Feline hepatobiliary neoplasia and mistaken age.

A cat, thought to be 5 years old, and with reduced appetite and weight loss, was presented for dental cleaning and extractions. Bile duct origin hepatic carcinoma was diagnosed. The progression of iris degeneration, dental disease, histological renal lesions, spondylosis, and hepatobiliary neoplasia suggest this cat was closer to 10 years old.

Néoplasie hépatobiliaire féline et âge erroné. Un chat, que l'on croyait âgé de 5 ans et qui souffrait d'une diminution d'appétit et d'une perte de poids, a été présenté pour un nettoyage des dents et une extraction dentaire. Un carcinome hépatique de la voie biliaire principale a été diagnostiqué. La progression de la dégénérescence de l'iris, la maladie dentaire, les lésions rénales histologiques, la spondylose et la néoplasie hépatobiliaire suggèrent que ce chat était probablement âgé d'environ 10 ans.(Traduit par Isabelle Vallières).

Regulation of B cell linker protein transcription by PU.1 and Spi-B in murine B cell acute lymphoblastic leukemia.

B cell acute lymphoblastic leukemia (B-ALL) is frequently associated with mutations or chromosomal translocations of genes encoding transcription factors. Conditional deletion of genes encoding the E26-transformation-specific transcription factors, PU.1 and Spi-B, in B cells (ΔPB mice) leads to B-ALL in mice at 100% incidence rate and with a median survival of 21 wk. We hypothesized that PU.1 and Spi-B may redundantly activate transcription of genes encoding tumor suppressors in the B cell lineage. Characterization of aging ΔPB mice showed that leukemia cells expressing IL-7R were found in enlarged thymuses. IL-7R-expressing B-ALL cells grew in culture in response to IL-7 and could be maintained as cell lines. Cultured ΔPB cells expressed reduced levels of B cell linker protein (BLNK), a known tumor suppressor gene, compared with controls. The Blnk promoter contained a predicted PU.1 and/or Spi-B binding site that was required for promoter activity and occupied by PU.1 and/or Spi-B as determined by chromatin immunoprecipitation. Restoration of BLNK expression in cultured ΔPB cells opposed IL-7-dependent proliferation and induced early apoptosis. We conclude that the tumor suppressor BLNK is a target of transcriptional activation by PU.1 and Spi-B in the B cell lineage.

Structure determination of a partially ordered layered silicate material with an NMR crystallography approach.

Structure determination of layered materials can present challenges for conventional diffraction methods due to the fact that such materials often lack full three-dimensional periodicity since adjacent layers may not stack in an orderly and regular fashion. In such cases, NMR crystallography strategies involving a combination of solid-state NMR spectroscopy, powder X-ray diffraction, and computational chemistry methods can often reveal structural details that cannot be acquired from diffraction alone. We present here the structure determination of a surfactant-templated layered silicate material that lacks full three-dimensional crystallinity using such an NMR crystallography approach. Through a combination of powder X-ray diffraction and advanced 29Si solid-state NMR spectroscopy, it is revealed that the structure of the silicate layer of this layered silicate material templated with cetyltrimethylammonium surfactant cations is isostructural with the silicate layer of a previously reported material referred to as ilerite, octosilicate, or RUB-18. High-field 1H NMR spectroscopy reveals differences between the materials in terms of the ordering of silanol groups on the surfaces of the layers, as well as the contents of the inter-layer space.