| 1. |
- Bratel, John, 1953, et al.
(författare)
-
The frequency of different T-cell receptor V-families in oral lichen planus and lichenoid contact lesions: an immunohistochemical study.
- 1998
-
Ingår i: Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology. - 0904-2512. ; 27:9, s. 415-9
-
Tidskriftsartikel (refereegranskat)abstract
- Oral lichen planus (OLP) and lichenoid contact lesions (CL) are recognized as different pathological conditions of the oral mucosa. Cutaneous delayed-type hypersensitivity to mercury displayed by patients with CL but not by OLP patients supports the concept of different etiological mechanisms behind the two lesions. It is not possible to reveal this difference by histopathological assessments, and differences in clinical appearances are at present the only way to discriminate between the two conditions. It has recently been observed that T cells in OLP lesions express T-cell receptors (TCR) belonging to the Vbeta3 family in a higher frequency than expected from a random distribution, suggesting an involvement of superantigens as an etiologic factor behind this condition. In an effort to discriminate more clearly between OLP and CL, and to provide clues to the etiological mechanisms behind the two lesions, the TCR V-family distributions in the inflammatory infiltrates of OLP and CL were compared. Biopsies were taken from 10 patients with manifest OLP and 10 patients with CL. Frozen sections were incubated with antibodies against TCR Vbeta3, Valpha2 and Vbeta5a utilizing a standard immunoperoxidase technique. The frequency of Vbeta3.1 (clone 8F10) was calculated as 7%, and for Valpha2 less than 3%, and the results did not reveal any differences between OLP and CL regarding the frequencies of T-cell V-families. Thus, it was not possible to discriminate between OLP and CL by immunohistochemistry staining for different V families.
|
|
| 2. |
- Rääf, Christopher, et al.
(författare)
-
Urinary excretion measurements for the assessment of body burden of radiocaesium in man: differences between potassium and creatinine normalisation
- 1999
-
Ingår i: Applied Radiation and Isotopes. - 0969-8043. ; 51:5, s. 505-514
-
Tidskriftsartikel (refereegranskat)abstract
- Relationships between 24-h urinary excretion and body burden of 137Cs obtained in a south-Swedish population, together with data from the literature, were applied to urine samples collected in 1994-95 from adult subjects living in Russia, in order to estimate their average body burden of 137Cs. Estimates obtained through creatinine normalisation of the 137Cs content in the Russian urine were a factor of 2 higher than estimates obtained through potassium normalisation. The accuracy of both these normalisation methods is discussed, as well as the influence of the difference in dietary habits between the two populations.
|
|
| 3. |
- Simark-Mattsson, Charlotte, 1955, et al.
(författare)
-
Distribution of interferon-gamma mRNA-positive cells in oral lichen planus lesions.
- 1998
-
Ingår i: Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology. - 0904-2512. ; 27:10, s. 483-8
-
Tidskriftsartikel (refereegranskat)abstract
- The present study investigated the potential involvement of interferon-gamma (IFN-gamma)-producing cells in the pathogenesis of oral lichen planus (OLP). On biopsies from 10 OLP patients, an in situ hybridization technique was employed to determine the topographical distribution of cells expressing IFN-gamma mRNA. It was estimated that approximately 1% or fewer lesional cells were IFN-gamma mRNA-positive. These cells were mainly encountered lining the basal membrane in a majority of the patients, or were in a few cases circumscribing the infiltrate, but were more seldom localized to the center of the lesion. A slightly higher, but not statistically significant, number of phytohemagglutinin (PHA)-induced IFN-gamma-producing cells, in vitro, was found in blood from 11 other OLP patients compared with blood from matched controls. Equal concentrations of IFN-gamma in supernatants from PHA-stimulated blood cells were detected in the two groups. Similarly, the IFN-gamma response towards C. albicans was alike in OLP and in healthy control (HC) blood cells, indicating normal immunological memory function in the OLP patients. A small set of cells with spontaneous IFN-gamma production was found in OLP and in HC peripheral blood. The data suggest that T-lymphocyte activation and cytokine production act locally and are not reflected in peripheral blood. The localization of the IFN-gamma mRNA-positive cells indicates that the antigenic peptides are presented at the periphery of the mononuclear cell infiltrate. Furthermore, the low frequency of IFN-gamma mRNA-positive cells in the lesions suggests that the disease is maintained by a small number of antigen-specific T cells.
|
|
| 4. |
|
|
| 5. |
- Simark-Mattsson, Charlotte, 1955, et al.
(författare)
-
Reduced in vivo cell-mediated immune responses to mumps, tuberculin, and streptokinase/streptodornase but not to Candida albicans in oral lichen planus.
- 1999
-
Ingår i: Journal of dental research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 78:11, s. 1704-10
-
Tidskriftsartikel (refereegranskat)abstract
- Oral lichen planus is considered to be a T-cell-mediated disease. The purpose of this study was to investigate the capacity of T-lymphocytes in oral lichen planus patients to respond to a number of commonly encountered environmental antigens in vivo. To do this, we assessed dermal delayed-type hypersensitivity responses to mumps, streptokinase/streptodornase, Candida albicans, and purified protein derivative of tuberculin (PPD) in 17 oral lichen planus patients and in matched controls. Reduced induration in response toward mumps, PPD, and streptokinase/streptodornase was demonstrated in oral lichen planus patients compared with controls. In addition, the total sum of induration diameters was decreased in the patients. However, C. albicans stimulation resulted in similar levels of response in both groups. The differences in induration size between matched patients and controls for mumps and PPD were thus significantly greater than the corresponding differences for the C. albicans antigen. This suggests that a selective difference in the response to these antigens exists in oral lichen planus patients. The results may point to a loss of memory T-helper function to infrequently encountered environmental antigens, represented by mumps, PPD, and streptokinase/streptodornase, contrarily to memory function to common antigens (C. albicans), which seem to be unaffected.
|
|
| 6. |
- Tillman, Carl, et al.
(författare)
-
Survival of mammalian cells exposed to ultrahigh dose rates from a laser-produced plasma x-ray source
- 1999
-
Ingår i: Radiology. - 1527-1315. ; 213:3, s. 860-865
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine whether intense laser-produced x rays have an increased radiation hazard. MATERIALS AND METHODS: Mammalian cells were exposed to x rays from a laser-produced plasma that produced ultrahigh peak absorbed dose rates, up to a factor of 10(10) higher than those produced by conventional x rays used in imaging. The cell survival was studied as a function of the absorbed dose. The survival of mammalian cells exposed to high peak absorbed dose rates with laser-produced x rays was compared with the survival of cells exposed to standard absorbed dose rates with conventional x-ray sources. Comparative survival studies were performed by using a conventional x-ray tube and a cobalt 60 source. The absorbed doses in the irradiation field were measured with thermoluminescent dosimeters. RESULTS: Cell survival following irradiation by filtered, laser-produced x rays with a high dose rate was not markedly different from the survival following irradiation by conventional sources. There was, however, a notable difference between the survival after exposure to filtered, laser-produced x rays and the survival after exposure to unfiltered laser-produced x rays. CONCLUSION: Exposure to filtered, laser-produced x rays with a high dose rate does not lead to increased harm to mammalian cells exposed in vitro compared with the harm from exposure to x rays from conventional sources, which indicates that the use of high-power laser facilities for medical imaging is justified
|
|
