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

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