The natural history of ankylosing spondylitis in the 21st century

Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects the axial skeleton and evolves in stiffnes followed by ankylosis and disability. However, it may be difficult to exactly establish the natural history of the disease and the influence of risk factors of progression, since most patients are treated with various pharmacologic or non-pharmacologic agents, which may potentially influence the natural progression of the disease. In this context, we report here a very interesting case of a 40 year old man, presented to our outpatient clinic, 28 years after the onset of AS. Previously for personal reasons, did not choose not to undergo any treatment. This case allows us to evaluate the natural radiological progression of the disease and the influence of predictive risk factors

Laboratory findings in psoriatic arthritis.

Psoriatic arthritis (PsA) has been classically defined as an inflammatory arthritis associated with psoriasis. However, in comparison with other relevant inflammatory arthropathies, in which a definite diagnosis is frequently possible only by means of laboratory investigations, in PsA true laboratory diagnostic markers are lacking. Some markers are utilised more to differentiate other diseases than to characterise PsA. For example in polyarticular PsA, which may be in some cases indistinguishable from RA, the rheumatoid factor (RF) or the more specific and recently introduced antibodies to cyclic citrullinated peptides (anti-CCP), may be useful to better identify RA. However, RF was found in 5% to 13% of patients with PsA, and anti-CCP may be observed in almost similar percentage. The determination of ESR and/or CRP is frequently disappointing in PsA, since they are both elevated in only half of the patients with PsA. However, ESR and/or CRP are included in the most utilised response criteria for RA, such as ACR and DAS, and, in addition are also considered reliable in the assessment of PsA. Furthermore, elevated levels of ESR have been proposed as one of the best predictors of damage progression and, in addition, a low ESR seems protective, while an ESR >15 mm/h is one of the factors associated with an increased mortality in PsA. The synovial fluid (SF) effusion is much higher in PsA, in comparison with other arthropathies. When available, SF analysis may offer additive information useful for the diagnosis, such as the increased number of leukocytes, which underlines the inflammatory nature of the effusion even in a patient with normal serum levels of acute phase response. We found that elevated IL-1 levels in SF of patients with early disease (<6 months), may be predictive of an evolution in polyarticular form at follow-up. This observation is in keeping with the crucial role that inflammatory cytokines play in PsA, probably related to a genetic predisposition. The recent introduction in PsA of anti-TNF-α agents and the demonstration of their efficacy in the management of many clinical disease expressions including peripheral arthropathy, axial involvement, enthesopathy and skin manifestations, have stimulated the research also in the field of the possible laboratory markers. Key words: Psoriatic arthritis, laboratory investigations arthriti

Determination of electromagnetic medium from the Fresnel surface

We study Maxwell's equations on a 4-manifold where the electromagnetic medium is described by an antisymmetric $2\choose 2$-tensor $\kappa$. In this setting, the Tamm-Rubilar tensor density determines a polynomial surface of fourth order in each cotangent space. This surface is called the Fresnel surface and acts as a generalisation of the light-cone determined by a Lorentz metric; the Fresnel surface parameterises electromagnetic wave-speed as a function of direction. Favaro and Bergamin have recently proven that if $\kappa$ has only a principal part and if the Fresnel surface of $\kappa$ coincides with the light cone for a Lorentz metric $g$, then $\kappa$ is proportional to the Hodge star operator of $g$. That is, under additional assumptions, the Fresnel surface of $\kappa$ determines the conformal class of $\kappa$. The purpose of this paper is twofold. First, we provide a new proof of this result using Gr\"obner bases. Second, we describe a number of cases where the Fresnel surface does not determine the conformal class of the original $2\choose 2$-tensor $\kappa$. For example, if $\kappa$ is invertible we show that $\kappa$ and $\kappa^{-1}$ have the same Fresnel surfaces.Comment: 23 pages, 1 figur

Non-Metric Gravity I: Field Equations

We describe and study a certain class of modified gravity theories. Our starting point is Plebanski formulation of gravity in terms of a triple B^i of 2-forms, a connection A^i and a ``Lagrange multiplier'' field Psi^ij. The generalization we consider stems from presence in the action of an extra term proportional to a scalar function of Psi^ij. As in the usual Plebanski general relativity (GR) case, a certain metric can be constructed from B^i. However, unlike in GR, the connection A^i no longer coincides with the self-dual part of the metric-compatible spin-connection. Field equations of the theory are shown to be relations between derivatives of the metric and components of field Psi, as well as its derivatives, the later being in contrast to the GR case. The equations are of second order in derivatives. An analog of the Bianchi identity is still present in the theory, as well as its contracted version tantamount to energy conservation equation.Comment: 21 pages, no figures (v2) energy conservation equation simplified, note on reality conditions added (v3) minor change

Radiation-dominated area metric cosmology

We provide further crucial support for a refined, area metric structure of spacetime. Based on the solution of conceptual issues, such as the consistent coupling of fermions and the covariant identification of radiation fields on area metric backgrounds, we show that the radiation-dominated epoch of area metric cosmology is equivalent to that epoch in standard Einstein cosmology. This ensures, in particular, successful nucleosynthesis. This surprising result complements the previously derived prediction of a small late-time acceleration of an area metric universe.Comment: 23 pages, no figures; references adde

Geometry and stability of dynamical systems

We reconsider both the global and local stability of solutions of continuously evolving dynamical systems from a geometric perspective. We clarify that an unambiguous definition of stability generally requires the choice of additional geometric structure that is not intrinsic to the dynamical system itself. While global Lyapunov stability is based on the choice of seminorms on the vector bundle of perturbations, we propose a definition of local stability based on the choice of a linear connection. We show how this definition reproduces known stability criteria for second order dynamical systems. In contrast to the general case, the special geometry of Lagrangian systems provides completely intrinsic notions of global and local stability. We demonstrate that these do not suffer from the limitations occurring in the analysis of the Maupertuis-Jacobi geodesics associated to natural Lagrangian systems.Comment: 22 pages, 2 figure

Prevalence of low back pain and its effect on health-related quality of life in 409 scholar adolescents from the veneto region

Low back pain (LBP) is a common condition with profound effects on well-being. We aimed to define the prevalence and the characteristics of LBP and to investigate its impact on the quality of life (QoL) of 409 students (265 females and 144 males), all high-school adolescents from the Veneto region. LBP was measured with a structured, self-report questionnaire, while the SF-36 questionnaire was used to measure physical and mental QoL. 253 students (61.3%) reported one or more episodes of LBP, with female predominance. Adolescents with LBP treated with drugs and rehabilitation cares have significantly poor belief in pain resolution (p=0.005), but more belief in a prevention program (p=0.006) than the others. After adjustment for sex, a significant association between the SF-36 dimension of vitality and the presence of LBP in males was observed. All SF-36 domains except mental health were significantly higher in females with LBP. Our study confirmed that LBP is frequent in Italian scholar adolescents and has an impact on QoL. Strategies for reducing the effects of LBP on QoL should be an important purpose for clinicians and health policy makers

Subclinical atherosclerosis in patients with psoriatic arthritis: a case-control study. Preliminary data

Objective: The aim of this study was to evaluate the prevalence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA), correlated with some traditional risk factors of atherosclerosis and with PsA-related disease factors. Methods: Forty-one patients and 41 healthy subjects were evaluated for intima-media thickness (IMT) and flow-mediated dilation (FMD), using carotid duplex scanning. IMT values were expressed like IMT mean (cumulative mean of all the IMT mean) and M-MAX (cumulative mean of all the higher IMT). Subclinical atherosclerosis markers were correlated with age, body mass index (BMI) and blood pressure in both groups, with duration of arthritis, duration of psoriasis, tender and swollen joints, BASDAI (Bath Ankylosing Spondylitis Disease Activity Index), BASFI (Bath Ankylosing Spondylitis Functional Index), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in patients. Results: IMT mean and M-MAX were both higher in PsA patients compared with controls (0.7±0.15 vs 0.62±0.09 mm; p<0.01 and 0.86±0.21 vs. 0.74±0.13 mm; p<0.01 respectively). FMD was smaller in patients than in controls (5.9±2 vs 7.5±2.8%; p<0.01). Univariate analysis showed a correlation between IMT mean and SBP (r=0.217; p=0.05) and a correlation between M-MAX and age (r=0.392; p<0.001), BMI (r=0.252; p<0.05), SBP (r=0.446; p<0.001) in both groups. In PsA patients M-MAX resulted correlated with ESR (r=0.338; p<0.05) and BASDAI (r=0.322; p<0.05). Conclusions: PsA patients exhibited endothelial dysfunctions which is an early marker of subclinical atherosclerosis, as well as an higher IMT. An interesting correlation between M-MAX and PsA activity index (ESR and BASDAI) was found

Septic arthritis: a 12 years retrospective study in a rheumatological university clinic

Background: Septic arthritis is a disabling and potentially life-threatening condition that requires prompt diagnosis and treatment. The most important risk factors are joint prosthesis, pre-existing joint disease and immunosuppressive drugs. The aim of our study therefore was to revaluate all septic arthritis cases discharged from our Rheumatologic Unit in the last 12 years, to assess the risk factors, the clinical and laboratory characteristics, the causative microorganisms and its possible increase in frequency. Methods: The medical records of 42 consecutive patients with septic arthritis discharged from our Rheumatology Unit between January 1995 and December 2006 were reviewed. The patients ranged in age from 23 to 90 and there isn't gender predominance. Septic arthritis was diagnosed based on the finding of purulent material in the joint space and/or the isolation of a bacterial pathogen from joint fluid. Demographic data, risk factors, co-morbidity, clinical manifestations, time interval between symptoms onset and diagnosis, treatment and laboratory data including serum white blood cell count, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), synovial white blood cells and culture results were analysed. We considered these parameters in the whole population and in two different age groups (≤60, >60) and tried to determine if there was a change of microorganisms involved in septic arthritis during the years. Results: Of 42 patients, 47% were aged 60 and younger. Only 10 patients were admitted to our unit before 2001. A predisposing factor was recorded in 90,5% of cases: 15 patients had rheumatoid arthritis, 8 were diabetic, 6 had seronegative arthritis, 4 had a connective tissue disease, 8 patients had a prosthetic infection and 3 were subjected recently to arthrocentesis. We found that patients aged 60 and younger were more frequently affected by joint disease and had a synovial white blood cell count lower than patients older than 60. Staphylococcus aureus caused septic arthritis in 70% of cases before 2001, and only in 35,8 % after 2001. Also, after 2001, some infections were caused by more unusual pathogens, prevalently in patients treated with TNF inhibitors. Instead Streptococcus infections were found only in patients aged 70 and older. Conclusion: The incidence of bacterial arthritis has increased in the last six years and there was a modification of microorganisms involved, possibly related to a greater therapeutic aggressiveness. The increased frequency of joint disease and the use of immunosuppressive drugs in patients under the age of 60 could be responsible for a lower synovial white blood cell count in these patient

Phenols, volatiles and sensory properties of primitivo wines from the "Gioia Del Colle" PDO area

The aim of this study was to characterise the phenol, anthocyanin, volatile and sensory profiles of Primitivo wines. The wines were produced in three wineries located in the Gioia del Colle PDO (Protected Designation of Origin) area (Southern Italy - Apulia Region). The grapes came from three vineyards of different ages and were grown according to different training systems. The winemaking techniques applied also differed in some technological variables. The results obtained showed that all wines had a high alcohol content (15 to 16% v/v) and were rich in total phenols and proanthocyanidins. The anthocyanin profile was characterised by the prevalence of non-acylated forms, of which malvidin-3-O-monoglucoside accounted for 62 to 67% of the total anthocyanin, followed by the coumarate, acetate and caffeate forms. The volatile fraction was constituted mainly alcohols and esters, the latter having concentrations above the odour threshold. From a sensory point of view, all wines were judged positively, and presented high olfactory and gustatory persistence. The main odour attributes found were soft fruits, cherry and cloves