Isolation of antigens recognized by coeliac disease autoantibodies and their use in enzyme immunoassay of endomysium and reticulin antibody-positive human sera

BACKGROUND & AIMS: Smooth muscle cells resident in the intestinal wall play a significant role in the healing of the injured intestine and in the fibrosis that complicates Crohn's disease. The cytokine interleukin 1 beta (IL-1 beta) is involved in inflammatory bowel disease. The aim of this study was to determine the action of IL-1 beta on proliferation and collagen metabolism in human intestinal smooth muscle cells. RESULTS: IL-beta caused a three-fold increase in [3H]thymidine uptake at 100 pmol/L. This mitogenic effect was equipotent with that of platelet-derived growth factor when cells were exposed to IL-beta for 48 vs. 24 hours. IL-beta inhibited the secretion of procollagen into culture medium by 70% and the accumulation of newly synthesized procollagen in cells by 55%. In addition, IL-beta caused a concentration-dependent inhibition of steady-state levels of procollagen I and III messenger RNA (85% inhibition at 100 pmol/L) and a 3-5-fold augmentation of collagenase messenger RNA levels. CONCLUSIONS: IL-beta is mitogenic for human intestinal smooth muscle cells, but this action is associated with a concomitant down-regulation of collagen synthesis and secretion and an augmention of collagenase expression.     

Intestinal obstruction in southeastern Nigerian children

In a 10-year (1981-1990) retrospective study of acute intestinal obstruction in the University of Calabar Teaching Hospital, Calabar, Nigeria, of the 295 paediatric cases reviewed, the major causes were ascaris worms (25%) and intussusception (22%). Other important lesions include imperforate anus (11%), volvulus (10%), external hernias (9%) and adhesions (7%) each. Ascaris-induced and hernial obstruction were most rampant in children aged above 5 years while intussusception had its peak frequency at the ages one to 12 months. Intussusception was largely (95%) ileo-caecal; volvulus involved mainly the ileum and ileo-caecum in 50% of cases each. The obstructed hernias were more common in the umbilicus (59%) than the groin (41%). The mortality (13%) was chiefly due to associated infection but lack of expertise in management of cases cannot be ignored. Generally, the pattern of intestinal obstruction among children in this region appears markedly different from that seen in Europe and North America. There is a need to create a specialist paediatric surgical unit as a means of reducing morbidity and mortality from this condition.     

Development of systemic lupus erythematosus in a male patient after 14 years on hemodialysis

Graves' disease (GD), myasthenia gravis (MG), and polymyositis (PM) are organ-specific autoimmune diseases. The association between GD and MG is well known, and an association between MG and PM has been reported. However, only one patient with all three diseases has been reported. We describe a patient with GD and PM developing 6 and 29 years, respectively after the onset of MG. This case suggests that the expression of autoimmunity occurred over a prolonged period of time and these organ-specific autoimmune diseases may be induced by a similar mechanism.     

Coupled B-snake grids and constrained thin-plate splines for analysis of 2-D tissue deformations from tagged MRI

Magnetic resonance imaging (MRI) is unique in its ability to noninvasively and selectively alter tissue magnetization and create tagged patterns within a deforming body such as the heart muscle. The resulting patterns define a time-varying curvilinear coordinate system on the tissue, which we track with coupled B-snake grids. B-spline bases provide local control of shape, compact representation, and parametric continuity. Efficient spline warps are proposed which warp an area in the plane such that two embedded snake grids obtained from two tagged frames are brought into registration, interpolating a dense displacement vector field. The reconstructed vector field adheres to the known displacement information at the intersections, forces corresponding snakes to be warped into one another, and for all other points in the plane, where no information is available, a C1 continuous vector field is interpolated. The implementation proposed in this paper improves on our previous variational-based implementation and generalizes warp methods to include biologically relevant contiguous open curves, in addition to standard landmark points. The methods are validated with a cardiac motion simulator, in addition to in-vivo tagging data sets.     

Neuropsychological dose effects of a freon, trifluoromethane (FC-23), compared to N2O

Animal studies show FC-23 to be a promising magnetic resonance imaging indicator of regional cerebral blood flow. In a Phase 1, dose ranging (investigative new drug) study, neuropsychological (NP) tests, subjective ratings, and intensive physiological monitoring were used to determine the maximum tolerated concentration of FC-23 for human application. Five normal healthy male volunteers were exposed to concentrations of FC-23 between 10% and 60% [randomly interleaved with exposures to both room air and 40% nitrous oxide (N2O)] in a within-subjects, double-blind design. Analyses of individual cases and ranked group data showed that individuals tolerated the 30% concentration of FC-23 according to established criteria. Planned comparisons indicated that inhalation of FC-23 produced smaller NP changes and fewer negative symptoms than 40% N2O but poorer NP performance and more negative symptoms than room air. This study indicated that FC-23 is not inert and that humans do not tolerate concentrations suitable for current MRI technology. NP and subjective data assisted in characterizing the sedative effect of FC-23.     

Differential concentrations of monocyte chemotactic protein-1 and interleukin-8 within the fluid compartments present during the first trimester of pregnancy

Monocyte chemotactic protein-1 (MCP-1) and interleukin-8 (IL-8) are important chemokines which effect the chemotaxis of monocytes and neutrophils, respectively. There is increasing evidence that such chemokines play an integral role in the control and maintenance of a normal pregnancy from implantation to parturition. However, little is known about the sites of secretion and function of MCP-1 and IL-8 in particular with respect to establishment of the placenta and membranes during first trimester. The aim of this study was therefore to investigate the concentrations and localization of MCP-1 and IL-8 in amniotic fluid and extra-embryonic coelomic fluid (EECF) collected by ultrasound-guided needle aspiration and maternal serum during the first trimester of pregnancy. Using specific enzyme-linked immunosorbent assays, MCP-1 was present at high concentrations in the EECF, significantly higher than those in amniotic fluid and maternal serum. IL-8 was also present predominantly in the EECF with concentrations being significantly higher than the low values detected in maternal serum and the very low amounts found in amniotic fluid. This strict compartmentalization of these cytokines in the fluid compartments of early pregnancy may be important for establishment and development of a viable pregnancy.     

Intracellular survival of Haemophilus somnus in bovine blood monocytes and alveolar macrophages

The mechanisms used by Haemophilus somnus to survive and multiply within bovine mononuclear phagocytes are not fully understood. In order to study the interaction between bovine mononuclear phagocytes and H. somnus, a colorimetric assay using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenylItetrazolium bromide (MTT) was developed to assess the survival of H. somnus within cultured bovine blood monocytes (BBM). Using this system, it was found that H. somnus was able to survive within BMM in vitro, and the kinetics of its survival were similar to that seen in BBM isolated from experimentally infected cattle. Using ultrastructural studies, it was possible to demonstrate the survival of H. somnus in freshly isolated bovine mononuclear phagocytes in membrane-bound vacuoles. To determine if activation of macrophage function would result in elimination of intracellular H. somnus, BBM were treated with E. coli lipopolysaccharide (LPS) or recombinant bovine (rBo) cytokines, interferon-gamma (IFN-gamma), granulocyte macrophage colony stimulating factor (GM-CSF), tumour necrosis factor-alpha (TNF-alpha) or interleukin-1beta (IL-1beta). Treatment of BBM with rBoIFN-gamma, rBoGM-CSF or E. coli LPS resulted in decreased intracellular survival of H. somnus at 18 and 48 h, whereas BBM treated with rBoTNF-alpha or rBoIL-1beta had reduced intracellular survival of H. somnus only at 18 h. However, none of these treatments resulted in complete elimination of the intracellular bacteria. The ability of H. somnus to survive and multiply in both freshly isolated and cytokine-treated cultured BBM demonstrated the capability of H. somnus to escape from macrophage killing mechanisms. This capability may play a role in the dissemination of H. somnus infection in the body.     

Copper-binding compounds from Methylosinus trichosporium OB3b

Two copper-binding compounds/cofactors (CBCs) were isolated from the spent media of both the wild type and a constitutive soluble methane monooxygenase (sMMOC) mutant, PP319 (P. A. Phelps et al., Appl. Environ. Microbiol. 58:3701-3708, 1992), of Methylosinus trichosporium OB3b. Both CBCs are small polypeptides with molecular masses of 1,218 and 779 Da for CBC-L1 and CBC-L2, respectively. The amino acid sequence of CBC-L1 is S?MYPGS?M, and that of CBC-L2 is SPMP?S. Copper-free CBCs showed absorption maxima at 204, 275, 333, and 356 with shoulders at 222 and 400 nm. Copper-containing CBCs showed a broad absorption maximum at 245 nm. The low-temperature electron paramagnetic resonance (EPR) spectra of copper-containing CBC-L1 showed the presence of a copper center with an EPR splitting constant between those of type 1 and type 2 copper centers (g = 2.087, g = 2.42 G, A = 128 G). The EPR spectrum of CBC-L2 was more complex and showed two spectrally distinct copper centers. One signal can be attributed to a type 2 Cu2+ center (g = 2.073, g = 2.324 G, A = 144 G) which could be saturated at higher powers, while the second shows a broad, nearly isotropic signal near g = 2.063. In wild-type strains, the concentrations of CBCs in the spent media were highest in cells expressing the pMMO and stressed for copper. In contrast to wild-type strains, high concentrations of CBCs were observed in the extracellular fraction of the sMMOC mutants PP319 and PP359 regardless of the copper concentration in the culture medium.