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L Seveus

Publications and source records attributed to L Seveus.

5 recordsLinked to original sources
PubMed2000

Human neutrophil lipocalin (HNL) and myeloperoxidase (MPO). Studies of lung lavage fluid and lung tissue.

Myeloperoxidase (MPO) and human neutrophil lipocalin (HNL) are proteins which are stored in neutrophil granulocytes, in the primary and secondary granules, respectively. These granules or their contents of MPO and HNL are secreted upon activation of the cells, and measurement of these soluble markers in biological fluids, such as bronchoalveolar lavage (BAL), has been proposed to mirror the degree of neutrophil activity in the tissue. We conducted a BAL study in 10 healthy volunteers, with the aim to evaluate the intra-individual variability of the concentration of HNL and MPO recovered in sequential aspirations, during a time period when the concentrations of HNL and MPO in BAL fluids were considered to have equilibrated with those in the underlying tissues. The concentrations of HNL were less variable than those of MPO (coefficients of variability 0.33 +/- 0.07 vs. 0.92 +/- 0.28; P = 0.01), suggesting HNL to be a more useful marker of neutrophil activity within the airspace. The specificity of HNL as a selective index of neutrophil cells was confirmed by means of immunohistochemical staining of uninvolved lung tissue specimens obtained from patients referred to pulmonectomy due to carcinoma. While HNL was located only to intracellular spaces of neutrophils, MPO was in addition located to other cells as well. We speculate that the dynamic changes of pressure across the membranes and flow of solutes during a lavage process might mobilize particulate matter and adherent cells, some of which may be loaded with MPO, and that this may introduce larger variability in the recovery of MPO than of HNL. We conclude that using HNL as a soluble indicator of neutrophil presence is more feasible than using MPO.

Acute-Phase Proteins↗
PubMed1992

Time-resolved fluorescence imaging of europium chelate label in immunohistochemistry and in situ hybridization.

Fluorescent lanthanide chelates with long decay times allow the suppression of the fast decaying autofluorescence in biological specimens. This property makes lanthanide chelates attractive as labels for fluorescence microscopy. As a consequence of the suppression of the background fluorescence the sensitivity can be increased. We modified a standard epifluorescence microscope for time-resolved fluorescence imaging by adding a pulsed light source and a chopper in the narrow aperture plane. A cooled CCD-camera was used for detection and the images were digitally processed. A fluorescent europium chelate was conjugated to antisera and to streptavidin. These conjugates were used for the localization of tumor associated antigen C242 in the malignant mucosa of human colon, for the localization of type II collagen mRNA in developing human cartilaginary growth plates, and for the detection of HPV type specific gene sequences in the squamous epithelium of human cervix. The specific slowly decaying fluorescence of the europium label could be effectively separated from the fast decaying background fluorescence. It was possible to use the europium label at the cell and tissue level and the autofluorescence was effectively suppressed in in situ hybridization and immunohistochemical reactions in both frozen and formaldehyde-fixed, wax-embedded specimens.

Alkaline Phosphatase↗
PubMed1980

Cryoultramicrotomy as a preparation method for x-ray microanalysis.

X-ray microanalysis allows "in situ" studies on ;the elemental composition of the cell and its compartments. The reliability of the results is almost entirely determined by the preparation method. Two criteria for a reliable preparation method have been formulated: (1) it must preserve the ultrastructure to permit identification of cellular compartments, (2) it must retain the elements in their in vivo location. We investigated cryoultramicrotomy and confirmed its validity as a preparation method for X-ray microanalysis of diffusible elements. The method is only truly reliable, however, under the following conditions: (1) the tissue must be frozen rapidly, (2) the sections must be cut in the ice crystal free surface layer, (3) the sections must be cut at low temperature (e.g. a specimen temperature of -140 degrees C, a knife temperature of -100 to -120 degrees C and a cryochamber temperature under -100 degrees C, and pressed onto the grid and freeze-dried at a temperature of -100 degrees C).

Electron Probe Microanalysis↗
PubMedDate not supplied

Expression of tumour associated antigens 12H12, 2E11, 7A9, CEA and DF3 in human breast cancer.

Expression of tumour associated antigens 12H12, 2E11, 7A9, CEA and DF3 was determined immunohistochemically in paraffin embedded biopsy specimens from 42 breast carcinomas. The mean (SD) of staining index (I) for 12H12 was 0.95(0.94), for 2E11 1.30(0.99), for FA9 1.11(0.92), for CEA 0.03(0.1) and for DF3 1.32(0.93). Of the 42 carcinomas, 3 (7.1%) were totally negative for 12H12, 3/42 (7.1%) for 2E11, 6/42 (14.3%) for 7A9, 34/42 (81%) for CEA and 6/45 (13.3%) for DF3. The 12H12 positivity was related significantly to axillary lymph node status (r = 0.41, p < 0.01), expression of 7A9 (r = 0.71, p < 0.001), expression of 2E11 (r = 0.76, p < 0.001), expression of DF3 (r = 0.40, p < 0.01) and TPA serum level (r = 0.41, p < 0.01). The 2E11 positivity was related to axillary lymph node status (r = 0.43, p < 0.01), expression of 7A9 (r = 0.95, p < 0.001) and 12H12 (r = 0.76, p < 0.001). The 7A9 positivity was related to axillary lymph node status (r = 0.44, p < 0.01), expression of 7A9 (r = 0.71, p < 0.001), 12H12 (r = 0.71, p < 0.001) and 2E11 (r = 0.95, p < 0.001). The DF3 positivity was significantly related to expression of 12H12 (r = 0.40, p < 0.01). The CEA positivity was not significantly related to any of the tested variables. The results suggest that antigens 12H12, 2E11 and 7A9 should be subject to further analysis in breast cancer research. Particularly, they may be helpful in separating benign breast lesions from the more malignant ones. Secondly, the relationship between high expression of the antigens and axillary lymph node status suggests that these antigens may have also prognostic value.

Antigens, Neoplasm↗