Dynamic holographic endoscopy--ex vivo investigations of malignant tumors in the human stomach.

Laser holographic interferometry is based on the superimposition of the holograms of different motional states of an object on a single holographic storing medium. Using a combination of holographic interferometry and endoscopic imaging, we tried to detect areas of focally disturbed tissue elasticity in gastric cancer preparations. By connecting a mobile electronic speckle pattern interferometry (ESPI) camera system (light source: double frequency Nd:YAG laser, lambda = 532 nm) to different types of endoscopes, ex vivo experiments were performed on ten formalin fixed human stomachs, nine containing adenocarcinomas and one with a gastric lymphoma. Linking the endoscopic ESPI camera complex to a fast image processing system, the method of double pulse exposure image subtraction was applied at a video frame rate of 12.5 Hz. Speckle correlation patterns and corresponding phase difference distributions resulting from gastric wall deformation by gentle touch with a guide wire were analyzed. Tumor-free gastric areas showed high-contrast concentric fringes around the point of stimulation. In contrast, fringe patterns and filtered phase difference distributions corresponding to the areas of malignancy in all the cases were characterized by largely parallel lines, indicating that stimulation of rigid tumor tissue primarily led to tilting. Our ex vivo investigations of malignant gastric tumors show that the application of dynamic holographic endoscopy makes it possible to distinguish areas of malignancy from surrounding healthy tissue based on the differences in tissue elasticity.

Relationship of clinical features and laboratory parameters to thyroid echogenicity measured by standardized grey scale ultrasonography in patients with Hashimoto's thyroiditis.

BACKGROUND: Hashimoto's thyroiditis is associated with a diffuse reduction in thyroid echo levels. The purpose of this study was to determine the degree of hypoechogenicity in correlation to clinical features and laboratory parameters. MATERIAL/METHODS: 52 patients with Hashimoto's thyroiditis under substitutive therapy with levothyroxine (50-200 g daily) and 100 normal euthyroid volunteers (with no features of autoimmune disease who were not taking any thyroid medication) as controls were investigated. Determination of plasma free thyroxine (FT4) and TSH as well as peroxidase- (TPO), thyroglobulin- and TSH receptor (TSH-R) antibodies were performed. Thyroid volume was measured by conventional ultrasonography. Tissue echogenicity was characterized by standardized grey scale ultrasonography under defined operating conditions. Mean densities were given in a histogram range of grey scales between 0-63 GWE (= Grauwerteinheiten). RESULTS: Patients with Hashimoto's thyroiditis revealed significantly lower echo levels (19.6+/-2.6 GWE) than controls (25.6+/-2.0 GWE, p<0.001). High graded hypoechogenicity was associated with large goiters, persistently increased TSH levels (subclinical hypothyroidism) and highly elevated TPO-antibodies. CONCLUSIONS: Standardized grey scale ultrasonography allows for reproducable correlations between functional status and morphological characteristics of the thyroid gland in Hashimoto's thyroiditis. The results hint at a stronger inflammatory process in higher grades of hypoechogenicity.

Development of an in vitro miniature model to simulate immunoadsorption in patients with systemic lupus erythematosus.

In SLE, immunoadsorption is used as an adjuvant therapy; however, adsorption profiles and binding mechanisms have not yet been completely investigated. Using a minicolumn filled with the sorbent IMPH with or without the ligand phenylalanine, we developed a model simulating clinical conditions in a reduced scale with a constant ratio of plasma to column volume and a constant plasma flow at room temperature. By desorbing the column, the adsorption efficacy for different antibodies could be measured directly. We demonstrate that the adsorption rate can be increased by a low plasma flow and by covering the column surface. Double perfusion of the same column did not increase the amount of adsorbed antibodies. We further demonstrate that the carrier material without a ligand is unable to bind antibodies or protein. In the IMPH sorbent anti-dsDNA antibodies were significantly better adsorbed than total IgG or total protein. After a single perfusion of 21 samples, we estimated a mean anti-dsDNA antibody adsorption rate of 22.5% (+/-13.6). A group of ten responders with a medium adsorption rate of 35.4% (+/-6.5) clearly differed from a second group of eleven nonresponders (10.9% +/- 4.2). Anti-cardiolipin antibodies (ACA) were adsorbed in a wide range (IgG type, 2.5-52.7%, IgM type, 1.1-37.8%) while anti-Ro (SSA) antibody adsorption was negligible. This in vitro minimodel provides a precise simulation of therapeutic immunoadsorption and helps to analyze the binding characteristics of the sorbent IMPH and shows its effectiveness in several antibody subsets of different patients.