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In order to quantify autoantibodies in the sera of patients with autoimmune disease, we have created a microarray-based immunoassay that allows the simultaneous analysis of 18 known autoantigens. The microarrays contain serial dilutions of the various antigens, thereby allowing accurate determination of autoantibody titer using minimal amounts of serum. The assay is very sensitive and highly specific: as little as 40 fg of a known protein standard can be detected with little or no cross-reactivity to nonspecific proteins. The signal intensities observed from serial dilutions of immobilized antigen correlate well with serial dilutions of autoimmune sera. Miniaturized and highly parallelized immunoassays like these will reduce costs by decreasing reagent consumption and improve efficiency by greatly increasing the number of assays that can be performed with a single serum sample. This system will significantly facilitate and accelerate the diagnostics of autoimmune diseases and can be adapted easily to any other kind of immunoassay.

The analysis of parameters in bronchoalveolar extracellular lining secretions has come into greater use in the diagnosis of diseases of the lung and respiratory passages. The bronchoalveolar lavage (BAL) method is thus used for sampling alveolar fluids or bronchial secretions. However, this method is invasive and therefore cannot be routinely employed for probe sampling. Based on the hypothesis that aerosol particles excreted in human breath reflect the composition of the bronchoalveolar extracellular lining fluid, experiments were performed to concentrate and analyze these aerosols directly using a noninvasive technique. Human exhaled air was directed through a set of cool traps and the condensate of 200 to 400 exhalations examined for nonvolatile components, such as proteins. In experiments conducted with volunteers, the amount of proteins in the breath condensate of 8 healthy individuals (of a total of 10) amounted to between 4 micrograms and 1.4 mg. The proteins were separated by two-dimensional polyacrylamide gel electrophoresis (PAGE) and compared to saliva samples of the respective volunteers. The results suggest that the proteins detected in breath originate partially from the naso-oropharyngeal tract and partially from lower regions of the airways. In clinical tests, the exhaled air of 13 patients suffering from various diseases of the respiratory tract was sampled and analyzed by immunoassays for inflammation parameters, such as interleukin-1 beta (IL-1 beta), soluble interleukin-2 receptor protein, light chain (sIL-2R), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha). In these tests, up to 370 pg IL-1 beta, 120 pg TNF-alpha, and 2,159 U sIL-2R per ml were measured in the breath condensate.(ABSTRACT TRUNCATED AT 250 WORDS)

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Arterial smooth muscle cells from rabbit aortic media were grown in first subcultures on hydrophilized and collagen-coated silicone membranes which were then subjected to directional cyclic stretches and relaxations at a frequency of 50 times/min. The membranes were stretched 2, 5 and 10% beyond their resting length. Cells on unstretched and stationary membranes in the same chamber served as controls. The cells which were stretched with an amplitude of 2% remained in random orientation after 14 days of continuously performed cyclic stretching. The cells which were stretched 5% for 12 days orientated at an angle of 61 ± 9° to the direction of stretching, while the cells which were stretched with an amplitude of 10% for 6 days orientated at an angle of 76 ± 5°. The cells on the stationary and unstretched membranes remained in random orientation. We were able to confirm that the angle of orientation is reversible, i.e. preorientated cells changed their orientation during application of another stretching amplitude. The results suggest that stretching of the artery wall by blood pulsation may be a factor influencing the orientation of smooth muscle cells within the media of the artery wall and of those smooth muscle cells which proliferate into the subendothelial space after mechanical injury of the endothelium or electrical stimulation of the artery wall. An apparatus is presented which produces cyclic and directional mechanical stimuli similar to those which may occur in the artery wall.