992 resultados para Biochemical Changes


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OBJECTIVE: To analyze the amount of glycosaminoglycans in the uterine cervix during each phase of the rat estrous cycle. DESIGN: Based on vaginal smears, forty female, regularly cycling rats were divided into four groups (n = 10 for each group): GI - proestrous, GII - estrous, GIII - metaestrous and GIV - diestrous. Animals were sacrificed at each phase of the cycle, and the cervix was immediately removed and submitted to biochemical extraction and determination of sulfated glycosaminoglycans and hyaluronic acid. The results were analyzed by ANOVA followed by the Bonferroni post-hoc test. RESULTS: The uterine cervix had the highest amount of total sulfated glycosaminoglycans and dermatan sulfate during the estrous phase (8.90 ± 0.55 mg/g of cetonic extract, p<0.001; and 8.86 ± 0.57 mg/g of cetonic extract, p<0.001). In addition, there was more heparan sulfate at the cervix during the proestrous phase (0.185 ± 0.03 mg/g of cetonic extract) than during any other phase (p<0.001). There were no significant changes in the concentration of hyaluronic acid in the uterine cervix during the estrous cycle. CONCLUSION: Our data suggest that the amount of total sulfated glycosaminoglycans may be influenced by hormonal fluctuations related to the estrous cycle, with dermatan sulfate and heparan sulfate being the glycosaminoglycans most sensitive to hormonal change.

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Stress is triggered by numerous unexpected environmental, social or pathological stimuli occurring during the life of animals, including humans, which determine changes in all of their systems. Although acute stress is essential for survival, chronic, long-lasting stress can be detrimental. In this review, we present data supporting the hypothesis that stress-related events are characterized by modifications of oxidative/nitrosative pathways in the brain in response to the activation of inflammatory mediators. Recent findings indicate a key role for nitric oxide (NO) and an excess of pro-oxidants in various brain areas as responsible for both neuronal functional impairment and structural damage. Similarly, cyclooxygenase-2 (COX-2), another known source of oxidants, may account for stress-induced brain damage. Interestingly, some of the COX-2-derived mediators, such as the prostaglandin 15d-PGJ2 and its peroxisome proliferator-activated nuclear receptor PPARγ, are activated in the brain in response to stress, constituting a possible endogenous anti-inflammatory mechanism of defense against excessive inflammation. The stress-induced activation of both biochemical pathways depends on the activation of the N-methyl-D-aspartate (NMDA) glutamate receptor and on the activation of the transcription factor nuclear factor kappa B (NFκB). In the case of inducible NO synthase (iNOS), release of the cytokine TNF-α also accounts for its expression. Different pharmacological strategies directed towards different sites in iNOS or COX-2 pathways have been shown to be neuroprotective in stress-induced brain damage: NMDA receptor blockers, inhibitors of TNF-α activation and release, inhibitors of NFκB, specific inhibitors of iNOS and COX-2 activities and PPARγ agonists. This article reviews recent contributions to this area addressing possible new pharmacological targets for the treatment of stress-induced neuropsychiatric disorders.

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Exercise-induced vessel changes modulate arterial pressure (AP) in male spontaneously hypertensive rats (SHR). Vascular endothelial growth factor (VEGF) is important for angiogenesis of skeletal muscle. The present study evaluated the time course of VEGF and angiogenesis after short- and long-term exercise training of female SHR and Wistar Kyoto (WKY) rats, 8-9 weeks (200-250 g). Rats were allocated to daily training or remained sedentary for 3 days (N = 23) or 13 weeks (N = 23). After training, the carotid artery was catheterized for AP measurements. Locomotor (tibialis anterior and gracilis) and non-locomotor skeletal muscles (temporalis) were harvested and prepared for histologic and protein expression analyses. Training increased treadmill performance by all groups (SHR = 28%, WKY = 64%, 3 days) and (SHR = 141%, WKY = 122%, 13 weeks). SHR had higher values of AP than WKY (174 ± 4 vs 111 ± 2 mmHg) that were not altered by training. Three days of running increased VEGF expression (SHR = 28%, WKY = 36%) simultaneously with an increase in capillary-to-fiber ratio in gracilis muscle (SHR = 19%, WKY = 15%). In contrast, 13 weeks of training increased gracilis capillary-to-fiber ratio (SHR = 18%, WKY = 19%), without simultaneous changes in VEGF expression. Training did not change VEGF expression and capillarity of temporalis muscle. We conclude that training stimulates time- and tissue-dependent VEGF protein expression, independent of pressure levels. VEGF triggers angiogenesis in locomotor skeletal muscle shortly after the exercise starts, but is not involved in the maintenance of capillarity after long-term exercise in female rats.

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The effects of thermal treatment on the wettability and shrink resistance of Araucaria angustifolia (Parana pine) were studied from 20 to 200 °C. The contact angles of water droplets on untreated and heat-treated samples were measured by the sessile drop method in the grain of heartwood and sapwood cut in the radial, longitudinal, and tangential directions. A significant increase of the contact angles was verified for the samples from room temperature to 120 °C, in particular in the radial and tangential directions; at higher temperatures, the contact angles assumed almost constant values. From 120 to 200 °C, the sapwood of Araucaria angustifolia showed better dimensional stability and lower thermal resistance when compared to the heartwood. Variations of color were also studied by using the CIELab system, which showed to be capable of accurately distinguishing samples treated at different temperatures.

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PURPOSE: Compare parents' reports of youth problems (PRYP) with adolescent problems self-reports (APSR) pre/post behavioral treatment of nocturnal enuresis (NE) based on the use of a urine alarm. MATERIALS AND METHODS: Adolescents (N = 19) with mono-symptomatic (primary or secondary) nocturnal enuresis group treatment for 40 weeks. Discharge criterion was established as 8 weeks with consecutive dry nights. PRYP and APSR were scored by the Child Behavior Checklist (CBCL) and Youth Self-Report (YSR). RESULTS: Pre-treatment data: 1) Higher number of clinical cases based on parent report than on self-report for Internalizing Problems (IP) (13/19 vs. 4/19), Externalizing Problems (EP) (7/19 vs. 5/19) and Total Problem (TP) (11/19 vs. 5/19); 2) Mean PRYP scores for IP (60.8) and TP (61) were within the deviant range (T score ≥ 60); while mean PRYP scores for EP (57.4) and mean APSR scores (IP = 52.4, EP = 49.5, TP = 52.4) were within the normal range. Difference between PRYP' and APSR' scores was significant. Post treatment data: 1) Discharge for majority of the participants (16/19); 2) Reduction in the number of clinical cases on parental evaluation: 9/19 adolescents remained within clinical range for IP, 2/19 for EP, and 7/19 for TP. 3) All post-treatment mean scores were within the normal range; the difference between pre and post evaluation scores was significant for PRYP. CONCLUSIONS: The behavioral treatment based on the use of urine alarm is effective for adolescents with mono-symptomatic (primary and secondary) nocturnal enuresis. The study favors the hypothesis that enuresis is a cause, not a consequence, of other behavioral problems.

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Changes in the Brazilian continental margins oceanic productivity and circulation over the last 27,000 years were reconstructed based on sedimentological and microfaunal analyses. Our results suggest that oceanic paleoproductivity and the supply of terrigenous sediments to the Brazilian continental margin were higher during the Last Glacial Maximum (LGM) than during the Holocene. These changes may have been primarily influenced by significant sea level fluctuations that have occurred since the late Pleistocene. During the LGM, the lower sea level, higher productivity and lower sea-surface paleotemperatures may have been the result of the offshore displacement of the main flow of the Brazil Current. However, during the Holocene, the warm waters of the Brazil Current were displaced toward the coast. This displacement contributed to the increase in water temperature and prevented an increase in oceanic productivity. The decrease in terrigenous supply since the LGM could be related to the increase of the extension of the continental shelf and/or drier climatic conditions.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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OBJETIVO: Avaliar se o conteúdo de auto-anticorpos anti-LDL oxidada (anti-LDLox) no plasma de adolescentes correlaciona-se com suas medidas antropométricas e com o perfil lipídico. MÉTODOS: O estudo incluiu 150 adolescentes com idade entre 10 e 15 anos, recrutados do ambulatório de obesidade da Universidade Federal de São Paulo (SP) e de escolas públicas de Piracicaba (SP). Foram avaliadas medidas antropométricas, como índice de massa corporal, circunferência de cintura e do braço, classificando os adolescentes em eutrófico, sobrepeso e obeso. Para as análises bioquímicas, foi realizado o perfil lipídico através de métodos enzimáticos colorimétricos, e para detecção do conteúdo de auto-anticorpos anti-LDLox, utilizou-se o método de ELISA. RESULTADOS: Segundo análises das variáveis antropométricas, o grupo obeso apresentou perfil alterado em relação aos grupos eutrófico e sobrepeso (p < 0,01), indicando risco cardiovascular. Quando o perfil lipídico foi avaliado, observaram-se diferenças estatisticamente significativas para as concentrações de colesterol total (p = 0,011), HDL-colesterol (p = 0,001) e LDL-colesterol (p < 0,042) nos grupos eutrófico e obeso. Para as análises de auto-anticorpos anti-LDLox plasmática, os grupos sobrepeso (p = 0,012) e obeso (p < 0,001) apresentaram valores superiores ao grupo eutrófico. Também houve correlações entre os auto-anticorpos anti-LDLox e variáveis antropométricas. CONCLUSÃO: A presença de auto-anticorpos anti-LDLox em adolescentes e as alterações metabólicas no perfil lipídico variaram de modo proporcional com parâmetros antropométricos, o que torna o conteúdo de anti-LDLox um potencial indicador bioquímico de risco para síndrome metabólica.

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A técnica de biópsia hepática em ruminantes tem importante valor no diagnóstico clínico de doenças tóxicas e metabólicas, em especial nos desequilíbrios minerais. As técnicas mais comumente utilizadas restringem análises devido ao limitado volume de tecido obtido. No presente trabalho, avaliou-se o uso de uma técnica de biópsia hepática por laparotomia paracostal em bovinos e búfalos. Foram utilizados 10 bovinos e 10 búfalos hígidos. Os animais foram mantidos em estação, sedados com xilazina e infiltrados localmente com lidocaína e epinefrina. O acesso à cavidade abdominal foi realizado por meio de uma incisão dorso-ventral de 15cm no flanco direito, iniciada ventralmente (cerca de 4-5cm) ao processo transverso da 2a ou 3a vértebra lombar e situada caudalmente (cerca de 4cm) e paralelamente à 13a costela, obtendo-se visualização do fígado. Foi então realizado pinçamento do bordo caudal do órgão com pinça Doyen para remoção de fragmento hepático (2 a 4g). Procedeu-se o fechamento da cavidade abdominal como de rotina. Foram analisados os parâmetros bioquímicos e hematológicos antes do procedimento (tempo zero) e após 24 horas, 48 horas, 5 dias e 10 dias após a biópsia. Todas as variáveis bioquímicas estudadas retornaram aos valores basais 5 e 10 dias após o procedimento nos bovinos e búfalos, respectivamente. O tempo médio de cirurgia por animal foi de 25 minutos. A biópsia hepática por laparotomia paracostal demonstrou ser uma técnica eficaz e de baixo risco à saúde dos animais, permitindo a coleta de suficiente quantidade de tecido hepática para realização de múltiplas análises.

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Yerba mate´ (Ilex paraguariensis) is rich in polyphenols, especially chlorogenic acids. Evidence suggests that dietary polyphenols could play a role in glucose absorption and metabolism. The aim of this study was to evaluate the antidiabetic properties of yerba mate´ extract in alloxan-induced diabetic Wistar rats. Animals (n ) 41) were divided in four groups: nondiabetic control (NDC, n=11), and diabetic yerba maté (DY, n = 10). The intervention consisted in the administration of yerba mate´ extract in a 1 g extract/ kg body weight dose for 28 days; controls received saline solution only. There were no significant differences in serum glucose, insulin, and hepatic glucose-6-phosphatase activity between the groups that ingested yerba maté extract (NDY and DY) and the controls (NDC and DC). However, the intestinal SGLT1 gene expression was significantly lower in animals that received yerba maté both in upper (p = 0.007) and middle (p < 0.001) small intestine. These results indicate that bioactive compounds present in yerba maté might be capable of interfering in glucose absorption, by decreasing SGLT1 expression

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In lymphocytes (LY), the well-documented antiproliferative effects of IFN-alpha are associated with inhibition of protein synthesis, decreased amino acid incorporation, and cell cycle arrest. However, the effects of this cytokine on the metabolism of glucose and glutamine in these cells have not been well investigated. Thus, mesenteric and spleen LY of male Wistar rats were cultured in the presence or absence of IFN-alpha, and the changes on glucose and glutamine metabolisms were investigated. The reduced proliferation of mesenteric LY was accompanied by a reduction in glucose total consumption (35%), aerobic glucose metabolism (55%), maximal activity of glucose-6-phosphate dehydrogenase (49%), citrate synthase activity (34%), total glutamine consumption (30%), aerobic glutamine consumption (20.3%) and glutaminase activity (56%). In LY isolated from spleen, IFN alpha also reduced the proliferation and impaired metabolism. These data demonstrate that in LY, the antiproliferative effects of IFN alpha are associated with a reduction in glucose and glutamine metabolisms.

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Though the replacement of European bees by Africanized honey bees in tropical America has attracted considerable attention, little is known about the temporal changes in morphological and genetic characteristics in these bee populations. We examined the changes in the morphometric and genetic profiles of an Africanized honey bee population collected near where the original African swarms escaped, after 34 years of Africanization. Workers from colonies sampled in 1968 and in 2002 were morphometrically analyzed using relative warps analysis and an Automatic Bee Identification System (ABIS). All the colonies had their mitochondrial DNA identified. The subspecies that mixed to form the Africanized honey bees were used as a comparison for the morphometric analysis. The two morphometric approaches showed great similarity of Africanized bees with the African subspecies, Apis mellifera scutellata, corroborating with other markers. We also found the population of 1968 to have the pattern of wing venation to be more similar to A. m. scutellata than the current population. The mitochondrial DNA of European origin, which was very common in the 1968 population, was not found in the current population, indicating selective pressure replacing the European with the African genome in this tropical region. Both morphometric methodologies were very effective in discriminating the A. mellifera groups; the non-linear analysis of ABIS was the most successful in identifying the bees, with more than 94% correct classifications.

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Introduction. We present some protocols aiming at partially characterizing banana fruit quality through measurement of some key biochemical parameters. The principle, key advantages, starting plant material, time required and expected results are presented. Materials and methods. This part describes the required laboratory materials and the steps necessary for achieving four protocols making it possible to measure sugar, organic acids and free ACC contents, and in vitro ACC oxidase activity. Results. Standard results obtained by using the protocols described are presented in the figures.

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The changing pattern of developing cuticle and associated epidermis is described during the imaginal molt in the honey bee. Observations began immediately after the pupal molt, and included histological analyses of the integument during apolysis and the subsequent deposition and differentiation of the adult cuticle. Apolysis coincides with a marked increase in the thickness and reorganization of the epidermal layer, reflecting changes in cell structure. The epidermis remains thickened during the period of cuticle deposition, suggesting intense biosynthetic activity, but turns into a very thin layer during cuticle differentiation, clearly indicating that secretory activity for cuticle formation is terminating. The thoracic cuticle differentiates earlier and becomes thicker than the abdominal. The observed changes in integument structure provide insights that permit an improved physiological characterization for staging pupal and pharate adult development.

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The aim of the present study was to investigate whether the perception of presentation durations of pictures of different body postures was distorted as function of the embodied movement that originally produced these postures. Participants were presented with two pictures, one with a low-arousal body posture judged to require no movement and the other with a high-arousal body posture judged to require considerable movement. In a temporal bisection task with two ranges of standard durations (0.4/1.6 s and 2/8 s), the participants had to judge whether the presentation duration of each of the pictures was more similar to the short or to the long standard duration. The results showed that the duration was judged longer for the posture requiring more movement than for the posture requiring less movement. However the magnitude of this overestimation was relatively greater for the range of short durations than for that of longer durations. Further analyses suggest that this lengthening effect was mediated by an arousal effect of limited duration on the speed of the internal clock system.