Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2004. / Vita. Bibliography: 148-158.

Dedicated to Valentine Mott, M.D. / Last page blank. Microform version available in the Readex Early American Imprints series.

Made available in DSpace on 2015-03-26T13:30:54Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3514510 bytes, checksum: 25d1dc8edd8426770340b8188e8a7bec (MD5) Previous issue date: 2007-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work evaluated ultrastrucural alterations in the midgut of Brontocoris tabidus Signoret (Heteroptera: Pentatomidae) caused by the starvig or feeding in differents periods, this condition can occur in its natural enviroment, being those important factors for the understanding the evolution of the alimentary habit of that predator. Adults of the B. tabidus received differents treatments (starvation or feeding with plant and prey) and their midgut were dissected and divided in anterior, medium and posterior, which were processed and analyzed in light and trasmission eletronic microscope. The epitelium of the midgut of B. tabidus is formed by digestive and regenerative cells. The anterior portion of the midgut of B. tabidus starved or feeding on eucalyptus leaves, didn t present glycogen storage. Brontocoris tabidus fed on plant have multivesicular bodies in this region and spherocrystals after six hour the feeding with prey. The microvilli of the medium midgut of B. tabidus are longer than ones of the anterior and posterior midgut. The posterior midgut differs of the other two parts, for presenting great amount the mitochondria, rough endoplasmatic reticule and double membrane vesicules in the apical region six hours after feeding. The anterior, medium and posterior regions of the midgut of B. tabidus synthesize digestive enzimes, absorb eletrolytes and nutrients, stored and excrete substances. / Este trabalho avaliou alterações ultra-estruturais no intestino médio de Brontocoris tabidus Signoret (Heteroptera: Pentatomidae) causado pelo jejum ou alimentação em diferentes períodos, condição esta que pode ocorrer em seu ambiente natural, sendo esses fatores importantes para o entendimento da evolução do hábito alimentar desse predador. Adultos de B. tabidus receberam diferentes tratamentos (jejum ou alimentado com planta e presa) e seu intestino médio foi dissecado e dividido em anterior, mediano e posterior, as quais foram processadas e analisadas em microscópio de luz e eletrônico de transmissão. O epitélio do intestino médio de B. tabidus é formado por células digestivas e regenerativas. A porção anterior do intestino médio de B. tabidus em jejum ou alimentado com folhas de eucalipto, não apresentou reservas de glicogênio. B. tabidus alimentado com planta apresentou corpos multivesiculares nessa região e esferocristais seis horas após a alimentação com presa. As microvilosidades do intestino médio mediano de B. tabidus são mais longas que as da região anterior e posterior. O intestino médio posterior difere das outras duas partes, por apresentar grande quantidade de mitocôndrias, retículo endoplasmático rugoso e vesículas de dupla membrana na região apical após seis horas de alimentação. As regiões anterior, mediana e posterior do intestino médio de B. tabidus sintetizam enzimas digestivas, absorvem eletrólitos, nutrientes, estocam e excretam substâncias.

Primary chick embryo liver cells were used to explore the regulation of δ-aminolevulinic acid synthase and heme oxygenase, the enzymes that catalyze the rate-limiting reactions of heme anabolism and catabolism, respectively. The general focus of the work was the exploration of the novel observation in which glutethimide and iron synergistically induced both δ-aminolevulinic acid synthase and heme oxygenase, a phenomenon that would not be predicted a priori. The course of events appeared to be: first, that heme synthesis was increased after addition of the glutethimide and that iron potentiated heme synthesis; second, the heme induced heme oxygenase five to ten fold; and third, that heme oxygenase degraded the heme permitting an uncontrolled induction of δ-aminolevulinic acid synthase. This induction of δ-aminolevulinic acid synthase could be prevented by the addition of a metalloporphyrin inhibitor of heme oxygenase. Induced δ-aminolevulinic acid synthase activity could be dramatically reduced by the addition of nanomolar concentrations of a metalloporphyrin, inhibitory for heme oxygenase, and heme. Specific observations related to the synergistic induction of heme oxygenase by glutethimide and iron was that the induction of heme oxygenase activity by glutethimide and iron occurred rapidly, with maximal increases occurring four to six hours after original treatment. Induction of heme oxygenase by glutethimide and iron was shown to be dependent on de novoheme synthesis since 4,6-dioxoheptanoic acid, a potent and specific inhibitor of heme biosynthesis, prevented the activity of heme oxygenase from increasing in the presence of glutethimide and iron. Induction of activity was associated with increases in heme oxygenase mRNA and protein; and, when induction was prevented by 4,6-dioxoheptanoic acid, no increase in either mRNA or immunoreactive protein was observed. δ-Aminolevulinic acid synthase activity was also synergistically increased by glutethimide and iron; this increase occurred 4-6 hours after maximal heme oxygenase activity had been attained. The temporal relationship between the induction of δ-aminolevulinic acid synthase and heme oxygenase suggested that the oxygenase depleted a regulatory heme pool that would normally prevent uncontrolled induction of the synthase. When cultures were exposed to tin-mesoporphyrin, a potent inhibitor of heme oxygenase, induction of δ-aminolevulinic acid synthase, normally produced by glutethimide and iron, was prevented. Addition of tin-mesoporphyrin after δ-aminolevulinic acid synthase induction had already been established promptly halted any further induction. When heme or a combination of heme and tin-mesoporphyrin was added after induction of δ-aminolevulinic acid synthase was established, activity of the synthase was rapidly reduced. Finally, experiments in primary chick embryo liver cells with tin-, zinc- and copper- chelated porphyrins were done to assess their effects on activities of δ-aminolevulinic acid synthase, induced by prior treatment of cells with glutethimide and iron. Nanomolar concentrations of zinc- or tin porphyrins reduced δ-aminolevulinic acid synthase activities, while copper-chelated porphyrins did not. When nanomolar concentrations of heme were added with zinc- or tin-porphyrins, δ-aminolevulinic acid synthase activity was further reduced. Effects of the non-heme metalloporphyrins on δ-aminolevulinic acid synthase were closely correlated with their abilities to inhibit heme oxygenase (r=0.78). The largest decrease of δ-aminolevulinic acid synthase (67%) was obtained with zinc-mesoporphyrin and heme. There was a rapid appearance of the cytosolic, precursor form of δ-aminolevulinic acid synthase in the presence of both 10 μM heme or 50 nM zinc-mesoporphyrin and 200 nM heme. Reduction of the half-life of the mRNA from 5.2 hours to 2.2-2.5 hours was observed in the presence of both 10 μM heme or 50 nM zinc-mesoporphyrin and 200 nM heme. In summary, the chick embryo liver cell culture model treated with glutethimide and iron may serve as one experimental model for patients suffering from acute porphyrias, in whom uncontrolled induction of hepatic δ-aminolevulinic acid synthase plays a key role in pathogenesis of disease. The synergistic induction of δ-aminolevulinic acid synthase in the presence of glutethimide and iron may serve as an experimental paradigm for this disease. The reduction of δ-aminolevulinic acid synthase by low doses of zinc-mesoporphyrin and heme may help form the experimental foundation for eventual studies in patients suffering from acute porphyrias.

The overall aim of this thesis was to determine how natural killer (NK) cells regulate virus infections in vivo. Anti-viral mechanisms by which NK cells control murine cytomegalovirus (MCMV) infection in the spleens and livers of adult C57BL/6 mice were first studied, revealing different mechanisms of control in different organs. Three days post-infection, MCMV titers in the spleens of perforin-deficient (perforin 0/0) mice were higher than in wild type controls, but no elevation of liver titers was found in perforin 0/0 mice. NK cell depletion in MCMV-infected perforin 0/0 mice resulted only in an increase in liver viral titers but not in spleen titers. Depletion of IFN-γ in adult C57BL/6 mice by injections with mAbs to IFN-γ resulted in an increase in viral titers in the liver but not in the spleen. Analyses using IFN-γ-receptor-deficient (IFN-γR0/0) mice, rendered chimeric with C57BL/6 bone marrow cells, indicated that even though the donor spleen cells could respond to IFN-γ, the depletion of NK cells in a recipient environment where the host cells could not respond to IFN-γ caused an increase in MCMV titers in the spleens but had little effect in the liver. IFN-γ has the ability to induce a variety of cells to produce nitric oxide (NO), and administrating the nitric oxide synthase (NOS) inhibitor Nω-monomethyl-L-arginine (L-NMA) into MCMV-infected adult C57BL/6 mice resulted in MCMV titer increases in the liver but not in the spleen. These data indicate that in adult C57BL/6 mice, there is a dichotomy in the mechanisms utilized by NK cells in the regulation of MCMV in different organs. In the spleen NK cells exert their effects in a perforin-dependent manner, suggesting a cytotoxic mechanism, whereas in the liver the production of IFN-γ by NK cells may be a predominant mechanism in the regulation of MCMV synthesis. These results may explain why the Cmv-1r (Cmv-1-resistant) locus, which maps closely to genes regulating NK cell cytotoxic function, confers an NK cell-dependent resistance to MCMV infection in the spleen but not in the liver. The ability of adoptively transferred cells to protect suckling mice from MCMV was another model used to study the mechanisms utilized by NK cells in the regulation of MCMV. Adoptive transfers of 129, C57BL/6 and perforin 0/0 spleen cells or lymphokine-activated killer (LAK) cells into 4 - 6 day old MCMV-infected C57BL/6 suckling mice significantly lowered the splenic MCMV titers in these mice compared to the infected controls. Adoptive transfers of C57BL/6 spleen cells into MCMV-infected 129 suckling mice also decreased the amount of MCMV in the 129 suckling mice, but C57BL/6 spleen cells could not regulate MCMV synthesis when adoptively transferred into 129/IFN-γR0/0 suckling mice. These results suggest that, in the suckling mouse model, the regulation of MCMV by the adoptively transferred NK cells is via an IFN-γ-dependent, perforin-independent, Cmv-1-independent mechanism. The Cmv-1 gene locus resides within the NK gene complex, in close proximity to the Ly49 NK cell receptor family. Analyses were carried out to determine if any of the 4 known Ly49 NK cell receptors (Ly49A, C, D and G2) played a role in the control of MCMV synthesis by NK cells. Studies comparing the expression of the different Ly49 NK cell subsets in the spleen and the peritoneal cavity revealed that there were differences in the distribution of the Ly49 receptors on NK1.1+ cells. Three days post-MCMV infection, the percentage of NK1.1+- Ly49+ NK cells in the spleen and the peritoneal cavity were different than in naive controls. Within the splenic NK1.1+ population, increases in NK1.1+ -Ly49A+ and NK1.1+-Ly49G2+ cells but decreases in NK1.1+-Ly49C+ and NK1.1+-Ly49D+ cells were observed. These changes in the spleen were accompanied by a concomitant decrease in NK1.1+ - Ly49A+ cells and increases in NK1.1+-Ly49C+, NK1.1+-Ly49D+ and NK1.1+-Ly49G2+ cells within the NK1.1+ population in the peritoneal cavity. These data suggest that 3 days post-MCMV infection, there may be movement of NK cells between the different organs. The role of Ly49 NK cell receptors in the regulation of MCMV was tested using adult C57BL/6 mice depleted of single or multiple Ly49 NK cell subsets. These in vivo depletions did not affect the ability of the residual NK cells to regulate MCMV synthesis. LAK cells sorted into the different Ly49 NK cell subsets and adoptively transferred into C57BL/6 suckling mice lowered the splenic MCMV titers in these mice. Together, these results indicate that even though there is a redistribution of the Ly49 NK cell subsets during MCMV infection, the presence or absence of anyone of the 4 tested Ly49 NK cell receptors does not affect the regulation of MCMV by NK cells. However, there remain a possibility that one of the undefined Ly49 receptors or an untested NK cell receptor may be important in the control ofMCMV. Most of the cloned NK cell receptors have been shown to bind to MHC class I molecules, and MHC class I antigens have been implicated as modulators of target cell sensitivity to NK cell-mediated lysis. The regulation of virus infections and the fate of NK cells and their natural targets was examined in β2-microglobulin-deficient mice [β2m (-/-)], which have defective MHC class I expression. Infections with either the NK cell-sensitive MCMV or the NK cell-resistant lymphocytic choriomeningitis virus (LCMV) significantly augmented NK cell activity in either C57BL/6 or β2m (-/-) mice. Depletion of NK cells in vivo with antiserum to asialo GM1 markedly enhanced the synthesis of MCMV but had no effect on the synthesis of LCMV in either strain of mouse. Adoptively transferred β2m (-/-) spleen cells lowered splenic MCMV titers in C57BL/6 suckling mice, not unlike adoptively transferred C57BL/6 spleen cells. Analysis of naturally NK cell-sensitive thymocyte targets from these virus-infected β2m (-/-) mice revealed no cell surface expression of class I MHC detectable by conformation-dependent or -independent antibodies, but the virus infections enhanced class I expression on thymocytes from C57BL/6 mice. The sensitivity of C57BL/6 thymocytes to NK cell-mediated lysis was markedly reduced after in vivo poly inosinic:cytidylic (poly I:C) treatment or viral infection; in contrast, the sensitivity of the β2m (-/-) thymocytes was significantly less affected by poly I:C or viral infection. These data indicate that the normal expression of MHC class I antigens on NK cells or their targets is not required for the anti-viral functions of NK cells against an NK-sensitive virus (MCMV) nor do they protect an NK-resistant virus (LCMV) from the anti-viral activity of NK cells. Together, the data presented in this thesis help to further our understanding of the mechanisms utilized by NK cells in the control ofMCMV in both adult and suckling mice, and also help clarify the roles played by Ly49 NK cell receptors and MHC class I molecules in the regulation of MCMV.

Resumo: Neste trabalho foi avaliado o uso de enzimas exógenas: amilase com endo-β-glucanase (AG) e fitase (Fi) em dietas para cachara (Pseudoplatystoma reticulatum). Foram realizados ensaios de digestibilidade de nutrientes de dietas contendo quatro diferentes níveis destas enzimas, em esquema fatorial 4x4. Este estudo mostrou que a adição das enzimas alteraram os valores dos coeficientes de digestibilidade aparente dos nutrientes e de absorção dos minerais. No entanto as alterações foram dependentes dos níveis utilizados, e houve interações entre os níveis das enzimas estudadas. Após, foi realizado um ensaio de desempenho com 70 dias de duração, no qual foi avaliado o efeito da ausência de enzimas ou adição de 150 mg de AG kg-1; 2.500 UF kg-1; 100 mg de AG kg-1 com 1.500 UF kg-1 em duas dietas (com 30 ou 60% da proteína de origem animal). Neste experimento, além do desempenho produtivo dos peixes, foram observadas alterações na produção endógena das enzimas digestivas; alterações histológicas do trato gastrintestinal, pâncreas e fígado; alterações na composição da carcaça; e na retenção de fósforo, cálcio e magnésio nos ossos. O sinergismo observado entre as enzimas estudadas sugere que o uso destas enzimas pode melhorar o aproveitamento das dietas para peixes carnívoros, aumentando a energia disponível, mas isto vai depender do balanceamento adequado da dieta em que são empregadas. As alterações das enzimas digestivas e histológicas observadas mostraram que as adições das enzimas exógenas avaliadas exerceram um papel importante na nutrição do cachara, no aumento do aproveitamento da proteína e dos carboidratos / Abstract: This work evaluated the exogenous enzymes amylase with endo-β-glucanase (AG) and phytase (Fi) in Barred sorubim (Pseudoplatystoma reticulatum) diets. Apparent nutrients digestibility assays were done with four different enzyme levels, in a 4x4 factorial scheme. This study showed that the enzymes addition changed the nutrients apparent digestibility coefficients and the minerals absorption. However, the alterations were dependents on the levels used, and there were interactions between the evaluated enzymes levels. After, a 70 days long performance assay was done, in which was evaluated the absence or presence of 150 mg of AG.kg-1; 2,500 UF.kg-1; 100 mg of AG.kg-1 + 1,500 UF.kg-1 enzymes in two diets (30 or 60% of animal-protein). In this experiment, fish performance and alterations in the endogenous production of the digestive enzymes; histologic changes in the gastrointestinal tract, pancreas, and liver; carcass composition changes; phosphorus, calcium, and magnesium retention in the bone were observed. The synergism observed among the enzymes evaluated suggests that its use can improve the diets profit to carnivore fishes, increasing the available energy, depending on the adequate balance in each diet though. The digestive and histologic enzymes alterations observed showed that the addition of the exogenous enzymes evaluated played an important role in the Barred sorubim nutrition, in the protein and carbohydrates profit improving / Orientador: Dalton José Carneiro / Coorientador: João Martins Pizauro Júnior / Banca: Wilson Massamitu Furuya / Banca: Antonio Carlos de Laurentiz / Banca: Elisabeth Criscuolo Urbinati / Banca: Marta Verardino De Stefani / Doutor

Streptococcus thermophilus est la bactérie lactique la plus utilisée après Lactococcus lactis dans l’industrie laitière pour la fabrication de yaourts et de fromages. Il s’agit du seul streptocoque à avoir le statut de bactérie GRAS (Generally Recognized As Safe). Malgré de récentes études montrant sa capacité à survivre dans le tractus digestif humain et des effets santé intéressants, le statut probiotique de S. thermophilus reste l’objet d’interrogations. Ainsi, les objectifs de cette thèse ont été (i) d’approfondir les connaissances sur la capacité de survie de S. thermophilus en conditions digestives humaines simulées, grâce, en particulier, au système dynamique multi-compartimenté TIM (TNO gastro-intestinal model) et (ii) d’identifier des gènes de S. thermophilus spécifiquement activés dans des conditions complexes comme l’environnement digestif, à l’aide de la technologie R-IVET (Recombinase-based In Vivo Expression Technology) basée sur l’excision d’un gène rapporteur. Le système R-IVET est composé d’un vecteur plasmidique portant la recombinase cre démunie de son promoteur et d’une cassette chromosomique composée d’un gène marqueur entouré de sites loxP reconnus par Cre. Ainsi, dans un premier temps, nous avons implanté la technologie R-IVET chez S. thermophilus LMD-9. Sa fonctionnalité a été testée et validée in vitro et dans le tractus digestif de la souris. Puis, l’étude de la survie de quatre souches de S. thermophilus dans le système TIM a montré que trois d’entre elles étaient plus résistantes que la quatrième, très sensible aux stress gastro-intestinaux. Ces résultats confirment donc que la survie de S. thermophilus dans l’environnement digestif est souche-dépendante. Ils montrent également que la survie de S. thermophilus est influencée par la matrice alimentaire, celle-ci étant plus importante en lait fermenté qu’en lait liquide. Enfin, dans un troisième temps, nous avons construit une première banque génomique R-IVET, en clonant en amont de cre des fragments d’ADN génomiques provenant de LMD-9. Cette banque a été testée uniquement en conditions gastriques simulées dans le TIM. Puis, après avoir optimisé notre outil chez S. thermophilus en améliorant la méthode d’identification des gènes activés, une seconde banque R-IVET a été testée dans l’ensemble du tractus gastro-intestinal (TIM) et en système batch en présence du microbiote intestinal. Ces expériences nous ont permis de mettre en évidence, pour la première fois, des gènes de S. thermophilus spécifiquement activés dans les différents compartiments digestifs de l’homme. Ce travail de thèse contribue ainsi à approfondir les connaissances sur le comportement de cette bactérie dans le tractus gastro-intestinal humain. A moyen terme, ces travaux devraient permettre d’identifier des marqueurs de survie de S. thermophilus et de mieux comprendre son activité métabolique dans l’environnement digestif, facilitant la sélection de souches dans la perspective de développement d’aliments fonctionnels. / Streptococcus thermophilus is the lactic acid bacterium most commonly used after Lactococcus lactis in the dairy industry for the production of yogurt and cheese. It is the only streptococcus strain to have the GRAS status (Generally Recognized As Safe). Despite recent studies showing its ability to survive through the human digestive tract and valuable health effects, the probiotic status of S. thermophilus remains questioned. Thus, the objectives of this pHD work were (i) to increase knowledge on the survival of S. thermophilus in human digestive environment, by using the dynamic multi-compartmental TIM system (TNO gastro-intestinal model) and (ii) to identify the genes from S. thermophilus that are specifically activated in complex digestive environment using the R-IVET technology (Recombinase-based In Vivo Expression Technology). R-IVET is based on the excision of a reporter gene and consists of a plasmid vector carrying the promoterless recombinase cre and a chromosomal cassette composed of a marker gene flanked by loxP recognized by Cre. First, we introduced the R-IVET technology in S. thermophilus LMD-9. Its functionality was tested and validated in vitro and in the mice digestive tract. Then, the survival of four S. thermophilus strains was investigated in the TIM system and we showed that 3 of these strains were more resistant than the other one, very sensitive to gastrointestinal stresses. These results strengthen the idea that the survival of S. thermophilus is strain-dependent. We also highlighted that the survival of S. thermophilus was influenced by the food matrix, being higher in fermented compared to liquid milk. Lastly, we constructed a first genomic R-IVET library, by cloning upstream of cre genomic DNA fragments from LMD-9. This library was tested only in gastric condition (TIM). After optimization of our tool in S. thermophilus (improvement of the method allowing identification of the activated genes), a second R-IVET library was tested throughout the gastrointestinal system (TIM) and in batch system including intestinal microbiota. By identifying bacterial genes specifically activated in human digestive conditions, this work contributes to extend our knowledge on the behavior of S. thermophilus in the human gastrointestinal tract. This could open up opportunities in determining survival markers for S. thermophilus and better describing its metabolic activity in the human gut, then facilitating the selection of strains that can be included in functional foods.

Made available in DSpace on 2015-07-22T20:49:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-29 / Objetivo: avaliar a ingestão alimentar, o estado nutricional e a prevalência de anemia por deficiência de ferro e de distúrbios digestivos em crianças com paralisia cerebral. Métodos: estudo realizado com 40 crianças até 10 anos de idade com paralisia cerebral. Realizou-se registro do consumo alimentar habitual de 24 horas, coleta de dados antropométricos, coleta de sangue por punção de veia periférica e registro de dados clínicos específicos para o diagnóstico dos distúrbios digestivos. Resultados: Os resultados encontrados garantem a necessidade de se realizar avaliação dietética personalizada. Em apenas 3 (7,5%) crianças foi diagnosticado anemia leve. Com relação ao estado nutricional, observou-se déficit mais acentuado no sexo masculino para estatura-idade. Dos 40 pacientes, 45% (n=18) e 40% (n=16) da amostra verificouse desnutrição aguda. Evidências de disfagia foram encontradas em 82,5% da amostra, sinais sugestivos de refluxo gastro-esofágico em 40,0% e constipação intestinal em 60,0% dos pacientes estudados. A ingestão hídrica das crianças com manifestações compatíveis com disfagia foi menor. Pacientes com evidência de disfagia apresentavam menor ingestão de líquidos (483,1±294,9 versus 992,9±292,2; p=0.001). As crianças com constipação, em relação às sem constipação apresentaram menor ingestão de fibras (9,2 ± 4,3 versus 12,3 ± 4,3; p=0,031) e líquidos (456,5 ± 283,1versus 741,1 ± 379,2; p=0,013). Conclusões: crianças com paralisia cerebral podem apresentar elevada prevalência de déficits antropométricos e distúrbios digestivos. Déficits de nutrientes na alimentação podem constituir risco para o desenvolvimento de distúrbios nutricionais exigindo uma avaliação dietética personalizada. / Objective: To evaluate food ingestion, the nutritional state and the prevalence of anemia by iron deficiency and the digestive disturbs in children with cerebral palsy. Methods: A study realized with 40 children with a maximum age of 10 years who suffer from cerebral palsy. A 24-hour food intake register and anthropometric evaluation were realized, the blood sample was collected by punction of a peripherical vein and the register of specific clinical data for the diagnostic of the digestive disturbs. Results: The results found guarantee the necessity to make a personal dietetic evaluation. In only 3 (7,5%) children the diagnostics revealed a mild anemia. Regarding the nutritional state, it was observed a more accentuated deficit in males by height-age. From 40 patients 45% (n=18) and 40% (n=16) of the sample it was observed a more acute malnutrition. Dysphagia evidences were found in 82,5% of the sample, suggestive signals of gastroesophageal reflow in 40,0% and intestinal constipation in 60,0% of the studied patients. Patients with a dysphagia evidence presented a smaller liquid intake (483,1±294,9 versus 992,9±292,2; p=0.001). The children with constipation, in relation to the ones without constipation presented less fiber intake (9,2 ± 4,3 versus 12,3 ± 4,3; p=0,031) and less liquid intake (456,5 ± 283,1versus 741,1 ± 379,2; p=0,013). Conclusions: Children with cerebral palsy can present an elevated prevalence of anthropometric deficits and digestive disturbs. Nutrient deficits in food intake can be a risk to start developing nutritional disturbs demanding a personal dietetic evaluation. / TEDE

Base teórica: Existem controvérsias quanto à quantidade ideal de calorias que pacientes críticos com insuficiência respiratória aguda devem receber, bem como aos efeitos das estratégias de terapia nutricional hipocalórica versus normocalórica nos desfechos clínicos e de tolerância gastrointestinal. Objetivo: Comparar o efeito de duas estratégias de terapia nutricional enteral (nutrição hipocalórica versus normocalórica) nos desfechos clínicos e na tolerância gastrointestinal de pacientes criticamente doentes em insuficiência respiratória aguda. Bases de dados pesquisadas: MEDLINE, EMBASE, SCOPUS e Cochrane Central Register of Controlled Trials até o período de agosto de 2014. Seleção dos estudos: Ensaios clínicos randomizados que compararam o efeito das estratégias de nutrição hipocalórica versus normocalórica nos desfechos clínicos principais [mortalidade na unidade de terapia intesiva (UTI), tempo de internação na UTI e tempo de ventilação mecânica] e nos sinais e sintomas gastrointestinais (regurgitação, aspiração, vômito, diarreia, constipação, distensão abdominal, elevado volume de resíduo gástrico e uso de agentes prócinéticos). Extração dos dados: Informações sobre a execução e qualidade dos estudos e características dos pacientes e dos desfechos de interesse foram extraídas. As estimativas de risco relativo (RR) e média da diferença (MD) foram sintetizadas sob o modelo de efeitos aleatórios. A heterogeneidade foi avaliada com Teste Q e I2. A análise de sensibilidade foi conduzida através de análise de subgrupos os quais foram classificados conforme a estratégia de terapia nutricional enteral utilizada (nutrição trófica versus nutrição hipocalórica moderada). A metanálise foi realizada com apoio do software RevMan v5.3. Resultados: Dentre os 798 estudos encontrados, quatro ensaios clínicos randomizados que avaliaram 1540 pacientes foram incluídos na avaliação qualitativa e quantitativa. Não houve diferença na mortalidade geral (RR, 0.92; 95% CI, 0.73 – 1,19; I2 31% p=0.23 para heterogeneidade). A análise de subgrupos verificou mortalidade geral significativamente menor no subgrupo que recebeu 59-72% das necessidades nutricionais (RR, 0.72; 95% CI, 0.53 – 0.98; I2 0% p=0.78 para heterogeneidade). Não foram encontradas diferenças entre os grupos quanto à mortalidade na UTI, tempo de permanência na UTI ou hospitalar e tempo de ventilação mecânica. Quanto à avaliação da tolerância gastrointestinal, o grupo que recebeu nutrição hipocalórica foi associado a uma menor ocorrência de vômitos, diarreia e constipação quando comparado ao grupo nutrição normocalórica. Não foram verificadas diferenças entre os grupos quanto aos sintomas de aspiração e distensão abdominal. Conclusão: A estratégia de terapia nutricional enteral hipocalórica em aporte moderado (59- 72%) foi associada à menor mortalidade geral. A tolerância gastrointestinal foi superior no grupo que recebeu nutrição hipocalórica. A oferta de terapia nutricional enteral hipocalórica em aporte moderado deve ser preferida em pacientes criticamente doentes. / Context: Controversy exists regarding the optimal amount of calories that critically ill patients with acute respiratory failure should consume as far as clinical outcomes and gastrointestinal tolerability are concerned. Objective: To compare the effect of two enteral nutrition strategies (underfeeding versus fullfeeding) on clinical outcomes and gastrointestinal tolerability in critically ill patients with acute respiratory failure. Data Sources: MEDLINE, EMBASE, SCOPUS and the Cochrane Central Register of Controlled Trials up to August 2014. Study Selection: Randomized Controlled Trials that compared the effects of underfeeding with full-feeding strategies on major clinical outcomes (ICU and overall mortality, ICU and hospital length of stay and mechanical ventilation) and gastrointestinal signs and symptoms (regurgitation, aspiration, vomiting, diarrhea, constipation, abdominal distention, elevated gastric residual volume and use of prokinetic agents). Data extraction: Studies’ information, patient’s characteristics and outcomes were extracted. Risk ratio (RR) and Mean Difference (MD) estimates were synthesized under a randomeffects model. Heterogeneity was evaluated using the Q test and I2. A sensitivity analysis on overall mortality was conducted, wherein the groups were classified according to the feeding strategy used (trophic versus hypocaloric nutrition). Meta-analyses were performed using RevMan v5.3 analysis software. Data synthesis: Among the 798 studies retrieved, four studies of 1540 patients were included. Interventional studies comparing underfeeding with full-feeding were not associated with significant difference in overall mortality (RR, 0.92; 95% CI, 0.73 – 1,19; I2 31% p=0.23 for heterogeneity). Subgroup analysis of the groups according to the amount of delivered calories showed that the overall mortality was significantly lower in the subgroup that achieved 59-72% of energy intake than in the full-feeding group (RR, 0.72; 95% CI, 0.53 – 0.98; I2 0% p=0.78 for heterogeneity). No differences were found between the underfeeding versus full-feeding groups regarding in the ICU mortality, ICU and hospital length of stay and duration of mechanical ventilation. As far as gastrointestinal tolerability is concerned, the underfeeding group showed lower occurrence of vomiting, regurgitation, use of prokinetic agents, elevated gastric residual volume occurrence, diarrhea and constipation when compared with the full-feeding strategy. No differences between the two groups were found for aspiration and abdominal distention. Conclusion: The underfeeding strategy was associated with lower overall mortality in the subgroup that achieved initial moderate intake. Gastrointestinal tolerability was improved by the underfeeding strategy. Initial moderate intake should be preferred rather than trophic or full-feeding in critically ill patients.

Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-18Bitstream added on 2014-06-13T19:04:37Z : No. of bitstreams: 1 stech_mr_dr_jabo.pdf: 1806594 bytes, checksum: c5ec84ba98becc882b11fe47213ba597 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Neste trabalho foi avaliado o uso de enzimas exógenas: amilase com endo-β-glucanase (AG) e fitase (Fi) em dietas para cachara (Pseudoplatystoma reticulatum). Foram realizados ensaios de digestibilidade de nutrientes de dietas contendo quatro diferentes níveis destas enzimas, em esquema fatorial 4x4. Este estudo mostrou que a adição das enzimas alteraram os valores dos coeficientes de digestibilidade aparente dos nutrientes e de absorção dos minerais. No entanto as alterações foram dependentes dos níveis utilizados, e houve interações entre os níveis das enzimas estudadas. Após, foi realizado um ensaio de desempenho com 70 dias de duração, no qual foi avaliado o efeito da ausência de enzimas ou adição de 150 mg de AG kg-1; 2.500 UF kg-1; 100 mg de AG kg-1 com 1.500 UF kg-1 em duas dietas (com 30 ou 60% da proteína de origem animal). Neste experimento, além do desempenho produtivo dos peixes, foram observadas alterações na produção endógena das enzimas digestivas; alterações histológicas do trato gastrintestinal, pâncreas e fígado; alterações na composição da carcaça; e na retenção de fósforo, cálcio e magnésio nos ossos. O sinergismo observado entre as enzimas estudadas sugere que o uso destas enzimas pode melhorar o aproveitamento das dietas para peixes carnívoros, aumentando a energia disponível, mas isto vai depender do balanceamento adequado da dieta em que são empregadas. As alterações das enzimas digestivas e histológicas observadas mostraram que as adições das enzimas exógenas avaliadas exerceram um papel importante na nutrição do cachara, no aumento do aproveitamento da proteína e dos carboidratos / This work evaluated the exogenous enzymes amylase with endo-β-glucanase (AG) and phytase (Fi) in Barred sorubim (Pseudoplatystoma reticulatum) diets. Apparent nutrients digestibility assays were done with four different enzyme levels, in a 4x4 factorial scheme. This study showed that the enzymes addition changed the nutrients apparent digestibility coefficients and the minerals absorption. However, the alterations were dependents on the levels used, and there were interactions between the evaluated enzymes levels. After, a 70 days long performance assay was done, in which was evaluated the absence or presence of 150 mg of AG.kg-1; 2,500 UF.kg-1; 100 mg of AG.kg-1 + 1,500 UF.kg-1 enzymes in two diets (30 or 60% of animal-protein). In this experiment, fish performance and alterations in the endogenous production of the digestive enzymes; histologic changes in the gastrointestinal tract, pancreas, and liver; carcass composition changes; phosphorus, calcium, and magnesium retention in the bone were observed. The synergism observed among the enzymes evaluated suggests that its use can improve the diets profit to carnivore fishes, increasing the available energy, depending on the adequate balance in each diet though. The digestive and histologic enzymes alterations observed showed that the addition of the exogenous enzymes evaluated played an important role in the Barred sorubim nutrition, in the protein and carbohydrates profit improving