90 resultados para N-15 Backbone Dynamics
Resumo:
FUNDAMENTO: Segundo a Organização Mundial de Saúde (OMS), as doenças cardiovasculares (DCV) são responsáveis por 16,7 milhões de mortes/ano. Evidências mostram que as DCV resultam da interação entre fatores de risco variados, presentes desde a infância. OBJETIVO: Verificar, em profissionais da área médica, a presença e evolução de alguns fatores de risco cardiovasculares (FRCV) em um intervalo de 15 anos. MÉTODOS: Analisamos um grupo de indivíduos ao ingressar na faculdade de medicina e repetimos a análise 15 anos depois, comparando os dados encontrados. Utilizamos questionários sobre FRCV (hipertensão arterial sistêmica (HAS), diabete melito (DM), dislipidemia e história familiar de DCV precoce, tabagismo, etilismo e sedentarismo). O colesterol, a glicemia, a PA, o peso, a altura, o índice de massa corpórea (IMC) foram determinados. RESULTADOS: Comparamos 100 indivíduos (sendo 64,0% homens com idade média de 19,9 anos), com os 72 (sendo 62,5% homens, 34,8 anos) incluídos 15 anos após. Houve aumento na prevalência de HAS (6,0% vs 16,7%, p = 0,024), excesso de peso (9,0% vs 26,4%, p = 0,002) e dislipidemia (4,0% vs 19,14%, p = 0,002). Os demais FRCV não se modificaram. Na análise dos valores de pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), colesterol, glicemia e IMC, encontramos elevação na média de todas variáveis (p < 0,05). Houve correlação positiva entre valores de PAS, PAD, IMC e glicemia no intervalo de tempo avaliado (p < 0,05). CONCLUSÃO: Em profissionais da área médica, encontramos elevação na PAS, PAD, glicemia, IMC e colesterol em 15 anos. Na análise da prevalência de FRCV, houve aumento de hipertensão arterial, excesso de peso e dislipidemia.
Fator de diferenciação de crescimento 15: um novo biomarcador em pacientes com disfunção diastólica?
Resumo:
FUNDAMENTO: O fator de diferenciação de crescimento-15 ou GDF-15, uma citocina de resposta ao estresse relacionada ao fator transformador de crescimento beta (TGF-ß), está elevado e independentemente relacionado à prognóstico adverso na insuficiência cardíaca sistólica. OBJETIVO: O objetivo do presente estudo é investigar os níveis plasmáticos de GDF-15 em pacientes com disfunção diastólica pré-clínica ou insuficiência cardíaca com fração de ejeção normal (ICFEN). MÉTODOS: Avaliamos 119 pacientes com fração de ejeção (FE) normal, encaminhados à angiografia coronariana eletiva, dos quais 75 (63%) tinham doença arterial coronariana (DAC). Os indivíduos foram classificados como tendo disfunção diastólica ventricular esquerda leve (DDVE grau I, n = 61), ICFEN (DDVE grau II ou III, n = 38) ou função diastólica normal (controles, n = 20). Em um subgrupo de 20 indivíduos, alterações no débito cardíaco (DC) foram medidas através de reinalação de gás inerte (Innocor®) em resposta a um teste hemodinâmico ortostático. RESULTADOS: Os níveis de GDF-15 na ICFEN [mediana 1,08, variação interquartil (0,88-1,30) ng/ml] eram significantemente mais altos do que nos controles [0,60 (0,50-0,71) ng/ml, p = 0,003] e em pacientes com DDVE grau I [0,78 (0,62-1,04) ng/ml, p < 0.001]. Além disso, os níveis de GDF-15 estavam significantemente elevados em pacientes com DDVE grau I, em comparação aos controles (p = 0,003). Adicionalmente, GDF-15 estava correlacionado com os marcadores ecocardiográficos de disfunção diastólica e estava correlacionado com a magnitude da resposta do CO à alteração na posição do corpo de ereta para supina (r = -0,67, p = 0,005). CONCLUSÃO: Os níveis de GDF-15 estão elevados em indivíduos com ICFEN e podem diferenciar função diastólica normal de DDVE. Além disso, os níveis de GDF-15 estão associados com uma redução na resposta do DC no teste hemodinâmico ortostático.
Resumo:
Abstract Background: Carotid intima-media thickness (CIMT) has been shown to be increased in children and adolescents with traditional cardiovascular risk factors such as obesity, hypertension, and chronic kidney disease, compared with those of healthy children. Objective: To assess the influence of sex, age and body mass index (BMI) on the CIMT in healthy children and adolescents aged 1 to 15 years. Methods: A total of 280 healthy children and adolescents (males, n=175; mean age, 7.49±3.57 years; mean BMI, 17.94±4.1 kg/m2) were screened for CIMT assessment. They were divided into 3 groups according to age: GI, 1 to 5 years [n=93 (33.2%); males, 57; mean BMI, 16±3 kg/m2]; GII, 6 to 10 years [n=127 (45.4%); males, 78; mean BMI, 17.9±3.7 kg/m2], and GIII, 11 to 15 years [n=60 (21.4%); males, 40; mean BMI, 20.9±4.5 kg/m2]. Results: There was no significant difference in CIMT values between male and female children and adolescents (0.43±0.06 mm vs. 0.42±0.05 mm, respectively; p=0.243). CIMT correlated with BMI neither in the total population nor in the 3 age groups according to Pearson correlation coefficient. Subjects aged 11 to 15 years had the highest CIMT values (GI vs. GII, p=0.615; GI vs. GIII, p=0.02; GII vs. GIII, p=0.004). Conclusions: CIMT is constant in healthy children younger than 10 years, regardless of sex or BMI. CIMT increases after the age of 10 years.
Resumo:
Abstract Background: Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. Objective: The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Methods: Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Results: Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. Conclusion: The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.
Resumo:
The organic and inorganic forms of soil nitrogen and how they participate in the process of fixation, immobilization and mineralization of ammonium in soils were evaluated, after different periods of incubaton, utilizing two soils, a Lithic Haplustoll and a Typic Eutrorthox. The results obtained permit to suggest that : 1) The method for determination of the ammonium fixing capacity based on the extraction with 2N KC1, is considered to be subject to interferences of other soil fractions capable of retaining ammonium. 2) The increase in exchangeable ammonium content is related to the decrease in amino acids and hydrolyzable ammonium. 3) The immobilization and mineralization processes are still held under mil microbial. The forms more affected by this condition are amino acids and hydrolyzable ammonium.
Resumo:
On the southern Brazilian coast, the penaeid pink shrimp Farfantepenaeus paulensis (Pérez-Farfante, 1967) is intensively captured by both artisanal and industrial fisheries. In the Ibiraquera Lagoon, artisanal fishing of juvenile stocks has declined sharply over the last 15 years. The traditional management methods used by fishermen are no longer sustainable due to conflicts with the demands of tourism and weak environmental and public agencies. The dynamics of the timing of the artificial opening and natural reformation of a sandbar across the mouth of the lagoon are regarded as a central socio-ecological problem. We evaluated the abundance and biomass variation of F. paulensis throughout the year and along a spatial gradient measured from the sandbar into the lagoon. We also explored the influence of opening the sandbar on the shrimp population. Samples were collected monthly from February 2004 to February 2005, using a 27 mm mesh cast net, in four different areas, with three sites being sampled per area. Small numbers of large shrimps were captured in the upper area, while greater biomass and abundance of small shrimps were observed near the sandbar, suggesting the role of the inner area as a refuge for growing. The highest records for biomass and abundance were recorded during warm months, regardless if the lagoon was open or closed by the sandbar. The Ibiraquera Lagoon could be more productive for fishermen if the sandbar opening was coincident to the period of natural post-larvae influx. Furthermore, coastal stocks could be improved by opening the sandbar again during summer in conjunction with fishing quotas.
Resumo:
The insects oviposition behavior is fundamental to study population dynamics, life history evolution, insect-plant and parasitoid-host interactions. Zabrotes subfasciatus (Boheman, 1833) females oviposition behavior in the presence and absence of a host is unknown. The main objective of this study was to describe in detail the oviposition behavior of host deprived or non-deprived females, and observe how the several situations of deprivation (days without host) influence oviposition. Six groups were assembled, three deprived of the host (for 2, 5 and 8 days) and three control groups (with host), each containing one newly-emerged couple (0-24h) of wild Z. subfasciatus, The non-deprived (control) groups received the hosts every day (5 bean seeds Phaseolus vulgaris (Fabaceae)) and the others were deprived for 2, 5 and 8 days, respectively. For each group 12 repetitions were made. Consequently, 12 couples were host deprived during two days, 12 couples were host deprived during five days and 12 couples were host deprived during eight days. When the seeds of the deprived groups were added the experiments started. There was a control group for each deprived group. The experiments and the insects were maintained at constant temperature 29 ± 2ºC and 70-80% relative humidity. At 15 minutes interval, the number of times the females manifested the different categories of behavior was observed (frequency). The behavior categories were: rest inside the box, locomotion, resource exploration (seeds), copulation and oviposition. The deprived females stayed most of the time in contact with the host to carry out oviposition, while the non-deprived (control) females spent most of the time at rest. This was observed in all the deprivation times. The results show that host deprivation influences the oviposition behavior of the studied species and also shows the flexibility in the oviposition strategies that these females present when the environment changes (absence and presence of resources)
Resumo:
Drosophila Fallen, 1823 (Diptera, Drosophilidae) is for long a well-established model organism for genetics and evolutionary research. The ecology of these flies, however, has only recently been better studied. Recent papers show that Drosophila assemblies can be used as bioindicators of forested environment degradation. In this work the bioindicator potential of drosophilids was evaluated in a naturally opened environment, a coastal strand-forest (restinga). Data from nine consecutive seasonal collections revealed strong temporal fluctuation pattern of the majority of Drosophila species groups. Drosophila willistoni group was more abundant at autumns, whereas D. cardini and D. tripunctata groups were, respectively, expressive at winters and springs, and D. repleta group at both seasons. The exotic species D. simulans Sturtevant, 1919 (from D. melanogaster group) and Zaprionus indianus Gupta, 1970 were most abundant at summers. Overall, the assemblage structure did not show the same characteristics of forested or urban environments, but was similar to the forests at winters and to cities at summers. This raises the question that this locality may already been under urbanization impact. Also, this can be interpreted as an easily invaded site for exotic species, what might lead to biotic homogenization and therefore can put in check the usage of drosophilid assemblages as bioindicators at open environments.
Resumo:
The Pinnotheridae family is one of the most diverse and complex groups of brachyuran crabs, many of them symbionts of a wide variety of invertebrates. The present study describes the population dynamics of the pea crab Austinixa aidae (Righi, 1967), a symbiont associated with the burrows of the ghost shrimp Callichirus major (Say, 1818). Individuals (n = 588) were collected bimonthly from May, 2005 to September, 2006 along a sandy beach in the southwestern Atlantic, state of São Paulo, Brazil. Our data indicated that the population demography of A. aidae was characterized by a bimodal size-frequency distribution (between 2.0 and 4.0 mm and between 8.0 and 9.0 mm CW) that remained similar throughout the study period. Sex ratio does not differ significantly from 1:1 (p > 0.05), which confirms the pattern observed in other symbiontic pinnotherids. Density values (1.72 ± 1.34 ind. ap.-1) are in agreement with those found for other species of the genus. The mean symbiosis incidence (75.6%) was one of the highest among species of the Pinnotheridae family, but it was the lowest among the three studied species of the genus. Recruitment pattern was annual, beginning in May and peaking in July, in both years, after the peak of ovigerous females in the population (from March to May). Our findings describe ecological and biological aspects of A. aidae similar to those of other species of this genus, even from different geographic localities.
Resumo:
We investigated the impact of fish cage culture on the zooplankton community structure in a tropical reservoir. We hypothesized that community abundance is greater near cages and increases over time due to the increase in food availability. Samplings were performed near, upstream and downstream from net cages, and before and after net cage installation. The abundance of zooplankton increased 15 days after the experiment was set up, followed by a reduction and finally increased. Rotifer abundance showed significant differences among sites (p<0.05) and sampling periods (p<0.001). Significant differences were also observed in total zooplankton and cladoceran abundance (p<0.001). The spatial and temporal variation of the physical and chemical variables were indirectly correlated with the structure and dynamic of the zooplankton community, as they indicated the primary production in the environment. Our hypothesis was rejected, since the zooplankton was abundant at the reference site. Only rotifers showed higher abundance near cages, due to the influence of food availability. Community dynamics during the experiment was also correlated to food availability. Our results suggest an impact of fish farming on the zooplankton community.