412 research outputs found
Specificity of DNA methylation in the hypertensive kidney
Background: Evidence suggests that DNA methylation (5mC) is important in the development of essential hypertension (EH). The 5mC percentage, a measurement for global methylation studies, in peripheral blood leukocytes (PBL) has been previously associated with hypertension. Methylation patterns are tissue-specific, contributing to differences in transcriptional regulation and cellular differentiation. So far, there have been no studies of 5mC in the kidney – an important effector organ in EH. Furthermore, there has been no investigation of the relationship between 5mC patterns in the hypertensive kidney and PBLs.
Aims: (i) To determine if global 5mC in the kidney is correlated to hypertension diagnosis and blood pressure (BP) regulation. (ii) To determine whether PBLs provide a surrogate for cross-tissue patterns of 5mC in the kidney.
Methods: We used 96 human kidney and 76 human PBL samples from the TRANSLATE study to investigate global 5mC percentage. TRANSLATE consists of carefully characterized collections of "apparently healthy" specimens of human kidneys. Global methylation was determined using the 5mC ELISA kit (Zymo Research) that measures the total amount of 5mC present in a sample.
Results: We found no association of global 5mC percentage in kidney (P=0.18) and PBL (P=0.54) with hypertension diagnosis, nor between PBL 5mC percentage and BP. However, a negative correlation was found between kidney 5mC percentage and systolic BP (r= –0.246; P <0.05), and diastolic BP (r= –0.319; P <0.01). This association was still evident after adjustment for antihypertensive medication for systolic BP (r= –0.210; P <0.05) and diastolic BP (r= –0.273; P <0.01). Furthermore, we found a strong positive correlation between normotensive kidneys and leukocyte 5mC percentages (r=0.864; P<0.01). Similarly, a strong positive correlation was evident for hypertensive kidneys and leukocyte 5mC percentages (r=0.916; P <0.01).
Conclusion: Our findings show that kidney 5mC, but not PBL 5m C, is correlated to BP regulation. No relationship was evident for global 5mC and hypertension diagnosis, regardless of the tissue type studied. Furthermore, PBL 5mC global methylation percentage was highly correlated to kidney 5mC percentage. These results highlight the importance of further studies on the involvement of kidney DNA methylation in hypertension, as well as further investigation of the relationship between methylation patterns in the kidney and blood
A potencialidade de Agropyron, espécie afim ao trigo cultivado, como fonte de introgressão de genes agronomicamente importantes.
bitstream/CNPT-2010/40626/1/p-do08.pd
Sistemas de rotação de culturas com trigo para a região sul do Brasil.
bitstream/item/84156/1/CNPT-COM.-TEC.-2-97.pd
Endangered plant-parrot mutualisms: seed tolerance to predation makes parrots pervasive dispersers of the Parana pine
Parrots are largely considered plant antagonists as they usually destroy the seeds they feed on.
However, there is evidence that parrots may also act as seed dispersers. We evaluated the dual role of
parrots as predators and dispersers of the Critically Endangered Parana pine (Araucaria angustifolia).
Eight of nine parrot species predated seeds from 48% of 526 Parana pines surveyed. Observations of
the commonest parrot indicated that 22.5% of the picked seeds were dispersed by carrying them in
their beaks. Another five parrot species dispersed seeds, at an estimated average distance of c. 250 m.
Dispersal distances did not differ from those observed in jays, considered the main avian dispersers.
Contrary to jays, parrots often dropped partially eaten seeds. Most of these seeds were handled
by parrots, and the proportion of partially eaten seeds that germinated was higher than that of
undamaged seeds. This may be explained by a predator satiation effect, suggesting that the large seeds
of the Parana pine evolved to attract consumers for dispersal. This represents a thus far overlooked key
plant-parrot mutualism, in which both components are threatened with extinction. The interaction is
becoming locally extinct long before the global extinction of the species involvedPeer reviewe
Immunization against Pertussis: An Almost Solved Problem or a Headache in Public Health
Whooping cough or pertussis is a serious infectious disease of the human respiratory tract, caused by Gram-negative bacteria Bordetella pertussis and Bordetella parapertussisHU. The current pertussis vaccines may consist of dead cells of B. pertussis (whole cell pertussis vaccines—wPs) or purified antigens from the bacterium (acellular pertussis vaccines—aPs). The aPs are less reactogenic and have been widely used in developed countries for more than two decades, but their high cost of production makes them prohibitive for developing countries, and the accelerated rate of epidemic outbreaks has led to the hypothesis that aPs are less effective than the wP ones. Considering cost-effectiveness, some authors have pointed out questions about the possibility of reintroduction of wP vaccines into the primary doses of pertussis vaccination. The Butantan Institute in São Paulo, Brazil, developed a wP vaccine with low endotoxicity (Plow) obtained by chemical extraction of the lipooligosaccharide (LOS) fraction from the outer membrane of the bacterial cell, showing to be less reactogenic and equally immunogenic and protective as the traditional wP vaccine. The Plow may possibly be introduced into the vaccination schedule for immunization of adolescents and young adults in Brazil, an important epidemiological contribution to reducing the circulation of B. pertussis
Tree-ring width wavelet and spectral analysis of solar variability and climatic effects on a Chilean cypress during the last two and a half millennia
International audienceSpectral and wavelet analysis were performed on a tree ring width time series obtained from a 2500 yr old cypress tree (Fitzroya cupressoides) from Costa del Osorno, Chile. The periods for analysis were selected at 95% confidence level. Both periodicities characteristic of solar activity and climatic variations were found in this tree ring width series. The 11 and 22 years solar cycle periods were present in tree ring data with a confidence level above 98%. This indicates the solar modulation of climatic variations is being recorded by the tree ring grown. However wavelet analysis shows that these are present only sparsely. Short-term variations, between 2-5 years, are also present in tree ring data, and are shown by wavelet maps to be a more permanent characteristic. This time scale is a signature of ENSO events. Long-term variations, above 200 years, are also present in tree ring data. The spectral analysis performed in this work shows that this species has the ability to record solar-ENSO variations that seems to be affecting the local environment of tree growth, and also that this region was influenced by ENSO events at least in the past 2500 yr interval covered by this study
Extracts of Tagetes minuta L. front of bacteria regarding bovine mastites.
Bovine mastitis is a problem in the context of animal health. However medicinal plants are a management strategy in agroecological production systems. In this context, the plant Tagetes minuta L. plays a leading role, due to its recognition in the popular pharmacopeia. Thus, the objective of this work was to assess the effect of hydroalcoholic extracts of T. minuta from different collection sites compared to ten bacteria related to bovine mastitis. The antimicrobial evaluation was done through the microdilution technique in syrup, in 96 well microplates in triplicate, for the determination of Minimal Bacterial Concentration (MBC) (%). In the microplates, the extracts of T. minuta and the inoculums of the bacteria were placed in addition to the growth control of the bacteria and the control of the extracts, which were incubated for 72 hours at 37°C in an oven. After this time, aliquots of 5?L of each orifice were transferred to plates containing 5% equine defibrinated blood agar and maintained in incubation for 24 hours at the same previous temperature. With this, the growth readings were performed, with the subsequent interpretation of the results by the geometric mean of the MBC (%). The results indicate that there is a difference in sensitivity to microorganisms by the extracts as a function of the collection sites and both present antimicrobial action
Estudo da curva de crescimento de bubalinos da raça Murrah criados no estado do Rio Grande do Sul.
Objetivou-se identificar um modelo, dentre oito citados na literatura, que melhor descreva a curva de crescimento de bubalinos da raça Murrah criados no estado de Rio Grande do Sul. Foram utilizadas informações de 42 machos e 48 fêmeas da raça Murrah, nascidos entre 2009 e 2011, totalizando 624 pares de registros peso-idade do nascimento até 750 dias de idades. Os parâmetros dos modelos foram estimados por meio de regressão não-linear pelo procedimento NLIN (SAS system), utilizando-se o método de Gauss Newton. Os critérios para a escolha do melhor ajuste foram: o quadrado médio dos resÃduos (QMR), o desvio médio absoluto (DMA), o Ãndice e a avaliação visual do gráfico dos valores observados e estimados. Com base no do QMR, DMA e o Ãndice, constatou-se que o modelo Richards (1959) apresentou melhor ajuste, seguido pelo modelo Von Bertalanffy (1957). Com isto, o modelo Richards (1959) dentre os testados foi capaz de descrever o crescimento de búfalos da raça Murrah criados no estado do Rio Grande do Sul
Estimativa de parâmetros e associações genéticas entre perÃmetro escrotal na desmama e caracterÃsticas produtivas na fase pós-desmama de bubalinos da raça Murrah.
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