The role of infection in juvenile chronic arthritis

Juvenile chronic arthritis covers a heterogeneous group of arthritides for which there appears to be a genetically determined susceptibility. The exact events which trigger or perpetuate an arthritic disease have yet to be defined. There is circumstantial clinical evidence that JCA can be initiated by environmental factors such as infection, and indirect laboratory evidence that immune responses to infectious agents are associated with ongoing JCA; such immune responses seem particularly vigorous within the joint space. Although the weight of evidence favours the hypothesis that the intra-articular inflammatory process is antigen-driven, none of the critical antigens have been identified, and it is still unclear whether they are derived from infectious agents or are true auto-antigens. We can however expect progress to be made, since techniques are now available for defining the antigenic specificity and TCR usage of synovial T cell populations, while PCR allows exquisitely sensitive detection of infectious agents deposited in the synovial space. Application of these techniques should lead to an enhanced understanding of whether (or in what circumstances) infectious agents are involved in the pathogenesis of arthritis in children.     

Design and evaluation of a system for microscope-assisted guided interventions (MAGI)

The problem of providing surgical navigation using image overlays on the operative scene can be split into four main tasks--calibration of the optical system; registration of preoperative images to the patient; system and patient tracking, and display using a suitable visualization scheme. To achieve a convincing result in the magnified microscope view a very high alignment accuracy is required. We have simulated an entire image overlay system to establish the most significant sources of error and improved each of the stages involved. The microscope calibration process has been automated. We have introduced bone-implanted markers for registration and incorporated a locking acrylic dental stent (LADS) for patient tracking. The LADS can also provide a less-invasive registration device with mean target error of 0.7 mm in volunteer experiments. These improvements have significantly increased the alignment accuracy of our overlays. Phantom accuracy is 0.3-0.5 mm and clinical overlay errors were 0.5-1.0 mm on the bone fiducials and 0.5-4 mm on target structures. We have improved the graphical representation of the stereo overlays. The resulting system provides three-dimensional surgical navigation for microscope-assisted guided interventions (MAGI).     

Identification of the defensive secretion from soldiers of the North American termite,Amitermes wheeleri (Desneux) (Isoptera: Termitidae)

Head capsule extracts ofAmitermes wheeleri soldiers yielded an isomeric mixture (67 μg/ soldier) of three sesquiterpene hydrocarbons identified by EIMS, [¹³C]-, and [¹H]NMR as (+)-(S,Z)-α-bisabolene (53%), (+)-(R)-β-bisabolene (16%), and (?)-(Z)-α₂-bisabolene (31%). When alarmed, the termite soldiers secreted the fluid onto the head surface surrounding the efferent pore of the frontal gland reservoir. A defensive function for the soldier secretion was indicated by the avoidance behavior displayed toward alarmed soldiers by the antagonistic ants,Pogonomyrmex rugosus andIridomyrmex humilis. Laboratory studies demonstrated that the sesquiterpene mixture is repellent to foragingI. humilis workers.     

Structure cristalline et proprietes physiques du spinelle Cu1−xTi2S4

The preparation, crystal structure and physical properties of normal spinel Cu_1−xTi₂S₄ are reported. A large range of compositions (0x0.44) has been observed. Single crystals have been obtained by chemical vapor transport reaction with iodine or chlorine pressure. The refinement of the structure (67 reflexions) corroborates the previous normal spinel structure and indicates for this crystal a composition of Cu_0.93Ti₂S₄. Electrical and magnetic properties have been measured for some single crystals. They are consistent with the metallic conductivity as shown by the proposed band structure model.     

Married women doctors'' training and re-employment schemes in the West Midlands Region, with particular reference to psychiatry

A 39-year-old woman with right ovarian vein syndrome accompanied by contralateral ovarian cyst is reported. Removal of the left ovarian cyst with right ureterolysis for removal of the mechanical obstruction gave a good result. It is concluded that the etiology in this case was compression of the ureter by the enlarged ovarian vein, which had an increased blood flow from contralateral venous anastomose.     

Differences in X-ray absorption due to cadmium treatment in Saponaria officinalis leaves

A method for detecting cadmium uptake in leaves of Saponaria officinalis doped with a solution of cadmium acetate is described. The technique based on the exposure of dried leaves to X-rays of a wavelength close to that of the metal K-edge could be useful for phytoremediation studies as it could reveal the bioaccumulation in plants due to the treatment either in vivo or in vitro with heavy metals. X-ray microradiography measurements are in agreement with those from peroxidase enzyme assay utilized to follow the oxidative damage induced by heavy metals. At present, as we will see in this report, microradiography has still poorer sensitivity in comparison with enzyme assay, but it has the advantage of being faster, not destructive, and usable even at very high doping levels, where the enzyme assay technique results are fully saturated. Further analysis of the optical density values could lead to a quantitative measurement of the heavy metal in the sample. Thus, the technology developed in this article could be useful for tracing the intake in phytoremediation studies.