27 research outputs found
Array analysis for T-cell associated cytokines in gingival crevicular fluid: Identifying altered profiles associated with periodontal disease status
Objective
Cytokine networks regulate innate and adaptive immune responses, which in turn are recognised to direct the progression or arrest of periodontal disease. This study aimed to compare the profile of seven cytokines, implicated in regulating T-cell networks, in gingival crevicular fluid (GCF) samples with differing classification of periodontal status.
Methods
GCF samples were collected from patients with strong clinical evidence for chronic periodontitis, aggressive periodontitis, gingivitis or no gingival inflammation. Cytokines IL-6, IFN-ɣ, IL-4, IL-2, IL-17 A, IL10 and TNFα were measured in each sample using a commercial cytometric bead array assay. Descriptive statistics were used to indicate central tendency, data scatter and analysis of variance for each cytokine concentrations between respective patient groups. Heat maps with dendrograms were produced to visualise hierarchical clustering and trends within the data.
Results
Median concentrations for all cytokines analysed were highest for gingivitis samples and lowest for aggressive periodontitis samples. The median concentration of IL-6 in gingivitis samples was observed to be 10.5 fold higher (˜17,300 pg/μl) than IL-6 in aggressive periodontitis samples (˜1600 pg/μl). Median concentrations of IL-10, IL-17 A and TNFα were also 2–2.2 fold higher in gingivitis samples compared to aggressive periodontitis.
Conclusions
Descriptive statistical analysis noted raised concentrations of IL-6, IL-17 A and TNFα associated with gingivitis; pro-inflammatory cytokines usually associated with periodontal tissue destruction, including bone. Our results would suggest that these cytokines can additionally provide protective roles in preventing progression to advanced forms of periodontal disease. Potential for how these cytokines contribute to providing this role is discussed.
Clinical significance
Defining the roles for the many cytokines involved in the pathogenesis of periodontal disease is far from complete. Consequently the results of this study serve to evidence proposals that cytokines can exhibit both pro- and anti-inflammatory effects, which is dependent on the signalling environment within which they exist and the antagonizing or modifying actions of other cytokines. Whilst future research is necessary to explore mechanistic action, our study contributes new knowledge suggesting that IL-6 and IL-17 A can provide roles in stabilising the lesion to limit disease progression, which does not preclude alternative roles in promoting periodontal bone loss in advanced forms of disease progression, which is also documented in the literature
A frustrated quantum spin-{\boldmath s} model on the Union Jack lattice with spins {\boldmath s>1/2}
The zero-temperature phase diagrams of a two-dimensional frustrated quantum
antiferromagnetic system, namely the Union Jack model, are studied using the
coupled cluster method (CCM) for the two cases when the lattice spins have spin
quantum number and . The system is defined on a square lattice and
the spins interact via isotropic Heisenberg interactions such that all
nearest-neighbour (NN) exchange bonds are present with identical strength
, and only half of the next-nearest-neighbour (NNN) exchange bonds are
present with identical strength . The bonds are
arranged such that on the unit cell they form the pattern of the
Union Jack flag. Clearly, the NN bonds by themselves (viz., with )
produce an antiferromagnetic N\'{e}el-ordered phase, but as the relative
strength of the frustrating NNN bonds is increased a phase transition
occurs in the classical case () at to a canted ferrimagnetic phase. In the quantum cases considered
here we also find strong evidence for a corresponding phase transition between
a N\'{e}el-ordered phase and a quantum canted ferrimagnetic phase at a critical
coupling for and for . In both cases the ground-state energy and its first
derivative seem continuous, thus providing a typical scenario of a
second-order phase transition at , although the order
parameter for the transition (viz., the average ground-state on-site
magnetization) does not go to zero there on either side of the transition.Comment: 1
Influence of remaining axial walls on of root filled teeth restored with a single crown and adhesively bonded fibre post: A systematic review and meta-analysis
Objectives
To synthesise evidence on structural failures and prevalence of post-treatment endodontic disease (PTD) in anterior and posterior root filled teeth with a single crown and adhesively bonded fibre post with regards to the number of axial walls.
Data
An electronic search was performed, no language constraints or restriction on the year of publication were applied.
Sources
PubMed, Medline, Cochrane and Scopus on 13th of July 2021.
Study selection
Clinical studies that reported the remaining number of axial walls for permanent anterior and posterior root filled teeth (RFT) restored with single crowns and adhesively bonded fibre posts with a minimum of 1 year follow-up were included. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines [1] were used. The number of axial walls and the success/failures were analysed as follows: fibre post and/or core decementation, post and/or core fracture and post treatment endodontic disease, and root fracture.
Conclusions
A total of 811 studies were identified with 5 meeting the inclusion criteria. The two randomized controlled trials included had ‘some concerns’ as determined by the Cochrane risk-of-bias 2 tool while the Newcastle-Ottawa scale found low risk of bias for the remaining three studies. The random effects model for subgroup meta-analysis revealed failures for posterior RFT increased with decreasing numbers of remaining walls. Failures for 0 remaining walls were 23% (95% CI = 10% - 36%) and for one remaining wall 15% (CI: 3% -26%), irrespective of follow-up times. Fibre post debonding and PTD increased with decreasing numbers of walls. Relative & catastrophic failure of posterior teeth restored with a fibre post and single crown after root canal treatment increased with decreasing numbers of remaining axial walls.
Clinical significance
This synthesis is unique as it minimizes the presence of confounding factors by reviewing evidence of failures and post-treatment endodontic disease associated with teeth restored with single crowns. Therefore, it provides valuable predictive evidence of potential coronal restoration catastrophes and post-treatment endodontic disease associated with root filled teeth
High-Order Coupled Cluster Method (CCM) Calculations for Quantum Magnets with Valence-Bond Ground States
In this article, we prove that exact representations of dimer and plaquette
valence-bond ket ground states for quantum Heisenberg antiferromagnets may be
formed via the usual coupled cluster method (CCM) from independent-spin product
(e.g. N\'eel) model states. We show that we are able to provide good results
for both the ground-state energy and the sublattice magnetization for dimer and
plaquette valence-bond phases within the CCM. As a first example, we
investigate the spin-half -- model for the linear chain, and we show
that we are able to reproduce exactly the dimerized ground (ket) state at
. The dimerized phase is stable over a range of values for
around 0.5. We present evidence of symmetry breaking by considering
the ket- and bra-state correlation coefficients as a function of . We
then consider the Shastry-Sutherland model and demonstrate that the CCM can
span the correct ground states in both the N\'eel and the dimerized phases.
Finally, we consider a spin-half system with nearest-neighbor bonds for an
underlying lattice corresponding to the magnetic material CaVO (CAVO).
We show that we are able to provide excellent results for the ground-state
energy in each of the plaquette-ordered, N\'eel-ordered, and dimerized regimes
of this model. The exact plaquette and dimer ground states are reproduced by
the CCM ket state in their relevant limits.Comment: 34 pages, 13 figures, 2 table
Magnetic order in spin-1 and spin-3/2 interpolating square-triangle Heisenberg antiferromagnets
Using the coupled cluster method we investigate spin- -
Heisenberg antiferromagnets (HAFs) on an infinite, anisotropic, triangular
lattice when the spin quantum number or . With respect to a
square-lattice geometry the model has antiferromagnetic () bonds
between nearest neighbours and competing () bonds between
next-nearest neighbours across only one of the diagonals of each square
plaquette, the same one in each square. In a topologically equivalent
triangular-lattice geometry, we have two types of nearest-neighbour bonds:
namely the bonds along parallel chains and the
bonds producing an interchain coupling. The model thus interpolates
between an isotropic HAF on the square lattice at and a set of
decoupled chains at , with the isotropic HAF on the
triangular lattice in between at . For both the and the
models we find a second-order quantum phase transition at
and respectively,
between a N\'{e}el antiferromagnetic state and a helical state. In both cases
the ground-state energy and its first derivative are
continuous at , while the order parameter for the transition
(viz., the average on-site magnetization) does not go to zero on either side of
the transition. The transition at for both the and
cases is analogous to that observed in our previous work for the
case at a value . However, for the higher
spin values the transition is of continuous (second-order) type, as in the
classical case, whereas for the case it appears to be weakly
first-order in nature (although a second-order transition could not be
excluded).Comment: 17 pages, 8 figues (Figs. 2-7 have subfigs. (a)-(d)
The ALERT-B questionnaire: A screening tool for the detection of gastroenterological late effects after radiotherapy for prostate cancer
There is an increasing need to measure treatment-related side effects in normal tissues following cancer therapy. The ALERT-B (Assessment of Late Effects of RadioTherapy - Bowel) questionnaire is a screening tool that is composed of four items related specifically to bowel symptoms. Those patients that respond with a “yes” to any of these items are referred on to gastroenterologist in order to improve the long-term consequences of these side effects of radiological treatment. Here we wish to test the ability of this questionnaire to identify these subsequent gastroenterological complications by tracking prostate cancer patients that were positive with respect to ALERT-B. We also carry out receiver-operator curve (ROC) analysis for baseline data for an overall ALERT-B questionnaire score with respect to subscale data for the Gastrointestinal Symptom Rating Scale (GSRS) and the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. 84.4% and 95.7% of patients identified by the ALERT-B questionnaire demonstrated complications diagnosed at 6 and 12 months post-treatment, respectively. ROC curve analysis of baseline data showed that ALERT-B detected clinically relevant levels of side effects established at baseline by the GSRS diarrhoea subscale (AUC = 0.867, 95% CI = 0.795 to 0.926) and at the minimally important level of side effects for the EPIC bowel subscale (AUC = 0.765, 95% CI = 0.617 to 0.913). These results show that ALERT-B provides a simple and effective screening tool for identifying gastroenterological complications after treatment for prostate cancer
Factors associated with higher levels of grief and support needs among people bereaved during the pandemic: results from a national online survey
We identified factors associated with higher levels of grief and support needs among 711 people bereaved during the COVID-19 pandemic in the UK (deaths 16 March 2020-2 January 2021). An
online survey assessed grief using the Adult Attitude to Grief (AAG) scale, which calculates an overall index of vulnerability (IOV) (range 0-36), and practical and emotional support needs in 13 domains.
Participants’ mean age was 49.5 (SD 12.9); 628 (88.6%) female. Mean age of deceased 72.2 (SD 16.1). 311 (43.8%) deaths were from confirmed/suspected COVID-19. High overall levels of grief and support needs were observed; 28.2% exhibited severe vulnerability (IOV ≥ 24). Grief and support needs were higher for close relationships with the deceased (versus more distant) and reported
social isolation and loneliness (P < 0.001), and lower with age of deceased above 40-50. Other associated factors were place of death and health professional support post-death (P < 0.05)
Critical properties of 1-D spin 1/2 antiferromagnetic Heisenberg model
We discuss numerical results for the 1-D spin 1/2 antiferromagnetic
Heisenberg model with next-to-nearest neighbour coupling and in the presence of
an uniform magnetic field. The model develops zero frequency excitations at
field dependent soft mode momenta. We compute critical quantities from finite
size dependence of static structure factors.Comment: talk given by H. Kr{\"o}ger at Heraeus Seminar Theory of Spin
Lattices and Lattice Gauge Models, Bad Honnef (1996), 20 pages, LaTeX + 18
figures, P
The Extended Coupled Cluster Treatment of Correlations in Quantum Magnets
The spin-half XXZ model on the linear chain and the square lattice are
examined with the extended coupled cluster method (ECCM) of quantum many-body
theory. We are able to describe both the Ising-Heisenberg phase and the
XY-Heisenberg phase, starting from known wave functions in the Ising limit and
at the phase transition point between the XY-Heisenberg and ferromagnetic
phases, respectively, and by systematically incorporating correlations on top
of them. The ECCM yields good numerical results via a diagrammatic approach,
which makes the numerical implementation of higher-order truncation schemes
feasible. In particular, the best non-extrapolated coupled cluster result for
the sublattice magnetization is obtained, which indicates the employment of an
improved wave function. Furthermore, the ECCM finds the expected qualitatively
different behaviours of the linear chain and the square lattice cases.Comment: 22 pages, 3 tables, and 15 figure
Quantum magnetism in two dimensions: From semi-classical N\'eel order to magnetic disorder
This is a review of ground-state features of the s=1/2 Heisenberg
antiferromagnet on two-dimensional lattices. A central issue is the interplay
of lattice topology (e.g. coordination number, non-equivalent nearest-neighbor
bonds, geometric frustration) and quantum fluctuations and their impact on
possible long-range order. This article presents a unified summary of all 11
two-dimensional uniform Archimedean lattices which include e.g. the square,
triangular and kagome lattice. We find that the ground state of the spin-1/2
Heisenberg antiferromagnet is likely to be semi-classically ordered in most
cases. However, the interplay of geometric frustration and quantum fluctuations
gives rise to a quantum paramagnetic ground state without semi-classical
long-range order on two lattices which are precisely those among the 11 uniform
Archimedean lattices with a highly degenerate ground state in the classical
limit. The first one is the famous kagome lattice where many low-lying singlet
excitations are known to arise in the spin gap. The second lattice is called
star lattice and has a clear gap to all excitations.
Modification of certain bonds leads to quantum phase transitions which are
also discussed briefly. Furthermore, we discuss the magnetization process of
the Heisenberg antiferromagnet on the 11 Archimedean lattices, focusing on
anomalies like plateaus and a magnetization jump just below the saturation
field. As an illustration we discuss the two-dimensional Shastry-Sutherland
model which is used to describe SrCu2(BO3)2.Comment: This is now the complete 72-page preprint version of the 2004 review
article. This version corrects two further typographic errors (three total
with respect to the published version), see page 2 for detail