Induced pluripotent stem cell models of frontotemporal dementia

The increasing prevalence of dementia in the ageing population combined with the lack of treatments and the burden on national healthcare systems globally, make dementia a public health priority. Despite the plethora of important research findings published over the past two decades, the mechanisms underlying dementia are still poorly understood and the progress in pharmacological interventions is limited. Recent advances in cellular reprogramming and genome engineering technologies offer an unprecedented new paradigm in disease modeling. Induced pluripotent stem cells (iPSCs) have enabled the study of patient-derived neurons in vitro, a significant progress in the field of dementia research. The first studies using iPSCs to model dementia have recently emerged, holding promise for elucidating disease pathogenic mechanisms and accelerating drug discovery. In this review, we summarise the major findings of iPSC-based studies in Frontotemporal Dementia (FTD) and FTD overlapping with Amyotrophic Lateral Sclerosis (FTD/ALS). We also discuss some of the main challenges in the use of iPSCs to model complex, late-onset neurodegenerative diseases such as dementias

Modelling frontotemporal dementia using patient-derived induced pluripotent stem cells

Frontotemporal dementia (FTD) describes a group of clinically heterogeneous conditions that frequently affect people under the age of 65 (1). There are multiple genetic causes of FTD, including coding or splice-site mutations in MAPT, GRN mutations that lead to haploinsufficiency of progranulin protein, and a hexanucleotide GGGGCC repeat expansion in C9ORF72. Pathologically, FTD is characterised by abnormal protein accumulations in neurons and glia. These aggregates can be composed of the microtubule-associated protein tau (observed in FTD with MAPT mutations), the DNA/RNA-binding protein TDP-43 (seen in FTD with mutations in GRN or C9ORF72 repeat expansions) or dipeptide proteins generated by repeat associated non-ATG translation of the C9ORF72 repeat expansion. There are currently no disease-modifying therapies for FTD and the availability of in vitro models that recapitulate pathologies in a disease-relevant cell type would accelerate the development of novel therapeutics. It is now possible to generate patient-specific stem cells through the reprogramming of somatic cells from a patient with a genotype/phenotype of interest into induced pluripotent stem cells (iPSCs). iPSCs can subsequently be differentiated into a plethora of cell types including neurons, astrocytes and microglia. Using this approach has allowed researchers to generate in vitro models of genetic FTD in human cell types that are largely inaccessible during life. In this review we explore the recent progress in the use of iPSCs to model FTD, and consider the merits, limitations and future prospects of this approach

Impaired Bioenergetics in Mutant Mitochondrial DNA Determines Cell Fate During Seizure-Like Activity

Mutations in genes affecting mitochondrial proteins are increasingly recognised in patients with epilepsy, but the factors determining cell fate during seizure activity in these mutations remain unknown. Fluorescent dye imaging techniques were applied to fibroblast cell lines from patients suffering from common mitochondrial mutations and to age-matched controls. Using live cell imaging techniques in fibroblasts, we show that fibroblasts with mutations in the mitochondrial genome had reduced mitochondrial membrane potential and NADH pools and higher redox indices, indicative of respiratory chain dysfunction. Increasing concentrations of ferutinin, a Ca2+ ionophore, led to oscillatory Ca2+ signals in fibroblasts resembling dynamic Ca2+ changes that occur during seizure-like activity. Co-monitoring of mitochondrial membrane potential (ΔΨm) changes induced by ferutinin showed accelerated membrane depolarisation and cell collapse in fibroblasts with mutations in the mitochondrial genome when compared to controls. Ca2+ flash photolysis using caged Ca2+ confirmed impaired Ca2+ handling in fibroblasts with mitochondrial mutations. Findings indicate that intracellular Ca2+ levels cannot be compensated during periods of hyperexcitability, leading to Ca2+ overload and subsequent cell death in mitochondrial diseases

Artificial Intelligence and Machine Learning in Optical Information Processing: Introduction to the Feature Issue

This special feature issue covers the intersection of topical areas in artificial intelligence (AI)/machine learning (ML) and optics. The papers broadly span the current state-of-the-art advances in areas including image recognition, signal and image processing, machine inspection/vision and automotive as well as areas of traditional optical sensing, interferometry and imaging

O plano individual de trabalho e o tempo de estudo autónomo como promotores da autonomia dos alunos no 1º ciclo do ensino básico

Relatório da Prática de Ensino Supervisionada apresentado no ISPA – Instituto Universitário para obtenção de grau de Mestre em Educação Pré-Escolar e Ensino do 1.ºCiclo do Ensino Básico, criado por Aviso n.º 11548/2020, publicado no Diário da República, 2.ª série, n.º 153, de 7 de Agosto de 2020.O presente relatório surge no âmbito do Mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico, articulado com a Unidade Curricular de Prática de Ensino Supervisionada em 1.º Ciclo do Ensino Básico. O estágio foi desenvolvido numa Instituição Particular de Solidariedade Social (IPSS), mais especificamente numa turma do 2.º ano de escolaridade, com dezassete crianças, sendo seis do sexo feminino e onze do sexo masculino. A professora titular de turma rege-se pelo Modelo do Movimento da Escola Moderna, onde o desenvolvimento da competência da autonomia está presente na rotina diária do grupo, mais especificamente nos momentos de Tempo de Estudo Autónomo (TEA), que são organizados pelo Plano Individual de Trabalho (PIT). Desta forma, a presente investigação teve como principal objetivo compreender de que forma o instrumento de pilotagem PIT, associado ao momento da agenda semanal TEA estão relacionados com a promoção da autonomia dos alunos. A metodologia utilizada foi de natureza qualitativa, sendo que as técnicas e instrumentos de investigação usados no desenvolvimento do presente relatório centraram-se numa observação naturalista, observação sistemática e realização de entrevistas. Os registos efetuados no diário de bordo, bem como no portefólio de estágio são, também, instrumentos que apoiaram a concretização deste estudo. A informação recolhida, bem como a sua análise permitiram compreender melhor as vantagens da utilização do Plano Individual de Trabalho e da realização do Tempo de Estudo Autónomo face à promoção da autonomia das crianças.This report comes within the scope of the Master in Pre-School Education and Teaching of the 1st Cycle of Basic Education, articulated with the Curricular Unit of Supervised Teaching Practice in the 1st Cycle of Basic Education. The internship was carried out in a Private Institution of Social Solidarity (IPSS), more specifically in a 2nd year class, with seventeen children, six female and eleven male. The class teacher is governed by the Modern School Movement Model, where the development of autonomy competence is present in the daily routine of the group, more specifically in the moments of Autonomous Study Time (AST), which are organized by the Individual Work Plan (IWP). In this way, the main objective of this investigation was to understand how the IWP piloting instrument, associated with the moment of the AST weekly schedule, is related to the promotion of student autonomy. The methodology used was of a qualitative nature, and the research techniques and instruments used in the development of this report focused on naturalistic observation, systematic observation and conducting interviews. The records made in the logbook, as well as in the internship portfolio are also instruments that supported the realization of this study. The information collected, as well as its analysis, allowed a better understanding of the advantages of using the Individual Work Plan and carrying out the Autonomous Study Time in terms of promoting children's autonomy

A presença de Pezothrips kellyanus (Bagnall) (Thysanoptera: Thripidae) e outros tripes em parcelas de limoeiro na região de Mafra

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - ULO presente trabalho teve como objetivo estudar, a diversidade e abundância de tripes, associados a três parcelas de limoeiro na região de Mafra, através de duas técnicas de captura, e avaliar o grau de presença de Pezothrips kellyanus (Bagnall), de forma a compreender a sua evolução naquela região. Foi identificado um total de 1797 tisanópteros, dos quais 1793 pertenciam à subordem Terebrantia, e apenas quatro à subordem Tubulifera. Quanto ao tripes da subordem Terebrantia, registaram-se 11 géneros e duas famílias. A família Thripidae foi a mais abundante, representando 92,9% dos indivíduos identificados, sendo que os restantes pertenciam à família Aeolothripidae (7,1%), género Aeolothrips. Entre os géneros presentes da família Thripidae, destacaram-se Thrips (64,4%), Pezothrips (19,5%), e Frankliniella (6,5%). Pela técnica das pancadas, aplicada às flores, foram identificados 586 exemplares, pertecentes a cinco géneros e oito espécies. As três parcelas revelaram diferenças substanciais entre elas, tanto a nível de abundância como de diversidade de espécies. P. kellyanus predominou apenas na Parcela 1 (82,6%), tendo sido Frankliniella occidentalis (Pergande) a espécie mais representada na Parcela 2 (72,1%). Thrips flavus Schrank foi a espécie mais abundante na Parcela 3 (43,5%), seguida de P. kellyanus (32,9%). Foram identificados 1211 indivíduos no conjunto das armadilhas cromotrópicas adesivas. Dos 11 géneros detetados por este método de amostragem, Thrips predominou nas três parcelas (85,9%, 79,1% e 80,4%). Na Parcela 1 o segundo género mais representado foi Pezothrips (5,5%), ao passo que nas Parcelas 2 e 3 o segundo género detetado com maior abundância foi Aeolothrips (8,9% e 12,9%, respetivamente). Foi detetada uma presença significativa de Frankliniella na Parcela 2 (8,5%). Por comparação com a última amostragem realizada, em 2003 (Costa et al., 2006), nesta região e salvaguardando os diferentes métodos de amostragem utilizados, Pezothrips revelou um aumento significativo na sua abundância

Combining Environmental Monitoring and Remote Sensing Technologies to Evaluate Cropping System Nitrogen Dynamics at the Field-Scale

Nitrogen (N) losses from cropping systems in the U.S. Midwest represent a major environmental and economic concern, negatively impacting water and air quality. While considerable research has investigated processes and controls of N losses in this region, significant knowledge gaps still exist, particularly related to the temporal and spatial variability of crop N uptake and environmental losses at the field-scale. The objectives of this study were (i) to describe the unique application of environmental monitoring and remote sensing technologies to quantify and evaluate relationships between artificial subsurface drainage nitrate (NO3-N) losses, soil nitrous oxide (N2O) emissions, soil N concentrations, corn (Zea mays L.) yield, and remote sensing vegetation indices, and (ii) to discuss the benefits and limitations of using recent developments in technology to monitor cropping system N dynamics at field-scale. Preliminary results showed important insights regarding temporal (when N losses primarily occurred) and spatial (measurement footprint) considerations when trying to link N2O and NO3-N leaching losses within a single study to assess relationship between crop productivity and environmental N losses. Remote sensing vegetation indices were significantly correlated with N2O emissions, indicating that new technologies (e.g., unmanned aerial vehicle platform) could represent an integrative tool for linking sustainability outcomes with improved agronomic efficiencies, with lower vegetation index values associated with poor crop performance and higher N2O emissions. However, the potential for unmanned aerial vehicle to evaluate water quality appears much more limited because NO3-N losses happened prior to early-season crop growth and image collection. Building on this work, we encourage future research to test the usefulness of remote sensing technologies for monitoring environmental quality, with the goal of providing timely and accurate information to enhance the efficiency and sustainability of food production

Autosomal-recessive cerebellar ataxia caused by a novel ADCK3 mutation that elongates the protein: clinical, genetic and biochemical characterisation

Background The autosomal-recessive cerebellar ataxias (ARCA) are a clinically and genetically heterogeneous group of neurodegenerative disorders. The large number of ARCA genes leads to delay and difficulties obtaining an exact diagnosis in many patients and families. Ubiquinone (CoQ10) deficiency is one of the potentially treatable causes of ARCAs as some patients respond to CoQ10 supplementation. The AarF domain containing kinase 3 gene (ADCK3) is one of several genes associated with CoQ10 deficiency. ADCK3 encodes a mitochondrial protein which functions as an electron-transfer membrane protein complex in the mitochondrial respiratory chain (MRC). Methods We report two siblings from a consanguineous Pakistani family who presented with cerebellar ataxia and severe myoclonus from adolescence. Whole exome sequencing and biochemical assessment of fibroblasts were performed in the index patient. Results A novel homozygous frameshift mutation in ADCK3 (p.Ser616Leufs*114), was identified in both siblings. This frameshift mutation results in the loss of the stop codon, extending the coding protein by 81 amino acids. Significant CoQ10 deficiency and reduced MRC enzyme activities in the index patient's fibroblasts suggested that the mutant protein may reduce the efficiency of mitochondrial electron transfer. CoQ10 supplementation was initiated following these genetic and biochemical analyses. She gained substantial improvement in myoclonic movements, ataxic gait and dysarthric speech after treatment. Conclusion This study highlights the importance of diagnosing ADCK3 mutations and the potential benefit of treatment for patients. The identification of this new mutation broadens the phenotypic spectrum associated with ADCK3 mutations and provides further understanding of their pathogenic mechanism

Hurdles at work: perceptions of hospital food handlers

<p>Abstract</p> <p>Background</p> <p>Food handlers have a very important role in preventing food contamination during its preparation and distribution. This responsibility is even greater in hospitals, since a large number of patients have low immunity and consequently food contamination by pathogenic bacteria could be particularly harmful. Therefore, a good working environment and periodic training should be provided to food handlers by upper management.</p> <p>Methods</p> <p>This study is qualitative research by means of focus group and thematic content analysis methodologies to examine, in detail, the statements by food handlers working in the milk and specific-diet kitchens in a hospital to understand the problems they face in the workplace.</p> <p>Results</p> <p>We found that food handlers are aware of the role they play in restoring patients' health; they consider it important to offer a good-quality diet. However, according to their perceptions, a number of difficulties prevent them from reaching this aim. These include: upper management not prioritizing human and material resources to the dietetic services when making resource allocation decisions; a perception that upper management considers their work to be of lesser importance; delayed overtime payments; lack of periodic training; managers lacking administrative skills; insufficient dietitian staff assistants, leading to overwork, at the same time as there is an excess of dietitians; unhealthy environmental working conditions – high temperature, high humidity, loud and constant noise level, poor ventilation; lack of food, and kitchen utensils and equipment; and relationship conflicts with chief dieticians and co-workers.</p> <p>Conclusion</p> <p>From these findings, improvement in staff motivation could be achieved by considering non-financial incentives, such as improvement in working conditions and showing appreciation and respect through supervision, training and performance appraisal. Management action, such as investments in intermediary management so that managers have the capacity to provide supportive supervision, as well as better use of performance appraisal and access to training, may help overcome the identified problems.</p

Disruption of ER-mitochondria tethering and signalling in C9orf72-associated amyotrophic lateral sclerosis and frontotemporal dementia

Hexanucleotide repeat expansions in C9orf72 are the most common cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The mechanisms by which the expansions cause disease are not properly understood but a favoured route involves its translation into dipeptide repeat (DPR) polypeptides, some of which are neurotoxic. However, the precise targets for mutant C9orf72 and DPR toxicity are not fully clear, and damage to several neuronal functions has been described. Many of these functions are regulated by signalling between the endoplasmic reticulum (ER) and mitochondria. ER-mitochondria signalling requires close physical contacts between the two organelles that are mediated by the VAPB-PTPIP51 ‘tethering’ proteins. Here, we show that ER-mitochondria signalling and the VAPB-PTPIP51 tethers are disrupted in neurons derived from induced pluripotent stem (iPS) cells from patients carrying ALS/FTD pathogenic C9orf72 expansions and in affected neurons in mutant C9orf72 transgenic mice. In these mice, disruption of the VAPB-PTPIP51 tethers occurs prior to disease onset suggesting that it contributes to the pathogenic process. We also show that neurotoxic DPRs disrupt the VAPB-PTPIP51 interaction and ER-mitochondria contacts and that this may involve activation of glycogen synthase kinases-3β (GSK3β), a known negative regulator of VAPB-PTPIP51 binding. Finally, we show that these DPRs disrupt delivery of Ca2+ from ER stores to mitochondria, which is a primary function of the VAPB-PTPIP51 tethers. This delivery regulates a number of key neuronal functions that are damaged in ALS/FTD including bioenergetics, autophagy and synaptic function. Our findings reveal a new molecular target for mutant C9orf72-mediated toxicity