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L Fort

Publications and source records attributed to L Fort.

14 recordsLinked to original sources

[Capnography].

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Anesthesia

Malignant melanoma primary in lymph node. The case of the missing link.

When malignant melanoma occurs in a lymph node, it is presumed to be metastatic, and the primary cutaneous/mucosal process is discovered to be either active, spontaneously regressed, previously excised, or occult. Nevus cell aggregates and nodal blue nevi are well-documented morphologic curiosities occurring in lymph nodes. It has been hypothesized that these nevus cell aggregates and blue nevi could be progenitors of lymph nodal malignant melanoma in patients without an obvious extranodal site of origin. We document a prototypical case of primary malignant melanoma evolving from precursor nevus cell aggregates associated with blue nevi in an axillary lymph node. The coexistence of nodal blue nevi and nevus cell aggregates implies a common origin from migratory neural crest cells arrested within mesenchyme.

Axilla

Role of the protein alpha helixes in histone-DNA interactions studied by vibrational spectroscopy.

The localization of structurally important histone-DNA interactions has been investigated by vibrational spectroscopy. Histones H2A, H2B, and H4 and their fragments (H2A, 1-56, 1-89, 73-129; H2B, 1-59, 1-83; H4, 1-53, 1-67, 1-84, 69-84, 85-102) have been prepared, characterized, and used to reconstitute protein-DNA complexes. Evidence is given for the existence of a direct relationship between the presence of ordered alpha-helical structures in the histones and a stabilization of the DNA in a B geometry. Infrared linear and ultraviolet dichroism measurements indicate that the N-terminal fragments, rich in basic residues and mostly in a random conformation, remain without any influence on the secondary structure of the nucleic acid, leaving it free in the complexes to undergo a total B----A conformational transition. On the contrary, histone fragments that involve some alpha-helical parts of the protein partially stabilize the DNA in a B geometry. Histone fragments that contain all of the alpha helixes of the protein block the DNA in the same way as the whole corresponding histone. A model for histone-DNA interactions in the core particle is discussed.

Amino Acids

Morphological alterations and DNase deficiency in phenobarbital promotion of N-nitrosomorpholine initiated rat hepatocarcinogenesis.

Tumorigenic effect in rat liver was increased when phenobarbital was given chronically after N-nitrosomorpholine. In these rats the liver parenchyma surrounding pre- and neo-plastic lesions demonstrated distinct, mainly centrilobular zones of hypertrophic hepatocytes with abundant eosinophilic, filamentous cytoplasm, increase in nucleic acids and decrease in DNase activity. These alterations might be considered as signs of tumor-promoting activity of phenobarbital.

Animals