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Derivação ventriculosinusal retrógrada em lactentes com hidrocefalia após correção de mielomeningocele / Retrograde ventriculosinus shunt in infants with hydrocephalus after treatment of myelomeningoceleOliveira, Matheus Fernandes de 27 March 2017 (has links)
INTRODUÇÃO. Atualmente, o tratamento da hidrocefalia é realizado principalmente através de uma Derivação ventrículo-peritoneal (DVP). Este estudo tem como objetivo descrever a aplicação da derivação ventrículosinusal retrógrada (DVSR) em pacientes com hidrocefalia após o tratamento cirúrgico de mielomeningocele. MÉTODO. Estudo prospectivo, randomizado e controlado. Foram selecionados consecutivamente 9 pacientes com hidrocefalia após correção cirúrgica de mielomeningocele de janeiro de 2010 a janeiro de 2012. Os pacientes foram submetidos à DVSR ou DVP eletiva. Cinco submetidos à DVSR e 4 à DVP, sendo seguidos por 1 ano com realização trimestral de avaliações clínicas, de imagem e aplicação do Doppler transcraniano. RESULTADOS. Os pacientes tratados com DVSR apresentaram desfechos clínicos semelhantes aos do grupo de DVP. O Doppler mostrou melhora significativa quando comparado o pré-operatório com o pós-operatório. O grupo DVSR apresentou perímetro cefálico significativamente maior que o grupo DVP. O desenvolvimento neuropsicomotor, complicações e desfechos centrados nos pacientes não diferiram entre os grupos. CONCLUSÕES. A técnica cirúrgica da derivação ventrículo-sinusal retrógrada é viável; ela é uma opção alternativa para o tratamento de hidrocefalia / INTRODUCTION. Currently, treatment of hydrocephalus is accomplished primarily through a ventricular-peritoneal shunt (VPS). This study aims to describe the application of retrograde ventricle-sinus shunt (RVSS) in patients with hydrocephalus after surgical treatment of myelomeningocele. METHOD. A prospective, randomized and controlled study. We consecutively enrolled 9 patients with hydrocephalus after surgical repair of myelomeningocele from January 2010 to January 2012. These patients underwent elective RVSS or VPS. Five underwent RVSS and 4 underwent VPS. These patients were followed for one year with quarterly clinical and image evaluations and application of transcranial Doppler. RESULTS. Patients treated with RVSS showed clinical outcomes similar to those of VPS group. Doppler showed significant improvement when comparing preoperative to the postoperative period. RVSS group showed significantly higher cephalic perimeter than VPS group. Neuropsychomotor development, complications and subjective outcomes did not differ between groups. CONCLUSIONS. Surgical technique of retrograde ventricle-sinus shunt is viable; it is an alternative option for the treatment of hydrocephalus
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Padronização de teste molecular para o diagnóstico de meningites bacterianas pós-neurocirurgia / Standardization of molecular test for the diagnosis of bacterial meningitis after neurosurgeryMedeiros, Micheli 08 February 2019 (has links)
Resumo: A meningite é uma inflamação das membranas que revestem o sistema nervoso central. As principais etiologias desta doença são de origem infecciosa, podendo ser bacteriana, fúngica ou viral. A meningite pode ocorrer como uma infecção hospitalar e pode ser associada a trauma ou neurocirurgia. Quando diagnosticada após um procedimento neurocirúrgico, a maior parte dos agentes infecciosos causadores da meningite provem da microbiota endógena da pele e do cabelo. No entanto, existem casos no qual o agente etiológico não é diagnosticado pelas técnicas laboratoriais convencionais, como a cultura microbiológica e bacterioscopia, dificultando a prescrição de terapias adequadas. O objetivo deste estudo foi identificar os agentes causadores de meningite após neurocirurgia (MAN) utilizando técnicas de biologia molecular e comparando-as com a cultura microbiológica. Foram incluídas amostras de líquido cefalorraquidiano (LCR) de pacientes submetidos a neurocirurgia e pacientes submetidos a cirurgias eletivas com uso de raquianestesia durante o período de 2015 a 2016. A reação em cadeia da polimerase (PCR) foi utilizada para avaliação da presença do gene 16S do DNA ribossômico, comum em microrganismos de origem bacteriana, e o sequenciamento do mesmo para a identificação do agente etiológico. As amostras foram classificadas em 5 grupos de acordo com a suspeita clínica e dados quimiocitológicos do LCR: meningite bacteriana (MB) confirmada, MB possível, MB provável, MB improvável e sem MB, neste último grupo estão apenas pacientes submetidos a cirurgias eletivas. Das 51 amostras de LCR incluídas (43 pós-neurocirurgia e 8 pré-anestésica), 21 (41,2%) apresentaram cultura microbiológica negativa com PCR positiva, sendo: 3 (14,2%) MB possível, 4 (19,0%) MB provável, 13 (62,0%) MB improvável, 1 (4,8%) sem MB. Do total de 15 amostras positivas para PCR foi identificada ao menos a família filogenética, houve predomínio de microrganismos Gram negativos, somando 11 contra 4 Gram positivos. A identificação dos agentes etiológicos na MAN, incluindo os não detectados por métodos convencionais de identificação laboratorial, demonstraram que a biologia molecular pode complementar o diagnóstico colaborando de forma positiva, guiando o tratamento para o microrganismo específico ou sua família / Abstract: Meningitis is an inflammation of the membranes covering the central nervous system. The main causes of this disease are bacterial, fungal or viral agents. Meningitis may be associated with trauma or neurosurgery. When meningitis is diagnosed after a neurosurgical procedure, the most common microorganisms belong to skin and hair microbiota. However, there are cases in which the etiological agent is not diagnosed by conventional laboratory techniques, such as microbial culture and bacterioscopy, which makes it difficult to establish adequate therapies. The objective of this study is to identify agents causing meningitis after neurosurgery (MAN) using polymerase chain reaction (PCR) and sequencing of the 16S rRNA gene, compared to the conventional microbiological culture. Cerebrospinal fluid (CSF) was collected from 43 patients who had undergone neurosurgery and 8 patients during spinal anesthesia were included during the period from 2015 to 2016. Polymerase chain reaction (PCR) was used to evaluate the presence of the 16S ribosomal RNA gene, common in microorganisms of bacterial origin, and the sequencing of the same for the identification of the etiological agent. Samples were classified into five groups according to clinical data and CSF analysis: confirmed bacterial meningitis (MB), probable MB, possible MB, unlikely MB, no meningitis, in this last group are only patients submitted to elective surgeries. There were 51 CSF samples included (43 post neurosurgery and 8 pre-spinal anesthesia), 21 samples (41.2%) presented negative microbial culture and were PCR-positive, divided as: 3 (14.2%) probable MB, 4 (19%) possible MB, 13 (62%) unlikely MB and 1 (4.8%) no meningitis. From the total of 15 PCR-positive samples at least the phylogenetic family was identified with a predominance of Gram negative microorganisms, (11). The identification of etiologic agents in MAN, including those not detected by conventional laboratory identification methods, suggests molecular biology can complement the diagnosis and collaborate in guiding the treatment for the specific microorganism or its family
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Contribution au développement de méthodes de diagnostic rapide des maladies innées du métabolisme associées à des troubles neurologiques / Contribution to the development of fast diagnosis methods of inborn errors of metabolism associated with neurological disordersGuibal, Pierre 16 December 2014 (has links)
Les erreurs innées du métabolisme (EIM) constituent un large panel de désordres métaboliques héréditaires. Parmi les EIM, les anomalies de la neurotransmission peuvent affecter, entre autres, la synthèse ou le transport des neurotransmetteurs, notamment les amines biogènes (dopamine et sérotonine) et les folates. La reconnaissance de ces affections est d’une importance capitale pour le diagnostic et le traitement éventuel. L’analyse chimique du liquide céphalo-rachidien (LCR) est incontournable pour le diagnostic de ces pathologies. Or, les méthodes actuelles de dosage ne sont pas simples. Longues et fastidieuses, elles ont été, pendant longtemps, réservées aux laboratoires spécialisés. L’objectif de ce travail était de développer des méthodes simples et rapides de diagnostic des troubles de la neurotransmission et d’établir les valeurs normales fréquentes dans la population française. Le travail réalisé a permis, dans un premier temps, de développer une méthode de dosage directe, en une seule étape, de la tetrahydrobioptérine (BH4), cofacteur des hydroxylases intervenant dans la synthèse des amines biogènes, et des ptérines impliquées dans le cycle de synthèse et de dégradation de ce cofacteur, dans le LCR. Auparavant, le dosage de ces substances nécessitait au moins deux analyses chromatographiques précédées chacune d’une étape propre de préparation de l’échantillon. Par la suite, nous avons développé une méthode de diagnostic rapide, en moins de 10 minutes, par UHPLC (chromatographie liquide à ultra haute performance), couplée à une détection séquentielle par coulométrie et par fluorescence, des troubles dopaminergique et sérotoninergique. Cette méthode permet de doser simultanément, en une seule étape, tous les métabolites de la dopamine, de la sérotonine et de la noradrénaline, ainsi que les ptérines d’intérêt diagnostic, principalement la dihydroneoptérine (NH2) et la dihydrobioptérine (BH2). L’ensemble de ces explorations nécessitait, auparavant, la mise en œuvre d’au moins trois méthodes de dosage par HPLC (chromatographie liquide à haute performance), précédées chacune d’une étape propre de préparation de l’échantillon. Pour compléter l’exploration du métabolisme de la BH4 et du suivi thérapeutique des troubles de la neurotransmission, nous avons également proposé une méthode de dosage rapide, en une seule étape, par UHPLC, de tous les métabolites et de toutes les ptérines, incluant la BH4. Enfin, une méthode rapide de dosage (moins de 2 minutes), par UHPLC, du 5-méthyltetrahydrofolate dans le LCR a été développée, afin de compléter le diagnostic biologique de l’ensemble des troubles neurologiques visés. L’application des outils ainsi développés à plus de 1400 patients nous a permis d’établir des valeurs normales fréquentes dans la population française ainsi que de poser le diagnostic de quelques déficits enzymatiques. / Inborn errors of metabolism (IEM) consist of a wide range of hereditary metabolic disorders. Among IEM, neurotransmission anomaly can affect the synthesis or the transport of neurotransmitters, notably biogenic amines (dopamine and serotonin) and folates. Early diagnosis of such affections is of utmost importance especially as some of them can be treated effectively. Chemical analysis of cerebrospinal fluid (CSF) is essential for the diagnosis of neurotransmitter disorders; however, current quantitative methods are tedious and time consuming. For a long time the chemical diagnosis of neurotransmitter disorders has been available only in specialized laboratories. The purpose of this work was to develop simple and fast diagnosis methods of neurotransmitter disorders as well as to establish the reference values in French population. For this purpose, in a first step, we developed a single step direct method of simultaneous quantification of tetrahydrobiopterin (BH4), which is the main cofactor of the hydroxylases involved in biogenic amines syntheses, and the relevant reduced and oxidized forms of pterins involved in the cycle of synthesis – regeneration of BH4. Formerly, the quantification of those compounds required at least two chromatographic methods with two specific sample preparation procedures. Thereafter we developed a method of fast diagnosis in less than 10 minutes of dopaminergic and serotoninergic disorders using UHPLC (ultra high performance liquid chromatography) hyphenated to a sequential coulometric and fluorimetric detection. With only a simple filtration step as sample preparation procedure, this method enables the simultaneous quantification of all dopamine, serotonin and noradrenaline metabolites as well as dihydroneopterin (NH2) and dihydrobiopterin (BH2), the relevant pterin forms for the complete diagnosis. Formerly, at least three HPLC (high performance liquid chromatography) quantification methods preceeded by three tedious specific sample preparation procedures were required for such a diagnosis. To complete the investigation of BH4 metabolism and the follow up of neurotransmission disorders, we also developed a fast UHPLC method of simultaneous quantification of all the cited metabolites and pterins including BH4. In order to complete the rapid diagnosis of all targeted neurological disorders, we finally developed an UHPLC method of 5-methyltetrahydrofolate quantification in CSF. The application of these analytical tools in more than 1400 CSF samples, collected from patients followed in some Neurology centers located in several French areas covering nearly the entirety of the territory, allowed us to establish the reference values in French population as well as to diagnose several cases of enzymatic deficits.
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Perfil proteômico do líquido cefalorraquidiano após transplantes intratecal de células estromais mesenquimais multipotentes em equinosSvicero, Denis Jeronimo. January 2019 (has links)
Orientador: Rogerio Martins Amorim / Resumo: Estudos com células estromais mesenquimais multipotentes (MSCs) estão em crescente progresso devido às suas propriedades imunomoduladoras, antiinflamatórias, antiapoptóticas e de regeneração tecidual, tornando essa modalidade de terapia celular promissora no tratamento de diversas doenças. Devido à limitada capacidade regenerativa do sistema nervoso central (CNS), causando sequelas funcionais, as MSCs estão sendo investigadas como uma alternativa terapêutica para condições neurológicas inflamatórias, vasculares, traumáticas e degenerativas em diversas espécies animais. A Mieloencefalite protozoária equina (EPM) causada por ambos os protozoários do filo Apicomplexa, Sarcocystis neurona e Neospora hughesi, permanece como uma importante doença neurológica dos equinos nas Américas, embora a maioria dos casos seja devida à infecção por S. neurona. A aplicação da proteômica com sua gama de ferramentas na clínica de equinos pode contribuir significativamente para o entendimento de processos patológicos e facilitar a descoberta de novos alvos terapêuticos ou marcadores diagnósticos. Neste contexto, os objetivos deste estudo foram avaliar o perfil proteômico do líquido cefalorraquidiano (CSF) antes e após múltiplos transplantes intratecal de MSCs em equinos hígidos e o perfil proteômico do CSF de equinos cronicamente afetados pela EPM. Doze cavalos adultos clinicamente saudáveis foram divididos aleatoriamente em três grupos experimentais: grupo DPBS (DPBS ou control; n = 4) onde a sol... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Multipotent mesenchymal stromal cell (MSCs) studies are under increasing progress because of their immunomodulatory, anti-inflammatory, antiapoptotic and tissue regeneration properties, making this modality of cell therapy promising in the treatment of various diseases. Due to the limited regenerative capacity of the central nervous system (CNS), causing functional sequelae, MSCs are being investigated as a therapeutic alternative for inflammatory, vascular, traumatic and degenerative neurological conditions in various animal species. Equine protozoal myeloencephalitis (EPM) caused by both protozoa of the Apicomplexa phylum, Sarcocystis neurona and Neospora hughesi, remains an important neurological disease in horses in the Americas, although most cases are due to S. neurona infection. The application of proteomics with its range of tools in the equine clinic can contribute significantly to the understanding of pathological processes and facilitate the discovery of new therapeutic targets or diagnostic markers. In this context, the objectives of this study were to evaluate the proteomic profiling of cerebrospinal fluid (CSF) before and after multiple intrathecal transplantations of MSCs in healthy horses and the CSF proteomic profiling of horses chronically affected by EPM. Twelve clinically healthy adult horses were randomly divided into three experimental groups: DPBS (DPBS or control; n = 4), in which intrathecal "transplants" with Dulbecco's phosphate buffered saline (DPB... (Complete abstract click electronic access below) / Doutor
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Alterações volumétricas cerebrais em indivíduos com dependência de álcool: um estudo utilizando ressonância magnética morfométrica com parcelamento semiautomático de sub-regiões frontais / Volumetric brain changes in subjects with alcohol dependence: a study using magnetic resonance imaging with semiautomatic parcellation of prefrontal areasCarvalho, Simone Villas Boas de 13 February 2012 (has links)
INTRODUÇÃO: A ressonância magnética (RM) é, atualmente, uma das técnicas mais utilizadas para avaliação quantitativa do volume das estruturas cerebrais. Estudos com pessoas que preenchem critérios diagnósticos para dependência de álcool, utilizando esta técnica, demonstram atrofia cerebral nestes sujeitos, sendo que a região mais sensível e afetada pelos efeitos do álcool parece ser o córtex pré-frontal. A literatura revisada sugere que as subporções do córtex pré-frontal que podem ser mais suscetíveis aos efeitos do uso crônico do álcool são as regiões filogeneticamente mais recentes, como as áreas anterior e dorsolateral, enquanto que a área orbital, mais antiga, pode estar mais preservada. No entanto, nenhum estudo de RM morfométrica até hoje investigou possíveis diferenças no grau de comprometimento morfológico entre áreas de Brodmann (AB) distintas na região pré-frontal, em indivíduos que preenchem diagnóstico para dependência de álcool em comparação com voluntários saudáveis. OBJETIVO: O presente trabalho teve como objetivo realizar um estudo detalhado do impacto do álcool, especialmente sobre o córtex pré-frontal, parcelando-o em áreas de Brodmann, o que pode auxiliar para uma maior compreensão dos danos cerebrais subjacentes aos déficits cognitivos presentes em alcoolistas e ajudar no planejamento de estratégias terapêuticas e de reabilitação cognitiva. METODOLOGIA: A amostra foi composta por dois grupos: o grupo dependentes de álcool (DA), com 98 sujeitos que preenchiam critérios diagnósticos para dependência de álcool, e o grupo controle, com 73 sujeitos saudáveis pareados por idade, sexo e dominância cerebral. RESULTADOS: Foram encontradas diferenças estatisticamente significantes na volumetria cerebral, especialmente, no córtex frontal (substância cinzenta e líquor p<0,05) e parietal (substância cinzenta e líquor p<0,05). Quando dividido em AB, as áreas mais afetadas foram a AB 8 (SC p<0,001; L p<0,006), AB 9 (SC e L p<0,002) e AB 44 (L p=0,036 , SB p<0,005). CONCLUSÃO: Foi possível confirmar a hipótese inicial de que as áreas filogeneticamente jovens são mais sensíveis e vulneráveis à neurotoxidade do álcool, o qual, por sua vez, acelera o processo natural do envelhecimento, implicando perdas de substância cinzenta, principalmente nas áreas cognitivamente mais sofisticadas, como a anterior e a dorsolateral do córtex pré-frontal / INTRODUCTION: Magnetic resonance imaging (MRI) is currently one of the most widely used techniques for quantitative evaluation brain volume. MRI studies with people who meet diagnostic criteria for alcohol dependence show brain atrophy, especially on the prefrontal cortex, which seems to be the most sensitive and affected area by the neurotoxic effects of alcohol. The reviewed literature suggests that the sub-portions of the prefrontal cortex that may be more susceptible to the effects of chronic alcohol use are the phylogenetically newer regions such as the anterior and dorsolateral areas, while the orbital area, older than the others, may be preserved. However, no morphometric MRI study has investigated possible differences in the degree of morphological changes at Brodmann areas (BA) in prefrontal regions of people who meet the diagnosis for alcohol dependence compared with healthy volunteers. OBJECTIVE: The aim of this study was deep investigate alcohols impact, especially in the prefrontal cortex, dividing it in BA, which can contribute to a better understanding of the brain damage, underlying cognitive deficits present in alcoholics, and to help to establish treatment strategies and cognitive rehabilitation. METHODS: The sample comprised two groups: a group of alcohol dependent (AD) with 98 subjects, who met diagnostic criteria for alcohol dependence, and the control group consisted of 73 healthy subjects matched for age, sex and cerebral dominance. RESULTS: Statistically significant differences were found in the brain volume, mainly in the frontal cortex (gray matter and CSF p <0.05) and parietal cortex (gray matter, white matter and CSF p <0.05). When divided in Brodmann areas, the most affected one was: BA 8 (gray matter p <0.001; CSF p<0.006), BA 9 (gray matter and CSF p<0.002) and BA 44 (CSF p = 0.036, white matter p<0.005). CONCLUSION: It was possible to confirm the initial hypothesis that the phylogenetically younger areas are more sensitive and vulnerable to alcohol neurotoxicity, which accelerates the natural process of aging, implying loss of gray matter, especially in areas more cognitively sophisticated such as the anterior and the dorsolateral prefrontal areas
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Etiologia das encefalites e meningites de líquor claro / Etiology of encephalitis and clear cerebrospinal meningitisNunes, Cristina Freitas 29 May 2018 (has links)
Infecções no sistema nervoso central (SNC) causadas por microrganismos desencadeiam sintomas de moderados a severos, dependendo da região atingida, podendo ser designadas como encefalites ou meningites. Os vírus são os agentes mais comuns nestas infecções. Os agentes virais responsáveis por essas enfermidades que apresentam maior incidência na população mundial são certos herpesvírus, flavivírus, influenza A, enterovírus e vírus da caxumba. Entretanto, essa prevalência varia de acordo com a população, estado imunológico do indivíduo, idade e região estudada. Embora existam dados bem estabelecidos da etiologia dessas doenças em alguns países, ainda há uma carência de informação no que diz respeito à etiologia dessas moléstias no Brasil. Assim, informações mais precisas em relação à prevalência desses agentes em nosso meio são necessárias para o desenvolvimento e aplicação de métodos de diagnósticos mais rápidos e eficientes. Neste trabalho, foram analisadas 120 amostras de liquido cefalorraquidiano (LCR), procedentes de dois centros da cidade de São Paulo (Irmandade Santa Casa de Misericórdia e Hospital das Clínicas da Faculdade de medicina da Universidade de São Paulo), as quais foram submetidas à reação em cadeia de polimerase para o herpesvirus simples 1 e 2 (HSV 1 e 2), vírus da varicela zoster (VZV), herpesvirus humano 6 (HHV-6), influenza A (FLUA), enterovírus, vírus da caxumba, poliomavírus vírus BK (BKV) e vírus JC (JCV) para flavivírus. Do total, 44 amostras (36,7%) apresentaram resultado positivo para algum dos vírus analisados no âmbito desta pesquisa, sendo 15 (12,5%) para poliomavírus BKV, 2 (1,7%) para poliomavírus JCV, 21 (17,5%) para HSV1 e 2, 5 (4,2%) foram positivos para BKV e HSV1 e 2 (coinfecção) e 1 (0,8%) para vírus Epstein-Barr (EBV). Uma parte das amostras negativas foi submetida a sequenciamento direto de nova geração (n=8 amostras), resultando em amostras positivas para vírus (vírus simio 40), protozoários e bactérias. Este estudo mostrou que infelizmente, menos de 50% das encefalites e meningites assépticas puderam ser relacionadas a algum agente viral. Houve uma alta prevalência de HSV no material estudado, de acordo com o esperado, mas a presença de poliomavírus no LCR destes indivíduos foi acima da observada na literatura. Esses, bem como os resultados de sequenciamento direto e sua associação a etiologia das encefalites e meningites, devem ser interpretados com cautela. / Central nervous system (CNS) infections caused by microorganism trigger moderate to severe symptoms, depending on the region affected and may be referred as encephalitis or meningitis. Viruses are the most common agents in these infections. The viral agents responsible for these diseases with highest incidence worldwide are certain herpesviruses, flaviviruses, influenza A, enteroviruses, and mumps virus. However, their prevalence vary according to the population, immunological state of the individual, age and region studied. Although there are well-established data on the etiology of these diseases in some countries, there is little information regarding the etiology of these diseases in Brazil. Thus, data regarding the prevalence of these agents in our environment is necessary for the development and application of faster and more efficient diagnostic methods. In this study, 120 cerebrospinal fluid (CSF) samples from two centers of the city of São Paulo (Hospital Santa Casa de Misericordia and Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo) were investigated by PCRs for herpes simplex virus (HSV 1 and 2), varicela zoster virus (VZV), human herpesvirus 6 (HHV6), influenza A, enterovirus, mumps virus, polyomavirus BK virus and JC virus and flaviviruses. From these, 44 samples (36.7%) presented positive result for one of the viruses analyzed, being 15 (12.5%) for polyomavirus BKV, 2 (1.7%) for polyomavirus JCV, 21 (17.5%) for HSV 1 and 2, 5 (4.2%) samples were positive for BKV and HSV1 and 2 (coinfection) and 1 (0.8%) for Epstein-Barr virus (EBV). A part of the negative samples (n=8) were submitted to next generation direct sequencing and revealed the presence of agents as viruses (simian virus 40), protozoa and bacteria. This study showed that unfortunately, less than 50% of the aseptic encephalitis and meningitis could be related to some viral agent. It was found high prevalence of HSV, as expected, but the presence of polyomavirus in the CSF of these individuals was higher than that observed in the literature. These results, as well as direct sequencing results and its relationship to the etiology of encephalitis and meningitis should be interpreted with caution.
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Entwicklung eines PrPc-Detektions-Assays zur Analyse der Fragestellung, welchen Einfluss PRNP-Mutationen oder Genpolymorphismen in CJK-Patienten auf die PrPc-Expression haben / Development of a new PrPc detection system to analyse PrPc expression in CJD patients with different PRNP mutations or gene polymorphismsWohlhage, Marie Charlotte 18 September 2019 (has links)
No description available.
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Electrifying the Molecules of Life : Peptide and Protein Analysis by Capillary Electrophoresis Coupled to Electrospray Ionization Mass SpectrometryWetterhall, Magnus January 2004 (has links)
<p>This thesis describes the current status and novel aspects of the analysis of the molecules of life, i.e. peptides and proteins, using capillary electrophoresis (CE) coupled to mass spectrometry (MS) via (sheathless) electrospray ionization (ESI). Early reports of sheathless CE-ESI-MS were plagued by limited lifetimes of the electrospray emitter. In this thesis, two new approaches, the Black Dust and the Black Jack methods, utilizing polymer-embedded graphite instead of noble metals are presented. These emitters have shown improved long-term stability and proven excellent for sheathless electrospray operation. Failure of an emitter is often caused by electrochemical reactions occurring at the emitter-liquid interface. The electrochemical properties of the graphite coated emitters were therefore evaluated by classical electrochemical methods, such as cyclic voltammetry and chronoamperometry. The graphite coated emitters showed excellent electrochemical stability and properties compared to noble metal and polymer configurations.</p><p>Analyte-wall interactions have long been known to cause problems in the CE analysis of biomolecules. This can be circumvented by internal modification of the capillary walls. Additionally, it is of outermost importance to have a stable and sufficiently high electroosmotic flow (EOF) to sustain the electrospray, when using a sheathless approach. New monomer and polymer coatings are presented for rapid and high-efficient CE-ESI-MS separations of peptides and proteins.</p><p>Furthermore, the use of CE-ESI coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) shows great potential for rapid proteomic probing of human cerebrospinal fluid. The results are comparable with more established techniques, such as liquid chromatography and two-dimensional gel electrophoresis coupled to MS. However, the CE-ESI-FTICRMS analysis has significantly lower sample consumption and faster analysis time compared to the other techniques. The applications and use of CE-ESI-MS is expected to have a bright future with continued growth as current trends of multidimensional hyphenation and microfabricated devices are further developed and explored.</p>
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Cerebrospinal Fluid Shunts in Children : Technical Considerations and Treatment of Certain ComplicationsArnell, Kai January 2007 (has links)
<p>Ventriculo-peritoneal shunting is the most commonly used method for the treatment of paediatric hydrocephalus. Despite improved shunts and surgical techniques there are still complications. This retrospective study focuses on diagnoses and treatment of shunt malfunction and infections. Cost/benefit of using an adjustable shunt was assessed. Two adjustable cerebrospinal fluid shunts and their compatible antisiphon devices were compared in-vitro.</p><p>In 21 of 46 children the standard shunt was changed to an adjustable one due to over-drainage. Adjustment of the shunt was performed in 73% of the children thereby avoiding surgery in several cases. This was a financial advantage.</p><p>Ascites or an abdominal pseudocyst without infection was detected in eight children due to resorption difficulties. A ventriculo-atrial shunt was inserted for a period of time. In three children it could successfully be reverted to a ventriculo-peritoneal.</p><p>In six children papilloedema was the only sign of shunt dysfunction. At revision the intracranial pressure ranged from 25 to 52 cm H<sub>2</sub>O. Fundoscopic examination in children older than 8 years may detect symptomless shunt malfunction.</p><p>During a 13-year period 39 shunt infections were diagnosed. Skin bacteria were found in 80%. Prolonged and anaerobic cultures increased the detection rate by more than one third. The intraventricular infections were treated with intraventricular and systemic antibiotics resulting in quick sterilisation. No relapses were encountered. In five older children with distal catheter infection <i>Propionibacterium acne</i> was found. These were treated with intravenous antibiotics and exchanging of the shunt system.</p><p>Strata NSC<sup>TM</sup> and Codman Hakim<sup>TM</sup> worked according to the manufacturers except at the lowest setting. The resistance was below and in the lower range of the physiological one respectively. The antisiphon device of Strata shunt had to be placed in line with shunt to function properly. </p>
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Electrifying the Molecules of Life : Peptide and Protein Analysis by Capillary Electrophoresis Coupled to Electrospray Ionization Mass SpectrometryWetterhall, Magnus January 2004 (has links)
This thesis describes the current status and novel aspects of the analysis of the molecules of life, i.e. peptides and proteins, using capillary electrophoresis (CE) coupled to mass spectrometry (MS) via (sheathless) electrospray ionization (ESI). Early reports of sheathless CE-ESI-MS were plagued by limited lifetimes of the electrospray emitter. In this thesis, two new approaches, the Black Dust and the Black Jack methods, utilizing polymer-embedded graphite instead of noble metals are presented. These emitters have shown improved long-term stability and proven excellent for sheathless electrospray operation. Failure of an emitter is often caused by electrochemical reactions occurring at the emitter-liquid interface. The electrochemical properties of the graphite coated emitters were therefore evaluated by classical electrochemical methods, such as cyclic voltammetry and chronoamperometry. The graphite coated emitters showed excellent electrochemical stability and properties compared to noble metal and polymer configurations. Analyte-wall interactions have long been known to cause problems in the CE analysis of biomolecules. This can be circumvented by internal modification of the capillary walls. Additionally, it is of outermost importance to have a stable and sufficiently high electroosmotic flow (EOF) to sustain the electrospray, when using a sheathless approach. New monomer and polymer coatings are presented for rapid and high-efficient CE-ESI-MS separations of peptides and proteins. Furthermore, the use of CE-ESI coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) shows great potential for rapid proteomic probing of human cerebrospinal fluid. The results are comparable with more established techniques, such as liquid chromatography and two-dimensional gel electrophoresis coupled to MS. However, the CE-ESI-FTICRMS analysis has significantly lower sample consumption and faster analysis time compared to the other techniques. The applications and use of CE-ESI-MS is expected to have a bright future with continued growth as current trends of multidimensional hyphenation and microfabricated devices are further developed and explored.
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