103 research outputs found

    A novel presenilin 1 mutation (L174M) in a large Cuban family with early onset Alzheimer disease.

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    We studied a Cuban family with presenile dementia (autosomal dominant) consisting of 281 members within six generations, the proband descended from a Spanish founder. Mean age at onset was 59 years of age. Memory impairment was the main symptom in all patients, additionally, ischemic episodes were described in 4 (n = 18) patients. Neuropathological examination of brain material (1 patient) revealed neuronal loss, amyloid plaques, and neurofibrillary tangles. Thirty DNA samples were genotyped (regions on chromosome 1, 3, 10, 12, 14, 17, 19, 20, and 21). A maximum Lod score of 3.79 at theta = 0 was obtained for marker D14S43, located in a 9-cM interval in which all patients shared the same haplotype. Sequencing of the PSEN1 gene revealed a heterozygous base substitution, C520A (exon 6), which is predicted to cause an amino acid change from leucine to methionine in the TMIII of the presenilin 1 protein. The mutation was found to co-segregate with the disease phenotype and the associated disease haplotype. The C --> A change was not observed in 80 control chromosomes from the Cuban population. Leucine at position 174 is highly conserved among species and is identical in prese

    Room Temperature Optically and Magnetically Active Edges in Phosphorene Nanoribbons

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    Nanoribbons - nanometer wide strips of a two-dimensional material - are a unique system in condensed matter physics. They combine the exotic electronic structures of low-dimensional materials with an enhanced number of exposed edges, where phenomena including ultralong spin coherence times, quantum confinement and topologically protected states can emerge. An exciting prospect for this new material concept is the potential for both a tunable semiconducting electronic structure and magnetism along the nanoribbon edge. This combination of magnetism and semiconducting properties is the first step in unlocking spin-based electronics such as non-volatile transistors, a route to low-energy computing, and has thus far typically only been observed in doped semiconductor systems and/or at low temperatures. Here, we report the magnetic and semiconducting properties of phosphorene nanoribbons (PNRs). Static (SQUID) and dynamic (EPR) magnetization probes demonstrate that at room temperature, films of PNRs exhibit macroscopic magnetic properties, arising from their edge, with internal fields of ~ 250 to 800 mT. In solution, a giant magnetic anisotropy enables the alignment of PNRs at modest sub-1T fields. By leveraging this alignment effect, we discover that upon photoexcitation, energy is rapidly funneled to a dark-exciton state that is localized to the magnetic edge and coupled to a symmetry-forbidden edge phonon mode. Our results establish PNRs as a unique candidate system for studying the interplay of magnetism and semiconducting ground states at room temperature and provide a stepping-stone towards using low-dimensional nanomaterials in quantum electronics.Comment: 18 pages, 4 figure

    Congenital cardiovascular defects in children with intestinal malrotation

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    Intestinal malrotation (IM) and cardiovascular defects (CCVD) are both common congenital defects. We investigated the prevalence and types of CCVD in a 25-year IM population, and its association with post-IM-operative morbidity and mortality. Data on the type of CCVD, other congenital defects, syndromes, associations, post-IM-operative morbidity and mortality were retrospectively reviewed from the records of IM patients born between 1980 and 2005. Data were analyzed on (significant) differences between CCVD subgroups, and risk factors for both morbidity and mortality were calculated. Seventy-seven of 284 IM patients (27.1%) were diagnosed with a major or minor CCVD (37 and 40 patients, respectively). Syndromes and associations were more frequently diagnosed in patients with major than with a minor CCVD (67.6 vs. 40%, respectively). Post-IM-operative complications, although frequently observed (61%), did not differ between patients with major and minor CCVD. Physical CCVD signs before IM surgery increased post-IM-operative morbidity significantly (OR 4.0, 95% CI 1.4–11.0). Fifteen patients died (19.5%), seven due to cardiovascular cause. Mortality risk was increased by intestinal ischemia and post-IM-operative complications and by major CCVD after correction for age at weight at the time of IM operation. Congenital cardiovascular defects in children with intestinal malrotation are common, with high morbidity and mortality rates after IM operation. Elective IM surgery in young patients with CCVD should be performed in a centre with adequate paediatric cardiac care. Benefits of laparoscopic intervention need further study

    LEARN 2 MOVE 2-3: a randomized controlled trial on the efficacy of child-focused intervention and context-focused intervention in preschool children with cerebral palsy

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    <p>Abstract</p> <p>Background</p> <p>Little is known about the efficacy and the working mechanisms of physical and occupational therapy interventions for children with cerebral palsy (CP). In recent years a shift from a child-focused intervention approach to a more context-focused intervention approach can be recognized. Until now the evidence on the efficacy and the working mechanisms of these interventions for children with CP is inconclusive. This study aims to evaluate the efficacy and working mechanisms of two intervention approaches compared to regular care intervention in improving mobility and self-care skills of children (2-3 years) with CP and their families: a child-focused intervention approach and a context-focused intervention approach.</p> <p>Methods/Design</p> <p>A multi-centre, randomized controlled trial research design will be used. Ninety-four children with CP (Gross Motor Function Classification System (GMFCS) level I-IV; age 2 to 3 years), their parents, and service providers (physical and occupational therapists) will be included. During a period of six months children will receive child-focused, context-focused or regular care intervention. Therapists will be randomly assigned to deliver either a child-focused intervention approach, a context-focused intervention approach or regular care intervention. Children follow their therapist into the allocated intervention arm. After the six months study-intervention period, all participants return to regular care intervention. Outcomes will be evaluated at baseline, after six months and at a three months follow-up period. Primary outcome is the capability of functional skills in self-care and mobility, using the Functional Skills Scale of the Pediatric Evaluation of Disability Inventory (PEDI). Other outcomes will be quality of life and the domains of the International Classification of Functioning, Disability and Health - for Children and Youth (ICF-CY), including body function and structure, activities (gross motor capacity and performance of daily activities), social participation, environmental variables (family functioning, parental empowerment).</p> <p>Discussion</p> <p>This paper presents the background information, design, description of interventions and protocol for this study on the efficacy and working mechanisms of child-focused intervention approach and context-focused intervention approach compared to regular care intervention in mobility and self-care skills of children (2-3 years) with CP.</p> <p>Trial registration</p> <p>This study is registered in the Dutch Trial Register as NTR1900</p

    NPHP4 Variants Are Associated With Pleiotropic Heart Malformations

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    Rationale: Congenital heart malformations are a major cause of morbidity and mortality, especially in young children. Failure to establish normal left-right (L-R) asymmetry often results in cardiovascular malformations and other laterality defects of visceral organs. Objective: To identify genetic mutations causing cardiac laterality defects. Methods and Results: We performed a genome-wide linkage analysis in patients with cardiac laterality defects from a consanguineous family. The patients had combinations of defects that included dextrocardia, transposition of great arteries, double-outlet right ventricle, atrioventricular septal defects, and caval vein abnormalities. Sequencing of positional candidate genes identified mutations in NPHP4. We performed mutation analysis of NPHP4 in 146 unrelated patients with similar cardiac laterality defects. Forty-one percent of these patients also had laterality defects of the abdominal organs. We identified 8 additional missense variants that were absent or very rare in control subjects. To study the role of nphp4 in establishing L-R asymmetry, we used antisense morpholinos to knockdown nphp4 expression in zebrafish. Depletion of nphp4 disrupted L-R patterning as well as cardiac and gut laterality. Cardiac laterality defects were partially rescued by human NPHP4 mRNA, whereas mutant NPHP4 containing genetic variants found in patients failed to rescue. We show that nphp4 is involved in the formation of motile cilia in Kupffer's vesicle, which generate asymmetrical fluid flow necessary for normal L-R asymmetry. Conclusions: NPHP4 mutations are associated with cardiac laterality defects and heterotaxy. In zebrafish, nphp4 is essential for the development and function of Kupffer's vesicle cilia and is required for global L-R patterning

    LEARN 2 MOVE 0-2 years:effects of a new intervention program in infants at very high risk for cerebral palsy; a randomized controlled trial

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    Background: It is widely accepted that infants at risk for cerebral palsy need paediatric physiotherapy. However, there is little evidence for the efficacy of physiotherapeutic intervention. Recently, a new intervention program, COPCA (Coping with and Caring for infants with special needs - a family centered program), was developed. COPCA has educational and motor goals. A previous study indicated that the COPCA-approach is associated with better developmental outcomes for infants at high risk for developmental disorders. LEARN 2 MOVE 0-2 years evaluates the efficacy and the working mechanisms of the COPCA program in infants at very high risk for cerebral palsy in comparison to the efficacy of traditional infant physiotherapy in a randomized controlled trial. The objective is to evaluate the effects of both intervention programs on motor, cognitive and daily functioning of the child and the family and to get insight in the working elements of early intervention methods.Methods/design: Infants are included at the corrected age of 1 to 9 months and randomized into a group receiving COPCA and a group receiving traditional infant physiotherapy. Both interventions are given once a week during one year. Measurements are performed at baseline, during and after the intervention period and at the corrected age of 21 months. Primary outcome of the study is the Infant Motor Profile, a qualitative evaluation instrument of motor behaviour in infancy. Secondary measurements focus on activities and participation, body functions and structures, family functioning, quality of life and working mechanisms. To cope with the heterogeneity in physiotherapy, physiotherapeutic sessions are video-recorded three times (baseline, after 6 months and at the end of the intervention period). Physiotherapeutic actions will be quantified and related to outcome.Discussion: LEARN 2 MOVE 0-2 years evaluates and explores the effects of COPCA and TIP. Whatever the outcome of the project, it will improve our understanding of early intervention in children with cerebral palsy. Such knowledge is a prerequisite for tailor-made guidance of children with CP and their families.Trial registration: The trial is registered under NTR1428.</p

    Physical training in boys with Duchenne Muscular Dystrophy: the protocol of the No Use is Disuse study

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    Contains fulltext : 89740.pdf (publisher's version ) (Open Access)BACKGROUND: "Use it or lose it" is a well known saying which is applicable to boys with Duchenne Muscular Dystrophy (DMD). Besides the direct effects of the muscular dystrophy, the increasing effort to perform activities, the fear of falling and the use of personal aids indirectly impair leg and arm functions as a result of disuse. Physical training could oppose this secondary physical deterioration. The No Use is Disuse (NUD) study is the first study in human subjects with DMD that will examine whether a low-intensity physical training is beneficial in terms of preservation of muscle endurance and functional abilities. The study consists of two training intervention studies: study 1 "Dynamic leg and arm training for ambulant and recently wheelchair-dependent boys with DMD and, study 2 "Functional training with arm support for boys with DMD who have been confined to a wheelchair for several years". This paper describes the hypotheses and methods of the NUD study. METHODS: Study 1 is an explorative randomized controlled trial with multiple baseline measurements. Thirty boys with a DNA-established diagnosis of DMD will be included. The intervention consists of a six-months physical training during which boys train their legs and arms with active and/or assisted cycling training equipment. The primary study outcomes are muscle endurance and functional abilities, assessed with a Six-Minute Bicycle Test and the Motor Function Measure. Study 2 has a within-group repeated measurements design and will include ten boys with DMD who have already been confined to a wheelchair for several years. The six-months physical training program consists of 1) a computer-assisted training and 2) a functional training with an arm support. The primary study outcome is functional abilities of the upper extremity, assessed with the Action Research Arm Test. DISCUSSION: The NUD study will fill part of the gap in the current knowledge about the possible effects of training in boys with DMD and will increase insight into what type of exercise should be recommended to boys with DMD. The study will finish at the end of 2010 and results are expected in 2011. TRIAL REGISTRATION: The Netherlands National Trial Register1631

    Kinderen en Posttraumatisch Dystrofie.

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    Preduodenal portal vein and malrotation: what causes the obstruction?

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    Contains fulltext : 71421.pdf (publisher's version ) (Closed access)AIM AND METHOD: Preduodenal portal vein is a rare congenital abnormality, and occurs either as a single malformation, in association with other malformations or as part of "polysplenia" syndrome. Preduodenal portal vein has seldom been reported as a cause of intestinal obstruction, however corrective surgery is nearly always performed. We conducted a 25-year retrospective study in a single centre to investigate the cause of obstruction in patients with preduodenal portal vein. Furthermore, we reviewed the literature on preduodenal portal vein. RESULTS: Over a period of 25 years, preduodenal portal vein was diagnosed in five patients. The diagnosis was made during surgery performed because of symptoms of high intestinal obstruction. All five patients had intestinal malrotation as well and, in all patients, another cause for high intestinal obstruction than preduodenal portal vein was found. CONCLUSION: Preduodenal portal vein is mainly asymptomatic. It is often associated with other intestinal congenital abnormalities more likely to cause high intestinal obstruction. Therefore, the (paediatric) surgeon should always be alert for another associated cause of intestinal obstruction. Because of the potential for technical problems from preduodenal portal vein during surgery, it nevertheless should be on the surgeon's mind during surgery when the patient has high intestinal obstruction
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