6,512 research outputs found
Cutibacterium acnes is present in non-herniated human discs; its positivity rate correlates with the patients age
Introduction:
The presence of bacteria in the intervertebral discs (IVDs) and their role in disc degeneration is an area of controversy. Numerous studies have detected Cutibacterium acnes and other microbes with 16S DNA Sequencing and microbial cultures. However, those studies fail to determine whether the bacteria are in-vivo disc bacteria or perioperative contamination. Capoor et al. 1 performed confocal scanning laser microscopy for a limited number of herniated IVDs and detected C. acnes biofilms within the human specimens. Our study investigated the presence of Gram-positive bacteria C. acnes and Staphylococcus aureus in non-herniated human IVDs. Furthermore, expression of cellular recognition receptors Toll-like receptor (TLR) 2, TLR4 and NLR family pyrin domain containing 3 (NLRP3) and the pyroptosis marker Gasdermin D were investigated.
Methods:
Immunohistochemical staining for Gram-positive bacteria, S. aureus, C.acnes TLR2, TLR4, NLRP3 and Gasdermin D was performed on 75 non-herniated human IVD samples. Cell detection and classification was performed using QuPath. Fluorescently labelled S. aureus cells were co-cultured with human NP cells in monolayer across multiplicity of Infection (MOI) range (1:10- 1:100), and analysed by confocal imaging. Furthermore, human nucleus pulposus (NP) cells in monolayer were treated with Lipopolysaccharide (LPS) (5-50μg/ml) and Peptidoglycan (PGN) (5-50 μg/ml) for 48h, and cells in 3D alginate with PGN for up to 72h. Secretome analysis was performed using Luminex for cytokines, chemokines, matrix degrading enzymes and other secreted factors. Statistical analysis was performed using Kruskal-Wallis, Dunn’s multiple comparison test and Pearson correlation.
Results
Co-culture of S. aureus with NP cells showed internalisation of bacteria. Immunohistochemical staining demonstrated gram positive bacteria was solely detected within cells and not as biofilm within the tissue. The positivity rate of C. acnes ranged between 5-99%. The number of C.acnes positive cells showed a correlation with the age of the patients (r=0.41, p= 0.007). However, it did not correlate with grade of degeneration. The positivity rate of TLR2 ranged between 5-99% and TLR4 from 3-72%. TLR2 and TLR4 showed a strong correlation (r= 0.62, p= 1.5e-006). A significant decrease in TLR2 was observed in females showing a mid-degenerative grade compared to females showing no signs of degeneration. Investigation of the presence and the correlation between NLRP3, GasderminD, S. aureus and the above-mentioned factors is undergoing. Treatment of NP cells with LPS and PGN resulted in an increase of several catabolic cytokines such as IL-1, TNF, IL-6 and IFN-γ alongside increased production of chemokines, neurotrophic and angiogenic factors associated with IVD degeneration.
Conclusion
This study demonstrated the presence of Gram-positive bacteria such as C. acnes in non-herniated and cadaveric human disc samples. The internalisation of bacteria by human NP cells was demonstrated and aligns with previous publications. Furthermore, this shows a correlation between age and the presence of C. acnes as well as a strong correlation between the two TLRs. Moreover, bacterial cell membrane components triggered a catabolic response in human disc cells. Ongoing interaction studies between bacteria and NP cells will give us insight it to the potential role of bacteria in disc degeneration
The effect of maleinized linseed oil as biobased plasticizer in poly (lactic acid)-based formulations
[EN] The use of maleinized linseed oil (MLO) as a potential biobased plasticizer for poly(lactic acid) (PLA) industrial formulations with improved toughness was evaluated. MLO content varied in the range 0-20 phr (parts by weight of MLO per hundred parts by weight of PLA). Mechanical, thermal and morphological characterizations were used to assess the potential of MLO as an environmentally friendly plasticizer for PLA formulations. Dynamic mechanical thermal analysis and differential scanning calorimetry revealed anoticeable decrease in the glass transition temperature of about 6.5 degrees C compared to neat PLA. In addition, the cold crystallization process was favoured with MLO content due to the increased chain mobility that the plasticizer provides. PLA toughness was markedly improved in formulations with 5 phr MLO, while maximum elongation at break was obtained for PLA formulations plasticized with MLO content in the range 15-20 phr. Scanning electron microscopy revealed evidence of plastic deformation. Nevertheless, phase separation was detected in plasticized PLA formulations with high MLO content (above 15-20 phr MLO), which had a negative effect on overall toughness. (C) 2017 Society of Chemical IndustryThis research was funded by the Ministry of Economy and Competitiveness - MINECO, ref. MAT2014-59242-C2-1-R. The authors also thank Conselleria d'Educacio, Cultura i Esport - Generalitat Valenciana, ref. GV/2014/008, for financial support. DG-G thanks the Spanish Ministry of Education, Culture and Sports for financial support through an FPU grant (FPU13/06011).Ferri, J.; Garcia-Garcia, D.; Montanes, N.; Fenollar, O.; Balart, R. (2017). The effect of maleinized linseed oil as biobased plasticizer in poly (lactic acid)-based formulations. Polymer International. 66(6):882-891. https://doi.org/10.1002/pi.5329S88289166
Access and utilisation of maternity care for disabled women who experience domestic abuse:a systematic review
BACKGROUND: Although disabled women are significantly more likely to experience domestic abuse during pregnancy than non-disabled women, very little is known about how maternity care access and utilisation is affected by the co-existence of disability and domestic abuse. This systematic review of the literature explored how domestic abuse impacts upon disabled women’s access to maternity services. METHODS: Eleven articles were identified through a search of six electronic databases and data were analysed to identify: the factors that facilitate or compromise access to care; the consequences of inadequate care for pregnant women’s health and wellbeing; and the effectiveness of existing strategies for improvement. RESULTS: Findings indicate that a mental health diagnosis, poor relationships with health professionals and environmental barriers can compromise women’s utilisation of maternity services. Domestic abuse can both compromise, and catalyse, access to services and social support is a positive factor when accessing care. Delayed and inadequate care has adverse effects on women’s physical and psychological health, however further research is required to fully explore the nature and extent of these consequences. Only one study identified strategies currently being used to improve access to services for disabled women experiencing abuse. CONCLUSIONS: Based upon the barriers and facilitators identified within the review, we suggest that future strategies for improvement should focus on: understanding women’s reasons for accessing care; fostering positive relationships; being women-centred; promoting environmental accessibility; and improving the strength of the evidence base
Ageing and dementia in low and middle income countries - Using research to engage with public and policy makers
Abstract While two thirds of the 24 million people with dementia worldwide live in low and middle income countries, very little research has been conducted to support policy making in these regions. Among the non-communicable diseases, dementia (in common with other chronic NCDs linked more to long-term disability than to mortality) has been relatively under-prioritized. International agreements, plans and policy guidelines have called for an end to ageist discrimination and a focus upon reducing disadvantage arising from poverty and the consequences of ill health. Social protection, access to good quality age-appropriate healthcare and addressing the problem of disability are all key issues. However, as yet, little progress has been made in addressing these concerns. In this review we outline the current international policy agenda for older individuals, and its specific relevance to those with dementia and other disabling non-communicable diseases. We consider the potential for epidemiological research to raise awareness, refine the policy agenda, and promote action, using the example of the dissemination strategy developed by the 10/66 Dementia Research Group
The 10/66 Dementia Research Group's fully operationalised DSM-IV dementia computerized diagnostic algorithm, compared with the 10/66 dementia algorithm and a clinician diagnosis: a population validation study
<p>Abstract</p> <p>Background</p> <p>The criterion for dementia implicit in DSM-IV is widely used in research but not fully operationalised. The 10/66 Dementia Research Group sought to do this using assessments from their one phase dementia diagnostic research interview, and to validate the resulting algorithm in a population-based study in Cuba.</p> <p>Methods</p> <p>The criterion was operationalised as a computerised algorithm, applying clinical principles, based upon the 10/66 cognitive tests, clinical interview and informant reports; the Community Screening Instrument for Dementia, the CERAD 10 word list learning and animal naming tests, the Geriatric Mental State, and the History and Aetiology Schedule – Dementia Diagnosis and Subtype. This was validated in Cuba against a local clinician DSM-IV diagnosis and the 10/66 dementia diagnosis (originally calibrated probabilistically against clinician DSM-IV diagnoses in the 10/66 pilot study).</p> <p>Results</p> <p>The DSM-IV sub-criteria were plausibly distributed among clinically diagnosed dementia cases and controls. The clinician diagnoses agreed better with 10/66 dementia diagnosis than with the more conservative computerized DSM-IV algorithm. The DSM-IV algorithm was particularly likely to miss less severe dementia cases. Those with a 10/66 dementia diagnosis who did not meet the DSM-IV criterion were less cognitively and functionally impaired compared with the DSMIV confirmed cases, but still grossly impaired compared with those free of dementia.</p> <p>Conclusion</p> <p>The DSM-IV criterion, strictly applied, defines a narrow category of unambiguous dementia characterized by marked impairment. It may be specific but incompletely sensitive to clinically relevant cases. The 10/66 dementia diagnosis defines a broader category that may be more sensitive, identifying genuine cases beyond those defined by our DSM-IV algorithm, with relevance to the estimation of the population burden of this disorder.</p
Genetic regulation of pituitary gland development in human and mouse
Normal hypothalamopituitary development is closely related to that of the forebrain and is dependent upon a complex genetic cascade of transcription factors and signaling molecules that may be either intrinsic or extrinsic to the developing Rathke’s pouch. These factors dictate organ commitment, cell differentiation, and cell proliferation within the anterior pituitary. Abnormalities in these processes are associated with congenital hypopituitarism, a spectrum of disorders that includes syndromic disorders such as septo-optic dysplasia, combined pituitary hormone deficiencies, and isolated hormone deficiencies, of which the commonest is GH deficiency. The highly variable clinical phenotypes can now in part be explained due to research performed over the last 20 yr, based mainly on naturally occurring and transgenic animal models. Mutations in genes encoding both signaling molecules and transcription factors have been implicated in the etiology of hypopituitarism, with or without other syndromic features, in mice and humans. To date, mutations in known genes account for a small proportion of cases of hypopituitarism in humans. However, these mutations have led to a greater understanding of the genetic interactions that lead to normal pituitary development. This review attempts to describe the complexity of pituitary development in the rodent, with particular emphasis on those factors that, when mutated, are associated with hypopituitarism in humans
GABAergic and glutamatergic identities of developing midbrain Pitx2 neurons
Pitx2 , a paired-like homeodomain transcription factor, is expressed in post-mitotic neurons within highly restricted domains of the embryonic mouse brain. Previous reports identified critical roles for PITX2 in histogenesis of the hypothalamus and midbrain, but the cellular identities of PITX2-positive neurons in these regions were not fully explored. This study characterizes Pitx2 expression with respect to midbrain transcription factor and neurotransmitter phenotypes in mid-to-late mouse gestation. In the dorsal midbrain, we identified Pitx2 -positive neurons in the stratum griseum intermedium (SGI) as GABAergic and observed a requirement for PITX2 in GABAergic differentiation. We also identified two Pitx2 -positive neuronal populations in the ventral midbrain, the red nucleus, and a ventromedial population, both of which contain glutamatergic precursors. Our data suggest that PITX2 is present in regionally restricted subpopulations of midbrain neurons and may have unique functions that promote GABAergic and glutamatergic differentiation. Developmental Dynamics 240:333–346, 2011. © 2011 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79425/1/22532_ftp.pd
Super-heavy fermion material as metallic refrigerant for adiabatic demagnetization cooling
Low-temperature refrigeration is of crucial importance in fundamental
research of condensed matter physics, as the investigations of fascinating
quantum phenomena, such as superconductivity, superfluidity and quantum
criticality, often require refrigeration down to very low temperatures.
Currently, cryogenic refrigerators with He gas are widely used for cooling
below 1 Kelvin. However, usage of the gas is being increasingly difficult due
to the current world-wide shortage. Therefore, it is important to consider
alternative methods of refrigeration. Here, we show that a new type of
refrigerant, super-heavy electron metal, YbCoZn, can be used for
adiabatic demagnetization refrigeration, which does not require 3He gas. A
number of advantages includes much better metallic thermal conductivity
compared to the conventional insulating refrigerants. We also demonstrate that
the cooling performance is optimized in YbScCoZn by
partial Sc substitution with 0.19. The substitution induces chemical
pressure which drives the materials close to a zero-field quantum critical
point. This leads to an additional enhancement of the magnetocaloric effect in
low fields and low temperatures enabling final temperatures well below 100 mK.
Such performance has up to now been restricted to insulators. Since nearly a
century the same principle of using local magnetic moments has been applied for
adiabatic demagnetization cooling. This study opens new possibilities of using
itinerant magnetic moments for the cryogen-free refrigeration
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