Age, Motion, Medical, and Psychiatric Associations With Incidental Findings in Brain MRI

Importance

Few investigations have evaluated rates of brain-based magnetic resonance imaging (MRI) incidental findings (IFs) in large lifespan samples, their stability over time, or their associations with health outcomes.

Objectives

To examine rates of brain-based IFs across the lifespan, their persistence, and their associations with phenotypic indicators of behavior, cognition, and health; to compare quantified motion with radiologist-reported motion and evaluate its associations with IF rates; and to explore IF consistency across multiple visits.

Design, Setting, and Participants

This cross-sectional study included participants from the Nathan Kline Institute-Rockland Sample (NKI-RS), a lifespan community-ascertained sample, and the Healthy Brain Network (HBN), a cross-sectional community self-referred pediatric sample focused on mental health and learning disorders. The NKI-RS enrolled participants (ages 6-85 years) between March 2012 and March 2020 and had longitudinal participants followed up for as long as 4 years. The HBN enrolled participants (ages 5-21 years) between August 2015 and October 2021. Clinical neuroradiology MRI reports were coded for radiologist-reported motion as well as presence, type, and clinical urgency (category 1, no abnormal findings; 2, no referral recommended; 3, consider referral; and 4, immediate referral) of IFs. MRI reports were coded from June to October 2021. Data were analyzed from November 2021 to February 2023.

Main Outcomes and Measures

Rates and type of IFs by demographic characteristics, health phenotyping, and motion artifacts; longitudinal stability of IFs; and Euler number in projecting radiologist-reported motion.

Results

A total of 1300 NKI-RS participants (781 [60.1%] female; mean [SD] age, 38.9 [21.8] years) and 2772 HBN participants (976 [35.2%] female; mean [SD] age, 10.0 [3.5] years) had health phenotyping and neuroradiology-reviewed MRI scans. IFs were common, with 284 of 2956 children (9.6%) and 608 of 1107 adults (54.9%) having IFs, but rarely of clinical concern (category 1: NKI-RS, 619 [47.6%]; HBN, 2561 [92.4%]; category 2: NKI-RS, 647 [49.8%]; HBN, 178 [6.4%]; category 3: NKI-RS, 79 [6.1%]; HBN, 30 [1.1%]; category 4: NKI-RS: 12 [0.9%]; HBN, 6 [0.2%]). Overall, 46 children (1.6%) and 79 adults (7.1%) required referral for their IFs. IF frequency increased with age. Elevated blood pressure and BMI were associated with increased T2 hyperintensities and age-related cortical atrophy. Radiologist-reported motion aligned with Euler-quantified motion, but neither were associated with IF rates.

Conclusions and Relevance

In this cross-sectional study, IFs were common, particularly with increasing age, although rarely clinically significant. While T2 hyperintensity and age-related cortical atrophy were associated with BMI and blood pressure, IFs were not associated with other behavioral, cognitive, and health phenotyping. Motion may not limit clinical IF detection.

The therapeutic potential of the neuroactive peptides of soluble amyloid precursor protein-alpha in Alzheimer's disease and related neurological disorders

Soluble amyloid precursor protein-alpha (sAPPα) is a multi-functional brain-derived protein that has neuroprotective, neurogenic and neurotropic properties. Moreover, it is known to facilitate synaptic function and promote neural repair. These properties suggest sAPPα may be useful as a therapeutic agent for the treatment of neurological diseases characterized by synaptic failure and neuronal loss, such as occurs in Alzheimer's disease, and for neural repair following traumatic brain injury and stroke. However, sAPPα's relatively large size and the difficulty of ongoing delivery of therapeutics to the brain mean this is not currently practicable. Importantly, however, sAPPα is composed of several neuroactive domains that each possess properties that collectively are remarkably similar to those of sAPPα itself. Here, we review the molecular structure of sAPPα and identify the domains that contribute to its overall functionality. Four peptide motifs present as possible targets for therapeutic development. We review their physiochemical and neuroactive properties, both within sAPPα and as isolated peptides, and discuss their potential for future development as multipurpose therapeutic agents for the treatment of Alzheimer's disease and other disorders of neuronal function. Further, we discuss the role of heparin binding sites, found within sAPPα's structure and overlapping with the neuroactive domains, as sites for interactions with effector proteins and synaptic receptors. The potential role of the neuroactive peptides known as Cationic Arginine-Rich Peptides (CARPs) as neuroprotective motifs is also reviewed. Mechanisms of peptide delivery to the brain are briefly discussed. Finally, we summarise the potential benefits and pitfalls of using the isolated peptides, either individually or in combination, for the treatment of neurological diseases.

Development of clinical practice guidelines for allied health and nursing assessment and management of Duchenne muscular dystrophy

PURPOSE

To provide evidence-based guidance specific to allied health and nursing practice for the assessment and management of individuals with Duchenne muscular dystrophy (DMD).

MATERIALS AND METHODS

Thirteen key focus areas were identified in consultation with health professionals and consumer advocacy groups. A series of systematic literature reviews were conducted to identify assessment and management strategies for each key focus area. A consensus process using modified Delphi methodology, including an Australia-New Zealand expert consensus meeting, was conducted. Recommendations underwent consultative review with key groups before being finalised and prepared for dissemination.

RESULTS

This clinical practice guideline (CPG) generated 19 evidence-based recommendations, 117 consensus-based recommendations and five research recommendations across the 13 focus areas to inform allied health assessment and management of individuals with DMD.

CONCLUSIONS

The resulting recommendations can be used in conjunction with existing medical CPGs to improve, standardise and advocate for allied health and rehabilitation care in DMD. The process used here may be useful for the development of CPGs in other rare diseases.Implications for rehabilitationImplementation-ready evidence-based statements to guide clinical care of individuals with DMD are provided with the potential to improve participation, function in the community and quality of life.A model for developing best practice statements for other rare neurological diseases is described.Allied health and nursing health professionals should focus research efforts to generate quality evidence to support rehabilitation practice.

Reliability and validity of the FSHD-composite outcome measure in childhood facioscapulohumeral dystrophy

This study aims to investigate intra-rater reliability and construct validity of the Facioscapulohumeral Dystrophy Composite Outcome Measure (FSHD-COM), in childhood FSHD. Participants included eighteen children with FSHD, and matched healthy controls. Reliability data were collected from 15 participants with FSHD over two testing sessions. Validity data were collected from all participants. Participants with FSHD completed; the FSHD-COM (and modified pediatric version), Motor Function Measure-32 (MFM-32), FSHD Severity Scales, Performance of the Upper Limb 2.0, Pediatric Quality of Life™ Neuromuscular Module and pediatric FSHD Health-Index Questionnaire. Both versions of the FSHD-COM showed excellent intra-rater reliability (ICC_1,2 > 0.99, lower 95%CI > 0.98) with a Minimal Detectable Change (MDC95%) of ≤14.5%. The FSHD-COM had robust and widespread correlations with other related outcome measures. The FSHD-COM versions and 6 min walk test effectively discriminated between children with and without FSHD; the MFM-32 and 10 m walk/run test did not. Ceiling effects were not observed on either version of the FSHD-COM. Reliability and validity findings in this childhood FSHD study concord with estimates in adults. Both versions of the FSHD-COM were effective in discriminating disease in children with mild FSHD symptoms. The FSHD-COM has the potential to be a useful measure of function across the life span.

Is Reluctance to Share Alzheimer's Disease Biomarker Status with a Study Partner a Barrier to Preclinical Trial Recruitment?

BACKGROUND

Preclinical Alzheimer's disease clinical trials test candidate treatments in individuals with biomarker evidence but no cognitive impairment. Participants are required to co-enroll with a knowledgeable study partner, to whom biomarker information is disclosed.

OBJECTIVE

We investigated whether reluctance to share biomarker results is associated with viewing the study partner requirement as a barrier to preclinical trial enrollment.

DESIGN

We developed a nine-item assessment on views toward the study partner requirement and performed in-person interviews based on a hypothetical clinical trial requiring biomarker testing and disclosure.

SETTING

We conducted interviews on campus at the University of California, Irvine.

PARTICIPANTS

Two hundred cognitively unimpaired older adults recruited from the University of California, Irvine Consent-to-Contact Registry participated in the study.

MEASUREMENTS

We used logistic regression models, adjusting for potential confounders, to examine potential associations with viewing the study partner requirement as a barrier to preclinical trial enrollment.

RESULTS

Eighteen percent of participants reported strong agreement that the study partner requirement was a barrier to enrollment. Ten participants (5%) agreed at any level that they would be reluctant to share their biomarker result with a study partner. The estimated odds of viewing the study partner requirement as a barrier to enrollment were 26 times higher for these participants (OR=26.3, 95% CI 4.0, 172.3), compared to those who strongly disagreed that they would be reluctant to share their biomarker result. Overall, participants more frequently agreed with positive statements than negative statements about the study partner requirement, including 76% indicating they would want their study partner with them when they learned biomarker results.

CONCLUSIONS

This is one of the first studies to explore how potential preclinical Alzheimer's disease trial participants feel about sharing their personal biomarker information with a study partner. Most participants viewed the study partner as an asset to trial enrollment, including having a partner present during biomarker disclosure.

Muscle architecture, voluntary activation, and low-frequency fatigue do not explain the greater fatigue of older compared with young women during high-velocity contractions

Although high-velocity contractions elicit greater muscle fatigue in older than young adults, the cause of this difference is unclear. We examined the potential roles of resting muscle architecture and baseline contractile properties, as well as changes in voluntary activation and low-frequency fatigue in response to high-velocity knee extensor work. Vastus lateralis muscle architecture was determined in quiescent muscle by ultrasonography in 8 young (23.4±1.8 yrs) and 8 older women (69.6±1.1). Maximal voluntary dynamic (MVDC) and isometric (MVIC), and stimulated (80Hz and 10Hz, 500ms) isometric contractions were performed before and immediately after 120 MVDCs (240°^.s^-1, one every 2s). Architecture variables did not differ between groups (p≥0.209), but the half-time of torque relaxation (T_1/2) was longer in older than young women at baseline (151.9±6.0 vs. 118.8±4.4 ms, respectively, p = 0.001). Older women fatigued more than young (to 33.6±4.7% vs. 55.2±4.2% initial torque, respectively; p = 0.004), with no evidence of voluntary activation failure (ΔMVIC:80Hz torque) in either group (p≥0.317). Low-frequency fatigue (Δ10:80Hz torque) occurred in both groups (p<0.001), as did slowing of T_1/2 (p = 0.001), with no differences between groups. Baseline T_1/2 was inversely associated with fatigue in older (r² = 0.584, p = 0.045), but not young women (r² = 0.147, p = 0.348). These results indicate that differences in muscle architecture, voluntary activation, and low-frequency fatigue do not explain the greater fatigue of older compared with young women during high-velocity contractions. The inverse association between baseline T_1/2 and fatigue in older women suggests that factors related to slower muscle contractile properties may be protective against fatigue during fast, repetitive contractions in aging.

Circulating Plasma microRNAs are Altered with Amyloidosis in a Mouse Model of Alzheimer's Disease

Pathological changes underlying Alzheimer's disease (AD) begin decades before the classical symptoms of memory loss become evident. As microRNAs are released from neurons and enter the bloodstream, circulating microRNAs may be reflective of AD progression and are ideal candidates as biomarkers for early-stage disease detection. Here, we provide a novel, in-depth analysis of how plasma microRNAs alter with aging, the most prominent risk factor for AD, and with development of amyloid-β (Aβ) plaque deposition. We assessed the circulating microRNAs in APPswe/PSEN1dE9 transgenic mice and wild-type controls at 4, 8 and 15 m (n = 8-10) using custom designed Taqman arrays representing 185 neuropathology-related microRNAs. We performed a linear mixed-effects model to investigate the effects of age and genotype on plasma microRNAs expression. Following this analysis, we found 8 microRNAs were significantly affected by age alone in wild-type animals and 12 microRNAs altered in APPswe/PSEN1dE9 mice, either prior to Aβ plaque deposition (4 m) or during the development of AD-like pathogenesis (8 m or 15 m). Importantly, we found that differing sets of microRNAs were identified at each time point. Functional analysis of these data revealed that while common biological pathways, such as Inflammatory Response, were enriched throughout the disease process, Free Radical Scavenging, Immunological Disease, and Apoptosis Signaling were specifically enriched later in the disease process. Overall, this study reinforces that distinct biological processes underpin the early versus late stages of AD-like pathogenesis and highlights potential pre-symptomatic microRNAs biomarkers of neurodegeneration.

An In Vitro Perfusion System to Enhance Outflow Studies in Mouse Eyes

Purpose

The molecular mechanisms controlling aqueous humor (AQH) outflow and IOP need much further definition. The mouse is a powerful system for characterizing the mechanistic basis of AQH outflow. To enhance outflow studies in mice, we developed a perfusion system that is based on human anterior chamber perfusion culture systems. Our mouse system permits previously impractical experiments.

Methods

We engineered a computer-controlled, pump-based perfusion system with a platform for mounting whole dissected mouse eyes (minus lens and iris, ∼45% of drainage tissue is perfused). We tested the system's ability to monitor outflow and tested the effects of the outflow-elevating drug, Y27632, a rho-associated protein kinase (ROCK) inhibitor. Finally, we tested the system's ability to detect genetically determined decreases in outflow by determining if deficiency of the candidate genes Nos3 and Cav1 alter outflow.

Results

Using our system, the outflow facility (C) of C57BL/6J mouse eyes was found to range between 7.7 and 10.4 nl/minutes/mm Hg (corrected for whole eye). Our system readily detected a 74.4% Y27632-induced increase in C. The NOS3 inhibitor L-NG-nitroarginine methyl ester (L-NAME) and a Nos3 null mutation reduced C by 28.3% and 35.8%, respectively. Similarly, in Cav1 null eyes C was reduced by 47.8%.

Conclusions

We engineered a unique perfusion system that can accurately measure changes in C. We then used the system to show that NOS3 and CAV1 are key components of mechanism(s) controlling outflow.

Dynamical properties of gene regulatory networks involved in long-term potentiation

The long-lasting enhancement of synaptic effectiveness known as long-term potentiation (LTP) is considered to be the cellular basis of long-term memory. LTP elicits changes at the cellular and molecular level, including temporally specific alterations in gene networks. LTP can be seen as a biological process in which a transient signal sets a new homeostatic state that is “remembered” by cellular regulatory systems. Previously, we have shown that early growth response (Egr) transcription factors are of fundamental importance to gene networks recruited early after LTP induction. From a systems perspective, we hypothesized that these networks will show less stable architecture, while networks recruited later will exhibit increased stability, being more directly related to LTP consolidation. Using random Boolean network (RBN) simulations we found that the network derived at 24 h was markedly more stable than those derived at 20 min or 5 h post-LTP. This temporal effect on the vulnerability of the networks is mirrored by what is known about the vulnerability of LTP and memory itself. Differential gene co-expression analysis further highlighted the importance of the Egr family and found a rapid enrichment in connectivity at 20 min, followed by a systematic decrease, providing a potential explanation for the down-regulation of gene expression at 24 h documented in our preceding studies. We also found that the architecture exhibited by a control and the 24 h LTP co-expression networks fit well to a scale-free distribution, known to be robust against perturbations. By contrast the 20 min and 5 h networks showed more truncated distributions. These results suggest that a new homeostatic state is achieved 24 h post-LTP. Together, these data present an integrated view of the genomic response following LTP induction by which the stability of the networks regulated at different times parallel the properties observed at the synapse.

Aging alters long-term potentiation--related gene networks and impairs synaptic protein synthesis in the rat hippocampus

During aging, memory retention and persistence of long-term potentiation (LTP) are impaired, suggesting an aging-related deterioration in mechanisms regulating information storage. Late-phase LTP requires synthesis of proteins at synapses as well as integrated regulation of gene networks. Because aging diminishes the persistence of LTP, primarily by affecting the transition between early and late phases, we assessed whether this was reflected in perturbation of gene networks. Using DNA microarray analysis, we compared LTP-associated gene expression in young (5 months), middle-aged (15 months), and old (22 months) male Sprague-Dawley rats. As expected, we found no significant difference in LTP measured 20 minutes postinduction; however, we found that overall more genes were regulated in the young group. Bioinformatics predicted not only dysregulation of activator protein-1 and nuclear factor kB transcription factor activity and epigenetic modifications but also dysregulation of protein synthesis. Notably, we confirmed an age-related impairment in metabotropic and ionotropic receptor-mediated synaptic protein synthesis. Together, these results demonstrate that LTP-specific gene expression is altered with aging and suggest that dysregulation of synaptic protein synthesis also contributes to the age-dependent reduction in LTP persistence.

Observations of body mass index in Duchenne muscular dystrophy: a longitudinal study

BACKGROUND/OBJECTIVES

Nutritional issues that are associated with Duchenne muscular dystrophy (DMD) remain poorly understood. The aim of this analysis was to describe and explore longitudinal observations of body mass index (BMI) in a cohort of children with DMD.

SUBJECTS/METHODS

Anthropometric and clinical characteristics were collected retrospectively and longitudinally for boys with DMD seen in two large neuromuscular clinics. BMI Z-scores were determined using the Centers for Disease Control and Prevention reference values for children (2000).

RESULTS

Medical records (n=193) were examined from which 75% were included for analysis. The mean age of the cohort at the time of data collection was 11.9 years, with 72% of patients currently or previously using steroids. The highest prevalence of obesity based on the BMI Z-score was 50% at the age of 10 years. Longitudinally, BMI Z-scores from the age of 2 to 12 years plot approximately one s.d. above the mean, after which there is a marked and progressive decline. BMI gainers were identified for whom BMI Z-score increased by 1.65 units compared with the 0.09 units in non-gainers. BMI gainers were younger when they had their first BMI measurement (5.9 vs 7.2 years), and this measure was significantly lower compared with the non-gainers (BMI Z-score: 0.04 vs 1.17). In this cohort, BMI was associated with age, ambulatory status and lung function.

CONCLUSIONS

This study demonstrates that boys with DMD using steroid therapy experience shifts in BMI. A declining BMI appears to be associated with increasing age. Interpretation of growth patterns is limited here by a lack of normative growth references in DMD.

Time-dependent changes in gene expression induced by secreted amyloid precursor protein-alpha in the rat hippocampus

Background

Differential processing of the amyloid precursor protein liberates either amyloid-ß, a causative agent of Alzheimer’s disease, or secreted amyloid precursor protein-alpha (sAPPα), which promotes neuroprotection, neurotrophism, neurogenesis and synaptic plasticity. The underlying molecular mechanisms recruited by sAPPα that underpin these considerable cellular effects are not well elucidated. As these effects are enduring, we hypothesised that regulation of gene expression may be of importance and examined temporally specific gene networks and pathways induced by sAPPα in rat hippocampal organotypic slice cultures. Slices were exposed to 1 nM sAPPα or phosphate buffered saline for 15 min, 2 h or 24 h and sAPPα-associated gene expression profiles were produced for each time-point using Affymetrix Rat Gene 1.0 ST arrays (moderated t-test using Limma: p < 0.05, and fold change ± 1.15).

Results

Treatment of organotypic hippocampal slice cultures with 1 nM sAPPα induced temporally distinct gene expression profiles, including mRNA and microRNA associated with Alzheimer’s disease. Having demonstrated that treatment with human recombinant sAPPα was protective against N-methyl d-aspartate-induced toxicity, we next explored the sAPPα-induced gene expression profiles. Ingenuity Pathway Analysis predicted that short-term exposure to sAPPα elicited a multi-level transcriptional response, including upregulation of immediate early gene transcription factors (AP-1, Egr1), modulation of the chromatin environment, and apparent activation of the constitutive transcription factors CREB and NF-κB. Importantly, dynamic regulation of NF-κB appears to be integral to the transcriptional response across all time-points. In contrast, medium and long exposure to sAPPα resulted in an overall downregulation of gene expression. While these results suggest commonality between sAPPα and our previously reported analysis of plasticity-related gene expression, we found little crossover between these datasets. The gene networks formed following medium and long exposure to sAPPα were associated with inflammatory response, apoptosis, neurogenesis and cell survival; functions likely to be the basis of the neuroprotective effects of sAPPα.

Conclusions

Our results demonstrate that sAPPα rapidly and persistently regulates gene expression in rat hippocampus. This regulation is multi-level, temporally specific and is likely to underpin the neuroprotective effects of sAPPα.

Temporal profiling of gene networks associated with the late phase of long-term potentiation in vivo

Long-term potentiation (LTP) is widely accepted as a cellular mechanism underlying memory processes. It is well established that LTP persistence is strongly dependent on activation of constitutive and inducible transcription factors, but there is limited information regarding the downstream gene networks and controlling elements that coalesce to stabilise LTP. To identify these gene networks, we used Affymetrix RAT230.2 microarrays to detect genes regulated 5 h and 24 h (n = 5) after LTP induction at perforant path synapses in the dentate gyrus of awake adult rats. The functional relationships of the differentially expressed genes were examined using DAVID and Ingenuity Pathway Analysis, and compared with our previous data derived 20 min post-LTP induction in vivo. This analysis showed that LTP-related genes are predominantly upregulated at 5 h but that there is pronounced downregulation of gene expression at 24 h after LTP induction. Analysis of the structure of the networks and canonical pathways predicted a regulation of calcium dynamics via G-protein coupled receptors, dendritogenesis and neurogenesis at the 5 h time-point. By 24 h neurotrophin-NFKB driven pathways of neuronal growth were identified. The temporal shift in gene expression appears to be mediated by regulation of protein synthesis, ubiquitination and time-dependent regulation of specific microRNA and histone deacetylase expression. Together this programme of genomic responses, marked by both homeostatic and growth pathways, is likely to be critical for the consolidation of LTP in vivo.

Rapidly induced gene networks following induction of long-term potentiation at perforant path synapses in vivo

The canonical view of the maintenance of long-term potentiation (LTP), a widely accepted experimental model for memory processes, is that new gene transcription contributes to its consolidation; however, the gene networks involved are unknown. To address this issue, we have used high-density Rat 230.2 Affymetrix arrays to establish a set of genes induced 20-min post-LTP, and using Ingenuity Pathway network analysis tools we have investigated how these early responding genes are interrelated. This analysis identified LTP-induced regulatory networks in which the transcription factors (TFs) nuclear factor-KB and serum response factor, which, to date, have not been widely recognized as coordinating the early gene response, play a key role alongside the more well-known TFs cyclic AMP response element-binding protein, and early growth response 1. Analysis of gene-regulatory promoter sites and chromosomal locations of the genes within the dataset reinforced the importance of these molecules in the early gene response and predicted that the coordinated action might arise from gene clustering on particular chromosomes. We have also identified a transcription-based response that affects mitogen-activated protein kinase signaling pathways and protein synthesis during the stabilization of the LTP response. Furthermore, evidence from biological function, networks, and regulatory analyses showed convergence on genes related to development, proliferation, and neurogenesis, suggesting that these functions are regulated early following LTP induction. This raises the interesting possibility that LTP-related gene expression plays a role in both synaptic reorganization and neurogenesis.

Two novel germline KRAS mutations: expanding the molecular and clinical phenotype

Noonan and Cardio-facio-cutaneous (CFC) syndromes are characterized by typical dysmorphic features, cardiac defects, short stature, variable ectodermal anomalies, and intellectual disability. Both belong to the Ras/mitogen-activated protein kinase pathway group of disorders and clinical features overlap other related conditions, notably LEOPARD and Costello syndromes. KRAS mutations account for about 2% of reported Noonan and <5% of reported CFC cases. The mutation spectrum includes recurrent missense changes clustering in particular domains of the KRAS protein and conferring gain-of-function. We report three patients from two unrelated families with novel missense KRAS mutations, p.K147E and p.Y71H. Both mutations affect a residue which is highly conserved in KRAS and other RAS isoforms. One of the families includes a mother and son pair who represent the first report of a vertically transmitted KRAS mutation. In addition, the mother and son pair had peripheral neuropathy, complicated by Charcot arthropathy in the mother. An unusual phenotypic effect of the specific KRAS mutation or a coincidence of two independent disorders may be considered. KRAS mutation-associated phenotypes appear to be subject to considerable clinical heterogeneity. All three cases highlight the challenges of clinical assessment in KRAS mutation-positive patients, and the utility of molecular testing as an adjunct to diagnosis.

Randomized, blinded trial of weekend vs daily prednisone in Duchenne muscular dystrophy

OBJECTIVE

To perform a double-blind, randomized study comparing efficacy and safety of daily and weekend prednisone in boys with Duchenne muscular dystrophy (DMD).

METHODS

A total of 64 boys with DMD who were between 4 and 10 years of age were randomized at 1 of 12 centers of the Cooperative International Neuromuscular Research Group. Efficacy and safety of 2 prednisone schedules (daily 0.75 mg/kg/day and weekend 10 mg/kg/wk) were evaluated over 12 months.

RESULTS

Equivalence was met for weekend and daily dosing of prednisone for the primary outcomes of quantitative muscle testing (QMT) arm score and QMT leg score. Secondary strength scores for QMT elbow flexors also showed equivalence between the 2 treatment groups. Overall side effect profiles of height and weight, bone density, cataract formation, blood pressure, and behavior, analyzed at 12 months, did not differ between weekend and daily dosing of prednisone.

CONCLUSIONS

Weekend dosing of prednisone is equally beneficial to the standard daily dosing of prednisone. Analysis of side effect profiles demonstrated overall tolerability of both dosing regimens.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that weekend prednisone dosing is as safe and effective as daily prednisone in preserving muscle strength and preventing body mass index increases in boys with DMD over a 12-month period.

Pediatric sciatic neuropathies: a 30-year prospective study

OBJECTIVE

The incidence, cause, and prognosis of sciatic neuropathy in children is not well understood. We report our 30-year experience of 53 patients with pediatric sciatic neuropathies (SN).

METHODS

Prospective review of the history, physical examination, electrophysiologic findings, and clinical course of children with SN.

RESULTS

The etiology of SN injury was varied and included trauma (13), iatrogenic causes (13) (8 orthopedic surgeries and 5 miscellaneous surgeries), prolonged extrinsic compression and immobilization (6), tumors (7), vascular (5), idiopathic and progressive (4), infantile and nonprogressive (2), and unknown, presumed postviral (3). Electrophysiologic studies demonstrated abnormalities in motor conduction studies of the peroneal nerve in 44/53 (83%) or tibial nerve in 35/51 (67%). Sensory conduction studies were abnormal in sural nerve in 34 of 43 cases (79%), and superficial peroneal nerves in 15/25 (60%). Needle EMG was abnormal in peroneal innervated muscles in all subjects, in tibial nerve innervated muscles in 43/51 (84%), and in the hamstrings in 18/29 (62%). Prognosis for recovery was variable and depended on the etiology and the severity of the nerve injury.

CONCLUSIONS

SN is an uncommon mononeuropathy in children. The causes of SN are varied in children compared to adults. Electrophysiologic studies in children may be limited by poor tolerance but play an important role in establishing the diagnosis.

A retrospective review of X-linked Charcot-Marie-Tooth disease in childhood

OBJECTIVE

X-linked Charcot-Marie-Tooth disease (CMTX) is infrequently diagnosed in childhood, and its clinical and neurophysiologic features are not well-described. We reviewed clinical, neurophysiologic, and pathologic findings in 17 children with CMTX.

METHODS

This was a retrospective review of children with CMTX from 2 tertiary pediatric hospitals. The diagnosis of CMTX was based on an identifiable connexin 32 mutation (CMTX1) or a consistent pedigree and neurophysiologic features in children without a connexin 32 mutation (CMTX-other).

RESULTS

Six boys and 2 girls from 8 kindreds had CMTX1, and 8 boys and 1 girl from 5 kindreds had other forms of CMTX (CMTX-other). Fifteen children, including males and carrier females, were symptomatic from infancy or early childhood (younger than 5 years). In addition to the typical Charcot-Marie-Tooth disease clinical phenotype, some patients had delayed motor development, sensorineural hearing loss, tremor, pathologic fractures, or transient CNS disturbances. Eleven children underwent nerve conduction studies. Median nerve motor nerve conduction velocities were in the intermediate to normal range (30-54 m/s) in all children older than 2 years. Axon loss, reflected by low-amplitude compound muscle action potentials, was present in all patients. A pattern of X-linked dominant inheritance, with carrier females showing an abnormal neurologic or neurophysiologic examination, correlated with the presence of a connexin 32 mutation in all but 2 pedigrees.

CONCLUSIONS

The clinical phenotype of CMTX is broader than previously reported. Onset in males and carrier females is most often in early childhood. Families with an X-linked dominant inheritance pattern are likely to have CMTX1.

Determinants of reduced health-related quality of life in pediatric inherited neuropathies

OBJECTIVE

We have shown that health-related quality of life (QOL) in children with inherited neuropathies (Charcot-Marie-Tooth disease [CMT]) is significantly reduced compared to population norms, thus establishing its utility as an outcome measure in therapeutic trials. However, the Australian ascorbic acid trial in children with CMT type 1A (CMT1A) identified no change in QOL scores despite a trend toward improvement in nerve conduction velocities in the treated group. The objective of this study was to identify clinical, electrophysiologic, and functional correlates of QOL in children with CMT1A, to guide future investigations of strategies to improve QOL and reduce disability in these patients.

METHODS

In this cross-sectional study, a series of multivariate regression models were developed to determine whether QOL scores could be explained by demographic and symptom data, standardized measures of gross motor function, foot/ankle and hand/finger involvement, electrophysiology, and gait characteristics in 70 children aged 5-16 years with CMT1A.

RESULTS

Independent determinants of reduced QOL in children with CMT1A, from strongest to weakest, were leg cramps, hand tremor, short step length, reduced long jump distance, ankle inflexibility, poor agility and endurance, advancing age, and foot drop. Many of the standardized clinical and electrophysiologic measures used as endpoints in clinical trials of CMT correlated poorly with QOL.

CONCLUSION

QOL is negatively affected by CMT1A in children. Multivariate modeling suggests that interventions designed to improve leg cramps, tremor, agility, endurance, and ankle flexibility might have a substantial effect on QOL in children with CMT1A.

Evolution of neuronal and endothelial transcriptomes in primates

The study of gene expression evolution in vertebrates has hitherto focused on the analysis of transcriptomes in tissues of different species. However, because a tissue is made up of different cell types, and cell types differ with respect to their transcriptomes, the analysis of tissues offers a composite picture of transcriptome evolution. The isolation of individual cells from tissue sections opens up the opportunity to study gene expression evolution at the cell type level. We have stained neurons and endothelial cells in human brains by antibodies against cell type-specific marker proteins, isolated the cells using laser capture microdissection, and identified genes preferentially expressed in the two cell types. We analyze these two classes of genes with respect to their expression in 62 different human tissues, with respect to their expression in 44 human "postmortem" brains from different developmental stages and with respect to between-species brain expression differences. We find that genes preferentially expressed in neurons differ less across tissues and developmental stages than genes preferentially expressed in endothelial cells. We also observe less expression differences within primate species for neuronal transcriptomes. In stark contrast, we see more gene expression differences between humans, chimpanzees, and rhesus macaques relative to within-species differences in genes expressed preferentially in neurons than in genes expressed in endothelial cells. This suggests that neuronal and endothelial transcriptomes evolve at different rates within brain tissue.

Autosomal dominant congenital spinal muscular atrophy--a possible developmental deficiency of motor neurones?

We describe a kindred with an unusual congenital lower motor neuron disorder with significant but static muscle weakness predominantly affecting the lower limbs. The proband had talipes equinovarus and congenital hip contractures and did not walk until 19 months of age. Lower-extremity predominant, primarily proximal weakness was identified on assessment at three years. Over a 20 year follow-up there has been no clinical progression. The proband has a four-year-old daughter with very similar clinical findings. Electromyography and muscle biopsy suggest reduced numbers of giant normal duration motor units with little evidence of denervation or reinnervation. Dominant congenital spinal muscular atrophy predominantly affecting the lower limbs is rarely described. It is possible that the disorder is due to a congenital deficiency of motor neurons.

Live-born infants of 24 to 28 weeks' gestation: survival and sequelae at two years of age

The survival rate of infants born alive between 24 and 28 weeks of gestation has increased significantly in this tertiary care centre, from about 9% in the first cohort studied (1966-1970), to 19.5% in the second cohort (1971-1974) and 50.3% in the third cohort (1977-1982); the borderline of practical viability decreased from 27 to 24 weeks over the years of the study. The number of mothers with a history of prior termination of pregnancy increased about sixfold from the second to the third cohorts but the rate of premature births increased by only 50%. The augmented survival rate was accompanied by an increase in the prevalence and total number of children with cerebral palsy, but bilateral blindness due to retinopathy of prematurity and severe sensorineural deafness were reduced. When 96% of children in the third cohort were assessed at two years of age. 13% had severe handicaps, 59% were considered normal and in 24% some handicap was suspected. The serious handicap rate was 28% for children born at 24-26 weeks compared with 8.5% for those born at 27-28 weeks of gestation.

Interventions for the prevention and treatment of pes cavus

BACKGROUND

People with pes cavus frequently suffer foot pain, which can lead to significant disability. Despite anecdotal reports, rigorous scientific investigation of this condition and how best to manage it is lacking.

OBJECTIVES

To assess the effects of interventions for the prevention and treatment of pes cavus.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Register (April 2007), MEDLINE (January 1966 to April 2007), EMBASE (January 1980 to April 2007), CINAHL (January 1982 to April 2007), AMED (January 1985 to April 2007), all EBM Reviews (January 1991 to April 2007), SPORTdiscuss (January 1830 to April 2007) and reference lists of articles. We also contacted known experts in the field to identify additional published or unpublished data.

SELECTION CRITERIA

We included all randomised and quasi-randomised controlled trials of interventions for the treatment of pes cavus. We also included trials aimed at preventing or correcting the cavus foot deformity.

DATA COLLECTION AND ANALYSIS

Two authors independently selected papers, assessed trial quality and extracted data.

MAIN RESULTS

Only one trial (custom-made foot orthoses) fully met the inclusion criteria. Two additional cross-over trials (off-the-shelf foot orthoses and footwear) were also included. Both studies assessed secondary biomechanical outcomes less than three-months after randomisation. Data used in the three studies could not be pooled due to heterogeneity of diagnostic groups and outcome measures. The one trial that fully met the inclusion criteria investigated the treatment of cavus foot pain in 154 adults over a three month period. The trial showed a significant reduction in the level of foot pain, measured using the validated 100-point Foot Health Status Questionnaire, with custom-made foot orthoses versus sham orthoses (WMD 10.90; 95% CI 3.21 to 18.59). Furthermore, a significant improvement in foot function measured with the same questionnaire was reported with custom-made foot orthoses (WMD 11.00; 95% CI 3.35 to 18.65). There was also an increase in physical functioning of the Medical Outcomes Short Form - 36 (WMD 9.50; 95% CI 4.07 to 14.93). There was no difference in reported adverse events following the allocation of custom-made (9%) or sham foot orthoses (15%) (RR 0.61; 95% CI 0.26 to 1.48).

AUTHORS' CONCLUSIONS

In one randomised controlled trial, custom-made foot orthoses were significantly more beneficial than sham orthoses for treating chronic musculoskeletal foot pain associated with pes cavus in a variety of clinical populations. There is no evidence for any other type of intervention for the treatment or prevention of foot pain in people with a cavus foot type.

Oropharyngeal dysphagia in juvenile dermatomyositis (JDM): an evaluation of videofluoroscopy swallow study (VFSS) changes in relation to clinical symptoms and objective muscle scores

OBJECTIVE

To determine if objective, validated scores of muscle weakness and function [manual muscle testing (MMT), childhood myositis assessment scale (CMAS)] or scores of general disease activity or function [childhood health assessment questionnaire and physician global assessment of disease activity visual analogue scale (VAS)], can predict children at risk of swallow abnormalities in juvenile dermatomyositis (JDM) measured by videofluoroscopic swallow studies (VFSS).

METHODS

Patients were referred for speech and language dysphagia assessment upon diagnosis of JDM or flare of disease. VFSS was used to document a swallow score indicating severity of swallow dysfunction. Clinical symptoms, examination findings and objective scores of disease activity were analysed. Any correlation was looked for using chi-squared Fisher exact test and linear regression models.

RESULTS

Fourteen patients with inflammatory myopathy (age 2-16 years) had clinical assessments and VFSS. VFSS was abnormal in 11 children (79%). Only two children were asymptomatic at assessment, but both had swallow dysfunction, including aspiration, on VFSS. In contrast, three of the symptomatic children had a normal VFSS. No relationship was found between objective disease severity scores and VFSS swallow score.

CONCLUSIONS

This study failed to show any correlation between swallow score and objective measures of muscle strength and function (MMT/CMAS) or general disease activity and function [physician VAS/childhood health assessment questionnaire (CHAQ)]. In the absence of a more accurate assessment method to determine which children with active JDM are most at risk of swallow dysfunction and aspiration, all children with active dermatomyositis should be referred for speech and language assessment and VFSS.

Conformational dynamics of the major yeast phosphatidylinositol transfer protein sec14p: insight into the mechanisms of phospholipid exchange and diseases of sec14p-like protein deficiencies

Molecular dynamics simulations coupled with functional analyses of the major yeast phosphatidylinositol/phosphatidylcholine transfer protein Sec14p identify structural elements involved in regulating the ability of Sec14p to execute phospholipid exchange. The molecular dynamics simulations suggest large rigid body motions within the Sec14p molecule accompany closing and opening of an A(10)/T(4)/A(11) helical gate, and that "state-of-closure" of this helical gate determines access to the Sec14p phospholipid binding cavity. The data also project that conformational dynamics of the helical gate are controlled by a hinge unit (residues F(212), Y(213), K(239), I(240), and I(242)) that links to the N- and C-terminal ends of the helical gate, and by a novel gating module (composed of the B(1)LB(2) and A(12)LT(5) substructures) through which conformational information is transduced to the hinge. The (114)TDKDGR(119) motif of B(1)LB(2) plays an important role in that transduction process. These simulations offer new mechanistic possibilities for an important half-reaction of the Sec14p phospholipid exchange cycle that occurs on membrane surfaces after Sec14p has ejected bound ligand, and is reloading with another phospholipid molecule. These conformational transitions further suggest structural rationales for known disease missense mutations that functionally compromise mammalian members of the Sec14-protein superfamily.

Local polarity and hydrogen bonding inside the Sec14p phospholipid-binding cavity: high-field multi-frequency electron paramagnetic resonance studies

Sec14p promotes the energy-independent transfer of either phosphatidylinositol (PtdIns) or phosphatidylcholine (PtdCho) between lipid bilayers in vitro and represents the major PtdIns/PtdCho transfer protein in the budding yeast Saccharomyces cerevisiae. Herein, we employ multi-frequency high-field electron paramagnetic resonance (EPR) to analyze the electrostatic and hydrogen-bonding microenvironments for series of doxyl-labeled PtdCho molecules bound by Sec14p in a soluble protein-PtdCho complex. A structurally similar compound, 5-doxyl stearic acid dissolved in a series of solvents, was used for experimental calibration. The experiments yielded two-component rigid limit 130- and 220-GHz EPR spectra with excellent resolution in the gx region. Those components were assigned to hydrogen-bonded and nonhydrogen-bonded nitroxide species. Partially resolved 130-GHz EPR spectra from n-doxyl-PtdCho bound to Sec14p were analyzed using this two-component model and allowed quantification of two parameters. First, the fraction of hydrogen-bonded nitroxide species for each n-doxyl-PtdCho was calculated. Second, the proticity profile along the phospholipid-binding cavity of Sec14p was characterized. The data suggest the polarity gradient inside the Sec14p cavity is a significant contributor to the driving molecular forces for extracting a phospholipid from the bilayer. Finally, the enhanced g-factor resolution of EPR at 130 and 220 GHz provides researchers with a spectroscopic tool to deconvolute two major contributions to the x-component of the nitroxide g-matrix: hydrogen-bond formation and local electrostatic effects.

Outcome of noninvasive ventilation in children with neuromuscular disease

OBJECTIVE

To assess the effect of institution of noninvasive ventilation (NIV) on clinical outcome and quality of life (QOL) in a cohort of children with severe neuromuscular disorders.

METHODS

We reviewed records and obtained clinical data from the year prior to commencing NIV and annually thereafter. Data obtained included diagnosis, patient symptoms, mortality, NIV adverse effects, pulmonary function tests, polysomnographic data, length of hospitalizations, and health care costs. Patients and parents completed questionnaires assessing QOL with NIV and recalling QOL before NIV.

RESULTS

Fourteen of 17 (82%) suitable patients were enrolled. Follow-up ranged from 6 to 84 months (median 30). Symptoms of daytime sleepiness (p = 0.003) and headache (p = 0.046) improved after initiation of NIV. Sleep quality assessed by polysomnography also improved. Hospitalization rates (p = 0.002) and health care costs (p = 0.003) decreased. QOL remained stable after NIV, despite disease progression.

CONCLUSION

Treatment of respiratory failure, in children with neuromuscular disease, with noninvasive ventilation results in a reduction in symptoms, hospitalizations, and health care costs without adverse effects on quality of life.

Gene expression analysis of bipolar disorder reveals downregulation of the ubiquitin cycle and alterations in synaptic genes

Bipolar affective disorder is a severe psychiatric disorder with a strong genetic component but unknown pathophysiology. We used microarray technology to determine the expression of approximately 22,000 mRNA transcripts in post-mortem tissue from two brain regions in patients with bipolar disorder and matched healthy controls. Dorsolateral prefrontal cortex tissue from a cohort of 70 subjects and orbitofrontal cortex tissue from a separate cohort of 30 subjects was investigated. The final analysis included 30 bipolar and 31 control subjects for the dorsolateral prefrontal cortex and 10 bipolar and 11 control subjects for the orbitofrontal cortex. Differences between disease and control groups were identified using a rigorous statistical analysis with correction for confounding variables and multiple testing. In the orbitofrontal cortex, 393 differentially expressed transcripts were identified by microarray analysis and a representative subset was validated by quantitative real-time PCR. Pathway analysis revealed significant upregulation of genes involved in G-protein coupled receptor signalling and response to stimulus (in particular the immune response), while genes relating to the ubiquitin cycle and intracellular transport showed coordinated downregulation in bipolar disorder. Additionally, several genes involved in synaptic function were significantly downregulated in bipolar disorder. No significant changes in gene expression were observed in the dorsolateral prefrontal cortex using microarray analysis or quantitative real-time PCR. Our findings implicate the orbitofrontal cortex as a region prominently involved in bipolar disorder and indicate that diverse processes are affected. Overall, our results suggest that dysregulation of the ubiquitin pathway and synaptic function may be central to the disease process.

The chemistry of phospholipid binding by the Saccharomyces cerevisiae phosphatidylinositol transfer protein Sec14p as determined by EPR spectroscopy

The major yeast phosphatidylinositol/phosphatidylcholine transfer protein Sec14p is the founding member of a large eukaryotic protein superfamily. Functional analyses indicate Sec14p integrates phospholipid metabolism with the membrane trafficking activity of yeast Golgi membranes. In this regard, the ability of Sec14p to rapidly exchange bound phospholipid with phospholipid monomers that reside in stable membrane bilayers is considered to be important for Sec14p function in cells. How Sec14p-like proteins bind phospholipids remains unclear. Herein, we describe the application of EPR spectroscopy to probe the local dynamics and the electrostatic microenvironment of phosphatidylcholine (PtdCho) bound by Sec14p in a soluble protein-PtdCho complex. We demonstrate that PtdCho movement within the Sec14p binding pocket is both anisotropic and highly restricted and that the C5 region of the sn-2 acyl chain of bound PtdCho is highly shielded from solvent, whereas the distal region of that same acyl chain is more accessible. Finally, high field EPR reports on a heterogeneous polarity profile experienced by a phospholipid bound to Sec14p. Taken together, the data suggest a headgroup-out orientation of Sec14p-bound PtdCho. The data further suggest that the Sec14p phospholipid binding pocket provides a polarity gradient that we propose is a primary thermodynamic factor that powers the ability of Sec14p to abstract a phospholipid from a membrane bilayer.

Sec14p-like proteins regulate phosphoinositide homoeostasis and intracellular protein and lipid trafficking in yeast

The major PI (phosphatidylinositol)/PC (phosphatidylcholine)-transfer protein in yeast, Sec14p, co-ordinates lipid metabolism with protein transport from the Golgi complex. Yeast also express five additional gene products that share 24–65% primary sequence identity with Sec14p. These Sec14p-like proteins are termed SFH (Sec Fourteen Homologue) proteins, and overexpression of certain individual SFH gene products rescues sec14-1ts-associated growth and secretory defects. SFH proteins are atypical in that these stimulate the transfer of PI, but not PC, between distinct membrane bilayer systems in vitro. Further analysis reveals that SFH proteins functionally interact with the Stt4p phosphoinositide 4-kinase to stimulate PtdIns(4,5)P2 synthesis which in turn activates phospholipase D. Finally, genetic analyses indicate that Sfh5p interfaces with the function of specific subunits of the exocyst complex as well as the yeast SNAP-25 (25 kDa synaptosome-associated protein) homologue, Sec9p. Our current view is that Sfh5p regulates PtdIns(4,5)P2 homoeostasis at the plasma membrane, and that Sec9p responds to that regulation. Thus SFH proteins individually regulate specific aspects of lipid metabolism that couple, with exquisite specificity, with key cellular functions.

Nonclassical PITPs Activate PLD via the Stt4p PtdIns-4-kinase and Modulate Function of Late Stages of Exocytosis in Vegetative Yeast

Phospholipase D (PLD) is a PtdCho-hydrolyzing enzyme that plays central signaling functions in eukaryotic cells. We previously demonstrated that action of a set of four nonclassical and membrane-associated Sec14p-like phosphatidylinositol transfer proteins (PITPs) is required for optimal activation of yeast PLD in vegetative cells. Herein, we focus on mechanisms of Sfh2p and Sfh5p function in this regulatory circuit. We describe several independent lines of in vivo evidence to indicate these SFH PITPs regulate PLD by stimulating PtdIns-4,5-P2 synthesis and that this stimulated PtdIns-4,5-P2 synthesis couples to action of the Stt4p PtdIns 4-kinase. Furthermore, we provide genetic evidence to suggest that specific subunits of the yeast exocyst complex (i.e. a component of the plasma membrane vesicle docking machinery) and the Sec9p plasma membrane t-SNARE are regulated by PtdIns(4,5)P2 and that Sfh5p helps regulate this interface in vivo. The collective in vivo and biochemical data suggest SFH-mediated stimulation of Stt4p activity is indirect, most likely via a substrate delivery mechanism.

Mitochondrial dysfunction in schizophrenia: evidence for compromised brain metabolism and oxidative stress

The etiology and pathophysiology of schizophrenia remain unknown. A parallel transcriptomics, proteomics and metabolomics approach was employed on human brain tissue to explore the molecular disease signatures. Almost half the altered proteins identified by proteomics were associated with mitochondrial function and oxidative stress responses. This was mirrored by transcriptional and metabolite perturbations. Cluster analysis of transcriptional alterations showed that genes related to energy metabolism and oxidative stress differentiated almost 90% of schizophrenia patients from controls, while confounding drug effects could be ruled out. We propose that oxidative stress and the ensuing cellular adaptations are linked to the schizophrenia disease process and hope that this new disease concept may advance the approach to treatment, diagnosis and disease prevention of schizophrenia and related syndromes.

Functional genomics and proteomics: application in neurosciences

The sequencing of the complete genome for many organisms, including man, has opened the door to the systematic understanding of how complex structures such as the brain integrate and function, not only in health but also in disease. This blueprint, however, means that the piecemeal analysis regimes of the past are being rapidly superseded by new methods that analyse not just tens of genes or proteins at any one time, but thousands, if not the entire repertoire of a cell population or tissue under investigation. Using the most appropriate method of analysis to maximise the available data therefore becomes vital if a complete picture is to be obtained of how a system or individual cell is affected by a treatment or disease. This review examines what methods are currently available for the large scale analysis of gene and protein expression, and what are their limitations.

Application and optimization of microarray technologies for human postmortem brain studies

A number of microarray investigations using human postmortem brain tissue have been published recently, exploring a multitude of human brain disorders with the aim of unraveling the underlying pathologies. Although the technology is still developing and lacks sufficient sensitivity with regard to detecting splice variants and low abundance transcripts, microarrays are becoming the prominent method for candidate gene screening in complex neuropsychiatric disorders. The use of postmortem tissue harbors a variety of potential pitfalls, however, which could result in unreliable or, at worst, meaningless results. During the course of our large-scale gene expression study on 150 human postmortem brain samples, using more than 200 Affymetrix GeneChips, we have identified several aspects within microarray experimental procedure that allows for the early identification of potentially unreliable samples. The general application of the guidelines and technical tips described here increase the efficiency, reliability, and amount of data generated by this powerful screening technology while reducing superfluous consumption of time and resources.

Oligodendrocyte dysfunction in schizophrenia and bipolar disorder

BACKGROUND

Results of array studies have suggested abnormalities in expression of lipid and myelin-related genes in schizophrenia. Here, we investigated oligodendrocyte-specific and myelination-associated gene expression in schizophrenia and bipolar affective disorder.

METHODS

We used samples from the Stanley brain collection, consisting of 15 schizophrenia, 15 bipolar affective disorder, and 15 control brains. Indexing-based differential display PCR was done to screen for differences in gene expression in schizophrenia patients versus controls. Results were cross-validated with quantitative PCR, which was also used to investigate expression profiles of 16 other oligodendrocyte and myelin genes in schizophrenia and bipolar disorder. These genes were further investigated with an ongoing microarray analysis.

FINDINGS

Results of differential display and quantitative PCR analysis showed a reduction of key oligodendrocyte-related and myelin-related genes in schizophrenia and bipolar patients; expression changes for both disorders showed a high degree of overlap. Microarray results of the same genes investigated by quantitative PCR correlated well overall.

INTERPRETATION

Schizophrenia and bipolar brains showed downregulation of key oligodendrocyte and myelination genes, including transcription factors that regulate these genes, compared with control brains. These results lend support to and extend observations from other microarray investigations. Our study also showed similar expression changes to the schizophrenia group in bipolar brains, which thus lends support to the notion that the disorders share common causative and pathophysiological pathways.

Clinical course correlates poorly with muscle pathology in nemaline myopathy

OBJECTIVE

To report pathologic findings in 124 Australian and North American cases of primary nemaline myopathy.

METHODS

Results of 164 muscle biopsies from 124 Australian and North American patients with primary nemaline myopathy were reviewed, including biopsies from 19 patients with nemaline myopathy due to alpha-actin (ACTA1) mutations and three with mutations in alpha-tropomyosin(SLOW) (TPM3). For each biopsy rod number per fiber, percentage of fibers with rods, fiber-type distribution of rods, and presence or absence of intranuclear rods were documented.

RESULTS

Rods were present in all skeletal muscles and diagnosis was possible at all ages. Most biopsies contained nemaline bodies in more than 50% of fibers, although rods were seen only on electron microscopy in 10 patients. Rod numbers and localization correlated poorly with clinical severity. Frequent findings included internal nuclei and increased fiber size variation, type 1 fiber predominance and atrophy, and altered expression of fiber type specific proteins. Marked sarcomeric disruption, increased glycogen deposition, and intranuclear rods were associated with more severe clinical phenotypes. Serial biopsies showed progressive fiber size variation and increasing numbers of rods with time. Pathologic findings varied widely in families with multiple affected members.

CONCLUSIONS

Very numerous nemaline bodies, glycogen accumulation, and marked sarcomeric disruption were common in nemaline myopathy associated with mutations in skeletal alpha-actin. Nemaline myopathy due to mutations in alpha-tropomyosin(SLOW) was characterized by preferential rod formation in, and atrophy of, type 1 fibers. Light microscopic features of nemaline myopathy correlate poorly with disease course. Electron microscopy may correlate better with disease severity and genotype.

Nemaline myopathy: a clinical study of 143 cases

We report 143 Australian and North American cases of primary nemaline myopathy. As classified by the European Neuromuscular Centre guidelines, 23 patients had severe congenital, 29 intermediate congenital, 66 typical congenital, 19 childhood-onset, and 6 adult-onset nemaline myopathy. Inheritance was autosomal recessive in 29 patients, autosomal dominant in 41, sporadic in 72, and indeterminate in 1. Twenty-two patients had skeletal muscle actin mutations and 4 had mutations in the alpha-tropomyosin(slow) gene. Obstetric complications occurred in 49 cases. Seventy-five patients had significant respiratory disease during the first year of life, and 79 had feeding difficulties. Atypical features in a minority of cases included arthrogryposis, central nervous system involvement, and congenital fractures. Progressive distal weakness developed in a minority of patients. Thirty patients died, the majority during the first 12 months of life. All deaths were due to respiratory insufficiency, which was frequently underrecognized in older patients. Arthrogryposis, neonatal respiratory failure, and failure to achieve early motor milestones were associated with early mortality. Morbidity from respiratory tract infections and feeding difficulties frequently diminished with increasing age. Aggressive early management is warranted in most cases of congenital nemaline myopathy.

Anterior horn cell disease and olivopontocerebellar hypoplasia

To date, fewer than 30 cases of anterior horn cell disease with associated olivopontocerebellar hypoplasia have been reported. We describe five patients and review the literature on this uncommon disorder. In addition to a syndrome of progressive spinal muscular atrophy similar to that seen in Werdnig-Hoffmann disease, this disorder is characterised by hypoplasia of the olivary nuclei, pons, and cerebellum. Additional clinical features may include dysmorphism, abnormal eye movements, stridor, congenital joint contractures, and enlarged kidneys. Pontocerebellar hypoplasia may be associated with posterior fossa cystic malformations, cerebral atrophy, and a demyelinating neuropathy.

Childhood chronic inflammatory demyelinating polyneuropathy: clinical course and long-term outcome

We reviewed the clinical history, electrophysiologic and pathologic findings, and response to therapy of 16 children with chronic inflammatory demyelinating polyneuropathy. The majority presented with lower limb weakness. Sensory loss was uncommon. The illness was monophasic in seven children, relapsing in six, and three had a slowly progressive course. All patients were treated with immunosuppressive agents. In 11, the initial treatment was prednisolone. All had at least a short-term response but five went on to develop a relapsing course. Intravenous immunoglobulin was the initial treatment in four patients. Three responded rapidly, with treatment being stopped after a maximum of 5 months. In resistant chronic inflammatory demyelinating neuropathy, in addition to prednisolone and immunoglobulin, plasma exchange, azathioprine, cyclosporine, methotrexate, cyclophosphamide and pulse methylprednisolone were tried at different times in different patients. On serial neurophysiologic testing slowing of nerve conduction persisted for long periods after clinical recovery. Follow-up was for an average of 10 years. When last seen 14 patients were asymptomatic, two having mild residual deficits. Childhood chronic inflammatory demyelinating neuropathy responds to conventional treatment and generally has a favourable long-term outcome.

Persistent or severe back pain and stiffness are ominous symptoms requiring prompt attention

BACKGROUND

Children with severe or persistent back pain and stiffness often have an underlying organic cause but there is a large differential diagnosis, examination may be difficult and the problem is relatively rare in general paediatric practice. These difficulties appeared to lead to delays in diagnosis and management of children with this problem.

OBJECTIVES

To provide an approach to the diagnosis and management children with severe or persistent back pain or stiffness based on our clinical experience and the literature.

METHODOLOGY

The case histories of 10 children with severe back pain seen by the authors over a 5-year period were reviewed. They were chosen as illustrative examples of the diagnostic and management problems and did not represent a systematic review of all cases seen by the authors over that time.

RESULTS

Underlying causes included infection, inflammation, neoplasm, trauma and vascular malformation. Four of the children had spinal cord compression which required urgent decompression. There was one child with a conversion disorder but three children with organic disease were initially felt to have a conversion disorder. Investigations generally proceeded relatively slowly and the problem was not regarded as a semi-urgent situation carrying the risk of permanent paraplegia. Magnetic resonance imaging (MRI) scan of the spine was the investigation of choice.

CONCLUSION

Children with severe or persistent back pain and stiffness have a wide variety of underlying causes. The possibility of underlying spinal cord compression should always be considered in children with this presentation. If the diagnosis is not obvious, MRI scan of the spine should be arranged without delay.

Cerebral vasculitis in a case of Sydenham's chorea

A 10-year-old girl with acute-onset hemichorea had multiple areas of abnormal signal seen on magnetic resonance imaging of the brain, associated with middle and anterior cerebral artery vasculitis seen on cerebral angiography. Her serology and clinical course were supportive of the diagnosis of Sydenham's chorea. Other causes of cerebral vasculitis were excluded. Follow-up studies revealed resolution of changes seen on magnetic resonance imaging and partial resolution of angiographic abnormalities. This is the first report of abnormal cerebral angiography in Sydenham's chorea.

Influenza A encephalitis with movement disorder

Influenza A is an uncommon but well-recognized cause of viral encephalitis in childhood, occurring most commonly during community influenza outbreaks. The authors report four cases of influenza A encephalitis that occurred during an Australian epidemic in 1997-1998. Choreoathetosis during the acute phase of infection or basal ganglia involvement on neuroimaging was observed in three of the four patients. These findings in pediatric encephalitis are suggestive of influenza A infection and may guide investigation and early diagnosis.

Coordination of two-joint rectus femoris and hamstrings during the swing phase of human walking and running

It has been hypothesized previously that because a strong correlation was found between the difference in electromyographic activity (EMG) of rectus femoris (RF) and hamstrings (HA; EMG(RF)-EMG(HA)) and the difference in the resultant moments at the knee and hip (Mk-Mh) during exertion of external forces on the ground by the leg, input from skin receptors of the foot may play an important role in the control of the distribution of the resultant moments between the knee and hip by modulating activation of the two-joint RF and HA. In the present study, we examined the coordination of RF and HA during the swing phase of walking and running at different speeds, where activity of foot mechanoreceptors is not modulated by an external force. Four subjects walked at speeds of 1.8 m/s and 2.7 m/s and ran at speeds of 2.7 m/s and 3.6 m/s on a motor-driven treadmill. Surface EMG of RF, semimembranosus (SM), and long head of biceps femoris (BF) and coordinates of the four leg joints were recorded. An inverse dynamics analysis was used to calculate the resultant moments at the ankle, knee, and hip during the swing phase. EMG signals were rectified and low-pass filtered to obtain linear envelopes and then shifted in time to account for electromechanical delay between EMG and joint moments. During walking and running at all studied speeds, mean EMG envelope values of RF were statistically (P<0.05) higher in the first half of the swing (or at hip flexion/knee extension combinations of joint moments) than in the second half (or at hip extension/knee flexion combinations of joint moments). Mean EMG values of BF and SM were higher (P<0.05) in the second half of the swing than in the first half. EMG and joint moment peaks were substantially higher (P<0.05) in the swing phase of walking at 2.7 m/s than during the swing phase of running at the same speed. Correlation coefficients calculated between the differences (EMG(RF)-EMG(HA)) and (Mk-Mh), taken every 1% of the swing phase, were higher than 0.90 for all speeds of walking and running. Since the close relationship between EMG and joint moments was obtained in the absence of an external force applied to the foot, it was suggested that the observed coordination of RF and HA can be regulated without a stance-specific modulation of cutaneous afferent input from the foot. The functional role of the observed coordination of RF and HA was suggested to reduce muscle fatigue.

Hysterectomy: social and psychosexual aspects

Studies of the psychological and sexual outcome of hysterectomy have often arrived at conflicting conclusions and this has resulted in some confusion among health professionals as well as among women themselves. This situation should cause concern, since the incidence of this surgery is high in most countries of the western world. The confusion about outcome arises out of the methodological problems that plagued earlier research. Some of the more recent studies using prospective design, standardized measures and appropriate statistical analysis have not implicated hysterectomy with increased psychological or sexual disorders. However, both before and after hysterectomy in samples studied, the rate of psychological disorder was higher than would have been expected in a normal population, although a clearer picture has emerged from the most recent study. In this paper, risk factors are identified, and the need to include women's own evaluation of the procedure is emphasized.

Antenatal HIV antibody testing in Australia

OBJECTIVE

To evaluate the role of voluntary antenatal testing in HIV surveillance and prevention by examining antenatal HIV antibody testing practice and policy in Australia.

DESIGN

Cross-sectional study using a self-administered questionnaire.

SUBJECTS AND SETTING

Specialist obstetricians and gynaecologists and general practitioners (GPs) affiliated with the Royal Australian College of Obstetricians and Gynaecologists and Australian public hospital antenatal clinics, August-November 1992.

MAIN OUTCOME MEASURES

The percentage of public hospital antenatal clinics and specialist and GP obstetricians in Australia who tested pregnant women for HIV antibody as part of their antenatal care, and the proportion of pregnant women in Australia who had an antenatal HIV antibody test in the 1991-92 financial year.

RESULTS

Questionnaires concerning antenatal HIV antibody testing were completed by 90% (993/1108) of specialists, 87% (2134/2461) of GPs and 93% (215/230) of public hospitals surveyed. Of the 706 specialists and 1503 GPs who reported that they were currently engaged in obstetric care, approximately 60% (430/706) and 935/1503, respectively) offered antenatal HIV testing either to all pregnant women or to selected groups at risk. There were significant differences in testing patterns between States and Territories. For the 95 public hospitals with antenatal clinics, 81% (77) offered the HIV antibody test to all or selected groups of pregnant women; these percentages did not differ significantly between States and Territories. It was estimated that 25% of pregnant women seen by specialists, 29% seen by GPs and 9% seen in public hospital clinics were tested for HIV antibody as part of their antenatal care in 1991-92.

CONCLUSIONS

In Australia approximately one in five pregnant women were tested for HIV antibody as part of their antenatal care in 1991-92. Voluntary HIV testing in pregnancy may provide unrepresentative data for measuring the prevalence of HIV infection in pregnant women.

The polyurethane nasotracheal tube

An uncuffed nasotracheal tube for use in minor maxillofacial surgery has been developed using polyurethane. The suitability of this tube as an alternative to the existing soft red rubber and harder polyvinyl chloride materials has been assessed at four centres during anaesthesia for routine oral surgery. The tube was found to be satisfactory.