257 research outputs found
Routine administration of oral polio vaccine in a subtropical area. Factors possibly influencing sero-conversion rates
Poliomyelitis is an important problem of public health in warm-climate countries. Studies of serological responses to vaccination in these countries have given conflicting results but in many investigations the rates have been considerably less than in countries with temperate climates. In this study three possible factors influencing sero-conversion were investigated - the season of the year when vaccine was given, the social status of the mother (as indicated by the number of years of schooling) and the presence of non-poliomyelitis viruses (NPV) in the gut when vaccine was given. Over 200 children about 2 months of age were included in the study. Each was given three doses of trivalent vaccine at 6-week intervals. The sero-conversion rates of the groups fed in winter were excellent but were slightly less good in summer. The differences were greatest in children in the lower socio-economic groups and in children excreting other enteroviruses. The conclusions are that, provided a potent vaccine is used, the factors which diminish the effectiveness of immunization in warm-climate countries can be overcome: (1) by giving three doses of trivalent vaccine; (2) by beginning vaccination at the earliest possible age (when enteroviruses are fewest); (3) by concentrating special attention on the lower socio-economic groups and if necessary by giving a reinforcing dose several months after the third dose has been given - preferably in the colder month
The relationship between seminal plasma aspartate aminotransferase activity, sperm osmotic resistance test value, and semen quality in boars
The relationship between the activity of aspartate aminotransferase (AspAT) in seminal plasma and the values of the osmotic resistance test (ORT) of acrosomal membranes and semen traits was examined on 120 young hybrid Pietrain and Duroc boars. The following semen quality traits were determined: the volume of the ejaculate, the percentage of spermatozoa with progressive motility, sperm concentration and the total number of spermatozoa in the ejaculate, percentage of spermatozoa with normal acrosome, the percentage of spermatozoa with major and minor morphological defects, ORT, and the activity of AspAT in seminal plasma. The activity of AspAT in seminal plasma was negatively correlated (p_0.01) with the spermatozoa concentration and total number per ejaculate, percentage of spermatozoa with progressive motility and percentage of spermatozoa with a normal acrosome, while positively with the percentage of spermatozoa with major (p≤0.001) and minor (p≤0.01) morphological defects. The ORT values negatively correlated with the percentage of spermatozoa with major (p≤0.05) and minor (p≤0.01) morphological defects, while positively (p≤0.001) with the percentage of spermatozoa with a normal acrosome
Allotetraploidization in Brachypodium May Have Led to the Dominance of One Parent’s Metabolome in Germinating Seeds
Seed germination is a complex process during which a mature seed resumes metabolic activity to prepare for seedling growth. In this study, we performed a comparative metabolomic analysis of the embryo and endosperm using the community standard lines of three annual Brachypodium species, i.e., B. distachyon (Bd) and B. stacei (Bs) and their natural allotetraploid B. hybridum (BdBs) that has wider ecological range than the other two species. We explored how far the metabolomic impact of allotetraploidization would be observable as over-lapping changes at 4, 12, and 24 h after imbibition (HAI) with water when germination was initiated. Metabolic changes during germination were more prominent in Brachypodium embryos than in the endosperm. The embryo and endosperm metabolomes of Bs and BdBs were similar, and those of Bd were distinctive. The Bs and BdBs embryos showed increased levels of sugars and the tricarboxylic acid cycle compared to Bd, which could have been indicative of better nutrient mobilization from the endosperm. Bs and BdBs also showed higher oxalate levels that could aid nutrient transfer through altered cellular events. In Brachypodium endosperm, the thick cell wall, in addition to starch, has been suggested to be a source of nutrients to the embryo. Metabolites indicative of sugar metabolism in the endosperm of all three species were not prominent, suggesting that mobilization mostly occurred prior to 4 HAI. Hydroxycinnamic and monolignol changes in Bs and BdBs were consistent with cell wall remodeling that arose following the release of nutrients to the respective embryos. Amino acid changes in both the embryo and endosperm were broadly consistent across the species. Taking our data together, the formation of BdBs may have maintained much of the Bs metabolome in both the embryo and endosperm during the early stages of germination. In the embryo, this conserved Bs metabolome appeared to include an elevated sugar metabolism that played a vital role in germination. If these observations are confirmed in the future with more Brachypodium accessions, it would substantiate the dominance of the Bs metabolome in BdBs allotetraploidization and the use of metabolomics to suggest important adaptive changes
Metabolic control level and glucose variability in adolescents with type 1 diabetes during low and high-intensity exercise
OBJECTIVE
The main purpose of this study was to characterize the determinants of metabolic changes in young type 1 diabetes (T1DM) and to determine glycemic variability during low and high-intensity exercise.
PATIENTS AND METHODS
20 young male T1DM patients were divided into two subgroups characterized by levels of glycated hemoglobin (HbA1c): HbA1c7.3% (worse HbA1c subgroup, n=10). All participants performed a maximal oxygen uptake test and two efforts of various intensities (45 minutes of aerobic exercise and 30 minutes of mixed aerobic-anaerobic intensity exercise). Continuous glucose monitors (CGM) were used to control the glucose concentration.
RESULTS
Changes in biomarkers describing the metabolic response were similar in both groups. A comparison of applied efforts exhibited that maximal capacity effort resulted in the highest values of blood glucose (BG) at the end (150.9-160.6 mg/dl) and 1 hour after the exercise (140.2-161.3 mg/dl). BG concentration before, during, 1 hour, and 24 hours after each exercise was insignificantly higher in the worse Hb1Ac group.
CONCLUSIONS
HbA1c levels are insufficient to confirm whether the applied effort is performed in acceptable glycemic values. The CGM monitors allow for precise control of BG variations and accurate planning of physical activity by adjusting the insulin and carbohydrate consumption dose
Defining the Cell Wall, Cell Cycle and Chromatin Landmarks in the Responses of Brachypodium distachyon to Salinity
Excess salinity is a major stress that limits crop yields. Here, we used the model grass
Brachypodium distachyon (Brachypodium) reference line Bd21 in order to define the key molecular
events in the responses to salt during germination. Salt was applied either throughout the germination
period (“salt stress”) or only after root emergence (“salt shock”). Germination was affected at
100 mM and root elongation at 75 mM NaCl. The expression of arabinogalactan proteins (AGPs),
FLA1, FLA10, FLA11, AGP20 and AGP26, which regulate cell wall expansion (especially FLA11), were
mostly induced by the “salt stress” but to a lesser extent by “salt shock”. Cytological assessment
using two AGP epitopes, JIM8 and JIM13 indicated that “salt stress” increases the fluorescence
signals in rhizodermal and exodermal cell wall. Cell division was suppressed at >75 mM NaCl.
The cell cycle genes (CDKB1, CDKB2, CYCA3, CYCB1, WEE1) were induced by “salt stress” in a
concentration-dependent manner but not CDKA, CYCA and CYCLIN-D4-1-RELATED. Under “salt
shock”, the cell cycle genes were optimally expressed at 100mMNaCl. These changes were consistent
with the cell cycle arrest, possibly at the G1 phase. The salt-induced genomic damage was linked with
the oxidative events via an increased glutathione accumulation. Histone acetylation and methylation
and DNA methylation were visualized by immunofluorescence. Histone H4 acetylation at lysine
5 increased strongly whereas DNA methylation decreased with the application of salt. Taken together,
we suggest that salt-induced oxidative stress causes genomic damage but that it also has epigenetic
effects, which might modulate the cell cycle and AGP expression gene. Based on these landmarks,
we aim to encourage functional genomics studies on the responses of Brachypodium to salt
Effect of sow age on the apparent total tract digestibility of nutrients in the diet
Abstract The objective of this research was to evaluate the effect of sow age on apparent total tract digestibility of nutrients and the concentration of metabolizable energy in the diet. The experiment was carried out on 20 gestating sows, divided into two groups: Group I -10 sows in first pregnancy (131 ± 4.5 kg) and Group II -10 sows in fourth pregnancy (225 ± 8.2 kg). Sows in the two groups were fed identical diets for sows during early pregnancy. The total collection of faeces began on day 30 of pregnancy and lasted eight days. Sows in the fourth pregnancy had greater digestibility coefficients of dry matter (4.1 percentage units), organic matter (3.4 percentage units), crude protein (5.5 percentage units) and crude fibre (6.2 percentage units) than sows in the first pregnancy. The total tract digestibility of ether extract, starch and sugars was not affected by pig age. The metabolizable energy, determined according to the content of digestible nutrients, in the sow diet in fourth pregnancy was 0.7 MJ/kg higher than in the diet of sows in their first pregnancy. Results of this research indicate that sow age should be considered when formulating diets during early pregnancy
Plant defensin PvD1 modulates the membrane composition of breast tumour-derived exosomes
This journal is © The Royal Society of Chemistry 2019One of the most important causes of failure in tumour treatment is the development of resistance to therapy. Cancer cells can develop the ability to lose sensitivity to anti-neoplastic drugs during reciprocal crosstalk between cells and their interaction with the tumour microenvironment (TME). Cell-to-cell communication regulates a cascade of interdependent events essential for disease development and progression and can be mediated by several signalling pathways. Exosome-mediated communication is one of the pathways regulating these events. Tumour-derived exosomes (TDE) are believed to have the ability to modulate TMEs and participate in multidrug resistance mechanisms. In this work, we studied the effect of the natural defensin from common bean, PvD1, on the formation of exosomes by breast cancer MCF-7 cells, mainly the modulatory effect it has on the level of CD63 and CD9 tetraspanins. Moreover, we followed the interaction of PvD1 with biological and model membranes of selected composition, by biophysical and imaging techniques. Overall, the results show that PvD1 induces a dual effect on MCF-7 derived exosomes: the peptide attenuates the recruitment of CD63 and CD9 to exosomes intracellularly and binds to the mature exosomes in the extracellular environment. This work uncovers the exosomemediated anticancer action of PvD1, a potential nutraceutical agent.The authors thank Fundação para a Ciência e a Tecnologia (FCT I.P., Portugal) for funding – PTDC/BBB-BQB/1693/2014, and also acknowledge financial support from the Brazilian agencies CNPq, CAPES, and FAPERJ (E-26/203.090/2016; E-26/202.132/2015). Julia Skalska, Filipa D. Oliveira, Tiago N. Figueira and Diana Gaspar acknowledge FCT I.P. for fellowships PD/BD/114177/2016, PD/BD/135046/2017, SFRH/BD/5283/2013 and SFRH/BPD/109010/2015 respectively. Marie Skłodowska-Curie Research and Innovation Staff Exchange (RISE) is also acknowledged for funding: call H2020-MSCA-RISE-2014, Grant agreement 644167, 2015–2019.info:eu-repo/semantics/publishedVersio
Migration without interbreeding: Evolutionary history of a highly selfing Mediterranean grass inferred from whole genomes
Wild plant populations show extensive genetic subdivision and are far from the ideal of panmixia which permeates population genetic theory. Understanding the spatial and temporal scale of population structure is therefore fundamental for empirical population genetics –and of interest in itself, as it yields insights into the history and biology of a species. In this study we extend the genomic resources for the wild Mediterranean grass Brachypodium distachyon to investigate the scale of population structure and its underlying history at whole-genome resolution. A total of 86 accessions were sampled at local and regional scales in Italy and France, which closes a conspicuous gap in the collection for this model organism. The analysis of 196 accessions, spanning the Mediterranean from Spain to Iraq, suggests that the interplay of high selfing and seed dispersal rates has shaped genetic structure in B. distachyon. At the continental scale, the evolution in B. distachyon is characterized by the independent expansion of three lineages during the Upper Pleistocene. Today, these lineages may occur on the same meadow yet do not interbreed. At the regional scale, dispersal and selfing interact and maintain high genotypic diversity, thus challenging the textbook notion that selfing in finite populations implies reduced diversity. Our study extends the population genomic resources for B. distachyon and suggests that an important use of this wild plant model is to investigate how selfing and dispersal, two processes typically studied separately, interact in colonizing plant species
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