Bone consists of separate inner endosteal and outer periosteal compartments, each with distinct contributions to bone physiology and each maintaining separate pools of cells owing to physical ...separation by the bone cortex. The skeletal stem cell that gives rise to endosteal osteoblasts has been extensively studied; however, the identity of periosteal stem cells remains unclear
. Here we identify a periosteal stem cell (PSC) that is present in the long bones and calvarium of mice, displays clonal multipotency and self-renewal, and sits at the apex of a differentiation hierarchy. Single-cell and bulk transcriptional profiling show that PSCs display transcriptional signatures that are distinct from those of other skeletal stem cells and mature mesenchymal cells. Whereas other skeletal stem cells form bone via an initial cartilage template using the endochondral pathway
, PSCs form bone via a direct intramembranous route, providing a cellular basis for the divergence between intramembranous versus endochondral developmental pathways. However, there is plasticity in this division, as PSCs acquire endochondral bone formation capacity in response to injury. Genetic blockade of the ability of PSCs to give rise to bone-forming osteoblasts results in selective impairments in cortical bone architecture and defects in fracture healing. A cell analogous to mouse PSCs is present in the human periosteum, raising the possibility that PSCs are attractive targets for drug and cellular therapy for skeletal disorders. The identification of PSCs provides evidence that bone contains multiple pools of stem cells, each with distinct physiologic functions.
Local antibiotic delivery systems with differing chemical and mechanical properties have been developed to assist in the management of osteomyelitis. We investigated the bone conductive and ...resorptive capabilities of a calcium phosphate-calcium sulfate (CaP/CaS) composite compared with commercially available polymethylmethacrylate (PMMA). In addition, we compared the in vivo preventative and treatment efficacies of both biomaterials in a proven osteomyelitis model.
Sixty-four, male Sprague-Dawley rats were inoculated with 10 μl of 1.5 x 108 CFU/ml of Staphylococcus aureus in a surgically drilled defect in the right proximal tibia. Infected animals were randomly allocated into prevention and treatment groups with 32 rats each. In the prevention group, the defect was filled with a plug containing either PMMA or CaP/CaS immediately after the inoculation. In the treatment group, the infected defects were irrigated, debrided, and filled with either a PMMA or CaP/CaS plug. Both CaP/CaS and PMMA were impregnated with 10% weight of vancomycin. Rats were sacrificed 6 weeks after cement insertion. Infection was detected by bacterial culture and histological analysis. Bone formation in the defect was assessed with micro-computed tomography and histology.
No bacteria were detected in any group. Both the prevention and treatment groups using CaP/CaS had significantly more bone volume fraction, bone area, and cartilage area than the PMMA groups.
When loaded with 10% of vancomycin, CaP/CaS and PMMA have the same efficacy for treatment and prevention of osteomyelitis. CaP/CaS enhances bone defect healing through improved bone remodeling in our osteomyelitis rat model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
While previous studies on navigated total hip replacement (nTHA) focused on acetabular component positioning, we compared the results of nTHA with conventional total hip replacement (cTHA) ...in respect of changes in leg length and hip offset. In a single-center study results radiographic parameters of patients with unilateral THA were included. Data were retrospectively analyzed from computer navigation data and radiographs. Analysis concentrated on the discrepancy in leg length (LLD) and hip offset (OSD) between the affected and unaffected hip. The effect of the procedure was defined as the difference between postoperative and preoperative LLD and OSD values in each group. 2332 patients were analyzed. Both nTHA and cTHA were effective in restoring LLD and OSD by reducing the preoperative value significantly (p < 0.001). Regarding changes in LLD, no statistical difference between nTHA and cTHA could be found. Changes in OSD nTHA was a slightly more effective than cTHA (− 2.06 ± 6.00 mm vs. − 1.50 ± 5.35 mm; p < 0.05). Both navigated and conventional THA were successful in reconstruction of leg length and hip offset, while postoperative offset discrepancy was significantly lower in the navigated group at the cost of longer operation times. If these results are clinically relevant further investigation is needed.
Plant-based (PB) meat and dairy alternatives are a growing trend with potential for contributing to improving the sustainability of global food systems. Despite sustained growth and interest, these ...products are still niche in most Western countries. From a sensory perspective, meat and dairy products possess unique flavor and textural properties that are not easily replicated in PB alternatives. The first part of this short review focuses on current challenges and strategies to improve the sensory quality of these products, which, despite advances, overall remain inferior to their dairy and meat counterparts. The second part highlights the need for a deeper integration of sensory and non-sensory factors, and the consideration of individual differences underlying consumer acceptance of PB products. In closing, we argue that future product development and public health efforts should move away from ‘one size fits all’ and toward targeted approaches catering to different consumer groups.
•Sensory and consumer studies of plant-based (PB) meat and dairy alternatives reviewed.•Sensory quality of PB products is lower than animal-based counterparts.•Improving sensory quality of PB products is crucial for wider acceptance.•Barriers to consumption of PB products also include non-sensory aspects.•Need to account for individual differences in perception and acceptance.
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•Effect of high pressure processing (HPP) on sensory quality of juices was reviewed.•HPP could preserve the most desired sensory quality of fresh juices and smoothies.•HPP parameters ...affected sensory quality of pressure-treated juices and smoothies.•A mismatch between sensory methods and panelists was observed in the literature.•Additional studies on consumer acceptability for these products are advised.
Increasing consumer demand for high-quality, additive-free fruit and vegetable products with ‘fresh-like’ sensory properties has led to the development of novel ‘minimal processing’ technologies. As a prime example, high pressure processing (HPP) is increasingly applied as an alternative to thermal processing (TP) to maintain the properties of fresh fruit-based juices and smoothies. However, the resulting products need to be validated from a sensory standpoint. Situated within this context, this paper provides a narrative review of sensory studies focused on high pressure treated fruit juices and smoothies published in the last ≈25 years (1995 to 2021), centered around three objectives: (i) to review methods used for assessing the sensory quality, (ii) to review knowledge of the effect of HPP on sensory quality, and (iii) to understand consumers’ acceptability towards these products.
Overall, most sensory studies concluded that a combination of HPP and low temperature storage preserved the sensory properties better than TP, and thereby enables the production of products with ‘fresh-like’ quality. Yet, most published studies employed very small panel sizes and often showed a mismatch between test type and assessors employed (for example, using consumers for analytic tests and trained assessors for affective tests), which might lead to biased results. In future research, a clearer focus on experimental conditions, proper sensory methods, and more focus on the relationship between sensory quality and consumer perception are needed to better understand the effect of HPP on the sensory quality of fruit juices and smoothies.
Diffusion and interaction dynamics of molecules at the plasma membrane play an important role in cellular signaling and are suggested to be strongly associated with the actin cytoskeleton. Here we ...use superresolution STED microscopy combined with fluorescence correlation spectroscopy (STED-FCS) to access and compare the diffusion characteristics of fluorescent lipid analogues and GPI-anchored proteins (GPI-APs) in the live-cell plasma membrane and in actin cytoskeleton-free, cell-derived giant plasma membrane vesicles (GPMVs). Hindered diffusion of phospholipids and sphingolipids is abolished in the GPMVs, whereas transient nanodomain incorporation of ganglioside lipid GM1 is apparent in both the live-cell membrane and GPMVs. For GPI-APs, we detect two molecular pools in living cells; one pool shows high mobility with transient incorporation into nanodomains, and the other pool forms immobile clusters, both of which disappear in GPMVs. Our data underline the crucial role of the actin cortex in maintaining hindered diffusion modes of many but not all of the membrane molecules and highlight a powerful experimental approach to decipher specific influences on molecular plasma membrane dynamics.
Context. Red supergiant (RSG) stars are very massive cool evolved stars. Recently, a weak magnetic field was measured at the surface of α Ori and this is so far the only M-type supergiant for which a ...direct detection of a surface magnetic field has been reported. Aims. By extending the search for surface magnetic field in a sample of late-type supergiants, we want to determine whether the surface magnetic field detected on α Ori is a common feature among the M-type supergiants. Methods. With the spectropolarimeter Narval at Télescope Bernard-Lyot we undertook a search for surface magnetic fields in a sample of cool supergiant stars, and we analysed circular polarisation spectra using the least-squares deconvolution technique. Results. We detect weak Zeeman signatures of stellar origin in the targets CE Tau, α1 Her and μ Cep. For the latter star, we also show that cross-talk from the strong linear polarisation signals detected on this star must be taken into account. For CE Tau and μ Cep, the longitudinal component of the detected surface fields is at the Gauss-level, such as in α Ori. We measured a longitudinal field almost an order of magnitude stronger for α1 Her. We also report variability of the longitudinal magnetic field of CE Tau and α1 Her, with changes in good agreement with the typical atmospheric dynamics time-scales. We also report a non-detection of magnetic field at the surface of the yellow supergiant star ρ Cas. Conclusions. The two RSG stars of our sample, CE Tau and μ Cep, display magnetic fields very similar to that of α Ori. The non-detection of a magnetic field on the post-RSG star ρ Cas suggests that the magnetic field disappears, or at least becomes undetectable with present methods, at later evolutionary stages. Our analysis of α1 Her supports the proposed reclassification of the star as an M-type asymptotic giant branch star.
In this study, we have imaged plasma membrane molecules labeled with quantum dots in live cells using a conventional wide-field microscope with high spatial precision at sampling frequencies of 1.75 ...kHz. Many of the resulting single molecule trajectories are sufficiently long (up to several thousand steps) to allow for robust single trajectory analysis. This analysis indicates that a majority of the investigated molecules are transiently confined in nanoscopic compartments with a mean size of (100–150 nm)2 for a mean duration of 50–100 ms.
Abstract IL-6 is a pleiotropic cytokine involved in cell signaling in the musculoskeletal system, but its role in bone healing remains uncertain. The purpose of this study was to examine the role of ...IL-6 in fracture healing. Eight-week-old male C57BL/6 and IL-6 −/− mice were subjected to transverse, mid-diaphyseal osteotomies on the right femora. Sacrifice time points were 1, 2, 4, or 6 weeks post-fracture ( N = 14 per group). Callus tissue properties was analyzed by microcomputed tomography (micro-CT) and Fourier transform infrared imaging spectroscopy (FT-IRIS). Cartilage and collagen content, and osteoclast density were measured histologically. In intact unfractured bone, IL-6 −/− mice had reduced crystallinity, mineral/matrix ratio, tissue mineral density (TMD), and bone volume fraction (BVF) compared to wildtype mice. This suggests that there was an underlying deficit in baseline bone quality in IL-6 −/− mice. At 2 weeks post-fracture, the callus of IL-6 −/− mice had reduced crystallinity and mineral/matrix ratio. These changes were less evident at 4 weeks. At 2 weeks, the callus of the IL-6 −/− mice had an increased tissue mineral density (TMD), an increased cartilage and collagen content, and reduced osteoclast density compared to these parameters in wildtype mice. By 4 and 6 weeks, these parameters were no longer different between the two strains of mice. In conclusion, IL-6 −/− mice had delayed callus maturity, mineralization, and remodeling compared with the callus of the wildtype mice. These effects were transient indicating that the role of IL-6 appears to be most important in the early stages of fracture healing.
Cold plasma processing of milk and dairy products Coutinho, Nathalia M.; Silveira, Marcelo R.; Rocha, Ramon S. ...
Trends in Food Science & Technology,
April 2018, 2018-04-00, 20180401, Letnik:
74
Journal Article
Recenzirano
Thermal pasteurization and sterilization are predominantly used in the dairy industry due to their efficacy in improving the product safety and shelf life. However, heat treatment can cause ...undesirable protein denaturation, non-enzymatic browning, loss of vitamins and volatile flavor compounds, freezing point depression, and flavour changes. Cold plasma is a non-thermal technology that has gained attention in recent years as a potential alternative method for chemical and thermal disinfection in foods using ambient or moderate temperatures and short treatment times.
This review aims to describe the fundamentals, parameters, and technology on cold plasma, discussing the critical processing factors involved in this technology. Also, it describes the mechanisms of microbial inactivation and provides an overview of the effects of non-thermal plasma on the quality of dairy products, considering a physicochemical, sensory and microbiology perspective.
Cold plasma uses less aggressive mechanisms of action to the milk matrix when compared to the techniques currently used, and has shown an excellent performance on the elimination of pathogenic and spoilage microorganisms besides maintaining, in many cases, the nutritional, functional, and sensory characteristics of the product.
•Cold plasma as non-thermal technology is reviewed.•Diversity of systems, operational parameters and mechanisms are revised.•Effects of cold plasma on the quality and safety of dairy foods are reported.
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