Malignant Peripheral Nerve Sheath Tumors with t(X;18). A Pathologic and Molecular Genetic Study
摘要:
Spindle cell sarcomas often present the surgical pathologist with a considerable diagnostic challenge. Malignant peripheral nerve sheath tumor, leiomyosarcoma, fibrosarcoma, and monophasic synovial sarcoma may all appear similar histologically. The application of ancillary diagnostic modalities, such as immunohistochemistry and electron microscopy, may be helpful in the differentiation of these tumors, but in cases in which these adjunctive: techniques fail to demonstrate any more definitive evidence of differentiation, tumor categorization may remain difficult. Cytogenetic and molecular genetic characterization of tumors have provided the basis for the application of molecular assays as the newest components of the diagnostic armamentarium. Because the chromosomal translocation t(X;18) has been observed repeatedly in many synovial sarcomas, it has been heralded as a diagnostic hallmark of synovial sarcoma To formally test the specificity of this translocation for the diagnosis of synovial sarcoma, RNA extracted from formalin-fixed, parrafin-embedded tissue from a variety of soft tissue and spindle cell tumors was evaluated fbr the presence of t(X;18) by reverse transcriptase-polymerase chain reaction. Although 85% of the synovial sarcomas studied demonstrated t(X;18), 75% of the malignant peripheral nerve sheath tumors in our cohort also demonstrated this translocation. We conclude that the translocation t(X;18) is not specific to synovial sarcoma and discuss the implications of the demonstration of t(X;18) in a majority of malignant peripheral nerve sheath tumors.
Oxidation of Triorganosilanes and Related Compounds by Chlorine Dioxide
作者:S. A. Grabovskiy、N. N. Kabal’nova
DOI:10.1134/s1070363221120069
日期:2021.12
mechanism explaining the formation of products and the observed regularities of the oxidation of silanes with chlorine dioxide has been proposed. A thermochemical analysis of some possible pathways in the gas phase using methods G4, G3, M05, and in an acetonitrile solution by the SMD-M05 method was carried out. The oxidation process can occur both with the participation of ionic and radical intermediates
Alkynylsilanes – a missing piece of different silylation agents, can serve as valuable substrates in the O‐silylation through a dealkynative coupling with alcohols or silanols. The described approach displays a whole array of advantages in terms of green chemistry and is a promising alternative to existing methodologies.
A new highly selective method for the synthesis of borasiloxanes through the O-borylation of silanols, disilanols, and disiloxanediols with vinylboronates in the presence of Ru0 complexes (mainly Ru3CO12) is described. The method leads to the formation of special compounds with a B–O–Si inorganic framework. When Ru0 complexes are used as a catalyst, no vinylboronate homocoupling is observed. A mechanism
Chemoselective and Catalyst-Free O-Borylation of Silanols: A Facile Access to Borasiloxanes
作者:K. Kuciński、G. Hreczycho
DOI:10.1002/cssc.201701648
日期:2017.12.8
highly chemoselective syntheses of various borasiloxanes from hydroboranes and silanols, achieved through catalyst‐free dehydrogenative coupling at room temperature. This green protocol, which uses easily accessible reagents, allows for the obtaining of borasiloxanes under air atmosphere and solvent‐free conditions.
The task is to provide a method for producing straight-chain trisiloxane with a hydroxyl group at one end of the molecular chain and a hydroxyl group or alkoxy group at the other end, using an easily accessible cyclic trisiloxane as a raw material, with high yield and in a single step. The solution involves reacting various cyclic trisiloxanes with water or alcohol in the presence of hydrogen gas and/or a hydrogen generator, as well as a transition metal catalyst, to produce the desired trisiloxane compound. No figures are included.