The role of synaptic activity in the development of the mouse central nervous system

Het doel van dit proefschrift was het karakteriseren van de rol die neurotransmitter speelt in de ontwikkeling en het stabiliseren van het zenuwstelsel in de muis. Hiertoe is de Munc18-1 deficiente muis als modelsysteem gebruikt. Allereerst bevestigde een vergelijking van wildtype, heterozygote en homozygote munc18-1 deficiente muizen de rol van munc18-1 in synaptische secretie. Heterozygote dieren zijn levensvatbaar, bevatten 50% munc18-1 eiwit (vergeleken met wildtype dieren) en hebben synapsen die in staat zijn tot neurotransmitter secretie. Homozygote dieren hebben geen munc18-1 eiwit en zijn niet levensvatbaar, maar ontwikkelen zich wel tot aan de geboorte zonder enige vorm van synaptische activiteit. Heterozygote dieren lieten minder spontane fusie en minder gestimuleerde fusie van neurotransmitter blaasjes zien alsmede een verlaagde respons op hypertone oplossingen en versnelde afzwakking van secretie bij hoogfrequente stimulatie. Uit deze bevindingen is geconcludeerd dat het munc18-1 eiwit nodig is voor secretie daar het synaptische blaasjes toegangkelijk maakt voor fusie (hoofdstuk 2). Homozygote dieren waren verlamd en stierven bij geboorte, vermoedelijk door gebrek aan ademhaling. Analyse van embryonale ontwikkeling door de tijd liet zien dat het mutante centrale zenuwstelsel werd gevormd maar vervolgens weer degenereerde. Neuronale connectiviteit was normaal en synapsen werden gevormd en daarom was het gebrek aan synaptische activiteit niet het gevolg van een gebrek aan neuronal uitgroei of het gebrek aan synapsen. Kennelijk was synaptische activiteit niet zozeer noodzakelijk voor het aanleggen van neuronale contacten in het brein, maar eerder voor het in stand houden hiervan (hoofdstuk 3). Op 16 ontwikkeling dag 16 (E16) gaf analyse van synapsen van de neocortex aan dat wildtype en homozygoot mutante dieren een vergelijkbare synapsmorfologie hadden. Tussen E16 en E18 ontwikkelden wildtype synapsen zich verder terwijl mutante synapsen dat niet deden. Op beide tijdspunten hadden wildtype dieren significant meer synapsen dat mutanten. Mutante dieren hadden daarentegen meer multivesiculaire structuren op E18. Dit suggereert dat de mutante synapsen van E16 werden aangepast tot multivesiculaire structuren op E18, en dat de synapsen die op E18 gezien werden nieuw waren. Onze resultaten geven ook aan dat een synaps die een paar synaptische blaasjes heeft zich alleen tot volwassenheid kan ontwikkelen wanneer het functioneel is (hoofdstuk 4). Anatomische analyse en gliële kleuring op E18 lieten zien dat neuronen stierven door apoptose voordat ze zich morfologisch konden differentiëren wanneer er geen synaptische activiteit is. Bovendien differentiëren glia zich eerder. TUNEL, macrofaag kleuring en electronen microscopie bevestigden dat cellen stierven door apoptose. Gliogenese vond voortijdig plaats op plekken waar neuronen gedegenereerd waren en met een patroon lijkend op dat in volwassenen. Deze resultaten geven aan dat, in de afwezigheid van fucntionele synapsen, neuronen niet verder differentiëren maar sterven door apoptose (hoofdstuk 5)

Occurrence of chiral bioactive compounds in the aquatic environment: A review

In recent decades, the presence of micropollutants in the environment has been extensively studied due to their high frequency of occurrence, persistence and possible adverse effects to exposed organisms. Concerning chiral micropollutants in the environment, enantiomers are frequently ignored and enantiomeric composition often neglected. However, enantioselective toxicity is well recognized, highlighting the need to include enantioselectivity in environmental risk assessment. Additionally, the information about enantiomeric fraction (EF) is crucial since it gives insights about: (i) environmental fate (i.e., occurrence, distribution, removal processes and (bio)degradation); (ii) illicit discharges; (iii) consumption pattern (e.g., illicit drugs, pharmaceuticals used as recreational drugs, illicit use of pesticides); and (iv) enantioselective toxicological effects. Thus, the purpose of this paper is to provide a comprehensive review about the enantioselective occurrence of chiral bioactive compounds in aquatic environmental matrices. These include pharmaceuticals, illicit drugs, pesticides, polychlorinated biphenyls (PCBs) and polycyclic musks (PCMs). Most frequently analytical methods used for separation of enantiomers were liquid chromatography and gas chromatography methodologies using both indirect (enantiomerically pure derivatizing reagents) and direct methods (chiral stationary phases). The occurrence of these chiral micropollutants in the environment is reviewed and future challenges are outlined. © 2017 by the authors.This work was developed at Laboratory of Environmental Research area/Environmental and Applied Chemistry research line of the IINFACTS-CESPU. The authors acknowledge the financial support from PARMADRUGS-CESPU-2014 and ChiralDrugs_CESPU_2017. This research was partially supported through national funds provided by FCT/MCTES: Foundation for Science and Technology from the Minister of Science, Technology and Higher Education (PIDDAC) and European Regional Development Fund (ERDF) through the COMPETE: Programa Operacional Factores de Competitividade (POFC) programme, under the Strategic Funding UID/Multi/04423/2013, in the framework of the programme PT2020. ARR and MSM acknowledge Fundação para a Ciência e Tecnologia (FCT) for their grants, SFRH/BD/86939/2012 and SFRH/BPD/101703/2014, respectivel

On the low-temperature performances of THGEM and THGEM/G-APD multipliers in gaseous and two-phase Xe

The performances of THGEM multipliers in two-phase Xe avalanche mode are presented for the first time. Additional results on THGEM operation in gaseous Xe at cryogenic temperatures are provided. Stable operation of a double-THGEM multiplier was demonstrated in two-phase Xe with gains reaching 600. These are compared to existing data, summarized here for two-phase Ar, Kr and Xe avalanche detectors incorporating GEM and THGEM multipliers. The optical readout of THGEMs with Geiger-mode Avalanche Photodiodes (G-APDs) has been investigated in gaseous Xe at cryogenic temperature; avalanche scintillations were recorded in the Near Infrared (NIR) at wavelengths of up to 950 nm. At avalanche charge gain of 350, the double-THGEM/G-APD multiplier yielded 0.07 photoelectrons per initial ionization electron, corresponding to an avalanche scintillation yield of 0.7 NIR photons per avalanche electron over 4pi. The results are compared with those of two-phase Ar avalanche detectors. The advantages, limitations and possible applications are discussed.Comment: 22 pages, 14 figures. Revised Figs. 10,11 and Table 1. To be published in JINS

Ânus anterior: está ou não associado com a constipação crônica na criança?

OBJECTIVE: To study the association between the anterior anus, measured through anal position index, and the presence of longstanding chronic constipation in children.MATERIALS AND METHODS: 195 pediatric patients of the outpatient unit at HCPA were analyzed (ages: from 10 days to 9 years and 10 months; sex: 94 girls and 101boys). Children were considered constipated when presenting a period of more than 3 days without bowel movements and large and hard, or pelletlike, stools. Anterior anus was identified by anal indexes lower than the average minus the standard deviation of the control group of children without constipation; that is < 0.40 for boys, and < 0.24 for girls.RESULTS: Chronic constipation was diagnosed in 58 of the 195 children (29.7%; 28.7% of boys, and 30.9% of girls). There was no significant difference in relation tosex, constipation, or regarding the presence of anterior anus. Fifty-eight children (39.4%) with constipation had anterior anus, whereas 60.6% of children without constipation had anterior anus. There was no significant correlation between anterior position of anus and chronic constipation.CONCLUSION: There was no correlation between chronic constipation and anterior anus among the analyzed children.OBJETIVO: Estudar a associação entre o deslocamento ventral do ânus, através da medida do índice ânus-genital, e a presença de constipação crônica em crianças.MATERIAL E MÉTODOS: Foram estudadas 195 crianças atendidas no ambulatório de gastroenterologia pediátrica do HCPA, com idades entre 10 dias e 9 anos e 10 meses, 94 meninas e 101 meninos. Foram consideradas constipadas as crianças que não evacuavam há mais de 3 dias e que apresentavam fezes disquézicas ou cibalosas. Ânus anteriorizado fois definido como IAG menor do que um desvio-padrãodaquele obtido da média das crianças controles não constipadas (IAG < 0,40 em meninos e < 0,24 em meninas).RESULTADOS: Foram identificadas 58/195 crianças (29,7%) com constipação crônica (28,7% em meninos e 30,9% em meninas). Não houve diferença estatisticamente significativa em relação ao sexo (30,9%) ou quanto à presença do ânus anterior. Entre as 58 crianças constipadas, 39,4% apresentavam ânus anteriorizado, enquanto que dentre as não constipadas 60,6% o apresentavam. Não houve correlação estatisticamente significativa entre a presença de ânus anteriorizado e constipação, ou entre constipação e as medidas do IAG.CONCLUSÃO: Não houve relação entre constipação e a posição anteriorizada do ânus nas crianças estudada

Advances in Cryogenic Avalanche Detectors

Cryogenic Avalanche Detectors (CRADs) are referred to as a new class of noble-gas detectors operated at cryogenic temperatures with electron avalanching performed directly in the detection medium, the latter being in gaseous, liquid or two-phase (liquid-gas) state. Electron avalanching is provided by Micro-Pattern Gas Detector (MPGD) multipliers, in particular GEMs and THGEMs, operated at cryogenic temperatures in dense noble gases. The final goal for this kind of detectors is the development of large-volume detectors of ultimate sensitivity for rare-event experiments and medical applications, such as coherent neutrino-nucleus scattering, direct dark matter search, astrophysical (solar and supernova) neutrino detection experiments and Positron Emission Tomography technique. This review is the first attempt to summarize the results on CRAD performances obtained by different groups. A brief overview of the available CRAD concepts is also given and the most remarkable CRAD physics effects are discussed.Comment: 60 pages, 58 figures. Invited talk at MPGD2011 Conference, Aug 29 - Sep 3, 2011, Kobe, Japan. Journal version + Fig. 1a adde

Vector-borne and other pathogens of potential relevance disseminated by relocated cats

Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue worldwide. Their relocation and homing are currently carried out in many parts of the world with the intention of relieving suffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat’s lifestyle and disease status by veterinary team professionals and those working with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector-borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unowned cats from a global perspective. We also review zoonotic and non-zoonotic infectious agents of cats and give a list of practical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consensus statement consolidated at the 15th Symposium of the Companion Vector-Borne Diseases (CVBD) World Forum in 2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping to prevent and manage vector-borne and other pathogens in relocated cats

Physical and metabolic alterations in "Prata Anã" banana induced by mechanical damage at room temperature

Bananas respond at the physical and physiological level to mechanical damage. Mechanical injuries cause alterations in color and flavor, tissue softening, faster ripening, increased weight loss, increased invasion of microorganisms, and higher enzyme activity in the affected area. The purpose of this study was to verify the physical and metabolic alterations in 'Prata Anã' bananas induced by mechanical stress at room temperature. The experiment was conducted in a completely randomized, split-plot in time design, consisting of one control and four mechanical injury types: cutting, abrasion, impact and compression, sampled over time. The percentage of accumulated and daily fresh weight loss, electrolyte leakage from the injured peel region, total soluble sugar and starch contents and enzyme activity of polyphenoloxidase and peroxidase were measured. The damage caused by cutting and abrasion resulted in the highest percentage of fresh weight loss. All types of mechanical damage increased electrolyte leakage during the evaluation period, in comparison with the control. The impact damage anticipated the ripening, besides affecting the conversion of starch into total soluble sugars in the pulp. By impact and abrasion injuries, the polyphenoloxidase and peroxidase activity in the peel was increased by up to 231% and 90%, and 618% and 956%, respectively, compared to the control.Bananas apresentam respostas físicas e fisiológicas ao dano mecânico. As injúrias mecânicas causam alterações na cor e sabor, amaciamento dos tecidos, amadurecimento mais rápido, aumento na perda de peso, aumento no ataque e invasão de microorganismos e maior atividade enzimática na área afetada. Verificaramse alterações físicas e metabólicas induzidas por estresse mecânico em bananas 'Prata Anã' mantidas em temperatura ambiente. Foi utilizado o esquema em parcelas subdivididas no tempo, constituído de testemunha e quatro fontes de dano mecânico: corte, abrasão, impacto e compressão, com amostragens ao longo do tempo, no delineamento inteiramente casualizado. As porcentagens de perda de massa fresca acumulada e diária, o extravasamento de eletrólitos da região danificada da casca, os teores de açúcares solúveis totais e amido e a atividade das enzimas polifenoloxidase e peroxidase foram avaliadas. Os danos por corte e abrasão promoveram maior porcentagem de perda de massa fresca. Todos os tipos de dano mecânico aumentaram extravasamento de eletrólitos em relação à testemunha ao longo do período de avaliação. O dano por impacto antecipou o amadurecimento, além de prejudicar a conversão de amido em açúcares solúveis totais na polpa. As injúrias por impacto e abrasão aumentaram a atividade das enzimas polifenoloxidase e peroxidase na casca em até 231 e 90%, e 618 e 957%, respectivamente, em relação ao controle