Publications by authors named "Daniel Valenzuela"

Objective: This study aimed to estimate amyotrophic lateral sclerosis (ALS) incidence and survival rates in the Metropolitan region of Chile.

Methods: We conducted a cohort study of ALS cases in the Metropolitan Region from 2016 to 2019. A total of 219 ALS patients were recruited from Corporación ELA-Chile registry, in collaboration with neurologists from Sociedad de Neurología, Psiquiatría y Neurocirugía de Chile.

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There is evolving evidence of non-uniform distribution of ALS worldwide, with apparently lower incident and prevalent rates outside populations of European origin. However, the phenotype, survival and environmental risk in populations of mixed ancestral origin have not been well established. Large scale population based studies of incidence, prevalence, phenotype and risk factors in admixed populations are necessary to determine the true demography of ALS, and to test the hypothesis of differential risk and phenotype in populations of mixed ancestry.

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Purpose: To describe a case of acute macular neuroretinopathy (AMN) in a patient immediately following administration of the Pfizer-BioNTech COVID-19 vaccine.

Observations: The patient complained of paracentral scotoma supported by paracentral visual field loss on multiple Humphrey visual fields that corresponded to outer retinal pathology on optical coherence tomography. The patient's symptoms resolved without treatment.

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Computational pan-genomics utilizes information from multiple individual genomes in large-scale comparative analysis. Genetic variation between case-controls, ethnic groups, or species can be discovered thoroughly using pan-genomes of such subpopulations. Whole-genome sequencing (WGS) data volumes are growing rapidly, making genomic data compression and indexing methods very important.

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Motivation: Variant calling workflows that utilize a single reference sequence are the de facto standard elementary genomic analysis routine for resequencing projects. Various ways to enhance the reference with pangenomic information have been proposed, but scalability combined with seamless integration to existing workflows remains a challenge.

Results: We present PanVC with founder sequences, a scalable and accurate variant calling workflow based on a multiple alignment of reference sequences.

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Objective: To compare social cognition performance between patients with amyotrophic lateral sclerosis (ALS) and those patients with behavioural variant frontotemporal dementia (bvFTD).

Methods: We included 21 participants with ALS, 20 with bvFTD and 21 healthy controls who underwent a comprehensive cognitive battery, including the short version of the Social Cognition and Emotional Assessment (Mini-SEA), which comprises the test and Facial Emotion Recognition Test (FERT); Mini-Mental State Examination; Frontal Assessment Battery; lexical fluency (F-A-S), category fluency (animals/minute), digit span (direct and backwards) tests and the Hayling test. A post hoc analysis was conducted with the patients with ALS divided into two subgroups: patients without cognitive impairment (ALScn; n=13) and patients with cognitive impairment (ALSci; n=8).

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Tuberculosis (TB) is a chronic infectious disease caused by . In the oral cavity, clinical manifestations are considered atypical lesions. The aim of this study was to report an unusual granular ulcer secondary oral TB that does not heal, chronic, had irregular appearance with deep depression of 2 cm in diameter, and was located in buccal mucosa of the premolar area-the left mandibular arch, of a 42-year-old woman.

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Objective: The aim of this study is to assess the surface roughness of the implant-retained mandibular bar overdenture (BOD) and the implant-retained mandibular ball joint overdenture (BJOD) in jaw and its relation with the adhesion of molds and yeasts and mesophyll aerobe, in time 30 and 180 days in mouth.

Materials And Methods: Five-systems titanium bar CARES and synOcta Straumann Dental Implant System, Holding AG Inc., Basel, Switzerland (BOD), and five-systems joint ball Klockner Implant System; Soadco Inc.

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Covering alignment problems arise from recent developments in genomics; so called pan-genome graphs are replacing reference genomes, and advances in haplotyping enable full content of diploid genomes to be used as basis of sequence analysis. In this paper, we show that the computational complexity will change for natural extensions of alignments to pan-genome representations and to diploid genomes. More broadly, our approach can also be seen as a minimal extension of sequence alignment to labelled directed acyclic graphs (labeled DAGs).

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Background: Typical human genome differs from the reference genome at 4-5 million sites. This diversity is increasingly catalogued in repositories such as ExAC/gnomAD, consisting of >15,000 whole-genomes and >126,000 exome sequences from different individuals. Despite this enormous diversity, resequencing data workflows are still based on a single human reference genome.

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What pathways specify retinal ganglion cell (RGC) fate in the developing retina? Here we report on mechanisms by which a molecular pathway involving Sox4/Sox11 is required for RGC differentiation and for optic nerve formation in mice , and is sufficient to differentiate human induced pluripotent stem cells into electrophysiologically active RGCs. These data place Sox4 downstream of RE1 silencing transcription factor in regulating RGC fate, and further describe a newly identified, Sox4-regulated site for post-translational modification with small ubiquitin-related modifier (SUMOylation) in Sox11, which suppresses Sox11's nuclear localization and its ability to promote RGC differentiation, providing a mechanism for the SoxC familial compensation observed here and elsewhere in the nervous system. These data define novel regulatory mechanisms for this SoxC molecular network, and suggest pro-RGC molecular approaches for cell replacement-based therapies for glaucoma and other optic neuropathies.

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Our objective was to describe amyotrophic lateral sclerosis (ALS) mortality rates in the Chilean population over a 17-year period. Chilean death records (1994-2010) were reviewed for the ICD-10 diagnosis G.12.

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Background: Traditionally biological similarity search has been studied under the abstraction of a single string to represent each genome. The more realistic representation of diploid genomes, with two strings defining the genome, has so far been largely omitted in this context. With the development of sequencing techniques and better phasing routines through haplotype assembly algorithms, we are not far from the situation when individual diploid genomes could be represented in their full complexity with a pair-wise alignment defining the genome.

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Recent genetic and neuropathologic advances support the concept that frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are overlapping multisystem disorders. While 10-15% of ALS patients fulfil criteria for FTD, features of motor neuron disease appear in approximately 15% of FTD patients, during the evolution of the disease. This overlap has been reinforced by the discovery of Transactive Response DNA Binding Protein 43 kDa (TDP43) inclusions as the main neuropathologic finding in the majority of ALS cases and almost a half of FTD cases.

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The central nervous system consists of complex groups of individual cells that receive electrical, chemical and physical signals from their local environment. Standard in vitro cell culture methods rely on two-dimensional (2-D) substrates that poorly simulate in vivo neural architecture. Neural cells grown in three-dimensional (3-D) culture systems may provide an opportunity to study more accurate representations of the in vivo environment than 2-D cultures.

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There is considerable interest in transplanting stem cells or progenitors into the injured nervous system and enhancing their differentiation into mature, integrated, functional neurons. Little is known, however, about what intrinsic or extrinsic signals control the integration of differentiated neurons, either during development or in the adult. Here we ask whether purified, postmitotic, differentiated retinal ganglion cells (RGCs) directly isolated from rat retina or derived from in vitro-differentiated retinal progenitor cells can survive, migrate, extend neurites, and form morphologic synapses in a host retina, in vivo and ex vivo.

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Retinal degenerative diseases, such as glaucoma and macular degeneration, affect millions of people worldwide and ultimately lead to retinal cell death and blindness. Cell transplantation therapies for photoreceptors demonstrate integration and restoration of function, but transplantation into the ganglion cell layer is more complex, requiring guidance of axons from transplanted cells to the optic nerve head in order to reach targets in the brain. Here we create a biodegradable electrospun (ES) scaffold designed to direct the growth of retinal ganglion cell (RGC) axons radially, mimicking axon orientation in the retina.

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Background: Plasmapheresis can be useful in myasthenia gravis, Guillain Barré syndrome and chronic demyelinating inflammatory polyradiculoneuritis.

Aim: To report our experience with plasmapheresis in patients with neurological diseases.

Material And Methods: Retrospective review of plasmapheresis procedures done between 1995 and 2001, in a public hospital.

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Hereditary hypercoagulability has been identified as risk factor in approximately 30% of cerebral venous thrombosis cases. We report three females with this association. A 38 years old female with a history of deep venous thrombosis of the lower limb, presented with headache, vomiting and a generalized seizure.

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