Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Staining with peanut agglutinin (PNA) and with polyclonal antibody to S100 protein have both been recommended as aids in the diagnosis of histiocytosis X (Langerhans' cell histiocytosis). Although a large body of literature attests to the utility of S100 staining in this condition, the few published studies that involve PNA staining have employed varying methods of radically different results. We studied formaldehyde solution-fixed, paraffin-embedded tissue from 29 cases of histiocytosis X by using standard avidin-biotin immunostaining for S100 protein, as well as two published methods of PNA staining. All cases stained positively for S100 protein. By utilizing prior trypsinization and a three-step procedure, all cases also stained with PNA. With a two-step PNA-staining procedure, however, 9 cases failed to stain with PNA, and 3 cases showed a diffuse staining pattern that was not considered characteristic of Langerhans' and histiocytosis X cells. We concluded that both the S100 and the three-step PNA procedures are sensitive methods for the diagnosis of histiocytosis X.
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PMID:A comparison study of two methods of peanut agglutinin staining with S100 immunostaining in 29 cases of histiocytosis X (Langerhans' cell histiocytosis) 170 4

The C-H activation of cyclic formaldehyde aminals LCH2 (L = RN-CH2CH2CH2-NR and RNCH2CH2-NR, R = Me, Et, iPr, tBu, or Ph) with S8 proceeds at unusually low temperatures (T< 160 degrees C) and results in the formation of the respective thioureas LC=S and H2S. The reaction constitutes a new, solvent-free method for the synthesis of thioureas that eliminates the toxic and highly flammable CS2. For R = tBu, the ionic carbenium thiocyanates [LCH]+ SCN- dominate the product spectrum and the respective thioureas are obtained in low yield. The reactivity of the analogous sulfur and oxygen ring systems towards S8 was investigated. 1,3-Dithiolane is cleanly converted into 1,3-dithiolane-2-thione (S8, 14 d, 190 degrees C) and resembles the cyclic formaldehyde aminals in this respect. 1,3-Dioxolane (L = OCH2CH2O) is completely inert towards sulfur even under forceful reaction conditions (190 degrees C, 14 d). The formation of thioureas from aminals was investigated at the CBS-4 and B3LYP/6-31G(d) levels of theory.
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PMID:C-H activation with elemental sulfur: synthesis of cyclic thioureas from formaldehyde aminals and S8. 1169 82

Context.-We investigated expression of the adhesion molecule CD31 in sinus histiocytosis with massive lymphadenopathy (SHML) and Langerhans cell histiocytosis (LCH) because (1) SHML and LCH cells express a variety of cellular adhesion molecules and (2) SHML has been characterized as a reactive histiocytic proliferation, and tissue macrophages (histiocytes) are known to express CD31. Objective.-The purpose of this study was to determine whether SHML and LCH cells express CD31 and whether dual staining with CD31 and S100 facilitates diagnosis of these disease states. Methods.-Formalin-fixed, paraffin-embedded archival tissues were immunohistochemically stained via the labeled streptavidin-biotin method using antibodies against CD31 and S100 protein after heat-induced epitope retrieval. Archival tissues included SHML (n = 2), LCH (n = 10), malignant melanoma (n = 5), sinus hyperplasia (n = 4), granulomas (n = 4), granular cell tumor (n = 6), and normal skin (n = 4). Results.-Normal Langerhans cells in the epidermis were CD31(-)/S100(+); neoplastic Langerhans cells in LCH were CD31(+)/S100(+). Histiocytes in granulomas and in sinus hyperplasia were CD31(+)/S100(-); abnormal histiocytes in SHML were CD31(+)/S100(+). S100(+) tumors (malignant melanoma and granular cell tumor) were CD31(-). Conclusions.-The spectrum of cell types that express CD31 is expanded to include SHML and LCH. We speculate that up-regulation of CD31 in neoplastic Langerhans cells contributes to the migratory capability of LCH cells. CD31 may be a useful nonlysosomal marker of macrophages and their neoplastic counterparts (true histiocytic sarcomas). An immunohistochemical staining panel that includes CD31 and S100 facilitates the diagnosis of SHML and LCH.
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PMID:Sinus histiocytosis with massive lymphadenopathy and Langerhans cell histiocytosis express the cellular adhesion molecule CD31. 1265 80

Pulmonary Langerhans' cell histiocytosis (PLCH) is a disease characterized by the occurrence of complex fibro-cellular interstitial lesions dominated by Langerhans' cells (LC), which occurs predominantly in young adult smokers. We undertook this retrospective study to better define the lymphohistiocytic cell populations in PLCH in order to obtain a greater insight into its pathogenesis. Formalin-fixed, paraffin-embedded, surgically excised, archival lung tissue from seven patients (two males, five females; average age 34.9 years) was immunostained with a panel of antibodies for lymphohistiocytic markers: CD1a, CD3, CD4, CD8, CD15, CD20, CD56, TIA-1, CD68-PGM1, Mac387, and mast cell tryptase. Double immunolabeling was performed with CD1a/Mac387. Leder cytochemical stain for chloroacetate esterase was also performed. A moderate number of lymphocytes, predominantly T lymphocytes, were scattered diffusely within the lesions. The mean CD4/CD8 ratio was 0.1/1. The CD3/CD8 ratio (1.18/1) substantiated the CD4/CD8 ratio. The CD8 subset was CD56-negative and TIA-1-positive, indicating a cytotoxic T lymphocyte phenotype. CD68-PGM1 was strongly positive in alveolar macrophages (AM) and weakly stained LC. Mac387, a marker of activated macrophages, weakly stained AM, while highlighting other interstitial cells. These interstitial cells appeared not to be LC (substantiated by CD1a/Mac387 dual labeling) or CD68-PGM-1-positive macrophages. Having excluded mast cells (positive with mast cell tryptase) and neutrophils (positive with CD15 and Leder stains), there appeared to be a residual population of non-Langerhans cell monocytoid cells (NLMC), which were Mac 387+, CD68-PGM1-, Mast cell tryptase-, CD15-, and CD1a-. Our results showed a predominance of CD8+, TIA-1+ cytotoxic T lymphocytes among the lymphocyte subsets which appear to interact with LC and AM in PLCH lesions. A small sub-population of NLMC was also present. Further studies are required to better define and to evaluate the role of cytotoxic T cells and NLMC in the pathogenesis of PLCH.
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PMID:Lymphocyte sub-populations and non-Langerhans' cell monocytoid cells in pulmonary Langerhans' cell histiocytosis. 1833 20

Langerhans cell histiocytosis (LCH) is a rare neoplastic disease originating from cells characterized by antigen-presenting Langerhans cell phenotype. The clinical spectrum of LCH is highly variable including localized and disseminated forms mostly occurring in children. Recently, about 60% of LCHs were reported to carry the activating BRAF mutation V600E. In our retrospective study, we evaluated the occurrence and prognostic impact of the V600E mutation in formaldehyde-fixed, paraffin-embedded samples from 15 pediatric LCH cases treated at our institution. Allele-specific polymerase chain reaction (PCR) and direct sequencing were used to demonstrate the presence of V600E mutation, and immunohistochemistry (IHC) using the mutant protein-specific VE1 antibody clone was performed to confirm mutant BRAF protein expression. Eight of 15 (53.3%) cases proved to be BRAF mutants by any of the methods applied, with a single case showing a discrepancy (PCR negative/IHC positive). Four of the BRAF-mutant cases (50.0%) showed refractory disease and progressed to death within 43 months, whereas the remaining mutant cases were stable and responded well to therapy. Wild-type BRAF cases (7/15, 46.6%) with generally comparable initial presentation were all treated successfully. In conclusion, activating V600E BRAF mutation can be frequently demonstrated in pediatric LCH by both allele-specific PCR and IHC. Unfavorable risk cases potentially also responding to BRAF-inhibitory therapy can be identified by mutation testing using archival formaldehyde-fixed, paraffin-embedded tumor samples.
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PMID:Activating BRAF V600E mutation in aggressive pediatric Langerhans cell histiocytosis: demonstration by allele-specific PCR/direct sequencing and immunohistochemistry. 2511 10