Importance of species‐specific antigens in the serodiagnosis of Chlamydia trachomatis reactive arthritis

Objectives. To determine the most sensitive and specific method of anti‐Chlamydia antibody measurement for the serodiagnosis of Chlamydia trachomatis reactive arthritis. Methods. Immunoblotting, enzyme‐linked immunosorbent assays using six synthetic peptides or recombinant antigens and a microimmunofluorescence test were used to determine the presence of IgG, IgM and IgA in serum samples from 17 patients with C. trachomatis reactive arthritis. Twenty patients with other inflammatory arthropathies without evidence of urogenital C. trachomatis infection were used as controls. Results. The best association of sensitivity (76%) and specificity (85%) was obtained when IgG and/or IgA reactivity to two species‐specific antigens was determined. These antigens were synthetic peptides, derived from species‐specific epitopes in the variable domain IV of the major outer membrane protein (MOMP) (Labsystems, Finland) and recombinant polypeptide encoded by open reading frame 3 of the plasmid (pgp3). Conclusions. IgG and/or IgA anti‐MOMP‐derived peptides and anti‐pgp3 could be useful for the diagnosis of probable C. trachomatis reactive arthriti

SYNOVIAL FLUID AND SERUM ANTIBODIES AGAINST CHLAMYDIA IN DIFFERENT FORMS OF ARTHRITIS: INTRA-ARTICULAR IgA PRODUCTION IN CHLAMYDIA SEXUALLY ACQUIRED REACTIVE ARTHRITIS

SUMMARY Since the presence of Chlamydia has been shown in synovial fluid (SF) from some patients with Chlamydia reactive arthritis, we investigated whether anti-Chlamydia antibodies present in the joint are derived from the circulation or are locally produced. We compared titres of IgG, IgM and IgA antibodies against Chlamydia, and against a control antigen (tetanus toxoid), by an enzyme-linked immunosorbent assay (ELISA), in paired samples of serum and SF from Chlamydia trachomatis sexually acquired reactive arthritis (CT-SARA) patients and from patients with other forms of arthritis. The ratio of serum/SF IgA anti-Chlamydia antibodies was significantly decreased in CT-SARA patients. It is concluded that, in our experimental conditions, we found evidence for intra-articular production of IgA anti-Chlamydia antibodie

THE VALUE OF ISOTYPE DETERMINATION OF SERUM ANTIBODIES AGAINST CHLAMYDIA FOR THE DIAGNOSIS OF CHLAMYDIA REACTIVE ARTHRITIS

SUMMARY In clinical rheumatology, the diagnosis of Chlamydia reactive arthritis is difficult because an incomplete form of the disease can closely resemble an undifferentiated seronegative mono/oligoarthritis. We investigated whether measuring specific isotypes of anti-Chlamydia antibodies in serum can improve the diagnosis, by comparing such antibody concentrations in the serum of patients with well-defined disease, i.e. Chlamydia trachomatis sexually acquired reactive arthritis (CT-SARA), with other arthritides. Antibody levels were determined by enzyme-linked immunosorbent assay (ELISA). When considering two different isotypes and their combination, the best sensitivity (63%) was obtained for IgM and/or IgA results with a specificity of 81%. The patients with CT-SARA and SARA had the highest levels of antibodies of all isotypes tested. It is concluded that, in our experimental conditions, only very high values of specific isotypes could indicate a diagnosis of Chlamydia reactive arthriti

Many--Particle Correlations in Relativistic Nuclear Collisions

Many--particle correlations due to Bose-Einstein interference are studied in ultrarelativistic heavy--ion collisions. We calculate the higher order correlation functions from the 2--particle correlation function by assuming that the source is emitting particles incoherently. In particular parametrizations of and relations between longitudinal, sidewards, outwards and invariant radii and corresponding momenta are discussed. The results are especially useful in low statistics measurements of higher order correlation functions. We evaluate the three--pion correlation function recently measured by NA44 and predict the 2--pion--2--kaon correlation function. Finally, many particle Coulomb corrections are discussed.Comment: 5 corrected misprints, 14 pages, revtex, epsfig, 6 figures included, manuscript also available at http://www.nbi.dk/~vischer/publications.htm

Inhomogeneous Nucleation of Quark-Gluon Plasma in High Energy Nuclear Collisions

We estimate the probability that a hard nucleon-nucleon collision is able to nucleate a seed of quark--gluon plasma in the surrounding hot and dense hadronic matter formed during a central collision of two large nuclei at AGS energies. The probability of producing at least one such seed is on the order of 1-100\%. We investigate the influence of quark--gluon plasma formation on the observed multiplicity distribution and find that it may lead to noticable structure in the form of a bump or shoulder.Comment: 16 pages, latex and 12 ps figures available on reques

Asynchronous division by non-ring FtsZ in the gammaproteobacterial symbiont of <em>Robbea hypermnestra</em>

The reproduction mode of uncultivable microorganisms deserves investigation as it can largely diverge from conventional transverse binary fission. Here, we show that the rod-shaped gammaproteobacterium thriving on the surface of the Robbea hypermnestra nematode divides by FtsZ-based, non-synchronous invagination of its poles-that is, the host-attached and fimbriae-rich pole invaginates earlier than the distal one. We conclude that, in a naturally occurring animal symbiont, binary fission is host-oriented and does not require native FtsZ to polymerize into a ring at any septation stage

Scattering in the Presence of Electroweak Phase Transition Bubble Walls

We investigate the motion of fermions in the presence of an electro\-weak phase transition bubble wall. We derive and solve the Dirac equation for such fer\-mions, and compute the transmission and reflection coefficients for fermions traveling from the symmetric to the asymmetric phases separated by the domain wall.Comment: TPI--MINN--54, NUC--MINN--93/30--T, UMN--TH--1226/93, LaTex, 29 page

Nucleation of Quark--Gluon Plasma from Hadronic Matter

The energy densities achieved during central collisions of large nuclei at Brookhaven's AGS may be high enough to allow the formation of quark--gluon plasma. Calculations based on relativistic nucleation theory suggest that rare events, perhaps one in every 10$^2$ or 10$^3$, undergo the phase transition. Experimental ramifications may include an enhancement in the ratio of pions to baryons, a reduction in the ratio of deuterons to protons, and a larger source size as seen by hadron interferometry.Comment: 22 pages, 7 figures available upon request, NUC--MINN--94/5--

Empathy, engagement, entrainment: the interaction dynamics of aesthetic experience

A recent version of the view that aesthetic experience is based in empathy as inner imitation explains aesthetic experience as the automatic simulation of actions, emotions, and bodily sensations depicted in an artwork by motor neurons in the brain. Criticizing the simulation theory for committing to an erroneous concept of empathy and failing to distinguish regular from aesthetic experiences of art, I advance an alternative, dynamic approach and claim that aesthetic experience is enacted and skillful, based in the recognition of others’ experiences as distinct from one’s own. In combining insights from mainly psychology, phenomenology, and cognitive science, the dynamic approach aims to explain the emergence of aesthetic experience in terms of the reciprocal interaction between viewer and artwork. I argue that aesthetic experience emerges by participatory sense-making and revolves around movement as a means for creating meaning. While entrainment merely plays a preparatory part in this, aesthetic engagement constitutes the phenomenological side of coupling to an artwork and provides the context for exploration, and eventually for moving, seeing, and feeling with art. I submit that aesthetic experience emerges from bodily and emotional engagement with works of art via the complementary processes of the perception–action and motion–emotion loops. The former involves the embodied visual exploration of an artwork in physical space, and progressively structures and organizes visual experience by way of perceptual feedback from body movements made in response to the artwork. The latter concerns the movement qualities and shapes of implicit and explicit bodily responses to an artwork that cue emotion and thereby modulate over-all affect and attitude. The two processes cause the viewer to bodily and emotionally move with and be moved by individual works of art, and consequently to recognize another psychological orientation than her own, which explains how art can cause feelings of insight or awe and disclose aspects of life that are unfamiliar or novel to the viewer