The superior transverse torus of the catarrhine mandible has been shown to effectively reduce bending at the symphysis during unilateral postcanine biting. While the adult superior transverse torus contains trabecular bone, the juvenile one is almost entirely filled by developing permanent incisors until their eruption. This study uses finite elements analysis (FEA) to investigate whether the presence of developing incisors in the juvenile symphysis increases strains on the superior transverse torus.
View Article and Find Full Text PDFParkinsonism Relat Disord
December 2010
NADH dehydrogenase ubiquinone flavoprotein 2 (NDUFV2), encoding a subunit of mitochondrial complex I, is a candidate gene for several neuronal diseases; schizophrenia, bipolar disorder and Parkinson disease (PD). We screened the entire coding region of NDUFV2 in 33 familial PD patients of North African Arab-Berber ethnicity in which all known genetic forms of PD had been excluded. We detected one novel substitution p.
View Article and Find Full Text PDFClinicogenetic and pathological studies have shown that mutations of the glucocerebrosidase gene (GBA) are a risk factor for Parkinson's disease and Lewy body disorders. In the present study, we have identified GBA mutations in 6.8% (4/59) of cases with a pathological diagnosis of diffuse Lewy body disease.
View Article and Find Full Text PDFIn this paper we report the use of adaptive optics to correct for sample induced aberrations in optical microscopy, crucially comparing individual pixel-by-pixel correction against a single correction for an entire optical section. Sample induced optical aberrations in slices of rat brain tissue were corrected with a deformable membrane mirror. Using axial resolution measurements, we demonstrate that a single aberration correction per optical slice achieves around 80% of the maximum possible improvement compared to individual pixel-by-pixel correction in both confocal and multiphoton microscopy.
View Article and Find Full Text PDFThe development of virtual methods for anatomical reconstruction and functional simulation of skeletal structures offers great promise in evolutionary and ontogenetic investigations of form-function relationships. Key developments reviewed here include geometric morphometric methods for the analysis and visualization of variations in form (size and shape), finite element methods for the prediction of mechanical performance of skeletal structures under load and multibody dynamics methods for the simulation and prediction of musculoskeletal function. These techniques are all used in studies of form and function in biology, but only recently have they been combined in novel ways to facilitate biomechanical modelling that takes account of variations in form, can statistically compare performance, and relate performance to form and its covariates.
View Article and Find Full Text PDFLeishmaniasis is a parasitic disease that is endemic to American, African, Asian and southern European countries. More than 350 million individuals in 88 countries are at risk of infection from this neglected tropical disease. No effective vaccinations are available against leishmaniasis, and control of the disease relies entirely on toxic drug treatments, some of which were developed as early as the 1940s.
View Article and Find Full Text PDFGenealogical investigation of a large Norwegian family (F04) with autosomal dominant parkinsonism has identified 18 affected family members over four generations. Genetic studies have revealed a novel pathogenic LRRK2 mutation c.4309 A>C (p.
View Article and Find Full Text PDFThe global impact of LRRK2 mutations is yet to be realized with a lack of studies in specific ethnic groups, including those of Asian and African descent. Herein, we investigated the frequency of common LRRK2 variants by complete exon sequencing in a series of publicly available African American Parkinson's disease patients. Our study identified three novel synonymous exonic variants and 13 known coding variations; however, there did not appear to be any frequent (>5%) pathogenic mutations.
View Article and Find Full Text PDFWhilst the periodontal ligament (PDL) acts as an attachment tissue between bone and tooth, hypotheses regarding the role of the PDL as a hydrodynamic damping mechanism during intraoral food processing have highlighted its potential importance in finite element (FE) analysis. Although experimental and constitutive models have correlated the mechanical function of the PDL tissue with its anisotropic, heterogeneous, viscoelastic and non-linear elastic nature, in many FE simulations the PDL is either present or absent, and when present is variably modelled. In addition, the small space the PDL occupies and the inability to visualize the PDL tissue using μCT scans poses issues during FE model construction and so protocols for the PDL thickness also vary.
View Article and Find Full Text PDFGenetic variation in the leucine-rich repeat and Ig domain containing 1 gene (LINGO1) was recently associated with an increased risk of developing essential tremor (ET) and Parkinson disease (PD). Herein, we performed a comprehensive study of LINGO1 and its paralog LINGO2 in ET and PD by sequencing both genes in patients (ET, n=95; PD, n=96) and by examining haplotype-tagging single-nucleotide polymorphisms (tSNPs) in a multicenter North American series of patients (ET, n=1,247; PD, n= 633) and controls (n=642). The sequencing study identified six novel coding variants in LINGO1 (p.
View Article and Find Full Text PDFBiochem Soc Trans
April 2010
Actin-rich dendritic spines are the locus of excitatory synaptic transmission and plastic events such as long-term potentiation (LTP). Morphological plasticity of spines accompanies activity-dependent changes in synaptic strength. Several Rho GTPase family members are implicated in regulating neuronal and, in particular, spine structure via actin and the actin-binding protein cofilin.
View Article and Find Full Text PDFFinite element analysis (FEA) is a fundamental method to study stresses and strains in complex structures, with the accuracy of an FEA being reliant on a number of variables, not least the precision and complexity of the model's geometry. Techniques such as computed tomography (CT) allow general geometries to be derived relatively quickly; however, constraints on CT image resolution mean defining subcortical geometries can be problematic. In relation to the overall mechanical response of a complex structure during FEA, the consequence of variable subcortical modelling is not known.
View Article and Find Full Text PDFHealthcare providers should be concerned with improving the quality of life (QOL) of patients with heart failure (HF) because disease-specific QOL is linked to disease progression. The present study investigated the significance of elevated b-type natriuretic peptide (BNP), NYHA classification and depression to HF-related QOL to develop better management strategies. Outpatient subjects with left ventricular systolic dysfunction (n=108; mean age=64.
View Article and Find Full Text PDFMutations in the glucocerebrosidase gene (GBA) have recently been associated with an increased risk of Parkinson disease (PD). GBA mutations have been observed to be particularly prevalent in the Ashkenazi Jewish population. Interestingly, this population also has a high incidence of the Lrrk2 p.
View Article and Find Full Text PDFBackground And Purpose: Whilst an association between the tau gene (MAPT)-containing H1 haplotype and supranuclear gaze palsy (PSP) has long been recognized, the effect of H1 on risk for Parkinson's disease (PD) has remained more contentious.
Methods: Herein, we examined the association of H1 and PD in three Caucasian PD patient-control series from Ireland, Norway, and the US (combined: n = 2619), by genotyping two H1/H2 single nucleotide polymorphisms (SNPs) in MAPT (rs1052553) and in the Saitohin gene (rs62063857) and one H1-specific SNP (rs242557).
Results: We identified a significant association between H1/H2 and risk of PD (rs1052553 OR: 1.
Alpha-synuclein gene (SNCA) mutations cause familial Parkinsonism but the role of SNCA variability in idiopathic Parkinson's disease (PD) remains incompletely defined. We report a study of SNCA genetic variation in 452 idiopathic PD cases and 245 controls. SNCA copy number mutations were not associated with early-onset disease in this population.
View Article and Find Full Text PDFEuropean J Org Chem
November 2009
Background/aims: Root length is strongly related to tooth stability but demonstrates considerable intraspecific variation. Previous studies have demonstrated an intraspecific relationship between root length and facial length in diverse mammalian taxa. These findings are indicative of plasticity in root length but with no clear developmental mechanism.
View Article and Find Full Text PDFMutations in GTP-cyclohydrolase 1 (GCH1) cause autosomal dominant dopa-responsive dystonia (DRD), characterized by childhood-onset foot dystonia that later generalizes. DRD patients frequently present with associated Parkinsonism. Conversely, early-onset Parkinson's disease (EOPD) patients commonly display dystonia.
View Article and Find Full Text PDFParkinsonism Relat Disord
February 2010
Recently, a variant in LINGO1 (rs9652490) was found to associate with increased risk of essential tremor. We set out to replicate this association in an independent case-control series of essential tremor from North America. In addition, given the clinical and pathological overlap between essential tremor and Parkinson disease, we also evaluate the effect of LINGO1 rs9652490 in two case-control series of Parkinson disease.
View Article and Find Full Text PDFA de novo alpha-synuclein A53T (p.Ala53 Th; c.209G > A) mutation has been identified in a Swedish family with autosomal dominant Parkinson's disease (PD).
View Article and Find Full Text PDFA number of in vitro, invasive in vivo, and non-invasive marker based multi-segment foot models (MSFMs) have reported significant motion in the articulations distal to the calcaneus during gait. Few studies, however, have applied a MSFM to the investigation of the effect of foot posture on gait kinematics. Differences in stance phase kinematics between participants with low-mobile (LMF) (n=11) versus "typical" (TYPF) (n=11) foot postures were investigated using a multi-segment medial foot model.
View Article and Find Full Text PDFObjective: Recently, mutations in DCTN1 were found to cause Perry syndrome, a parkinsonian disorder with TDP-43-positive pathology. Previously, mutations in DCTN1 were identified in a family with lower motor neuron disease, in amyotrophic lateral sclerosis (ALS), and in a family with ALS/frontotemporal dementia (FTD), suggesting a central role for DCTN1 in neurodegeneration.
Methods: In this study we sequenced all DCTN1 exons and exon-intron boundaries in 286 samples diagnosed with Parkinson disease (PD), frontotemporal lobar degeneration (FTLD), or ALS.
It has been proposed that the hippocampal theta rhythm (4-7 Hz) can contribute to memory formation by separating encoding (storage) and retrieval of memories into different functional half-cycles (Hasselmo et al. (2002) Neural Comput 14:793-817). We investigate, via computer simulations, the biophysical mechanisms by which storage and recall of spatio-temporal input patterns are achieved by the CA1 microcircuitry.
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