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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

The fate of neonate calves : a discussion of the bovine infant health implications of dairying in antiquity, using archaeozoological studies of six Orcadian contexts

Davis, Geoffrey W. January 2010 (has links)
A methodology for ageing foetal and neonatal cattle is developed, involving radiographic examination of infant mandibles for early developmental stages in molariform teeth; tooth-wear methodologies are imprecise at this stage before wear commences. Known-age modern bovine foetal and neonate material are collected as a control assemblage for method development (n=73); six Neolithic to Norse era assemblages from Orkney are examined using the modified technique together with standard tooth-wear analysis and other methodologies. Foetal and died-at-birth material is diagnosed at most sites using the new technique, together with a range of other peri-natal age-groups. Ageing at this early stage is highly relevant in the diagnosis of milking as a palaeoeconomy: the accepted view is that unwanted (male) calves were slaughtered to maximise milk for human consumption, hence a surfeit of neonate calf remains, as at the study sites. The diagnosis of foetal and died-at-birth material challenges this view, suggesting that attritional causes may have contributed to deaths at this stage. Although milking was probably carried out at most of the study sites, this may have been combined with slaughter of cattle for meat in a pragmatic exploitation strategy. Literary research shows possible attritional causes of abortion and early death in calves, in particular dietary insufficiency in pregnant cows, microbial infections, and also inadequate colostrum uptake. Additionally, research is used to consider the challenges to health that early milking might have posed, to the calf as mentioned, but also to the cow, where three main health issues are highlighted: infertility, mastitis and lameness.
82

Optimisation des profils lipidiques du cerveau de rats déficients en oméga-3 au sevrage par l'utilisation de matière grasse laitière : conséquences au niveau du lipidome / Optimization of lipid profiles in the brain of rats deficient in omega-3 at weaning by the use of dairy-fat : consequence at the lipidomics level

Du, Qin 17 December 2010 (has links)
L‟acide docosahexaénoïque (DHA) s‟accumule principalement dans les membranes cérébrales humaines durant la période périnatale et les 2 premières années de la vie. Optimiser l‟incorporation des acides gras polyinsaturés à longue chaîne (AGPI-LC) n-3 dans le système nerveux central, notamment le DHA, constitue l‟un des objectifs majeurs de la nutrition néonatale et infantile. Ce projet étudie l‟effet de régimes à base de matière grasse laitière anhydre (MGLA) afin d‟améliorer la bioconversion des AGPI n-3 et l‟incorporation du DHA dans le cerveau. L‟autre objectif, au-delà des effets sur les acides gras, est d‟évaluer si l‟impact des apports destinés au jeune n‟exercent pas un effet plus large tels qu‟appréciés au niveau du lipidome du cerveau.Nous avons mis au point un modèle d‟expérimentation animale permettant d‟étudier les effets de mélanges de MGLA et d‟huiles végétales. Des mères sont nourries avec un régime déficient en acide α-linoléique (ALA) (0,4% des acides gras totaux (AGT)) pendant 6 semaines avant accouplement et pendant toute la gestation et la lactation. Après sevrage, quatre-vingts petits rats mâles et femelles ainsi carencés en AGPI n-3 sont séparés en 4 groupes et reçoivent des régimes à 10% de lipides pendant 6 semaines, soit à base d‟huile de palme mélangée avec des huiles vegétales pour un apport à 1,5%ALA (P1), ou 1,5% ALA supplementé avec 0,12%DHA et 0,4% acide arachidonique (ARA) (P2); soit à base de MGLA et d‟huiles végétales apportant 1,5%ALA (B1) ou 2,3%ALA (B2). Les acides gras cérébraux, plasmatiques et érythrocytaires ainsi que le profil lipidomique cérébral sont mesurés, et les résultats sont analysés en statistiques multivariées. Le régime B1 est supérieur aux deux régimes à base d‟huile de palme à 1,5 %ALA, pour restaurer la quantité de DHA du cerveau (augmentation de 14.38%, P < 0.05) ; le régime (B2) présente un bénéfice supplémentaire sur ce paramètre. Les concentrations cérébrales en DHA chez les rats mâles sont significativement plus faibles que chez les femelles en raison des interactions de l‟effet sexe sur l‟effet régime, mais cet effet s‟atténue avec les régimes MGLA ou l‟ajout de DHA préformés dans le régime palme (P2).Nous avons calculé un nouvel indice à l‟aide des profils en acides gras des globules rouges et du plasma pour prédire le contenu en DHA cérébral, et dont la performance est meilleure que celle des indices existants. Pour la première fois, nous avons pu mettre en évidence un effet majeur et inconnu jusqu‟alors, des régimes sur le lipidome du cerveau (analyse des espèces moléculaires de lipides), affectant près de 15% des espèces analysées. Ces changements semblent être liés, entre autres, au métabolisme du cholestérol, des acides gras et des messagers lipidiques.En conclusion, nos données sont susceptibles d„améliorer les formules infantiles. La première utilisation de l‟approche de lipidomique sans a priori que nous avons mise en oeuvre ouvre des perspectives nouvelles en nutrition infantile. / The accretion of docosahexaenoic acid (DHA) in brain membranes mainly occurs around delivery and during the first two years of life. One of the main goals of neonatal nutrition is to optimize the incorporation of n-3 long chain polyinsaturate fatty acids (LC-PUFA) into the central nervous system, including DHA. Our goal was to study the impact of several kinds of diets based on dairy-fat to improve the n-3 LC-PUFA bioconversion and DHA accretion into brain. The other endpoint was to assess if beyond the brain fatty acid profiles, the dietary intakes would bring about a wider effect such as the one that can be appreciated through a lipidomic approach.We compared the nutritional effect of dairy-fat based diets to that of palm-oil based diets in the rat reproductive model. Mother rats were made deficient in α-linoleic acid (ALA) (0.4% of fatty acids (FA) for 6 weeks prior to mating and throughout gestation and lactation. After weaning, the resulting deficient 40 rat pups of either gender were split into 4 groups and received 10% fat diets made with either 1.5%ALA palm oil blend (P1), same added with 0.12% DHA and 0.4% arachidonic acid (ARA) (P2) , 1.5% ALA dairy-fat blend (B1) or 2.5% ALA dairy-fat blend (B2). The brain, red blood cell (RBC) and plasma fatty acid profiles were analyzed and treated using multivariate statistics. B1 was superior to both palm-oil based diets to improve the brain DHA contents (14.4% increase, P < 0.05). B2 brought an additional benefit for this parameter. The brain DHA contents in males were significantly lower than for the female because of a diet x gender interaction. This effect was smoothed with the dairy-fat diets or the palm-oil based diet augmented with preformed DHA.We calculated a new fatty acid index to predict the brain DHA contents, based on the fatty acid profiles measured in RBC and plasma, and which demonstrated a better performance than the existing published index. For the first time, we showed a profound and yet unsuspected effect of diets until now on the brain lipidome (lipids molecular species), affecting about 15% of the features detected. These changes were ascribed to the cholesterol and fatty acid metabolism, and to the lipid messengers, among others.In conclusion, our data appear highly relevant to improve infant formulas. The first use of the lipidomic approach in neonatal nutrition open the paths of new researches in the area of infant nutrition
83

Avaliação da acuidade visual de recém-nascidos pequenos para a idade gestacional pelos métodos do potencial visual evocado de varredura e cartões de acuidade de Teller / Evaluation of Visual Acuity in Small-for-Gestational-Age Newborns Using Sweep VEP and Teller Acuity Card Methods

França, Valtenice de Cássia Rodrigues de Matos 09 December 2008 (has links)
Objetivo: Avaliar os efeitos da desnutrição intra-uterina na acuidade visual (AV) de resolução de grades pelo Potencial Visual Evocado de Varredura (PVEv) e Cartões de Acuidade de Teller (CAT). Método: Avaliamos a AV de resolução de grades, binocularmente, de 41 recém-nascidos com idade estacional 37 semanas, destes 23 nasceram com o peso adequado para a idade gestacional (AIG - Idade: 14,3 ± 7,5 semanas) e 18 nasceram pequenos para a idade gestacional (PIG - Idade: 10,7 ± 4,1semanas). A AV foi determinada usando ambas as técnicas psicofísica (CAT) e eletrofisiológica (PVEv). Durante o teste dos CAT foram apresentados cartões contendo em um dos lados grades de ondas quadradas pretas e brancas com freqüência espacial entre 0,23 e 19 ciclos por grau de ângulo visual a 55 cm do participante. O teste iniciou com o cartão com a freqüência espacial mais baixa com orientação randômica desconhecida pelo experimentador. Cartões contendo freqüências espaciais mais altas foram apresentados gradativamente até que uma resposta incorreta ocorresse, então o cartão anterior era apresentado novamente. A AV foi definida pela média aritmética das freqüências espaciais contidas nos cartões para 4 reversões. Para o registro do PVEv, o sistema PowerDiva (Brosnahan et al., 1998) foi usado para gerar todos os estímulos e analisar as repostas provocadas. Estímulos de grades senoidais em reversão de fase em 3, 6 ou 10 Hz foram apresentados em monitor de vídeo monocromático de 21 polegadas com luminância média de 161,13 cd/m2. Registramos o eletroencefalograma com três eletrodos ativos (O1, Oz, O2) relacionados ao eletrodo de referência no vertex. Durante cada tentativa com duração de 10 segundos, resentávamos uma faixa de freqüência espacial que aumentava linearmente. Para cada condição (freqüência temporal - FT) foram usadas no mínimo três tentativas para estimar o limiar. Consideramos o canal que registrou a AV mais alta com boa razão sinal-ruído (SNR>3:1), fase constante e critério estatístico. Resultados: Não encontramos diferenças significativas na AV entre os grupos para nenhum dos métodos. Para o PVEv, não encontramos diferenças significativas na AV, amplitude, ruído ou SNR entre os grupos para nenhuma das FT. Análises intra-grupos mostraram que os valores de amplitude, SNR e ruído foram significativamente diferentes entre as freqüências temporais apenas para os PIG. Entretanto, os PIG até 8 semanas de idade mostraram uma tendência para amplitudes e SNR mais altas para a FT de 3 Hz comparadas aos AIG. Esses mesmos PIG mostraram uma tendência para valores de fase maiores respostas lentas) em comparação aos AIG. Entretanto, a taxa de desenvolvimento da fase foi maior para os PIG do que para os AIG em todas as FT. Conclusão. Não há alteração significativa na AV de recém-nascidos PIG, entretanto as informações de medidas supra-limiares são consistentes com a hipótese que a desnutrição intra-uterina torna as respostas visuais mais lentas entre a retina e o córtex visual. Os dados também sugerem de forma sutil que tais efeitos são passageiros afetando primariamente o grupo de recém-nascidos mais jovens e que o sistema visual dos PIG tem plasticidade suficiente para atingir rapidamente os níveis normais. Mais dados serão necessários para validar esta interpretação. / Objective: To evaluate the effects of intra-uterine malnutrition on grating visual acuity (VA) using Sweep VEP and Teller Acuity Cards (TAC). Method: Binocular grating acuity was evaluated in 41 newborns with gestational age 37 weeks. Twentythree were born with appropriate weight for gestational age (AGA age: 14.3 ± 7.5 weeks) and 18 were born small for gestational age (SGA age: 10.7 ± 4.1 weeks). Visual acuity was determined using both psychophysical (Teller Acuity Cards) and electrophysiological (sVEP) techniques. For the TAC evaluation, cards having calibrated black and white square waves gratings at spatial frequencies (SFs) between 0.23 and 19 cycles/degree were presented 55 cm from the subject. The test began with the lowest SF card in random orientation to which the experimenter was blind. Subsequent cards were presented in order of increasing SF until an incorrect response was made, at which time the prior (lower-SF) card was presented again. Visual acuity was defined as the average of the SF values for 4 reversals. For the sVEP recordings, the PowerDIVA VEP system (Brosnahan et al., 1998) was used to generate all stimuli and analyze the evoked responses. Stimuli were spatial luminance sinewave gratings presented on a 21-inch monochromatic high-resolution monitor (1600x1200 pixels) with an average luminance of 161.1 cd/m2. Gratings were phase-reversed at either 3, 6 or 10 Hz. The electroencephalogram was recorded using 3 active electrodes (O1,Oz,O2) related to the reference electrode at vertex. During each 10-sec sVEP trial a linear sweep of increasing SF was presented. Sweep ranges were selected according to the subjects age. For each condition (each TF), a minimum of 3 trials were used to estimate thresholds, but the majority of measures were the result of a vector average of 5 to 10 trials. For each condition, the acuity estimate used derived from the channel with the highest acuity with statistically significant signal-to-noise ratio (>3:1) and stable phase during the high-SNR portion of the response. Results: There were no statistical differences in visual acuity between the two groups (SGA and AGA) for either method (sVEP or TAC). For the sVEP, acuities were not statistically different for the different TFs. There were also no statistical differences between groups for the sVEP measures of amplitude, phase, noise or signal-to-noise ratio. Intra-group analysis of the sVEP measures at the three TFs revealed statistical differences for amplitude, noise and signal-to-noise ratio, but only for SGA group. However, the SGA subjects less than or equal to 8 weeks of age showed a tendency for higher amplitudes and SNR for 3Hz temporal frequency compared to AGA subjects, and these same SGA subjects showed tendency for larger phase values (slower responses) compared to AGA. However, phase development rate was faster for SGA than for AGA for all temporal frequencies. Conclusion: There were no significant alterations of visual acuity in SGA babies, but the data from suprathreshold measures are consistent with the hypothesis that intrauterine malnutrition results in slower visual responses between retina and cortex. The data obtained so far suggest that such affects are transient, affecting primarily the younger group of infants, and that the visual system in SGA infants has sufficient plasticity to recover rapidly to normal levels. More data is needed to validate this interpretation of the results.
84

Estudo da imunogenicidade da proteína de classe 3 (PorB) purificada da membrana externa de Neisseria miningitidis: imunização intranasal/intramuscular em camundongos adultos e neonatos utilizando Bordetella pertussis como adjuvante. / Study of the immunogenecity of the class 3 proteins (PorB) purified from the outer mebrane of Neisseria meningitidis: intranasal and intramuscular immunization in adult and neonate mice using Bordetella pertussis as adjuvant.

Raphael, Mariana Lopes Teixeira 28 March 2008 (has links)
As proteínas de classe 3 são candidatas na preparação de uma vacina contra a doença meningocócica. O objetivo deste estudo é determinar a imunogenicidade da proteína de classe 3 purificada da cepa de Neisseria meningitidis do sorogrupo B juntamente com a capacidade adjuvante de whole cells de Bordetella pertussis. Foram imunizados camundongos BALB/c neonatos em um intervalo de 3 a 12 dias entre 1 e 4 doses da proteína de classe 3 mais adjuvante, pela via intranasal e no 21º dia pela via intramuscular com a proteína de classe 3 emulsificada com hidróxido de alumínio. Os resultados demonstraram que após 2 doses pela via intranasal e 1 dose pela via intramuscular houve rápido estímulo das células imunes nos camundongos adultos BALB/c e neonatos BALB/c e outbred. Todos os soros foram analisados por ELISA e immunoblot. O adjuvante B. pertussis administrado pelas vias intranasal ou intramuscular, aumentou a resposta imune comparada com os controles. Anticorpos bactericidas e de alta afinidade foram produzidos. / Proteins of class 3 sound candidates in the preparation of vaccine against meningococcal illness. The aim of this study was to determine the immunogenicity of class 3 proteins purified of Neisseria meningitidis of the serogroup B along with whole cells of Bordetella pertussis as adjuvant. BALB/c and outbred neonate mice between 3 and 12 days old were immunized with 1 to 4 doses of the purified class 3 proteins with or without adjuvant given by the intranasal route, and on the 21st day the animals received an intramuscular dose of the class 3 proteins with or without aluminum hydroxide. The results demonstrated that after 2 doses by the intranasal route and 1 dose intramuscular there was a rapid stimulation of the immune cells in BALB/c adult mice as well as BALB/c and outbred neonates mice. All sera were analyzed by ELISA and immunoblot. The adjuvant B. pertussis used in the present investigation and given via the intranasal or intramuscular route increased the immune response compared with the controls. High affinity and bactericidal antibodies were produced.
85

Desenvolvimento das funções de acuidade visual e sensibilidade ao contraste visual medidas por potenciais visuais provocados de varredura em crianças nascidas a termo e prematuras / Development of visual acuity functions and visual contrast sensitivity mesaured by visual evoked potentials in premature and term babies

Oliveira, André Gustavo Fernandes de 08 August 2007 (has links)
A prematuridade ao nascimento é um fator de risco para a visão, podendo causar retinopatia, uma condição em que há descolamento da retina. Retinopatia da prematuridade ocorre em uma parcela relativamente pequena dos recém nascidos prematuros e não sabemos se os demais, cujo desenvolvimento visual é aparentemente normal, seguem de fato o mesmo curso que o observado em bebes nascidos após uma gestação completa, ou se também sofrem algum prejuízo devido ao nascimento prematuro. Alternativamente, estes bebês poderiam ter um desenvolvimento visual acelerado pela sua exposição mais longa ao mundo visual. Para saber se a condição de prematuridade acelera, retarda, ou não altera o desenvolvimento da visão, o presente trabalho comparou o desenvolvimento das funções de acuidade visual e de sensibilidade ao contraste espacial de luminância em bebês nascidos prematuros e a termo. O estudo utilizou o método dos Potenciais Visuais Corticais Provocados de Varredura para examinar essas funções. Possíveis correlações entre os limiares visuais obtidos durante o primeiro ano de vida e idade gestacional, índices de Apgar, e valores de peso ao nascimento, foram examinadas. Os participantes foram 57 bebês de ambos os sexos encaminhados pelo Hospital Universitário da Universidade de São Paulo, dos quais 31 prematuros e 26 nascidos a termo. As avaliações foram realizadas principalmente em 3 fases do desenvolvimento visual: 4, 6 e 12 meses de vida. Os bebês prematuros tiveram suas idades corrigidas com relação à idade gestacional para a comparação com os grupos de termos. Um grupo de 14 sujeitos adultos também foi avaliado com os mesmos estímulos visuais. As avaliações das funções de acuidade visual e sensibilidade ao contraste foram realizadas através do método de potenciais visuais corticais provocados de varredura. Eletrodos posicionados no escalpo da região occipital dos pacientes captaram as respostas eletrofisiológicas provocadas por estímulos gerados em um monitor de alta resolução por um sistema computadorizado (sistema NuDiva). Estes estímulos consistiam de grades quadradas com valor de contraste fixo (80%) para avaliação da acuidade visual, e grades senoidais de 4 freqüências espaciais: 0,2 , 0,8 , 2,0 e 4,0 ciclos por grau para a avaliação da sensibilidade ao contraste. Prematuros e termos não apresentaram diferenças estatísticas significantes nas funções visuais avaliadas em nenhuma fase do desenvolvimento. O pico de sensibilidade ao contraste ocorreu entre .8 e 2.0 cpg de 4 meses de idade. No sexto mês o pico deslocou-se para 2.0 cpg, e entre os meses 9 e 12 passou para freqüências espaciais mais altas, por volta de 4.0 cpg coincidindo com o pico encontrado para os adultos. Nossos dados sugerem que nem a experiência visual, maior nos prematuros em relação aos termos, nem o tempo de gestação, maior nos termos em relação aos prematuros, afetam o desenvolvimento da visão espacial em humanos. / Prematurity at birth is a risk factor for vision, since it may lead to retinopathy - a condition in which there is retinal detachment. Retinopathy of prematurity occurs in a relatively small percentage of premature infants and it is not known if the remainder, whose visual development is apparently normal, follow the same course as in term babies after a complete gestational period, or if they also suffer some loss from having been born before complete development. Alternatively, these babies might have an accelerated visual development due to their longer exposure to the visual world, compared to term babies. To examine if prematurity accelerates, slows down, or does not affect visual development, the present study compared the development of visual acuity and contrast sensitivity in premature and term babies. The study used the methodology of the sweep visual evoked potentials to examine these functions. Possible correlations between visual thresholds obtained during the first year of life and gestational age, apgar index and birth weight, were examined. Participants were 57 infants of both genders, recruited by the University Hospital of São Paulo University, of which 31 were prematurely born and 26 were term infants. Evaluations were performed at three visual developmental epochs: 4, 6 e 12 months of age. The age of preterm infants was corrected by their gestational ages in order to allow comparison with the term infants. Another group with 14 adult subjects was tested with the same visual stimulus. Visual acuity and contrast sensitivity tests were performed with the sweep visual evoked potential method. Electrodes placed over the infant\'s scalp at the occipital role recorded electrophysiological responses evoked to visual stimuli generated by a high resolution monitor of a computerized system. The stimuli were square wave gratings with 80% of contrast to evaluate visual acuity, and sine wave gratings of 4 spatial frequencies: 0,2 , 0,8 , 2,0 e 4,0 cycles per degree to evaluate contrast sensitivity. Preterm and term infants did not show statistical differences in the evaluated visual functions in any developmental phase. The contrast sensitivity peak occurred between 0.8 and 2.0 cpd at 4 months of age. At the sixth month the peak moved to 2.0 cpd and it was displaced to a higher spatial frequency (4.0 cpd) at 12 months, where it coincides with the adult SCS peak. Our data suggest that neither visual experience, longer in the preterm, nor gestational age, longer in the term infants, seems to affect spatial vision functions in humans.
86

Achados timpanométricos em neonatos:medidas e interpretações / Timpanometry in neonates: Measures and Interpretations

Silva, Kilza de Arruda Lyra e 23 August 2005 (has links)
Made available in DSpace on 2016-04-27T18:11:46Z (GMT). No. of bitstreams: 1 Dissertacao_KilzaArruda.pdf: 594058 bytes, checksum: a238824dfa6ae7f27d50010de62bd6ee (MD5) Previous issue date: 2005-08-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Introduction. Early identification and diagnosis of hearing impairment in newborns aim at establishing adequate amplification and intervention, as early as possible, in order to reduce negative consequences in language, individual and social development of the child. Tympanometry is part of a test battery for the diagnosis of hearing losses and is used to differentiate between conductive and sensorineural hearing losses. Before six months of age the results obtained using a probe tone of 226 Hz can be misleading. Therefore many studies have been done assessing the use of a high frequency probe tone of 678 and 1000 Hz aiming at a more valid procedure. Goal. The goal of the present study was to describe and discuss interpretations and measurements obtained in timpanometry of normal hearing neonates, using tone probes of 226, 678 and 1000 Hz. The following aspects were described: tympanometric curve type, Peak Compensated Static Acoustic Admittance (Ytm), Tympanometric Width (TW), Tympanometric Peak Pressure (PPT) and Equivalent Ear Canal Volume (Vea). Method. All subjects had normal otoacoustic emissions and no risk for hearing impairment. The curves were obtained in a quiet room using a middle ear analyzer GSI 33 II with tone probes of 226, 678 and 1000 Hz. All babies were calm or sleeping during the test. Results. 110 neonates were tested with the three tone probes therefore 660 curves were obtained. Age range was 6 to 30 days (58 boys and 52 girls). When a probe tone of 226 Hz was used, single peak curve was observed in 105 (47,7%) ears and double peak was found in 115 (52,3%) ears. Results with a probe tone of 678 Hz, revealed 56 (25,4%) single peak curves, 16 (7,3%) inverted curves (I) and 148 (67,3%) asymmetric (AS). Results with a probe tone of 1000 Hz showed 156 (70,9%) single peak tympanograms, 62 (28,2%) asymmetric and 2 (0,9%) inverted. Among the quantitative measurements analyzed, Vea demonstrated a significant difference in gender with probe tones of 226 Hz. Ytm, was also significantly different by gender with the probe tone of 1000 Hz, larger for the boys. For all the other variables no significant difference was found for ear or gender. When the curves were analyzed using the protocol proposed by Sutton et al (2002), 208 (94,5%) ears were considered normal and 12 (5,5%) abnormal with the probe tone of 678 Hz. For the probe tone of 1000 Hz, 217 (98,6%) ears were considered normal, and just 3 (1,4%) of the tympanograms were classified as abnormal. Conclusion. The tympanometric findings in this study were similar to those described in the literature with prevalence of single peaked curves for the probe tone of 1000 Hz and a similar number of single and double peaked curves with the probe tone of 226 Hz. The quantitative measurements were, in general, in agreement with the literature reviewed. The interpretation of the results with the probe tone of 1000 Hz using the protocol suggested by Sutton et al (2002) was the method that allowed the classification of normal for the greatest percentage of the ears tested suggesting that it can be very useful when neonates are evaluated. Further research with this protocol is suggested. / Introdução. A identificação e a caracterização precoce da perda auditiva em neonatos visam estabelecer condições para uma intervenção adequada, tão cedo quanto possível, a fim de reduzir as conseqüências negativas no desenvolvimento pessoal e social da criança. A timpanometria faz parte da bateria de testes do diagnóstico da perda auditiva e é utilizada para avaliação da orelha média, para diferenciar perdas condutivas de neurossensoriais. A timpanometria realizada em neonatos com menos de seis meses, quando executadas com tom sonda de baixa freqüência (226 Hz), pode gerar dúvidas, pois nesse tipo de sonda, neonatos com otite média podem revelar timpanograma aparentemente normal. Com isso, tem-se investigado o uso de tom sonda de alta freqüência (678 e 1000 Hz) em busca de resultados mais confiáveis. Objetivo. Descrever e analisar interpretações de características e medidas obtidas na timpanometria de neonatos ouvintes com sonda de tom prova de 226, 678 e 1000 Hz. São descritos os seguintes aspectos do timpanograma: características da curva timpanométrica, Admitância Acústica Estática de Pico Compensado na Altura da Membrana Timpânica (Ymt), Largura Timpanométrica (LT), Pressão do Pico Timpanométrico (PPT) e Volume Equivalente do Meato Acústico Externo (Vea). Metodologia. Os sujeitos analisados passaram por uma triagem que incluiu anamnese e teste de emissões otoacústicas. Para a realização das timpanometrias foi utilizado o analisador de orelha média GSI-33-II, com tons sonda de 226, 678 e 1000 Hz, em sala silenciosa e com a criança em estado tranqüilo. Resultados. Foram obtidos timpanogramas de 110 neonatos ouvintes com 6 a 30 dias de idade (58 meninos e 52 meninas), perfazendo um total de 660 timpanogramas. No tom sonda de 226 Hz, o tipo de curva pico único (A) apareceu em 105 (47,7%) orelhas e o tipo pico duplo (PD) em 115 (52,3%) orelhas. Os resultados na freqüência de 678 Hz indicaram 56 (25,5%) ocorrências de curva tipo A, 16 (7,3%) do tipo invertida (I) e 148 (67,3%) curvas do tipo assimétrica (AS). Na sonda de 1000 Hz foram registradas 156 (70,9%) curvas do tipo A, 62 (28,2%) do tipo AS e 2 (0,9%) do tipo I. Dentre as variáveis quantitativas analisadas, apenas o Vea apresentou efeito de significância por orelha na sonda de tom prova de 1000 Hz. O Vea apresentou efeito de significância em relação ao gênero nas freqüências de 226 e 1000 Hz. A Ymt, também, apresentou efeito de significância por gênero, na sonda de 1000 Hz, sendo maior nos meninos. Nas demais variáveis não foi encontrado efeito de significância nem por orelha e nem por gênero. Quando interpretados de acordo com o protocolo recomendado por Sutton et al (2002), obteve-se, em 678 Hz, 208 (94,5%) orelhas com resultado normal, enquanto 12 (5,5%) foram interpretadas como anormais. Na sonda de tom prova de 1000 Hz, 217 (98,6%) das orelhas foram normais, e apenas 3 (1,4%) dos timpanogramas foram classificados como anormais. Conclusão. Os achados timpanométricos, tanto em 226 Hz quanto em 1000 Hz, foram compatíveis com os resultados presentes na literatura, que descrevem alta ocorrência de curvas do tipo A em sonda de 1000 Hz e equilíbrio entre os tipos de curva A e PD em sonda de 226 Hz. Os dados registrados para as medidas quantitativas, também, estiveram de acordo com o indicado na literatura. A interpretação das curvas timpanométricas com sonda de 1000 Hz utilizando o protocolo proposto por Sutton et al (2002) foi a que possibilitou a classificação de normal na maior porcentagem das orelhas avaliadas, sugerindo que este pode ser um método de grande utilidade na avaliação de bebês. Recomenda-se que pesquisas futuras com esse protocolo sejam realizadas.
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Avaliação da acuidade visual de recém-nascidos pequenos para a idade gestacional pelos métodos do potencial visual evocado de varredura e cartões de acuidade de Teller / Evaluation of Visual Acuity in Small-for-Gestational-Age Newborns Using Sweep VEP and Teller Acuity Card Methods

Valtenice de Cássia Rodrigues de Matos França 09 December 2008 (has links)
Objetivo: Avaliar os efeitos da desnutrição intra-uterina na acuidade visual (AV) de resolução de grades pelo Potencial Visual Evocado de Varredura (PVEv) e Cartões de Acuidade de Teller (CAT). Método: Avaliamos a AV de resolução de grades, binocularmente, de 41 recém-nascidos com idade estacional 37 semanas, destes 23 nasceram com o peso adequado para a idade gestacional (AIG - Idade: 14,3 ± 7,5 semanas) e 18 nasceram pequenos para a idade gestacional (PIG - Idade: 10,7 ± 4,1semanas). A AV foi determinada usando ambas as técnicas psicofísica (CAT) e eletrofisiológica (PVEv). Durante o teste dos CAT foram apresentados cartões contendo em um dos lados grades de ondas quadradas pretas e brancas com freqüência espacial entre 0,23 e 19 ciclos por grau de ângulo visual a 55 cm do participante. O teste iniciou com o cartão com a freqüência espacial mais baixa com orientação randômica desconhecida pelo experimentador. Cartões contendo freqüências espaciais mais altas foram apresentados gradativamente até que uma resposta incorreta ocorresse, então o cartão anterior era apresentado novamente. A AV foi definida pela média aritmética das freqüências espaciais contidas nos cartões para 4 reversões. Para o registro do PVEv, o sistema PowerDiva (Brosnahan et al., 1998) foi usado para gerar todos os estímulos e analisar as repostas provocadas. Estímulos de grades senoidais em reversão de fase em 3, 6 ou 10 Hz foram apresentados em monitor de vídeo monocromático de 21 polegadas com luminância média de 161,13 cd/m2. Registramos o eletroencefalograma com três eletrodos ativos (O1, Oz, O2) relacionados ao eletrodo de referência no vertex. Durante cada tentativa com duração de 10 segundos, resentávamos uma faixa de freqüência espacial que aumentava linearmente. Para cada condição (freqüência temporal - FT) foram usadas no mínimo três tentativas para estimar o limiar. Consideramos o canal que registrou a AV mais alta com boa razão sinal-ruído (SNR>3:1), fase constante e critério estatístico. Resultados: Não encontramos diferenças significativas na AV entre os grupos para nenhum dos métodos. Para o PVEv, não encontramos diferenças significativas na AV, amplitude, ruído ou SNR entre os grupos para nenhuma das FT. Análises intra-grupos mostraram que os valores de amplitude, SNR e ruído foram significativamente diferentes entre as freqüências temporais apenas para os PIG. Entretanto, os PIG até 8 semanas de idade mostraram uma tendência para amplitudes e SNR mais altas para a FT de 3 Hz comparadas aos AIG. Esses mesmos PIG mostraram uma tendência para valores de fase maiores respostas lentas) em comparação aos AIG. Entretanto, a taxa de desenvolvimento da fase foi maior para os PIG do que para os AIG em todas as FT. Conclusão. Não há alteração significativa na AV de recém-nascidos PIG, entretanto as informações de medidas supra-limiares são consistentes com a hipótese que a desnutrição intra-uterina torna as respostas visuais mais lentas entre a retina e o córtex visual. Os dados também sugerem de forma sutil que tais efeitos são passageiros afetando primariamente o grupo de recém-nascidos mais jovens e que o sistema visual dos PIG tem plasticidade suficiente para atingir rapidamente os níveis normais. Mais dados serão necessários para validar esta interpretação. / Objective: To evaluate the effects of intra-uterine malnutrition on grating visual acuity (VA) using Sweep VEP and Teller Acuity Cards (TAC). Method: Binocular grating acuity was evaluated in 41 newborns with gestational age 37 weeks. Twentythree were born with appropriate weight for gestational age (AGA age: 14.3 ± 7.5 weeks) and 18 were born small for gestational age (SGA age: 10.7 ± 4.1 weeks). Visual acuity was determined using both psychophysical (Teller Acuity Cards) and electrophysiological (sVEP) techniques. For the TAC evaluation, cards having calibrated black and white square waves gratings at spatial frequencies (SFs) between 0.23 and 19 cycles/degree were presented 55 cm from the subject. The test began with the lowest SF card in random orientation to which the experimenter was blind. Subsequent cards were presented in order of increasing SF until an incorrect response was made, at which time the prior (lower-SF) card was presented again. Visual acuity was defined as the average of the SF values for 4 reversals. For the sVEP recordings, the PowerDIVA VEP system (Brosnahan et al., 1998) was used to generate all stimuli and analyze the evoked responses. Stimuli were spatial luminance sinewave gratings presented on a 21-inch monochromatic high-resolution monitor (1600x1200 pixels) with an average luminance of 161.1 cd/m2. Gratings were phase-reversed at either 3, 6 or 10 Hz. The electroencephalogram was recorded using 3 active electrodes (O1,Oz,O2) related to the reference electrode at vertex. During each 10-sec sVEP trial a linear sweep of increasing SF was presented. Sweep ranges were selected according to the subjects age. For each condition (each TF), a minimum of 3 trials were used to estimate thresholds, but the majority of measures were the result of a vector average of 5 to 10 trials. For each condition, the acuity estimate used derived from the channel with the highest acuity with statistically significant signal-to-noise ratio (>3:1) and stable phase during the high-SNR portion of the response. Results: There were no statistical differences in visual acuity between the two groups (SGA and AGA) for either method (sVEP or TAC). For the sVEP, acuities were not statistically different for the different TFs. There were also no statistical differences between groups for the sVEP measures of amplitude, phase, noise or signal-to-noise ratio. Intra-group analysis of the sVEP measures at the three TFs revealed statistical differences for amplitude, noise and signal-to-noise ratio, but only for SGA group. However, the SGA subjects less than or equal to 8 weeks of age showed a tendency for higher amplitudes and SNR for 3Hz temporal frequency compared to AGA subjects, and these same SGA subjects showed tendency for larger phase values (slower responses) compared to AGA. However, phase development rate was faster for SGA than for AGA for all temporal frequencies. Conclusion: There were no significant alterations of visual acuity in SGA babies, but the data from suprathreshold measures are consistent with the hypothesis that intrauterine malnutrition results in slower visual responses between retina and cortex. The data obtained so far suggest that such affects are transient, affecting primarily the younger group of infants, and that the visual system in SGA infants has sufficient plasticity to recover rapidly to normal levels. More data is needed to validate this interpretation of the results.
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Determinants of high neonatal mortality rates in Migori County Referral Hospital in Kenya

Masaba, Brian Barasa 05 1900 (has links)
The purpose of this study was to investigate the determinants of high neonatal mortality rates in Migori County, Kenya. The neonatal mortality cases were utilised as the target population to the study. A quantitative, descriptive, cross-sectional, non-experimental research design was used. A systematic sampling technique was employed to draw a sample of 201 archived neonatal cases out of 420 neonatal mortality medical records, which constituted the study population. Data were collected by means of a developed questionnaire. The Statistical Package for Social Sciences (SPSS) Version 21 was used to analyse data. The main findings revealed the leading determinants of neonatal mortality were early neonatal period, prematurity, poor 1st Apgar score, low birth weight and neonates with intrapartum complications. Obstetrical haemorrhage and HIV were the main maternal complications associated to neonatal mortalities, while the leading direct causes of death in this study were birth asphyxia and sepsis. Other determinants were gender, rural residence, lowly educated and informally employed mothers. To reduce mortalities, a multifaceted approach is needed to establish quality improvement in neonatal intensive care, reduce preterm birth incidences, and empower mothers socio-economically. / Health Studies / M.A. (Nursing Science)
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Impacto da exposição fetal ao HIV-1 na função das células T e das células dendríticas de neonatos não infectados / Impact of HIV-1 fetal exposition in Tcells and dendritic cells function from non infected neonates

Juliana do Outeiro Santos 23 August 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / A síndrome da imunodeficiência adquirida (AIDS), causada pelo vírus da imunodeficiência humana (HIV), é uma das epidemias mais impactantes do milênio e, desde o início, o número de mulheres jovens infectadas vem aumentando vertiginosamente, principalmente nos países em desenvolvimento onde muitas destas engravidam precocemente. Apesar da grande maioria dos casos de AIDS pediátrico no mundo resultar da transmissão vertical, aproximadamente dois terços dos neonatos expostos ao HIV durante a vida fetal não são contaminados. Neste sentido, seguindo as recomendações do consenso brasileiro (Ministério da Saúde), toda criança cuja transmissão vertical tenha sido descartada laboratorialmente não necessita de acompanhamento ambulatorial particularizado. Entretanto, resultados anteriores obtidos pelo nosso grupo demonstraram que, gestantes infectadas pelo HIV-1 que não controlam a carga viral plasmática (CVP), apresentam níveis elevados de citocinas inflamatórias e, no presente estudo, resultados revelam que neonatos não-infectados nascidos dessas gestantes apresentam anormalidades imunofuncionais no compartimento das células T do cordão umbilical quando expostos in vitro a ativadores policlonais, mas não aos antígenos do HIV-1. Ademais, quando comparada a neonatos não expostos, a ativação in vitro das células T de neonatos expostos ao HIV-1 com anti-CD3/anti-CD28 induziu a produção de níveis elevados de IL-17 e reduzidos de IL-10. Interessantemente, essa tendência das células T em secretar IL-17 parece estar relacionada à liberação de níveis elevados de IL-23 pelas células dendríticas derivadas de monócitos do sangue do cordão umbilical estimuladas com lipopolissacarídeo bacteriano. Uma ausência de sensibilização uterina aos antígenos do HIV-1 sugere que essas alterações possam traduzir um efeito adverso da produção elevada de citocinas inflamatórias maternas sobre o sistema imune do neonato, o que pode desequilibrar os eventos envolvidos na maturação e homeostasia imune fetal e neonatal, favorecendo o predomínio de fenótipos Th anômalos, tal como Th17. Essa hiper-responsividade das células Th17 pode vir a comprometer não apenas a capacidade da criança em responder de forma adequada a diferentes estímulos antigênicos ao longo de sua vida, como também pode torná-la mais suscetível a desordens imunomediadas / The acquired immunodeficiency syndrome (AIDS), caused by human immunodeficiency virus (HIV), is one of the most impelling epidemic in the world, and the HIV-infection in young women has been increasing fast in the recent times, mainly in developing countries where most of them become pregnant precociously. Although the great majority of the pediatric AIDS cases all over the world results from vertical transmission, approximately, two thirds of the children exposed to HIV during fetal life are not contaminated. In this context, following brazilian consensus recommendations (Health Ministry), every child whom vertical transmission had been laboratorialy discarded does not need a specific ambulatorial follow up. However, our previous results demonstrated that HIV-1-infected pregnant women who did not control their plasma viral load presented elevated levels of inflammatory cytokines, and in the present study our results revealed that non-infected neonates, born from these pregnant women display immune functional abnormalities in umbilical cord T cells compartment when exposed in vitro to policlonal activators, but not to HIV-1 antigens. Furthermore, when compared to non-exposed neonates, T cell in vitro activation with anti-CD3/anti-CD28 from neonates exposed to HIV-1 induced production of high IL-17 levels and decreased of IL-10. Interestingly, this T cell bias in secreting IL-17 seem to be related to liberation of high IL-23 levels by dendritic cells derived from umbilical cord blood monocytes following stimulation with bacterial lipopolysacharide (LPS). The lack of uterine sensitization to HIV-1 antigens suggests that, these alterations, may translate an adverse effect of a high level maternal inflammatory cytokines production on neonates immune system, which may unbalance events related to neonatal and fetal immune maturation and homeostasis, favoring Th anomalous phenotypes predominance, such as Th17. This Th17 hyper-responsiveness may then compromise not only the childs capacity to respond in an adequate way to different antigenic stimuli through life, as well as becoming them more susceptible to immune-mediated disorders
90

Optimizing iodine nutrition in Belgium: a selective, progressive and monitored approach to control iodine deficiency

Vandevijvere, Stefanie 14 December 2012 (has links)
Since 1990, many countries world-wide implemented salt iodisation programs in an effort to<p>tackle iodine deficiency. It was however only during the last few years that an effort was<p>undertaken in order to eliminate iodine deficiency as a public health problem in Belgium. In autumn 1998, a nation-wide study among children clearly showed mild iodine deficiency in<p>Belgium, but no action was taken before 2009. It was only in the framework of the first<p>National Nutrition and Health Plan 2005-2010 that iodine deficiency was formally recognized<p>as a public health problem. An agreement between the Ministry of Health and the bakery<p>sector in April 2009 aimed to encourage and increase the use of iodised salt in the<p>production of bread. A selective and progressive approach was used in order to keep control<p>and to avoid a too rapid increase of iodine intake or an excessive iodine intake among the<p>population. It was calculated that the net yearly savings after installation of such a program<p>amount to at least 14 million Euros a year.<p>A recent national survey among school-aged children in autumn 2010 showed a clear and<p>significant improvement in iodine status compared to more than 10 years ago, suggesting<p>iodine sufficiency among school-aged children. The median urinary iodine concentration was<p>however at the lower end of the optimal range and seasonal effects were not taken into<p>account. The improvement was at least partly linked to the increasing use of iodised salt in<p>the bakery industry. However, some further silent iodine prophylaxis might also have<p>occurred, due to changing dietary habits (milk and fish consumption). Pregnant women and<p>women of child-bearing age in Belgium were found to still suffer from mild iodine deficiency<p>according to the current recommendations. This is at least partly linked to their lower<p>consumption of milk and dairy drinks compared to children and due to the higher iodine<p>requirements during pregnancy. Although the use of iodine-containing supplements among<p>pregnant women was found to be quite high in Belgium compared to other European<p>countries, because of the low iodine status among women of child-bearing age, women<p>became pregnant with a suboptimal iodine status.<p>In view of these findings, a further increase in the use of iodised instead of non-iodised<p>household salt and iodised salt by the bakers is recommended. In addition, one should put<p>efforts in increasing awareness among the public and among health professionals with<p>regard to iodine-rich food sources and with regard to the use of iodine-containing<p>supplements starting before conception and continuing during lactation.<p>In order to further improve iodine status in Belgium and sustain an optimal iodine status<p>over time, a legal framework is necessary. Mandatory fortification of all household salt and<p>bread is recommended, while non-iodised alternatives could still be offered upon specific<p>request. A rigorous monitoring program is indispensable, including vulnerable groups such as<p>pregnant and lactating women and infants. In addition, sustainability is a key issue as iodine<p>deficiency re-emerged in several industrial countries due to lack of interest, regulations and<p>monitoring. Political willing, salt reduction measures, changes in dietary habits among the<p>population and changes in industrial practices all may affect iodine status in Belgium in the<p>future. Therefore the strategy of controlling iodine deficiency needs to be directed and<p>monitored by a Belgian Scientific Committee for the Control of iodine deficiency disorders. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

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