Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-069X
    Keywords: HLA-DR expression ; Keratinocytes ; Lupus erythematosus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary It has been suggested that aberrant expression of HLA-DR plays an important role in the induction of an autoimmune reaction. In lupus erythematosus (LE), skin represents a major target for autoimmune attack. We therefore tested lesional and nonlesional skin from 11 patients with different clinical subtypes of LE for the presence of HLA-DR molecules on keratinocytes using a monoclonal antibody against a non-polymorphic HLA-DR determinant. In all lesions tested, HLA-DR-positive keratinocytes were present, whereas in nonlesional skin, these cells remained HLA-DR negative. To exclude the possibility of passive absorption of DR molecules, the de novo synthesis of HLA-DR was demonstrated by the presence of cytoplasmic HLA-DR γ chains in keratinocytes. If aberrant HLA-DR expression is a primary event, it could facilitate the recognition of autoantigens on keratinocytes by immunocompetent cells. Alternatively, the synthesis of DR molecules could be induced as a secondary event by mediators derived from the inflammatory infiltrate.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We investigated the co-distribution of lymphocyte subpopulations and non-lymphoid ‘accessory’ cells in 35 cases of cutaneous lymphoproliferative diseases (T-cell lymphoma, 10 cases; B-cell lymphoma, 17 cases; pseudolymphoma, 8 cases) using immunohistochemical methods. T-zone histiocytes and particularly Langerhans cells were abundant in all cutaneous T-cell lymphomas, but were also found in B-cell lymphomas. T-zone histiocytes were associated with T-lymphocytes, especially T-helper cells, but not with T-suppressor cells. Dendritic reticulum cells were essentially confined to well differentiated germinal centres. Macrophages occurred in both lymphomas and pseudolymphomas without definite relationship with either B- or T -cells. In malignant lymphomas of high grade malignancy, macrophages represented the only non-lymphoid cell type.Our results indicate that malignant lymphoid cells, like normal lymphocytes, require definite micro-environments which are, at least in part, maintained by certain non-lymphoid cells.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-069X
    Keywords: Histiocytosis X ; Plasminogen activator ; dendritic cells ; Langerhans cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Plasminogen activators (PA) play an important role in cell migration and tissue degradation. Considering the strong epidermotropism of atypical mononuclear cells in histiocytosis X (HX) skin infiltrates leading to intraepidermal abscess formation, it was the purpose of this study to look for tissue-type PA (t-PA) and/or urokinase-type PA (u-PA) on HX cells. Four monoclonal antibodies against PA were used, employing the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique on cryostat sections from four patients with HX. Twenty percent to 40% of infiltrating cells in the epidermis expressed the t-PA antigen. t-PA+ cells were present in the follicular centers of human tonsil, absent in normal epidermis and scanty in cutaneous infiltrates from mycosis fungoides and lupus erythematosus. Double labeling with anti-PA and T6 (CD1) or S100 protein revealed some of the HX cells to express both antigens (t-PA+ CD1+ or t-PA+ S100+). We conclude that cutaneous infiltrates of HX contain PA+ dendritic cells which are different from normal Langerhans cells and which may be responsible for the strong epidermal alterations in HX.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-069X
    Keywords: Mycosis fungoides ; Histopathology ; Benign inflammatory dermatoses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cutaneous infiltrate in mycosis fungoides (MF) is predominantly composed of T4-positive T-cells. Attempts to distinguish the early stages of this condition from benign inflammatory infiltrates using anti-T3, T4 and other T-cell-associated antibodies have hitherto been unsucessful. Recently a monoclonal antibody BE 2 has been described as selectively reacting against leukemic cells in patients with cutaneous T-cell lymphoma. To investigate whether the BE 2 antigen is differentially expressed in different stages of MF and benign dermatoses, thus facilitating diagnosis, especially of early MF, the reactivity of monoclonal antibody BE 2 against cutaneous infiltrates from such conditions was assessed. In the early stages of MF only a small number of reactive cells was present. In benign inflammatory infiltrates, especially in those that clinically and histologically were hardly distinguishable from early MF, BE 2 reactivity was essentially the same as in eczematous-stage MF. Lesions from plaque and tumor stage MF contained large numbers of BE 2-reactive cells. Our results indicate that expression of BE 2 is associated with the stage of a given MF lesion and is essentially identical in early MF and eczematous lesions with a similar histopathological appearance.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-069X
    Keywords: T-lymphocyte subsets ; Monoclonal antibodies ; Psoriasis vulgaris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cryostat tissue sections from skin lesions of 16 patients suffering from chronic stationary psoriasis vulgaris were assayed for the presence of distinct T-cell subpopulations with monoclonal antibodies. Using two pan-T surface markers (M-T 4–11 and Lyt 3) the total number of infiltrating T-cells was measured. This cell population was further dissected into Leu 3a (helper/inducer) and M-T 8–11 (cytotoxic/suppressor) positive subsets. Percentages of T-cell subpopulations were within the ranges found in healthy peripheral blood and were thus regarded as normal.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary Multíple bíopsíes taken from 76 European human Immunodeficiency virus (HIV)-negative patients with primary cutaneous T-cell lymphoproliferations, including mycosis fungoides (MF), pleomorphic T-cell lymphoma (PMTCL). anaplastic large cell lympboma (ALCLI and lymphomatoid papulosis (LyP) were investigated for the presence of Epstein-Barr virus (EBV) through a combined approach. Polymerase chain reaction (PCR) was employed for EBV-DNA detection, in situ hybridization (ISH) for cellular localization of EBV-encoded nuclear RNAs (EBKR1 and EBER2) and immediate early Bam H-fragment: lower frame (BHLF) RNA. and immunohistology (IH) for the identification of EBV-encoded latent membrane protein 1 (LMP1) and of nuclear antigen (EBNA) 2 expression. EBV-DNA was detectable by PCR in 15 of 76 cases (19·7%). EBER-ISH combined with IH identified a variable, usually very low, number of infected neoplastic cells in only seven of the 15 EBV-ONA-harbouring cases. This discrepancy between the results obtained with PCR and ISH is apparently caused by the low number of the infected cells per tissue section. The PMTCL entity produced the greatest number of positive cases, whilst ALCL and LyP cases were almost constantly devoid of the virus. BHLF transcripts were not detectable in any case, nor did any of the EBER-positive cells show an LMP1 or EBNA2 expression. These data show that primary cutaneous T-cell lymphoproliferations display an infrequent association with a latent EBV infection and that the pathogenic role of the virus in the positive cases remains obscure as the virus frequently infects only a minority of the atypical cells.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The immunophenotype and genotype of atypical cells in skin and lymph node infiltrates were investigated in a patient with lymphomatoid papulosis (LyP) complicated by anaplastic large-cell lymphoma of the lymph nodes. The large atypical cells in both skin and lymph nodes displayed an almost identical immunophenotype, i.e. CD30+ and CD25+ .Southern blot analysis for T-cell receptor β-chain gene rearrangement revealed an identical gene configuration in DNA extracted from skin and lymph node. Our results strongly support the hypothesis that clonal populations of T cells arising in cutaneous LyP lesions may undergo malignant transformation, spread into regional lymph nodes, and give rise to secondary malignant lymphomas, such as anaplastic large-cell lymphoma.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary The prevalence of the t(2:5)(p23;q35) and/or anaplastic lymphoma kinase (ALK) gene products in cutaneous anaplastic large cell (ALC) lymphomas and a potential precursor lesion, lymphomatoid papulosis (LyP). is controversial. ALK gene products, which are absent from normal lymphohae-matopoietic cells, are a phenotypic marker of lymphomas carrying the t(2:5). We used in situ hybridization and immunohistology to screen 14 cutaneous ALC lymphomas, 21 cases of LyP, and one nodal ALC lymphoma associated with LyP for ALK gene products. ALK gene products were not detectable in these cases. In contrast, ALK gene products were found in a lymphonodal ALC lymphoma with subsequent extension to the skin and in t(2:5)-positive cell lines. Detection of the Epstein-Barr virus (EBV)-encoded small nuclear transcripts (EBER), and of immunoglobulin light chain transcripts served to check for the presence of cellular RNA in the tissue sections. EBER transcripts were found in scattered reactive lymphoid cells, but not in atypical or tumour cells. ALK gene expression and EBV infection seem to be a rare finding in cutaneous ALC lymphomas and LyP. This points to a molecular aetiology of primary cutaneous ALC lymphomas and LyP distinct from that of extracutaneous CD30+ lymphoproliferative disease. Detection of the t(2;5) or ALK gene products in cutaneous lymphoproliferative lesions therefore requires exclusion of extracutaneous ALC lymphoma in such patients.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Kutane T-Zellymphome ; Klonalität ; Gamma-T-Zellrezeptor ; Polymerasekettenreaktion (PCR) ; Key words Cutaneous T-cell lymphoma ; Clonality ; Gamma-T-cell receptor ; Polymerase chain reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Differentiation of a cutaneous lymphoma from a reactive lymphoid infiltrate is a demanding challenge for the pathologist. In this retrospective study we examined 24 paraffin-embedded tissue samples from lesions diagnosed as lymphomas and 7 control samples of skin affected by benign changes and with pronounced lymphoid infiltrates for clonal rearrangement of the gamma T-cellreceptor. Using PCR technology we demonstrated clonality in 22 cases of lymphoma (92 %). Thus, the primer combination used in this study covering the four main groups (I–IV) of the variable region of the gamma T-cell receptor gene allows high sensitivity. No clonality was demonstrable in any of the 7 control cases. This study demonstrates the growing importance of PCR technology for the diagnosis of lymphoma.
    Notes: Zusammenfassung Die Unterscheidung eines kutanen Lymphoms von einem reaktiven lymphoiden Infiltrat gehört zu den anspruchsvollsten Differentialdiagnosen in der Dermatohistopathologie. Im Rahmen einer retrospektiven Studie untersuchten wir 24 in Paraffin eingebettete Proben von Hautveränderungen, bei denen klinisch und histologisch ein T-Zellymphom diagnostiziert wurde, auf ein klonales Rearrangement des Gamma-T-Zellrezeptors mittels der Polymerasekettenreaktion (PCR). Als Kontrollen wurden 7 Biopsien entzündlicher Hautveränderungen mit einem ausgeprägten lymphoiden Infiltrat untersucht. Der Klonalitätsnachweis gelang in 22 von 24 Fällen der Lymphome (92 %). Bei den 7 Kontrollbiopsien konnte keine Klonalität nachgewiesen werden. Insofern ermöglicht die von uns gewählte Primerkombination, die jede der vier Hauptgruppen des Gam- ma-T-Zellrezeptorgens (V γ 1–8, V γ 9, V γ 10 und V γ 11) berücksichtigt, eine hohe Sensitivität. Die Untersuchung bestätigt die wachsende Bedeutung dieser Technik für die Diagnostik von Lymphomen.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...