163 research outputs found
An optimization of hematopoietic stem and progenitor cell isolation for scientific and clinical purposes by the application of a new parameter determining the hematopoietic graft efficacy.
The transplantation of hematopoietic stem and progenitor cells (HSPC) is an established lifesaving therapy. Bone marrow (BM), harvested from heparinized cadaveric organ donors, peripheral blood (PB) and cord blood (CB), are important sources of hematopoietic stem cells. HSPCs, which are used for transplantation purposes, are routinely evaluated in terms of number of mononuclear cells (MNCs), CD34+ MNCs count and viability. The efficacy of grafting is determined additionally in clonogenic tests in vitro. These tests deliver important information about the number of HSPCs and their proliferative potential. Unfortunately, they do not give a possibility to evaluate the functional HSPC chemotactic reactivity in the SDF-1 gradient, which is probably the key phenomenon for HSPC homing after transplantation procedure. Thus, the aim of our study was to optimize HSPC isolation according to their chemotactic reactivity in SDF-1 gradient. Using multiparameter cell sorter (FACS Aria, BD) we examined the HSPCs attracted by SDF-1 on a single cell level. The population of cells which participated in the chemotactic process was highly enriched in CXCR4+lin-AC133+CD45+ cells (referred as hematopoietic stem cells) and to our surprise in CXCR4+lin-AC133+CD45- cells (referred as pluripotent stem cells) in quantitative amounts. Since reactivity of HSPCs may depend on various factors involved in the protocol of their isolation and short-term storage, we tested the most commonly used anticoagulants (ACD, CPDA-1, EDTA and Heparin) and culture media (DME, IMDM, RPMI). HSPCs, harvested from CB, PB and BM, were subsequently investigated for clonogenic growth of CFU-GM in methylcellulose cultures and for the level of apoptosis by employing annexin V staining. Evaluating clonogenic potential, ability of chemotactic reactivity in SDF-1 gradient and intensification of apoptosis of HSPC as the most safe anticoagulant and medium were selected. This study has proved that chemotactic reactivity of HSPCs is a new but very important parameter which should be included in the procedure of their isolation
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
Protein intake and bone mineral density: Cross-sectional relationship and longitudinal effects in older adults
Background: There are several mechanisms via which increased protein intake might maintain or improve bone mineral density (BMD), but current evidence for an association or effect is inconclusive. The objectives of this study were to investigate the association between dietary protein intake (total, plant and animal) with BMD (spine and total body) and the effects of protein supplementation on BMD. Methods: Individual data from four trials that included either (pre-)frail, undernourished or healthy older adults (aged â„65 years) were combined. Dietary intake was assessed with food records (2, 3 or 7 days) and BMD with dual-energy X-ray absorptiometry (DXA). Associations and effects were assessed by adjusted linear mixed models. Results: A total of 1570 participants [57% women, median (inter-quartile range): age 71 (68â75) years] for which at least total protein intake and total body BMD were known were included in cross-sectional analyses. In fully adjusted models, total protein intake was associated with higher total body and spine BMD [beta (95% confidence interval): 0.0011 (0.0006â0.0015) and 0.0015 (0.0007â0.0023) g/cm2, respectively]. Animal protein intake was associated with higher total body and spine BMD as well [0.0011 (0.0007â0.0016) and 0.0017 (0.0010â0.0024) g/cm2, respectively]. Plant protein intake was associated with a lower total body and spine BMD [â0.0010 (â0.0020 to â0.0001) and â0.0019 (â0.0034 to â0.0004) g/cm2, respectively]. Associations were similar between sexes. Participants with a high ratio of animal to plant protein intake had higher BMD. In participants with an adequate calcium intake and sufficient serum 25(OH)D concentrations, the association between total protein intake with total body and spine BMD became stronger. Likewise, the association between animal protein intake with total body BMD was stronger. In the longitudinal analyses, 340 participants [58% women, median (inter-quartile range): age 75 (70â81) years] were included. Interventions of 12 or 24 weeks with protein supplementation or protein supplementation combined with resistance exercise did not lead to significant improvements in BMD. Conclusions: An association between total and animal protein intake with higher BMD was found. In contrast, plant protein intake was associated with lower BMD. Research is warranted to further investigate the added value of dietary protein alongside calcium and vitamin D for BMD improvement, especially in osteopenic or osteoporotic individuals. Moreover, more research on the impact of a plant-based diet on bone health is needed
Mediterranean diet intervention alters the gut microbiome in older people reducing frailty and improving health status : the NU-AGE 1-year dietary intervention across five European countries
Objective Ageing is accompanied by deterioration of multiple bodily functions and inflammation, which collectively contribute to frailty. We and others have shown that frailty co-varies with alterations in the gut microbiota in a manner accelerated by consumption of a restricted diversity diet. The Mediterranean diet (MedDiet) is associated with health. In the NU-AGE project, we investigated if a 1-year MedDiet intervention could alter the gut microbiota and reduce frailty. Design We profiled the gut microbiota in 612 non-frail or pre-frail subjects across five European countries (UK, France, Netherlands, Italy and Poland) before and after the administration of a 12-month long MedDiet intervention tailored to elderly subjects (NU-AGE diet). Results Adherence to the diet was associated with specific microbiome alterations. Taxa enriched by adherence to the diet were positively associated with several markers of lower frailty and improved cognitive function, and negatively associated with inflammatory markers including C-reactive protein and interleukin-17. Analysis of the inferred microbial metabolite profiles indicated that the diet-modulated microbiome change was associated with an increase in short/branch chained fatty acid production and lower production of secondary bile acids, p-cresols, ethanol and carbon dioxide. Microbiome ecosystem network analysis showed that the bacterial taxa that responded positively to the MedDiet intervention occupy keystone interaction positions, whereas frailty-associated taxa are peripheral in the networks. Conclusion Collectively, our findings support the feasibility of improving the habitual diet to modulate the gut microbiota which in turn has the potential to promote healthier ageing.Peer reviewe
Strategies for twoâdimensional and threeâdimensional field computation in the design of permanent magnet motors
This study discusses strategies for the design of permanent magnet motors (PMMs) exploiting two-dimensional (2D) and 3D field models. Five most common methodologies are compared and errors arising from 2D classical models considered. Examples comparing 2D and 3D results are presented and discussed for two selected types of motors. An approach has been put forward which allows the accuracy of classical 2D models to be improved by introducing correction coefficients arising from preliminary 3D simulations. A possibility of employing quasi-3D models has also been explored for the design and analysis of PMMs with the stator and rotor lamination packets of different lengths. Comparative analysis of results has been provided arising from the 2D and 3D models for a classical and a double rotor PMM
A finite strain fibre-reinforced viscoelasto-viscoplastic model of plant cell wall growth
A finite strain fibre-reinforced viscoelasto-viscoplastic model implemented in a finite element (FE) analysis is presented to study the expansive growth of plant cell walls. Three components of the deformation of growing cell wall, i.e. elasticity, viscoelasticity and viscoplasticity-like growth, are modelled within a consistent framework aiming to present an integrative growth model. The two aspects of growthâturgor-driven creep and new material depositionâand the interplay between them are considered by presenting a yield function, flow rule and hardening law. A fibre-reinforcement formulation is used to account for the role of cellulose microfibrils in the anisotropic growth. Mechanisms in in vivo growth are taken into account to represent the corresponding biologycontrolled behaviour of a cell wall. A viscoelastic formulation is proposed to capture the viscoelastic response in the cell wall. The proposed constitutive model provides a unique framework for modelling both the in vivo growth of cell wall dominated by viscoplasticity-like behaviour and in vitro deformation dominated by elastic or viscoelastic responses. A numerical scheme is devised, and FE case studies are reported and compared with experimental data
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