessing the potential outcomes. By more explicitly considering the pre- and post-partnership asset levels (that is, social, human, physical, financial and natural assets) for different collaborators, the potential benefits and challenges associated with community–researcher partnerships can be collaboratively assessed. In order to help refine this approach, we conducted a survey of those involved in developing and maintaining community–researcher partnerships across Arctic Canada. Results indicate that the proposed approach could be useful for research funding agencies seeking to better understand partnership outcomes and promote more effective community–researcher interactions. Challenges include adequately capturing the qualitative nature of different capital assets, pointing to future research and policy needs. Better understanding the role of research in northern development has the potential to improve northern research, policy and practice.
We examined longitudinally the course and predictors of treatment resistance in a large cohort of first-episode psychosis (FEP) patients from initiation of antipsychotic treatment. We hypothesized that antipsychotic treatment resistance is: (a) present at illness onset; and (b) differentially associated with clinical and demographic factors.
The study sample comprised 323 FEP patients who were studied at first contact and at 10-year follow-up. We collated clinical information on severity of symptoms, antipsychotic medication and treatment adherence during the follow-up period to determine the presence, course and predictors of treatment resistance.
From the 23% of the patients, who were treatment resistant, 84% were treatment resistant from illness onset. Multivariable regression analysis revealed that diagnosis of schizophrenia, negative symptoms, younger age at onset, and longer duration of untreated psychosis predicted treatment resistance from illness onset.
The striking majority of treatment-resistant patients do not respond to first-line antipsychotic treatment even at time of FEP. Clinicians must be alert to this subgroup of patients and consider clozapine treatment as early as possible during the first presentation of psychosis.